arm imx25 touchscreen/ADC drivers

This is the core driver for imx25 touchscreen/adc driver. The module has one shared ADC and two different conversion queues which use the ADC. The two queues are identical. Both can be used for general purpose ADC but one is meant to be used for touchscreens.

This driver is the core which manages the central components and registers of the TSC/ADC unit. It manages the IRQs and forwards them to the correct components.

Signed-off-by Markus Pargmann <[email protected]>

---
 .../devicetree/bindings/mfd/fsl-imx25-tsadc.txt    |  46 ++++
 drivers/mfd/Kconfig                                |   9 +
 drivers/mfd/Makefile                               |   2 +
 drivers/mfd/fsl-imx25-tsadc.c                      | 234 +++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h                    | 138 ++++++++++++
 5 files changed, 429 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +36 -0

new file mode 100644
index 0000000..a857af0e
@@ -0,0 +1,46 @@
+Freescale mx25 ADC/TSC multifunction device
+
+This device combines two general purpose conversion queues one used for general
+ADC and the other used for touchscreens.
+
+Required properties:
+ - compatible: Should be "fsl,imx25-tsadc".
+ - reg: Memory range of the device.
+ - interrupts: Interrupt for this device as described in
+   interrupts/interrupts.txt
+ - clocks: An 'ipg' clock defined as described in clocks/clock.txt
+ - interrupt-controller: This device is an interrupt controller. It controls
+   the interrupts of both conversion queues.
+ - #interrupt-cells: Should be '<1>'.
+ - #address-cells: Should be '<1>'.
+ - #size-cells: Should be '<1>'.
+ - ranges
+
+This device includes two conversion queues which can be added as subnodes.
+The first queue is for the touchscreen, the second for general purpose ADC.
+
+Example:
+       tscadc: tscadc at 50030000 {
+               compatible = "fsl,imx25-tsadc";
+               reg = <0x50030000 0xc>;
+               interrupts = <46>;
+               clocks = <&clks 119>;
+               clock-names = "ipg";
+               interrupt-controller;
+               #interrupt-cells = <1>;
+               #address-cells = <1>;
+               #size-cells = <1>;
+               ranges;
+
+               tsc: tcq at 50030400 {
+                       compatible = "fsl,imx25-tcq";

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +4 -0

+static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
+                            irq_hw_number_t hwirq)
+{
+       struct mx25_tsadc_priv *priv = d->host_data;

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +45 -0

+static int mx25_tsadc_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct device_node *np = dev->of_node;
+       struct mx25_tsadc_priv *priv;
+       struct resource *iores;
+       int ret;
+       void __iomem *iomem;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       iomem = devm_ioremap_resource(dev, iores);
+       if (IS_ERR(iomem)) {
+               dev_err(dev, "Failed to remap iomem\n");
+               return PTR_ERR(iomem);
+       }
+
+       priv->regs = regmap_init_mmio(dev, iomem, &mx25_tsadc);
+       if (IS_ERR(priv->regs)) {
+               dev_err(dev, "Failed to initialize regmap\n");
+               return PTR_ERR(priv->regs);
+       }
+
+       priv->clk = devm_clk_get(dev, "ipg");
+       if (IS_ERR(priv->clk)) {
+               dev_err(dev, "Failed to get ipg clock\n");
+               return PTR_ERR(priv->clk);
+       }
+
+       /* Enable clock and reset the component */
+       regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
+                       MX25_TGCR_CLK_EN);
+       regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
+                       MX25_TGCR_TSC_RST);
+
+       /* Setup powersaving mode, but enable internal reference voltage */
+       regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
+                       MX25_TGCR_POWERMODE_SAVE);
+       regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
+                       MX25_TGCR_INTREFEN);
+
+       ret = mx25_tsadc_setup_irq(pdev, priv);

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +12 -0

+
+       return 0;
+}
+
+static const struct of_device_id mx25_tsadc_ids[] = {
+       { .compatible = "fsl,imx25-tsadc", },
+       { /* Sentinel */ }
+};
+
+static struct platform_driver mx25_tsadc_driver = {
+       .driver         = {
+               .name   = "mx25-tsadc",

Hi Markus,

Quoted 5 lines · Markus Pargmann

This is the core driver for imx25 touchscreen/adc driver. The module has one shared ADC and two different conversion queues which use the ADC. The two queues are identical. Both can be used for general purpose ADC but one is meant to be used for touchscreens.

Quoted 5 lines

This driver is the core which manages the central components and registers of the TSC/ADC unit. It manages the IRQs and forwards them to the correct components.

Signed-off-by Markus Pargmann <[email protected]>

That's great :-) Nice work!

Quoted 58 lines

---
 .../devicetree/bindings/mfd/fsl-imx25-tsadc.txt    |  46 ++++
 drivers/mfd/Kconfig                                |   9 +
 drivers/mfd/Makefile                               |   2 +
 drivers/mfd/fsl-imx25-tsadc.c                      | 234 +++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h                    | 138 ++++++++++++
 5 files changed, 429 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +41 -0

new file mode 100644
index 0000000..a857af0e
@@ -0,0 +1,46 @@
+Freescale mx25 ADC/TSC multifunction device
+
+This device combines two general purpose conversion queues one used for general
+ADC and the other used for touchscreens.
+
+Required properties:
+ - compatible: Should be "fsl,imx25-tsadc".
+ - reg: Memory range of the device.
+ - interrupts: Interrupt for this device as described in
+   interrupts/interrupts.txt
+ - clocks: An 'ipg' clock defined as described in clocks/clock.txt
+ - interrupt-controller: This device is an interrupt controller. It controls
+   the interrupts of both conversion queues.
+ - #interrupt-cells: Should be '<1>'.
+ - #address-cells: Should be '<1>'.
+ - #size-cells: Should be '<1>'.
+ - ranges
+
+This device includes two conversion queues which can be added as subnodes.
+The first queue is for the touchscreen, the second for general purpose ADC.
+
+Example:
+       tscadc: tscadc at 50030000 {
+               compatible = "fsl,imx25-tsadc";
+               reg = <0x50030000 0xc>;
+               interrupts = <46>;
+               clocks = <&clks 119>;
+               clock-names = "ipg";
+               interrupt-controller;
+               #interrupt-cells = <1>;
+               #address-cells = <1>;
+               #size-cells = <1>;
+               ranges;
+
+               tsc: tcq at 50030400 {
+                       compatible = "fsl,imx25-tcq";
+                       reg = <0x50030400 0x60>;
+                       ...
+               };
+
+               adc: gcq at 50030800 {

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt line 46

Quoted 5 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +5 -0

+                       compatible = "fsl,imx25-gcq";
+                       reg = <0x50030800 0x60>;
+                       ...
+               };
+       };

The meaning of 'tcq' and 'gcq' acronyms are not obvious. Could they be written more explicitily?

Also, what does the '...' mean?

Quoted 9 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +9 -0

+static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
+                            irq_hw_number_t hwirq)
+{
+       struct mx25_tsadc_priv *priv = d->host_data;
+
+       irq_set_chip_data(irq, priv);
+       irq_set_chip_and_handler(irq, &mx25_tsadc_irq_chip,
+                                handle_level_irq);
+

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt

Quoted 5 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +5 -0

+#ifdef CONFIG_ARM
+       set_irq_flags(irq, IRQF_VALID);
+#else
+       irq_set_noprobe(irq);
+#endif

Do we really need these ifdef's? Can't we just assume that CONFIG_ARM is always selected for this driver?

Quoted 50 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +49 -0

+static int mx25_tsadc_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct device_node *np = dev->of_node;
+       struct mx25_tsadc_priv *priv;
+       struct resource *iores;
+       int ret;
+       void __iomem *iomem;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       iomem = devm_ioremap_resource(dev, iores);
+       if (IS_ERR(iomem)) {
+               dev_err(dev, "Failed to remap iomem\n");
+               return PTR_ERR(iomem);
+       }
+
+       priv->regs = regmap_init_mmio(dev, iomem, &mx25_tsadc);
+       if (IS_ERR(priv->regs)) {
+               dev_err(dev, "Failed to initialize regmap\n");
+               return PTR_ERR(priv->regs);
+       }
+
+       priv->clk = devm_clk_get(dev, "ipg");
+       if (IS_ERR(priv->clk)) {
+               dev_err(dev, "Failed to get ipg clock\n");
+               return PTR_ERR(priv->clk);
+       }
+
+       /* Enable clock and reset the component */
+       regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
+                       MX25_TGCR_CLK_EN);
+       regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
+                       MX25_TGCR_TSC_RST);
+
+       /* Setup powersaving mode, but enable internal reference voltage */
+       regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
+                       MX25_TGCR_POWERMODE_SAVE);
+       regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
+                       MX25_TGCR_INTREFEN);
+
+       ret = mx25_tsadc_setup_irq(pdev, priv);
+       if (ret) {
+               dev_err(dev, "Failed to setup irqs\n");
+               return ret;
+       }

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt

Quoted 6 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +6 -0

+
+       platform_set_drvdata(pdev, priv);
+
+       of_platform_populate(np, NULL, NULL, dev);
+
+       dev_info(dev, "i.MX25/25 Touchscreen and ADC core driver loaded\n");

You could remove the double '25/25'.

Quoted 17 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +16 -0

+
+       return 0;
+}
+
+static const struct of_device_id mx25_tsadc_ids[] = {
+       { .compatible = "fsl,imx25-tsadc", },
+       { /* Sentinel */ }
+};
+
+static struct platform_driver mx25_tsadc_driver = {
+       .driver         = {
+               .name   = "mx25-tsadc",
+               .owner  = THIS_MODULE,
+               .of_match_table = mx25_tsadc_ids,
+       },
+       .probe          = mx25_tsadc_probe,

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt

Quoted 6 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +6 -0

+};
+module_platform_driver(mx25_tsadc_driver);
+
+MODULE_DESCRIPTION("MFD for ADC/TSC for Freescale mx25");
+MODULE_AUTHOR("Markus Pargmann <[email protected]>");
+MODULE_LICENSE("GPL v2");

MODULE_ALIAS() as well?

Hi Markus,

Quoted 10 lines · Markus Pargmann

This is the core driver for imx25 touchscreen/adc driver. The module has one shared ADC and two different conversion queues which use the ADC. The two queues are identical. Both can be used for general purpose ADC but one is meant to be used for touchscreens.

This driver is the core which manages the central components and registers of the TSC/ADC unit. It manages the IRQs and forwards them to the correct components.

Signed-off-by Markus Pargmann <[email protected]>

That's great :-) Nice work!

Quoted 53 lines

---
 .../devicetree/bindings/mfd/fsl-imx25-tsadc.txt    |  46 ++++
 drivers/mfd/Kconfig                                |   9 +
 drivers/mfd/Makefile                               |   2 +
 drivers/mfd/fsl-imx25-tsadc.c                      | 234 +++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h                    | 138 ++++++++++++
 5 files changed, 429 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +36 -0

new file mode 100644
index 0000000..a857af0e
@@ -0,0 +1,46 @@
+Freescale mx25 ADC/TSC multifunction device
+
+This device combines two general purpose conversion queues one used for general
+ADC and the other used for touchscreens.
+
+Required properties:
+ - compatible: Should be "fsl,imx25-tsadc".
+ - reg: Memory range of the device.
+ - interrupts: Interrupt for this device as described in
+   interrupts/interrupts.txt
+ - clocks: An 'ipg' clock defined as described in clocks/clock.txt
+ - interrupt-controller: This device is an interrupt controller. It controls
+   the interrupts of both conversion queues.
+ - #interrupt-cells: Should be '<1>'.
+ - #address-cells: Should be '<1>'.
+ - #size-cells: Should be '<1>'.
+ - ranges
+
+This device includes two conversion queues which can be added as subnodes.
+The first queue is for the touchscreen, the second for general purpose ADC.
+
+Example:
+       tscadc: tscadc at 50030000 {
+               compatible = "fsl,imx25-tsadc";
+               reg = <0x50030000 0xc>;
+               interrupts = <46>;
+               clocks = <&clks 119>;
+               clock-names = "ipg";
+               interrupt-controller;
+               #interrupt-cells = <1>;
+               #address-cells = <1>;
+               #size-cells = <1>;
+               ranges;
+
+               tsc: tcq at 50030400 {
+                       compatible = "fsl,imx25-tcq";

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt line 46

Quoted 10 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +10 -0

+                       reg = <0x50030400 0x60>;
+                       ...
+               };
+
+               adc: gcq at 50030800 {
+                       compatible = "fsl,imx25-gcq";
+                       reg = <0x50030800 0x60>;
+                       ...
+               };
+       };

The meaning of 'tcq' and 'gcq' acronyms are not obvious. Could they be written more explicitily?

Also, what does the '...' mean?

This is a driver for the imx25 ADC/TSC module. It controls the touchscreen conversion queue and creates a touchscreen input device. The driver currently only supports 4 wire touchscreens. The driver uses a simple conversion queue of precharge, touch detection, X measurement, Y measurement, precharge and another touch detection.

This driver uses the regmap from the parent to setup some touch specific settings in the core driver and setup a idle configuration with touch detection.

Signed-off-by Markus Pargmann <[email protected]>

---
 .../bindings/input/touchscreen/fsl-mx25-tcq.txt    |  29 +
 drivers/input/touchscreen/Kconfig                  |   6 +
 drivers/input/touchscreen/Makefile                 |   1 +
 drivers/input/touchscreen/fsl-imx25-tcq.c          | 589 +++++++++++++++++++++
 4 files changed, 625 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
 create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt new file +29 -0

new file mode 100644
index 0000000..4214a99
@@ -0,0 +1,29 @@
+Freescale mx25 TS conversion queue module
+
+mx25 touchscreen conversion queue module which controls the ADC unit of the
+mx25 for attached touchscreens.
+
+Required properties:
+ - compatible: Should be "fsl,imx25-tcq".
+ - reg: Memory range of the device.
+ - interrupts: Should be the interrupt number associated with this module within
+   the tscadc unit (<0>).
+ - interrupt-parent: Should be a phandle to the tscadc unit.
+ - fsl,wires: Should be '<4>' or '<5>'
+
+Optional properties:
+ - fsl,pen-debounce: Pen debounce time.
+ - fsl,pen-threshold: Pen-down threshold for the touchscreen.
+ - fsl,settling-time: Settling time in nanoseconds.
+
+This device includes two conversion queues which can be added as subnodes.
+The first queue is for the touchscreen, the second for general purpose ADC.
+
+Example:
+	tsc: tcq at 50030400 {
+		compatible = "fsl,imx25-tcq";
+		reg = <0x50030400 0x60>;
+		interrupt-parent = <&tscadc>;
+		interrupts = <0>;
+		fsl,wires = <4>;
+	};

drivers/input/touchscreen/Kconfig +6 -0

index 07e9e82..d52c055 100644
@@ -715,6 +715,12 @@ config TOUCHSCREEN_USB_COMPOSITE
 	  To compile this driver as a module, choose M here: the
 	  module will be called usbtouchscreen.
 
+config TOUCHSCREEN_MX25
+	tristate "Freescale i.MX25 touchscreen input driver"
+	depends on MFD_MX25_TSADC
+	help
+	  Enable support for touchscreen connected to your i.MX25.
+
 config TOUCHSCREEN_MC13783
 	tristate "Freescale MC13783 touchscreen input driver"
 	depends on MFD_MC13XXX

drivers/input/touchscreen/Makefile +1 -0

index 62801f2..c891f30 100644
@@ -38,6 +38,7 @@ obj-$(CONFIG_TOUCHSCREEN_INEXIO)	+= inexio.o
 obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)	+= intel-mid-touch.o
 obj-$(CONFIG_TOUCHSCREEN_LPC32XX)	+= lpc32xx_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MAX11801)	+= max11801_ts.o
+obj-$(CONFIG_TOUCHSCREEN_MX25)		+= fsl-imx25-tcq.o
 obj-$(CONFIG_TOUCHSCREEN_MC13783)	+= mc13783_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MCS5000)	+= mcs5000_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o

drivers/input/touchscreen/fsl-imx25-tcq.c new file +273 -0

new file mode 100644
index 0000000..436cc8b
@@ -0,0 +1,589 @@
+/*
+ * Copyright 2014 Markus Pargmann, Pengutronix <[email protected]>
+ * Based on driver from 2011 Juergen Beisert, Pengutronix <[email protected]>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * This is the driver for the imx25 TCQ (Touchscreen Conversion Queue)
+ * connected to the imx25 ADC.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/mfd/imx25-tsadc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static const char mx25_tcq_name[] = "mx25-tcq";
+
+enum mx25_tcq_mode {
+	MX25_TS_4WIRE,
+};
+
+struct mx25_tcq_priv {
+	struct regmap *regs;
+	struct regmap *core_regs;
+	struct input_dev *idev;
+	enum mx25_tcq_mode mode;
+	unsigned int pen_threshold;
+	unsigned int sample_count;
+	unsigned int expected_samples;
+	unsigned int repeat_wait;
+	unsigned int pen_debounce;
+	unsigned int settling_time;
+	struct clk *clk;
+};
+
+static struct regmap_config mx25_tcq_regconfig = {
+	.fast_io = true,
+	.max_register = 0x5c,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static struct of_device_id mx25_tcq_ids[] = {
+	{ .compatible = "fsl,imx25-tcq", },
+	{ /* Senitel */ }
+};
+
+#define TSC_4WIRE_PRE_INDEX 0
+#define TSC_4WIRE_X_INDEX 1
+#define TSC_4WIRE_Y_INDEX 2
+#define TSC_4WIRE_POST_INDEX 3
+#define TSC_4WIRE_LEAVE 4
+
+#define MX25_TSC_DEF_THRESHOLD 80
+#define TSC_MAX_SAMPLES 16
+
+
+enum mx25_adc_configurations {
+	MX25_CFG_PRECHARGE = 0,
+	MX25_CFG_TOUCH_DETECT,
+	MX25_CFG_X_MEASUREMENT,
+	MX25_CFG_Y_MEASUREMENT,
+};
+
+#define MX25_PRECHARGE_VALUE (\
+			MX25_ADCQ_CFG_YPLL_OFF | \
+			MX25_ADCQ_CFG_XNUR_OFF | \
+			MX25_ADCQ_CFG_XPUL_HIGH | \
+			MX25_ADCQ_CFG_REFP_INT | \
+			MX25_ADCQ_CFG_IN_XP | \
+			MX25_ADCQ_CFG_REFN_NGND2 | \
+			MX25_ADCQ_CFG_IGS)
+
+#define MX25_TOUCH_DETECT_VALUE (\
+			MX25_ADCQ_CFG_YNLR | \
+			MX25_ADCQ_CFG_YPLL_OFF | \
+			MX25_ADCQ_CFG_XNUR_OFF | \
+			MX25_ADCQ_CFG_XPUL_OFF | \
+			MX25_ADCQ_CFG_REFP_INT | \
+			MX25_ADCQ_CFG_IN_XP | \
+			MX25_ADCQ_CFG_REFN_NGND2 | \
+			MX25_ADCQ_CFG_PENIACK)
+
+static void imx25_setup_queue_cfgs(struct mx25_tcq_priv *priv,
+		unsigned int settling_time)
+{
+	u32 precharge_cfg =
+			MX25_PRECHARGE_VALUE |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time);
+	u32 touch_detect_cfg =
+			MX25_TOUCH_DETECT_VALUE |
+			MX25_ADCQ_CFG_NOS(1) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time);
+
+	regmap_write(priv->core_regs, MX25_TSC_TICR, precharge_cfg);
+
+	/* PRECHARGE */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_PRECHARGE),
+			precharge_cfg);
+
+	/* TOUCH_DETECT */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_TOUCH_DETECT),
+			touch_detect_cfg);
+
+	/* X Measurement */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_X_MEASUREMENT),
+			MX25_ADCQ_CFG_YPLL_OFF |
+			MX25_ADCQ_CFG_XNUR_LOW |
+			MX25_ADCQ_CFG_XPUL_HIGH |
+			MX25_ADCQ_CFG_REFP_XP |
+			MX25_ADCQ_CFG_IN_YP |
+			MX25_ADCQ_CFG_REFN_XN |
+			MX25_ADCQ_CFG_NOS(priv->sample_count) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time));
+
+	/* Y Measurement */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_Y_MEASUREMENT),
+			MX25_ADCQ_CFG_YNLR |
+			MX25_ADCQ_CFG_YPLL_HIGH |
+			MX25_ADCQ_CFG_XNUR_OFF |
+			MX25_ADCQ_CFG_XPUL_OFF |
+			MX25_ADCQ_CFG_REFP_YP |
+			MX25_ADCQ_CFG_IN_XP |
+			MX25_ADCQ_CFG_REFN_YN |
+			MX25_ADCQ_CFG_NOS(priv->sample_count) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time));
+
+	/* Enable the touch detection right now */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, touch_detect_cfg |
+			MX25_ADCQ_CFG_IGS);
+}
+
+static int imx25_setup_queue_4wire(struct mx25_tcq_priv *priv,
+		unsigned settling_time, int *items)
+{
+	imx25_setup_queue_cfgs(priv, settling_time);
+
+	/* Setup the conversion queue */
+	regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
+			MX25_ADCQ_ITEM(0, MX25_CFG_PRECHARGE) |
+			MX25_ADCQ_ITEM(1, MX25_CFG_TOUCH_DETECT) |
+			MX25_ADCQ_ITEM(2, MX25_CFG_X_MEASUREMENT) |
+			MX25_ADCQ_ITEM(3, MX25_CFG_Y_MEASUREMENT) |
+			MX25_ADCQ_ITEM(4, MX25_CFG_PRECHARGE) |
+			MX25_ADCQ_ITEM(5, MX25_CFG_TOUCH_DETECT));
+
+	/* We measure X/Y with 'sample_count' number of samples and execute a
+	 * touch detection twice, with 1 sample each */
+	priv->expected_samples = priv->sample_count * 2 + 2;
+	*items = 6;
+
+	return 0;
+}
+
+static void mx25_tcq_disable_touch_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK,
+			MX25_ADCQ_CR_PDMSK);
+}
+
+static void mx25_tcq_enable_touch_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, 0);
+}
+
+static void mx25_tcq_disable_fifo_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ,
+			MX25_ADCQ_MR_FDRY_IRQ);
+}
+
+static void mx25_tcq_enable_fifo_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, 0);
+}
+
+static void mx25_tcq_force_queue_start(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS,
+			MX25_ADCQ_CR_FQS);
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS, 0);
+}
+
+static void mx25_tcq_force_queue_stop(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS, 0);
+}
+
+static void mx25_tcq_fifo_reset(struct mx25_tcq_priv *priv)
+{
+	u32 tcqcr;
+
+	regmap_read(priv->regs, MX25_ADCQ_CR, &tcqcr);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST,
+			MX25_ADCQ_CR_FRST);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST,
+			0);
+	regmap_write(priv->regs, MX25_ADCQ_CR, tcqcr);
+}
+
+static void mx25_tcq_re_enable_touch_detection(struct mx25_tcq_priv *priv)
+{
+	/* stop the queue from looping */
+	mx25_tcq_force_queue_stop(priv);
+
+	/* for a clean touch detection, preload the X plane */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_PRECHARGE_VALUE);
+
+	/* waste some time now to pre-load the X plate to high voltage */
+	mx25_tcq_fifo_reset(priv);
+
+	/* re-enable the detection right now */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_TOUCH_DETECT_VALUE |
+			MX25_ADCQ_CFG_IGS);
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_PD,
+			MX25_ADCQ_SR_PD);
+
+	/* enable the pen down event to be a source for the interrupt */
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_PD_IRQ, 0);
+
+	/* lets fire the next IRQ if someone touches the touchscreen */
+	mx25_tcq_enable_touch_irq(priv);
+}
+
+static int mx25_tcq_create_event_for_4wire(struct mx25_tcq_priv *priv,
+		u32 *sample_buf, int samples)
+{
+	unsigned int x_pos = 0;
+	unsigned int y_pos = 0;
+	unsigned int touch_pre = 0;
+	unsigned int touch_post = 0;
+	unsigned i;
+	int ret = 0;
+
+	for (i = 0; i < samples; i++) {
+		unsigned int index = MX25_ADCQ_FIFO_ID(sample_buf[i]);
+		unsigned int val = MX25_ADCQ_FIFO_DATA(sample_buf[i]);
+
+		switch (index) {
+		case 1:
+			touch_pre = val;
+			break;
+		case 2:
+			x_pos = val;
+			break;
+		case 3:
+			y_pos = val;
+			break;
+		case 5:
+			touch_post = val;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	if (ret == 0 && samples != 0) {
+		/*
+		 * only if both touch measures are below a treshold,
+		 * the position is valid

drivers/input/touchscreen/fsl-imx25-tcq.c new file +25 -0

+					touch_post >= priv->pen_threshold) {
+				/*
+				 * if both samples are invalid,
+				 * generate a release report
+				 */
+				input_report_key(priv->idev, BTN_TOUCH, 0);
+				input_sync(priv->idev);
+				mx25_tcq_re_enable_touch_detection(priv);
+			} else {
+				/*
+				 * if only one of both touch measurements are
+				 * below the threshold, still some bouncing
+				 * happens. Take additional samples in this
+				 * case to be sure
+				 */
+				mx25_tcq_force_queue_start(priv);
+				mx25_tcq_enable_fifo_irq(priv);
+			}
+		}
+	}
+
+	return ret;
+}
+
+static irqreturn_t mx25_tcq_irq_thread(int irq, void *dev_id)

drivers/input/touchscreen/fsl-imx25-tcq.c new file +173 -0

+		}
+	}
+
+	mx25_tcq_create_event_for_4wire(priv, sample_buf, samples);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mx25_tcq_irq(int irq, void *dev_id)
+{
+	struct mx25_tcq_priv *priv = (struct mx25_tcq_priv *)dev_id;
+	u32 stat;
+	int ret = IRQ_HANDLED;
+
+	regmap_read(priv->regs, MX25_ADCQ_SR, &stat);
+
+	if (stat & (MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR))
+		mx25_tcq_fifo_reset(priv);
+
+	if (stat & MX25_ADCQ_SR_PD) {
+		mx25_tcq_disable_touch_irq(priv);
+		mx25_tcq_force_queue_start(priv);
+		mx25_tcq_enable_fifo_irq(priv);
+	}
+
+	if (stat & MX25_ADCQ_SR_FDRY) {
+		mx25_tcq_disable_fifo_irq(priv);
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
+			MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD |
+			MX25_ADCQ_SR_EOQ,
+			MX25_ADCQ_SR_FRR |
+			MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD |
+			MX25_ADCQ_SR_EOQ);
+
+	return ret;
+}
+
+/* configure the statemachine for a 4-wire touchscreen */
+static int mx25_tcq_init(struct mx25_tcq_priv *priv)
+{
+	u32 tgcr;
+	unsigned int ipg_div;
+	unsigned int adc_period;
+	unsigned int repeat_wait;
+	unsigned int debounce_cnt;
+	unsigned int settling_time;
+	int itemct;
+	int ret;
+
+	regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr);
+	ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr));
+	adc_period = clk_get_rate(priv->clk) / (ipg_div * 2 + 2);
+	repeat_wait = fls(DIV_ROUND_UP(priv->repeat_wait, adc_period));
+	debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1;
+	settling_time = DIV_ROUND_UP(priv->settling_time, adc_period);
+
+
+	/* Reset */
+	regmap_write(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QRST |
+			MX25_ADCQ_CR_FRST);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QRST |
+			MX25_ADCQ_CR_FRST, 0);
+
+	/* up to 128 * 8 ADC clocks are possible */
+	if (debounce_cnt > 127)
+		debounce_cnt = 127;
+
+	if (repeat_wait > 15)
+		repeat_wait = 15;
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_RWAIT_MASK,
+			MX25_ADCQ_CR_RWAIT(repeat_wait));
+
+	ret = imx25_setup_queue_4wire(priv, 0x0, &itemct);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_LITEMID_MASK |
+			MX25_ADCQ_CR_WMRK_MASK,
+			MX25_ADCQ_CR_LITEMID(itemct - 1) |
+			MX25_ADCQ_CR_WMRK(priv->expected_samples - 1));
+
+	/* setup debounce count */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR,
+			MX25_TGCR_PDBTIME_MASK,
+			MX25_TGCR_PDBTIME(debounce_cnt));
+
+	/* enable debounce */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDBEN,
+			MX25_TGCR_PDBEN);
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDEN,
+			MX25_TGCR_PDEN);
+
+	/* enable the engine on demand */
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QSM_FQS,
+			MX25_ADCQ_CR_QSM_FQS);
+
+	mx25_tcq_re_enable_touch_detection(priv);
+
+	return 0;
+}
+
+static int mx25_tcq_parse_dt(struct platform_device *pdev,
+		struct mx25_tcq_priv *priv)
+{
+	struct device_node *np = pdev->dev.of_node;
+	u32 wires;
+	int ret;
+
+	/* Setup defaults */
+	priv->pen_threshold = 500;
+	priv->sample_count = 3;
+	priv->repeat_wait = 15000000;
+	priv->pen_debounce = 1000000;
+	priv->settling_time = 250000;
+
+	ret = of_property_read_u32(np, "fsl,wires", &wires);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to find fsl,wires properties\n");
+		return ret;
+	}
+
+	if (wires == 4) {
+		priv->mode = MX25_TS_4WIRE;
+	} else {
+		dev_err(&pdev->dev, "%u-wire mode not supported\n", wires);
+		return -EINVAL;
+	}
+
+	/* These are optional, we don't care about the return values */
+	of_property_read_u32(np, "fsl,pen-threshold", &priv->pen_threshold);
+	of_property_read_u32(np, "fsl,settling-time", &priv->settling_time);
+	of_property_read_u32(np, "fsl,pen-debounce", &priv->pen_debounce);
+
+	return 0;
+}
+
+static int mx25_tcq_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct input_dev *idev;
+	struct mx25_tcq_priv *priv;
+	struct resource *res;
+	void __iomem *mem;
+	int ret;
+	int irq;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mem = devm_ioremap_resource(dev, res);
+	if (!mem) {
+		dev_err(dev, "Failed to get iomem");
+		return -ENOMEM;
+	}
+
+	ret = mx25_tcq_parse_dt(pdev, priv);
+	if (ret)
+		return ret;
+
+	priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_tcq_regconfig);
+	if (IS_ERR(priv->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(priv->regs);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {

drivers/input/touchscreen/fsl-imx25-tcq.c new file +42 -0

+
+	idev = devm_input_allocate_device(dev);
+	if (!idev) {
+		dev_err(dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	idev->name = mx25_tcq_name;
+	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+	input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
+
+	idev->id.bustype = BUS_HOST;
+
+	ret = input_register_device(idev);
+	if (ret) {
+		dev_err(dev, "Failed to register input device\n");
+		return ret;
+	}
+
+	priv->idev = idev;
+
+	priv->core_regs = mx25_tsadc_get_regmap(pdev->dev.parent);
+	priv->clk = mx25_tsadc_get_ipg(pdev->dev.parent);
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable ipg clock\n");
+		return ret;
+	}
+
+	ret = mx25_tcq_init(priv);
+	if (ret) {
+		dev_err(dev, "Failed to init tcq\n");
+		goto error_tcq_init;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+

drivers/input/touchscreen/fsl-imx25-tcq.c new file +18 -0

+
+	return 0;
+}
+
+static struct platform_driver mx25_tcq_driver = {
+	.driver		= {
+		.name	= "mx25-tcq",
+		.owner	= THIS_MODULE,
+		.of_match_table = mx25_tcq_ids,
+	},
+	.probe		= mx25_tcq_probe,
+	.remove		= mx25_tcq_remove,
+};
+module_platform_driver(mx25_tcq_driver);
+
+MODULE_DESCRIPTION("TS input driver for Freescale mx25");
+MODULE_AUTHOR("Markus Pargmann <[email protected]>");
+MODULE_LICENSE("GPL v2");

Signature · 1 line

1.8.5.3

Hi Marjus,

Quoted 367 lines · Markus Pargmann

This is a driver for the imx25 ADC/TSC module. It controls the touchscreen conversion queue and creates a touchscreen input device. The driver currently only supports 4 wire touchscreens. The driver uses a simple conversion queue of precharge, touch detection, X measurement, Y measurement, precharge and another touch detection.

This driver uses the regmap from the parent to setup some touch specific settings in the core driver and setup a idle configuration with touch detection.

Signed-off-by Markus Pargmann <[email protected]>

---
 .../bindings/input/touchscreen/fsl-mx25-tcq.txt    |  29 +
 drivers/input/touchscreen/Kconfig                  |   6 +
 drivers/input/touchscreen/Makefile                 |   1 +
 drivers/input/touchscreen/fsl-imx25-tcq.c          | 589 +++++++++++++++++++++
 4 files changed, 625 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
 create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt new file +29 -0

new file mode 100644
index 0000000..4214a99
@@ -0,0 +1,29 @@
+Freescale mx25 TS conversion queue module
+
+mx25 touchscreen conversion queue module which controls the ADC unit of the
+mx25 for attached touchscreens.
+
+Required properties:
+ - compatible: Should be "fsl,imx25-tcq".
+ - reg: Memory range of the device.
+ - interrupts: Should be the interrupt number associated with this module within
+   the tscadc unit (<0>).
+ - interrupt-parent: Should be a phandle to the tscadc unit.
+ - fsl,wires: Should be '<4>' or '<5>'
+
+Optional properties:
+ - fsl,pen-debounce: Pen debounce time.
+ - fsl,pen-threshold: Pen-down threshold for the touchscreen.
+ - fsl,settling-time: Settling time in nanoseconds.
+
+This device includes two conversion queues which can be added as subnodes.
+The first queue is for the touchscreen, the second for general purpose ADC.
+
+Example:
+	tsc: tcq at 50030400 {
+		compatible = "fsl,imx25-tcq";
+		reg = <0x50030400 0x60>;
+		interrupt-parent = <&tscadc>;
+		interrupts = <0>;
+		fsl,wires = <4>;
+	};

drivers/input/touchscreen/Kconfig +6 -0

index 07e9e82..d52c055 100644
@@ -715,6 +715,12 @@ config TOUCHSCREEN_USB_COMPOSITE
 	  To compile this driver as a module, choose M here: the
 	  module will be called usbtouchscreen.
 
+config TOUCHSCREEN_MX25
+	tristate "Freescale i.MX25 touchscreen input driver"
+	depends on MFD_MX25_TSADC
+	help
+	  Enable support for touchscreen connected to your i.MX25.
+
 config TOUCHSCREEN_MC13783
 	tristate "Freescale MC13783 touchscreen input driver"
 	depends on MFD_MC13XXX

drivers/input/touchscreen/Makefile +1 -0

index 62801f2..c891f30 100644
@@ -38,6 +38,7 @@ obj-$(CONFIG_TOUCHSCREEN_INEXIO)	+= inexio.o
 obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)	+= intel-mid-touch.o
 obj-$(CONFIG_TOUCHSCREEN_LPC32XX)	+= lpc32xx_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MAX11801)	+= max11801_ts.o
+obj-$(CONFIG_TOUCHSCREEN_MX25)		+= fsl-imx25-tcq.o
 obj-$(CONFIG_TOUCHSCREEN_MC13783)	+= mc13783_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MCS5000)	+= mcs5000_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o

drivers/input/touchscreen/fsl-imx25-tcq.c new file +277 -0

new file mode 100644
index 0000000..436cc8b
@@ -0,0 +1,589 @@
+/*
+ * Copyright 2014 Markus Pargmann, Pengutronix <[email protected]>
+ * Based on driver from 2011 Juergen Beisert, Pengutronix <[email protected]>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * This is the driver for the imx25 TCQ (Touchscreen Conversion Queue)
+ * connected to the imx25 ADC.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/mfd/imx25-tsadc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static const char mx25_tcq_name[] = "mx25-tcq";
+
+enum mx25_tcq_mode {
+	MX25_TS_4WIRE,
+};
+
+struct mx25_tcq_priv {
+	struct regmap *regs;
+	struct regmap *core_regs;
+	struct input_dev *idev;
+	enum mx25_tcq_mode mode;
+	unsigned int pen_threshold;
+	unsigned int sample_count;
+	unsigned int expected_samples;
+	unsigned int repeat_wait;
+	unsigned int pen_debounce;
+	unsigned int settling_time;
+	struct clk *clk;
+};
+
+static struct regmap_config mx25_tcq_regconfig = {
+	.fast_io = true,
+	.max_register = 0x5c,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static struct of_device_id mx25_tcq_ids[] = {
+	{ .compatible = "fsl,imx25-tcq", },
+	{ /* Senitel */ }
+};
+
+#define TSC_4WIRE_PRE_INDEX 0
+#define TSC_4WIRE_X_INDEX 1
+#define TSC_4WIRE_Y_INDEX 2
+#define TSC_4WIRE_POST_INDEX 3
+#define TSC_4WIRE_LEAVE 4
+
+#define MX25_TSC_DEF_THRESHOLD 80
+#define TSC_MAX_SAMPLES 16
+
+
+enum mx25_adc_configurations {
+	MX25_CFG_PRECHARGE = 0,
+	MX25_CFG_TOUCH_DETECT,
+	MX25_CFG_X_MEASUREMENT,
+	MX25_CFG_Y_MEASUREMENT,
+};
+
+#define MX25_PRECHARGE_VALUE (\
+			MX25_ADCQ_CFG_YPLL_OFF | \
+			MX25_ADCQ_CFG_XNUR_OFF | \
+			MX25_ADCQ_CFG_XPUL_HIGH | \
+			MX25_ADCQ_CFG_REFP_INT | \
+			MX25_ADCQ_CFG_IN_XP | \
+			MX25_ADCQ_CFG_REFN_NGND2 | \
+			MX25_ADCQ_CFG_IGS)
+
+#define MX25_TOUCH_DETECT_VALUE (\
+			MX25_ADCQ_CFG_YNLR | \
+			MX25_ADCQ_CFG_YPLL_OFF | \
+			MX25_ADCQ_CFG_XNUR_OFF | \
+			MX25_ADCQ_CFG_XPUL_OFF | \
+			MX25_ADCQ_CFG_REFP_INT | \
+			MX25_ADCQ_CFG_IN_XP | \
+			MX25_ADCQ_CFG_REFN_NGND2 | \
+			MX25_ADCQ_CFG_PENIACK)
+
+static void imx25_setup_queue_cfgs(struct mx25_tcq_priv *priv,
+		unsigned int settling_time)
+{
+	u32 precharge_cfg =
+			MX25_PRECHARGE_VALUE |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time);
+	u32 touch_detect_cfg =
+			MX25_TOUCH_DETECT_VALUE |
+			MX25_ADCQ_CFG_NOS(1) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time);
+
+	regmap_write(priv->core_regs, MX25_TSC_TICR, precharge_cfg);
+
+	/* PRECHARGE */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_PRECHARGE),
+			precharge_cfg);
+
+	/* TOUCH_DETECT */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_TOUCH_DETECT),
+			touch_detect_cfg);
+
+	/* X Measurement */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_X_MEASUREMENT),
+			MX25_ADCQ_CFG_YPLL_OFF |
+			MX25_ADCQ_CFG_XNUR_LOW |
+			MX25_ADCQ_CFG_XPUL_HIGH |
+			MX25_ADCQ_CFG_REFP_XP |
+			MX25_ADCQ_CFG_IN_YP |
+			MX25_ADCQ_CFG_REFN_XN |
+			MX25_ADCQ_CFG_NOS(priv->sample_count) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time));
+
+	/* Y Measurement */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_Y_MEASUREMENT),
+			MX25_ADCQ_CFG_YNLR |
+			MX25_ADCQ_CFG_YPLL_HIGH |
+			MX25_ADCQ_CFG_XNUR_OFF |
+			MX25_ADCQ_CFG_XPUL_OFF |
+			MX25_ADCQ_CFG_REFP_YP |
+			MX25_ADCQ_CFG_IN_XP |
+			MX25_ADCQ_CFG_REFN_YN |
+			MX25_ADCQ_CFG_NOS(priv->sample_count) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time));
+
+	/* Enable the touch detection right now */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, touch_detect_cfg |
+			MX25_ADCQ_CFG_IGS);
+}
+
+static int imx25_setup_queue_4wire(struct mx25_tcq_priv *priv,
+		unsigned settling_time, int *items)
+{
+	imx25_setup_queue_cfgs(priv, settling_time);
+
+	/* Setup the conversion queue */
+	regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
+			MX25_ADCQ_ITEM(0, MX25_CFG_PRECHARGE) |
+			MX25_ADCQ_ITEM(1, MX25_CFG_TOUCH_DETECT) |
+			MX25_ADCQ_ITEM(2, MX25_CFG_X_MEASUREMENT) |
+			MX25_ADCQ_ITEM(3, MX25_CFG_Y_MEASUREMENT) |
+			MX25_ADCQ_ITEM(4, MX25_CFG_PRECHARGE) |
+			MX25_ADCQ_ITEM(5, MX25_CFG_TOUCH_DETECT));
+
+	/* We measure X/Y with 'sample_count' number of samples and execute a
+	 * touch detection twice, with 1 sample each */
+	priv->expected_samples = priv->sample_count * 2 + 2;
+	*items = 6;
+
+	return 0;
+}
+
+static void mx25_tcq_disable_touch_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK,
+			MX25_ADCQ_CR_PDMSK);
+}
+
+static void mx25_tcq_enable_touch_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, 0);
+}
+
+static void mx25_tcq_disable_fifo_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ,
+			MX25_ADCQ_MR_FDRY_IRQ);
+}
+
+static void mx25_tcq_enable_fifo_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, 0);
+}
+
+static void mx25_tcq_force_queue_start(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS,
+			MX25_ADCQ_CR_FQS);
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS, 0);
+}
+
+static void mx25_tcq_force_queue_stop(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS, 0);
+}
+
+static void mx25_tcq_fifo_reset(struct mx25_tcq_priv *priv)
+{
+	u32 tcqcr;
+
+	regmap_read(priv->regs, MX25_ADCQ_CR, &tcqcr);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST,
+			MX25_ADCQ_CR_FRST);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST,
+			0);
+	regmap_write(priv->regs, MX25_ADCQ_CR, tcqcr);
+}
+
+static void mx25_tcq_re_enable_touch_detection(struct mx25_tcq_priv *priv)
+{
+	/* stop the queue from looping */
+	mx25_tcq_force_queue_stop(priv);
+
+	/* for a clean touch detection, preload the X plane */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_PRECHARGE_VALUE);
+
+	/* waste some time now to pre-load the X plate to high voltage */
+	mx25_tcq_fifo_reset(priv);
+
+	/* re-enable the detection right now */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_TOUCH_DETECT_VALUE |
+			MX25_ADCQ_CFG_IGS);
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_PD,
+			MX25_ADCQ_SR_PD);
+
+	/* enable the pen down event to be a source for the interrupt */
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_PD_IRQ, 0);
+
+	/* lets fire the next IRQ if someone touches the touchscreen */
+	mx25_tcq_enable_touch_irq(priv);
+}
+
+static int mx25_tcq_create_event_for_4wire(struct mx25_tcq_priv *priv,
+		u32 *sample_buf, int samples)
+{
+	unsigned int x_pos = 0;
+	unsigned int y_pos = 0;
+	unsigned int touch_pre = 0;
+	unsigned int touch_post = 0;
+	unsigned i;
+	int ret = 0;
+
+	for (i = 0; i < samples; i++) {
+		unsigned int index = MX25_ADCQ_FIFO_ID(sample_buf[i]);
+		unsigned int val = MX25_ADCQ_FIFO_DATA(sample_buf[i]);
+
+		switch (index) {
+		case 1:
+			touch_pre = val;
+			break;
+		case 2:
+			x_pos = val;
+			break;
+		case 3:
+			y_pos = val;
+			break;
+		case 5:
+			touch_post = val;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	if (ret == 0 && samples != 0) {
+		/*
+		 * only if both touch measures are below a treshold,
+		 * the position is valid
+		 */
+		if (touch_pre < priv->pen_threshold &&
+					touch_post < priv->pen_threshold) {
+			/* valid samples, generate a report */

drivers/input/touchscreen/fsl-imx25-tcq.c line 283

Quoted 6 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +6 -0

+			x_pos /= priv->sample_count;
+			y_pos /= priv->sample_count;
+			input_report_abs(priv->idev, ABS_X, x_pos);
+			input_report_abs(priv->idev, ABS_Y, y_pos);
+			input_report_key(priv->idev, BTN_TOUCH,
+					0xfff - ((touch_pre + touch_post) / 2));

Hmm, are you trying to report pressure here?

drivers/input/touchscreen/fsl-imx25-tcq.c line 290

Quoted 8 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +7 -0

+			input_sync(priv->idev);
+
+			/* get next sample */
+			mx25_tcq_force_queue_start(priv);
+			mx25_tcq_enable_fifo_irq(priv);
+		} else {
+			if (touch_pre >= priv->pen_threshold &&

You can convert this to "else if" and save indentation level here.

Quoted 30 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +29 -0

+					touch_post >= priv->pen_threshold) {
+				/*
+				 * if both samples are invalid,
+				 * generate a release report
+				 */
+				input_report_key(priv->idev, BTN_TOUCH, 0);
+				input_sync(priv->idev);
+				mx25_tcq_re_enable_touch_detection(priv);
+			} else {
+				/*
+				 * if only one of both touch measurements are
+				 * below the threshold, still some bouncing
+				 * happens. Take additional samples in this
+				 * case to be sure
+				 */
+				mx25_tcq_force_queue_start(priv);
+				mx25_tcq_enable_fifo_irq(priv);
+			}
+		}
+	}
+
+	return ret;
+}
+
+static irqreturn_t mx25_tcq_irq_thread(int irq, void *dev_id)
+{
+	struct mx25_tcq_priv *priv = (struct mx25_tcq_priv *) dev_id;
+	u32 sample_buf[TSC_MAX_SAMPLES];
+	int samples = 0;

drivers/input/touchscreen/fsl-imx25-tcq.c line 325

Quoted 6 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +6 -0

+
+	/* read all samples */
+	while (1) {
+		u32 stats;
+
+		regmap_read(priv->regs, MX25_ADCQ_SR, &stats);

Error handling for I/O operations?

drivers/input/touchscreen/fsl-imx25-tcq.c line 336

Quoted 12 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +11 -0

+		if (stats & MX25_ADCQ_SR_EMPT)
+			break;
+
+		if (samples < TSC_MAX_SAMPLES) {
+			regmap_read(priv->regs, MX25_ADCQ_FIFO,
+					&sample_buf[samples]);
+			++samples;
+		} else {
+			u32 discarded;
+			/* discard samples */
+			regmap_read(priv->regs, MX25_ADCQ_FIFO, &discarded);

Should there be some upper bound for number of discarded samples?

Quoted 179 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +178 -0

+		}
+	}
+
+	mx25_tcq_create_event_for_4wire(priv, sample_buf, samples);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mx25_tcq_irq(int irq, void *dev_id)
+{
+	struct mx25_tcq_priv *priv = (struct mx25_tcq_priv *)dev_id;
+	u32 stat;
+	int ret = IRQ_HANDLED;
+
+	regmap_read(priv->regs, MX25_ADCQ_SR, &stat);
+
+	if (stat & (MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR))
+		mx25_tcq_fifo_reset(priv);
+
+	if (stat & MX25_ADCQ_SR_PD) {
+		mx25_tcq_disable_touch_irq(priv);
+		mx25_tcq_force_queue_start(priv);
+		mx25_tcq_enable_fifo_irq(priv);
+	}
+
+	if (stat & MX25_ADCQ_SR_FDRY) {
+		mx25_tcq_disable_fifo_irq(priv);
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
+			MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD |
+			MX25_ADCQ_SR_EOQ,
+			MX25_ADCQ_SR_FRR |
+			MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD |
+			MX25_ADCQ_SR_EOQ);
+
+	return ret;
+}
+
+/* configure the statemachine for a 4-wire touchscreen */
+static int mx25_tcq_init(struct mx25_tcq_priv *priv)
+{
+	u32 tgcr;
+	unsigned int ipg_div;
+	unsigned int adc_period;
+	unsigned int repeat_wait;
+	unsigned int debounce_cnt;
+	unsigned int settling_time;
+	int itemct;
+	int ret;
+
+	regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr);
+	ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr));
+	adc_period = clk_get_rate(priv->clk) / (ipg_div * 2 + 2);
+	repeat_wait = fls(DIV_ROUND_UP(priv->repeat_wait, adc_period));
+	debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1;
+	settling_time = DIV_ROUND_UP(priv->settling_time, adc_period);
+
+
+	/* Reset */
+	regmap_write(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QRST |
+			MX25_ADCQ_CR_FRST);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QRST |
+			MX25_ADCQ_CR_FRST, 0);
+
+	/* up to 128 * 8 ADC clocks are possible */
+	if (debounce_cnt > 127)
+		debounce_cnt = 127;
+
+	if (repeat_wait > 15)
+		repeat_wait = 15;
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_RWAIT_MASK,
+			MX25_ADCQ_CR_RWAIT(repeat_wait));
+
+	ret = imx25_setup_queue_4wire(priv, 0x0, &itemct);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_LITEMID_MASK |
+			MX25_ADCQ_CR_WMRK_MASK,
+			MX25_ADCQ_CR_LITEMID(itemct - 1) |
+			MX25_ADCQ_CR_WMRK(priv->expected_samples - 1));
+
+	/* setup debounce count */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR,
+			MX25_TGCR_PDBTIME_MASK,
+			MX25_TGCR_PDBTIME(debounce_cnt));
+
+	/* enable debounce */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDBEN,
+			MX25_TGCR_PDBEN);
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDEN,
+			MX25_TGCR_PDEN);
+
+	/* enable the engine on demand */
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QSM_FQS,
+			MX25_ADCQ_CR_QSM_FQS);
+
+	mx25_tcq_re_enable_touch_detection(priv);
+
+	return 0;
+}
+
+static int mx25_tcq_parse_dt(struct platform_device *pdev,
+		struct mx25_tcq_priv *priv)
+{
+	struct device_node *np = pdev->dev.of_node;
+	u32 wires;
+	int ret;
+
+	/* Setup defaults */
+	priv->pen_threshold = 500;
+	priv->sample_count = 3;
+	priv->repeat_wait = 15000000;
+	priv->pen_debounce = 1000000;
+	priv->settling_time = 250000;
+
+	ret = of_property_read_u32(np, "fsl,wires", &wires);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to find fsl,wires properties\n");
+		return ret;
+	}
+
+	if (wires == 4) {
+		priv->mode = MX25_TS_4WIRE;
+	} else {
+		dev_err(&pdev->dev, "%u-wire mode not supported\n", wires);
+		return -EINVAL;
+	}
+
+	/* These are optional, we don't care about the return values */
+	of_property_read_u32(np, "fsl,pen-threshold", &priv->pen_threshold);
+	of_property_read_u32(np, "fsl,settling-time", &priv->settling_time);
+	of_property_read_u32(np, "fsl,pen-debounce", &priv->pen_debounce);
+
+	return 0;
+}
+
+static int mx25_tcq_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct input_dev *idev;
+	struct mx25_tcq_priv *priv;
+	struct resource *res;
+	void __iomem *mem;
+	int ret;
+	int irq;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mem = devm_ioremap_resource(dev, res);
+	if (!mem) {
+		dev_err(dev, "Failed to get iomem");
+		return -ENOMEM;
+	}
+
+	ret = mx25_tcq_parse_dt(pdev, priv);
+	if (ret)
+		return ret;
+
+	priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_tcq_regconfig);
+	if (IS_ERR(priv->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(priv->regs);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "Failed to get IRQ\n");
+		return irq;
+	}
+
+	ret = devm_request_threaded_irq(dev, irq, mx25_tcq_irq,

drivers/input/touchscreen/fsl-imx25-tcq.c line 519

Quoted 5 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +5 -0

+			mx25_tcq_irq_thread, IRQF_ONESHOT, pdev->name, priv);
+	if (ret) {
+		dev_err(dev, "Failed requesting IRQ\n");
+		return ret;
+	}

Are we sure the device is quiesce here? Otherwise interrupts will start coming but input device is not there yet.

Quoted 43 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +42 -0

+
+	idev = devm_input_allocate_device(dev);
+	if (!idev) {
+		dev_err(dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	idev->name = mx25_tcq_name;
+	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+	input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
+
+	idev->id.bustype = BUS_HOST;
+
+	ret = input_register_device(idev);
+	if (ret) {
+		dev_err(dev, "Failed to register input device\n");
+		return ret;
+	}
+
+	priv->idev = idev;
+
+	priv->core_regs = mx25_tsadc_get_regmap(pdev->dev.parent);
+	priv->clk = mx25_tsadc_get_ipg(pdev->dev.parent);
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable ipg clock\n");
+		return ret;
+	}
+
+	ret = mx25_tcq_init(priv);
+	if (ret) {
+		dev_err(dev, "Failed to init tcq\n");
+		goto error_tcq_init;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+

drivers/input/touchscreen/fsl-imx25-tcq.c line 571

Quoted 10 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +10 -0

+error_tcq_init:
+	clk_disable_unprepare(priv->clk);
+	return ret;
+}
+
+static int mx25_tcq_remove(struct platform_device *pdev)
+{
+	struct mx25_tcq_priv *priv = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(priv->clk);

Hmm, if you disable clk all other operations will likely to fail. We really need devm clk interface, I guess I need to dust off my old patch...

Quoted 13 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +13 -0

+
+	return 0;
+}
+
+static struct platform_driver mx25_tcq_driver = {
+	.driver		= {
+		.name	= "mx25-tcq",
+		.owner	= THIS_MODULE,
+		.of_match_table = mx25_tcq_ids,
+	},
+	.probe		= mx25_tcq_probe,
+	.remove		= mx25_tcq_remove,
+};

Quoted 8 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +5 -0

+module_platform_driver(mx25_tcq_driver);
+
+MODULE_DESCRIPTION("TS input driver for Freescale mx25");
+MODULE_AUTHOR("Markus Pargmann <[email protected]>");
+MODULE_LICENSE("GPL v2");

Signature · 1 line

1.8.5.3

This is a conversion queue driver for the mx25 SoC. It uses the central ADC which is used by two seperate independent queues. This driver prepares different conversion configurations for each possible input. For a conversion it creates a conversionqueue of one item with the correct configuration for the chosen channel. It then executes the queue once and disables the conversion queue afterwards.

The reference voltages are configurable through devicetree subnodes, depending on the connections of the ADC inputs.

Signed-off-by Markus Pargmann <[email protected]>

drivers/iio/adc/Kconfig +0 -0

index 2209f28..a421445 100644

+const struct iio_chan_spec mx25_gcq_channels[MX25_NUM_CFGS] = {

drivers/iio/adc/Makefile +38 -0

+}
+
+static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
+		struct mx25_gcq_priv *priv)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *child;
+	struct device *dev = &pdev->dev;
+	int ret;
+	int i;
+
+	/* Setup all configurations registers with a default conversion
+	 * configuration for each input */
+	for (i = 0; i != MX25_NUM_CFGS; ++i)
+		regmap_write(priv->regs, MX25_ADCQ_CFG(i),
+				MX25_ADCQ_CFG_YPLL_OFF |
+				MX25_ADCQ_CFG_XNUR_OFF |
+				MX25_ADCQ_CFG_XPUL_OFF |
+				MX25_ADCQ_CFG_REFP_INT |
+				(i << 4) |
+				MX25_ADCQ_CFG_REFN_NGND2);
+
+	for_each_child_of_node(np, child) {
+		u32 reg;
+		u32 refn;
+		u32 refp;
+
+		ret = of_property_read_u32(child, "reg", &reg);
+		if (ret) {
+			dev_err(dev, "Failed to get reg property\n");
+			return ret;
+		}
+		if (reg > MX25_NUM_CFGS) {
+			dev_err(dev, "reg value is greater than the number of available configuration registers\n");
+			return -EINVAL;
+		}
+
+		ret = of_property_read_u32(child, "fsl,adc-refn", &refn);

drivers/iio/adc/Makefile +27 -0

+
+		regmap_update_bits(priv->regs, MX25_ADCQ_CFG(reg),
+				MX25_ADCQ_CFG_REFP_MASK |
+				MX25_ADCQ_CFG_REFN_MASK,
+				(refp << 7) | (refn << 2));
+	}
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+			MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST,
+			MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST);
+
+	regmap_write(priv->regs, MX25_ADCQ_CR,
+			MX25_ADCQ_CR_PDMSK |
+			MX25_ADCQ_CR_QSM_FQS);
+
+	return 0;
+}
+
+static int mx25_gcq_probe(struct platform_device *pdev)
+{
+	struct iio_dev *idev;
+	struct mx25_gcq_priv *priv;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	int ret;
+	int irq;
+	void __iomem *mem;
+

drivers/iio/adc/Makefile +6 -0

+		return ret;
+	}
+
+	ret = mx25_gcq_setup_cfgs(pdev, priv);
+	if (ret)
+		return ret;

drivers/iio/adc/Makefile +4 -0

+	if (ret) {
+		dev_err(dev, "Failed to enable clock\n");
+		return ret;
+	}

drivers/iio/adc/Makefile +4 -0

+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}

Quoted 7 lines · Markus Pargmann

This is a conversion queue driver for the mx25 SoC. It uses the central ADC which is used by two seperate independent queues. This driver prepares different conversion configurations for each possible input. For a conversion it creates a conversionqueue of one item with the correct configuration for the chosen channel. It then executes the queue once and disables the conversion queue afterwards.

Quoted 4 lines

The reference voltages are configurable through devicetree subnodes, depending on the connections of the ADC inputs.

Signed-off-by Markus Pargmann <[email protected]>

Looks good mostly. Just a couple of minor code-style issues. Try to run checkpatch, sparse and friends on your driver before submission. They catch most of the stuff that needs to be fixed in this driver.

[..]

Quoted 8 lines

drivers/iio/adc/Kconfig +0 -0

index 2209f28..a421445 100644
@@ -113,6 +113,13 @@ config EXYNOS_ADC
 	  of SoCs for drivers such as the touchscreen and hwmon to use to share
 	  this resource.
 

drivers/iio/adc/Kconfig config EXYNOS_ADC · line 122

Quoted 7 lines

drivers/iio/adc/Kconfig +7 -0

+config MX25_ADC
+	tristate "Freescale MX25 ADC driver"
+	depends on MFD_MX25_TSADC
+	help
+	  Generic Conversion Queue driver used for general purpose ADC in the
+	  MX25. This driver supports single measurements using the MX25 ADC.
+

alphabetical order

drivers/iio/adc/Makefile obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o · line 25

Quoted 13 lines

drivers/iio/adc/Kconfig +0 -0

 config LP8788_ADC
 	bool "LP8788 ADC driver"
 	depends on MFD_LP8788

drivers/iio/adc/Makefile +1 -0

index ba9a10a..63daa2c 100644
@@ -22,3 +22,4 @@ obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
 obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
 obj-$(CONFIG_TWL6030_GPADC) += twl6030-gpadc.o
 obj-$(CONFIG_VIPERBOARD_ADC) += viperboard_adc.o
+obj-$(CONFIG_MX25_ADC) += fsl-imx25-gcq.o

Here too

[...]

Quoted 1 line

+const struct iio_chan_spec mx25_gcq_channels[MX25_NUM_CFGS] = {

static

Quoted 11 lines

drivers/iio/adc/Makefile +10 -0

+	MX25_IIO_CHAN(0, "xp"),
+	MX25_IIO_CHAN(1, "yp"),
+	MX25_IIO_CHAN(2, "xn"),
+	MX25_IIO_CHAN(3, "yn"),
+	MX25_IIO_CHAN(4, "wiper"),
+	MX25_IIO_CHAN(5, "inaux0"),
+	MX25_IIO_CHAN(6, "inaux1"),
+	MX25_IIO_CHAN(7, "inaux2"),
+};
+

Quoted 1 line

+struct iio_info mx25_gcq_iio_info = {

static const

drivers/iio/adc/Makefile

Quoted 5 lines

drivers/iio/adc/Makefile +4 -0

+	.read_raw = mx25_gcq_read_raw,
+};
+
+static struct regmap_config mx25_gcq_regconfig = {

const

drivers/iio/adc/Makefile

Quoted 2 lines

drivers/iio/adc/Makefile +1 -0

+	.fast_io = true,

You don't need to set fast_io since this is already done at the regmap_bus level.

Quoted 4 lines

drivers/iio/adc/Makefile +3 -0

+	.max_register = 0x5c,
+	.reg_bits = 32,
+	.val_bits = 32,

drivers/iio/adc/Makefile

Quoted 10 lines

drivers/iio/adc/Makefile +10 -0

+	.reg_stride = 4,
+};
+
+static void mx25_gcq_iio_dev_setup(struct platform_device *pdev,
+		struct iio_dev *idev)
+{
+	idev->dev.parent = &pdev->dev;
+	idev->channels = mx25_gcq_channels;
+	idev->num_channels = ARRAY_SIZE(mx25_gcq_channels);
+	idev->info = &mx25_gcq_iio_info;

Any reason why this needs to be in a separate function and can't be inlined in probe()?

Quoted 43 lines

drivers/iio/adc/Makefile +42 -0

+}
+
+static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
+		struct mx25_gcq_priv *priv)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *child;
+	struct device *dev = &pdev->dev;
+	int ret;
+	int i;
+
+	/* Setup all configurations registers with a default conversion
+	 * configuration for each input */
+	for (i = 0; i != MX25_NUM_CFGS; ++i)
+		regmap_write(priv->regs, MX25_ADCQ_CFG(i),
+				MX25_ADCQ_CFG_YPLL_OFF |
+				MX25_ADCQ_CFG_XNUR_OFF |
+				MX25_ADCQ_CFG_XPUL_OFF |
+				MX25_ADCQ_CFG_REFP_INT |
+				(i << 4) |
+				MX25_ADCQ_CFG_REFN_NGND2);
+
+	for_each_child_of_node(np, child) {
+		u32 reg;
+		u32 refn;
+		u32 refp;
+
+		ret = of_property_read_u32(child, "reg", &reg);
+		if (ret) {
+			dev_err(dev, "Failed to get reg property\n");
+			return ret;
+		}
+		if (reg > MX25_NUM_CFGS) {
+			dev_err(dev, "reg value is greater than the number of available configuration registers\n");
+			return -EINVAL;
+		}
+
+		ret = of_property_read_u32(child, "fsl,adc-refn", &refn);
+		if (ret) {
+			dev_err(dev, "Failed to get fsl,adc-refn property\n");
+			return ret;
+		}

drivers/iio/adc/Makefile

Quoted 6 lines

drivers/iio/adc/Makefile +6 -0

+
+		ret = of_property_read_u32(child, "fsl,adc-refp", &refp);
+		if (ret) {
+			dev_err(dev, "Failed to get fsl,adc-refp property\n");
+			return ret;
+		}

Range check for refp and refn?

Quoted 32 lines

drivers/iio/adc/Makefile +31 -0

+
+		regmap_update_bits(priv->regs, MX25_ADCQ_CFG(reg),
+				MX25_ADCQ_CFG_REFP_MASK |
+				MX25_ADCQ_CFG_REFN_MASK,
+				(refp << 7) | (refn << 2));
+	}
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+			MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST,
+			MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST);
+
+	regmap_write(priv->regs, MX25_ADCQ_CR,
+			MX25_ADCQ_CR_PDMSK |
+			MX25_ADCQ_CR_QSM_FQS);
+
+	return 0;
+}
+
+static int mx25_gcq_probe(struct platform_device *pdev)
+{
+	struct iio_dev *idev;
+	struct mx25_gcq_priv *priv;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	int ret;
+	int irq;
+	void __iomem *mem;
+
+	idev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
+	if (!idev)
+		return -ENOMEM;
+

drivers/iio/adc/Makefile

Quoted 6 lines

drivers/iio/adc/Makefile +6 -0

+	priv = iio_priv(idev);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mem = devm_ioremap_resource(dev, res);
+	if (!mem) {
+		dev_err(dev, "Failed to get iomem");

devm_ioremap_resource already prints a error message for you

drivers/iio/adc/Makefile

Quoted 12 lines

drivers/iio/adc/Makefile +11 -0

+		return -ENOMEM;
+	}
+
+	priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_gcq_regconfig);
+	if (IS_ERR(priv->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(priv->regs);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {

0 is not a valid IRQ number either

drivers/iio/adc/Makefile

Quoted 7 lines

drivers/iio/adc/Makefile +6 -0

+		dev_err(dev, "Failed to get IRQ\n");
+		return irq;
+	}
+
+	ret = devm_request_irq(dev, irq, mx25_gcq_irq, IRQF_ONESHOT, pdev->name,
+			priv);

IRQF_ONESHOT does not make much sense for non-threaded IRQs. Also it is probably safer to use the non managed variant of request_irq here.

drivers/iio/adc/Makefile

Quoted 3 lines

drivers/iio/adc/Makefile +2 -0

+	if (ret) {
+		dev_err(dev, "Failed requesting IRQ\n");

It usually makes sense to include the error number in the message. Same for the other error messages in probe.

Quoted 7 lines

drivers/iio/adc/Makefile +6 -0

+		return ret;
+	}
+
+	ret = mx25_gcq_setup_cfgs(pdev, priv);
+	if (ret)
+		return ret;

drivers/iio/adc/Makefile

Quoted 10 lines

drivers/iio/adc/Makefile +10 -0

+
+	mx25_gcq_iio_dev_setup(pdev, idev);
+
+	ret = iio_device_register(idev);
+	if (ret) {
+		dev_err(dev, "Failed to register iio device\n");
+		return ret;
+	}
+
+	init_completion(&priv->completed);

Should be done before the interrupt handler is registered. You reference it in there.

drivers/iio/adc/Makefile

Quoted 3 lines

drivers/iio/adc/Makefile +3 -0

+
+	priv->clk = mx25_tsadc_get_ipg(pdev->dev.parent);
+	ret = clk_prepare_enable(priv->clk);

The clock should probably also be enabled before the interrupt handler and the IIO device are registered.

Quoted 5 lines

drivers/iio/adc/Makefile +4 -0

+	if (ret) {
+		dev_err(dev, "Failed to enable clock\n");
+		return ret;
+	}

drivers/iio/adc/Makefile

Quoted 10 lines

drivers/iio/adc/Makefile +10 -0

+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static int mx25_gcq_remove(struct platform_device *pdev)
+{
+	struct mx25_gcq_priv *priv = platform_get_drvdata(pdev);
+

iio_device_unregister().

drivers/iio/adc/Makefile

Quoted 5 lines

drivers/iio/adc/Makefile +4 -0

+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}

From: Markus Pargmann <[email protected]>

This is the core driver for imx25 touchscreen/adc driver. The module has one shared ADC and two different conversion queues which use the ADC. The two queues are identical. Both can be used for general purpose ADC but one is meant to be used for touchscreens.

This driver is the core which manages the central components and registers of the TSC/ADC unit. It manages the IRQs and forwards them to the correct components.

Signed-off-by Markus Pargmann <[email protected]>

Signed-off-by Denis Carikli <[email protected]>

---
  .../devicetree/bindings/mfd/fsl-imx25-tsadc.txt    |   46 ++++
  drivers/mfd/Kconfig                                |    9 +
  drivers/mfd/Makefile                               |    2 +
  drivers/mfd/fsl-imx25-tsadc.c                      |  232 ++++++++++++++++++++
  include/linux/mfd/imx25-tsadc.h                    |  138 ++++++++++++
  5 files changed, 427 insertions(+)

create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
create mode 100644 include/linux/mfd/imx25-tsadc.h

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +46 -0

new file mode 100644
index 0000000..a857af0e
@@ -0,0 +1,46 @@
+Freescale mx25 ADC/TSC multifunction device
+
+This device combines two general purpose conversion queues one used for general
+ADC and the other used for touchscreens.
+
+Required properties:
+ - compatible: Should be "fsl,imx25-tsadc".
+ - reg: Memory range of the device.
+ - interrupts: Interrupt for this device as described in
+   interrupts/interrupts.txt
+ - clocks: An 'ipg' clock defined as described in clocks/clock.txt
+ - interrupt-controller: This device is an interrupt controller. It controls
+   the interrupts of both conversion queues.
+ - #interrupt-cells: Should be '<1>'.
+ - #address-cells: Should be '<1>'.
+ - #size-cells: Should be '<1>'.
+ - ranges
+
+This device includes two conversion queues which can be added as subnodes.
+The first queue is for the touchscreen, the second for general purpose ADC.
+
+Example:
+	tscadc: tscadc@50030000 {
+		compatible = "fsl,imx25-tsadc";
+		reg = <0x50030000 0xc>;
+		interrupts = <46>;
+		clocks = <&clks 119>;
+		clock-names = "ipg";
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		tsc: tcq@50030400 {
+			compatible = "fsl,imx25-tcq";
+			reg = <0x50030400 0x60>;
+			...
+		};
+
+		adc: gcq@50030800 {
+			compatible = "fsl,imx25-gcq";
+			reg = <0x50030800 0x60>;
+			...
+		};
+	};

drivers/mfd/Kconfig +9 -0

index ee8204c..73f4e66 100644
@@ -183,6 +183,15 @@ config MFD_DA9063
  	  Additional drivers must be enabled in order to use the functionality
  	  of the device.
 
+config MFD_MX25_TSADC
+	tristate "Freescale i.MX25 integrated Touchscreen and ADC unit"
+	depends on ARCH_MXC
+	select REGMAP_MMIO
+	help
+	  Enable support for the integrated Touchscreen and ADC unit of the
+	  i.MX25 processors. They consist of a conversion queue for general
+	  purpose ADC and a queue for Touchscreens.
+
  config MFD_MC13XXX
  	tristate
  	depends on (SPI_MASTER || I2C)

drivers/mfd/Makefile +2 -0

index 8afedba..7ff1013 100644
@@ -78,6 +78,8 @@ obj-$(CONFIG_TWL4030_POWER)    += twl4030-power.o
  obj-$(CONFIG_MFD_TWL4030_AUDIO)	+= twl4030-audio.o
  obj-$(CONFIG_TWL6040_CORE)	+= twl6040.o
 
+obj-$(CONFIG_MFD_MX25_TSADC)	+= fsl-imx25-tsadc.o
+
  obj-$(CONFIG_MFD_MC13XXX)	+= mc13xxx-core.o
  obj-$(CONFIG_MFD_MC13XXX_SPI)	+= mc13xxx-spi.o
  obj-$(CONFIG_MFD_MC13XXX_I2C)	+= mc13xxx-i2c.o

drivers/mfd/fsl-imx25-tsadc.c new file +96 -0

new file mode 100644
index 0000000..10332c2
@@ -0,0 +1,232 @@
+/*
+ * Copyright 2014 Markus Pargmann, Pengutronix <[email protected]>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/mfd/imx25-tsadc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+struct mx25_tsadc_priv {
+	struct regmap *regs;
+	struct irq_domain *domain;
+	struct clk *clk;
+};
+
+static struct regmap_config mx25_tsadc = {
+	.fast_io = true,
+	.max_register = 0x8,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+struct regmap *mx25_tsadc_get_regmap(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct mx25_tsadc_priv *priv;
+
+	if (!dev)
+		return NULL;
+
+	pdev = container_of(dev, struct platform_device, dev);
+	priv = platform_get_drvdata(pdev);
+	if (IS_ERR_OR_NULL(priv->regs))
+		return NULL;
+
+	return priv->regs;
+}
+EXPORT_SYMBOL(mx25_tsadc_get_regmap);
+
+struct clk *mx25_tsadc_get_ipg(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct mx25_tsadc_priv *priv;
+
+	if (!dev)
+		return NULL;
+
+	pdev = container_of(dev, struct platform_device, dev);
+	priv = platform_get_drvdata(pdev);
+	if (IS_ERR_OR_NULL(priv->clk))
+		return NULL;
+
+	return priv->clk;
+}
+EXPORT_SYMBOL(mx25_tsadc_get_ipg);
+
+static void mx25_tsadc_irq_handler(u32 irq, struct irq_desc *desc)
+{
+	struct mx25_tsadc_priv *priv = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_get_chip(irq);
+	u32 status;
+
+	chained_irq_enter(chip, desc);
+
+	regmap_read(priv->regs, MX25_TSC_TGSR, &status);
+
+	if (status & MX25_TGSR_GCQ_INT)
+		generic_handle_irq(irq_find_mapping(priv->domain, 1));
+
+	if (status & MX25_TGSR_TCQ_INT)
+		generic_handle_irq(irq_find_mapping(priv->domain, 0));
+
+	chained_irq_exit(chip, desc);
+}
+
+static void mx25_tsadc_nop(struct irq_data *d)
+{
+}
+
+static int mx25_tsadc_set_wake_nop(struct irq_data *d, unsigned int state)

drivers/mfd/fsl-imx25-tsadc.c new file +40 -0

+	set_irq_flags(irq, IRQF_VALID);
+
+	return 0;
+}
+
+static struct irq_domain_ops mx25_tsadc_domain_ops = {
+	.map = mx25_tsadc_domain_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+static int mx25_tsadc_setup_irq(struct platform_device *pdev,
+		struct mx25_tsadc_priv *priv)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	int irq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "Failed to get irq\n");
+		return irq;
+	}
+
+	priv->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
+			priv);
+	if (!priv->domain) {
+		dev_err(dev, "Failed to add irq domain\n");
+		return -ENOMEM;
+	}
+
+	irq_set_chained_handler(irq, mx25_tsadc_irq_handler);
+	irq_set_handler_data(irq, priv);
+
+	return 0;
+}
+
+static int mx25_tsadc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;

drivers/mfd/fsl-imx25-tsadc.c new file +64 -0

+	iomem = devm_ioremap_resource(dev, iores);
+	if (IS_ERR(iomem)) {
+		dev_err(dev, "Failed to remap iomem\n");
+		return PTR_ERR(iomem);
+	}
+
+	priv->regs = regmap_init_mmio(dev, iomem, &mx25_tsadc);
+	if (IS_ERR(priv->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(priv->regs);
+	}
+
+	priv->clk = devm_clk_get(dev, "ipg");
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "Failed to get ipg clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	/* Enable clock and reset the component */
+	regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
+			MX25_TGCR_CLK_EN);
+	regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
+			MX25_TGCR_TSC_RST);
+
+	/* Setup powersaving mode, but enable internal reference voltage */
+	regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
+			MX25_TGCR_POWERMODE_SAVE);
+	regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
+			MX25_TGCR_INTREFEN);
+
+	ret = mx25_tsadc_setup_irq(pdev, priv);
+	if (ret) {
+		dev_err(dev, "Failed to setup irqs\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	of_platform_populate(np, NULL, NULL, dev);
+
+	dev_info(dev, "i.MX25 Touchscreen and ADC core driver loaded\n");
+
+	return 0;
+}
+
+static const struct of_device_id mx25_tsadc_ids[] = {
+	{ .compatible = "fsl,imx25-tsadc", },
+	{ /* Sentinel */ }
+};
+
+static struct platform_driver mx25_tsadc_driver = {
+	.driver		= {
+		.name	= "mx25-tsadc",
+		.owner	= THIS_MODULE,
+		.of_match_table = mx25_tsadc_ids,
+	},
+	.probe		= mx25_tsadc_probe,
+};
+module_platform_driver(mx25_tsadc_driver);
+
+MODULE_DESCRIPTION("MFD for ADC/TSC for Freescale mx25");
+MODULE_AUTHOR("Markus Pargmann <[email protected]>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:mx25-tsadc");

include/linux/mfd/imx25-tsadc.h new file +138 -0

new file mode 100644
index 0000000..6fba341
@@ -0,0 +1,138 @@
+#ifndef _LINUX_INCLUDE_INPUT_IMX25_TSADC_H_
+#define _LINUX_INCLUDE_INPUT_IMX25_TSADC_H_
+
+struct regmap;
+struct device;
+struct clk;
+
+struct regmap *mx25_tsadc_get_regmap(struct device *dev);
+struct clk *mx25_tsadc_get_ipg(struct device *dev);
+
+#define MX25_TSC_TGCR 0x00
+#define MX25_TSC_TGSR 0x04
+#define MX25_TSC_TICR 0x08
+
+/* The same register layout for TC and GC queue */
+#define MX25_ADCQ_FIFO 0x00
+#define MX25_ADCQ_CR 0x04
+#define MX25_ADCQ_SR 0x08
+#define MX25_ADCQ_MR 0x0c
+#define MX25_ADCQ_ITEM_7_0 0x20
+#define MX25_ADCQ_ITEM_15_8 0x24
+#define MX25_ADCQ_CFG(n) (0x40 + ((n) * 0x4))
+
+/* Register values */
+/* Queue Config register */
+#define MX25_ADCQ_MR_MASK 0xffffffff
+
+/* TGCR */
+#define MX25_TGCR_PDBTIME(x) ((x) << 25)
+#define MX25_TGCR_PDBTIME_MASK MX25_TGCR_PDBTIME(0x7f)
+#define MX25_TGCR_PDBEN (1 << 24)
+#define MX25_TGCR_PDEN (1 << 23)
+#define MX25_TGCR_ADCCLKCFG(x) ((x) << 16)
+#define MX25_TGCR_GET_ADCCLK(x) (((x) >> 16) & 0x1f)
+#define MX25_TGCR_INTREFEN (1 << 10)
+#define MX25_TGCR_POWERMODE_MASK (3 << 8)
+#define MX25_TGCR_POWERMODE_SAVE (1 << 8)
+#define MX25_TGCR_POWERMODE_ON (2 << 8)
+#define MX25_TGCR_STLC (1 << 5)
+#define MX25_TGCR_SLPC (1 << 4)
+#define MX25_TGCR_FUNC_RST (1 << 2)
+#define MX25_TGCR_TSC_RST (1 << 1)
+#define MX25_TGCR_CLK_EN (1 << 0)
+
+/* TGSR */
+#define MX25_TGSR_SLP_INT (1 << 2)
+#define MX25_TGSR_GCQ_INT (1 << 1)
+#define MX25_TGSR_TCQ_INT (1 << 0)
+
+/* ADCQ_ITEM_* */
+#define _MX25_ADCQ_ITEM(item, x) ((x) << ((item) * 4))
+#define MX25_ADCQ_ITEM(item, x) ((item) >= 8 ? \
+		_MX25_ADCQ_ITEM((item) - 8, (x)) : _MX25_ADCQ_ITEM((item), (x)))
+
+/* ADCQ_FIFO (TCQFIFO and GCQFIFO) */
+#define MX25_ADCQ_FIFO_DATA(x) (((x) >> 4) & 0xfff)
+#define MX25_ADCQ_FIFO_ID(x) ((x) & 0xf)
+
+/* ADCQ_CR (TCQR and GCQR) */
+#define MX25_ADCQ_CR_PDCFG_LEVEL (1 << 19)
+#define MX25_ADCQ_CR_PDMSK (1 << 18)
+#define MX25_ADCQ_CR_FRST (1 << 17)
+#define MX25_ADCQ_CR_QRST (1 << 16)
+#define MX25_ADCQ_CR_RWAIT_MASK (0xf << 12)
+#define MX25_ADCQ_CR_RWAIT(x) ((x) << 12)
+#define MX25_ADCQ_CR_WMRK_MASK (0xf << 8)
+#define MX25_ADCQ_CR_WMRK(x) ((x) << 8)
+#define MX25_ADCQ_CR_LITEMID_MASK (0xf << 4)
+#define MX25_ADCQ_CR_LITEMID(x) ((x) << 4)
+#define MX25_ADCQ_CR_RPT (1 << 3)
+#define MX25_ADCQ_CR_FQS (1 << 2)
+#define MX25_ADCQ_CR_QSM_MASK 0x3
+#define MX25_ADCQ_CR_QSM_PD 0x1
+#define MX25_ADCQ_CR_QSM_FQS 0x2
+#define MX25_ADCQ_CR_QSM_FQS_PD 0x3
+
+/* ADCQ_SR (TCQSR and GCQSR) */
+#define MX25_ADCQ_SR_FDRY (1 << 15)
+#define MX25_ADCQ_SR_FULL (1 << 14)
+#define MX25_ADCQ_SR_EMPT (1 << 13)
+#define MX25_ADCQ_SR_FDN(x) (((x) >> 8) & 0x1f)
+#define MX25_ADCQ_SR_FRR (1 << 6)
+#define MX25_ADCQ_SR_FUR (1 << 5)
+#define MX25_ADCQ_SR_FOR (1 << 4)
+#define MX25_ADCQ_SR_EOQ (1 << 1)
+#define MX25_ADCQ_SR_PD (1 << 0)
+
+/* ADCQ_MR (TCQMR and GCQMR) */
+#define MX25_ADCQ_MR_FDRY_DMA (1 << 31)
+#define MX25_ADCQ_MR_FER_DMA (1 << 22)
+#define MX25_ADCQ_MR_FUR_DMA (1 << 21)
+#define MX25_ADCQ_MR_FOR_DMA (1 << 20)
+#define MX25_ADCQ_MR_EOQ_DMA (1 << 17)
+#define MX25_ADCQ_MR_PD_DMA (1 << 16)
+#define MX25_ADCQ_MR_FDRY_IRQ (1 << 15)
+#define MX25_ADCQ_MR_FER_IRQ (1 << 6)
+#define MX25_ADCQ_MR_FUR_IRQ (1 << 5)
+#define MX25_ADCQ_MR_FOR_IRQ (1 << 4)
+#define MX25_ADCQ_MR_EOQ_IRQ (1 << 1)
+#define MX25_ADCQ_MR_PD_IRQ (1 << 0)
+
+/* ADCQ_CFG (TICR, TCC0-7,GCC0-7) */
+#define MX25_ADCQ_CFG_SETTLING_TIME(x) ((x) << 24)
+#define MX25_ADCQ_CFG_IGS (1 << 20)
+#define MX25_ADCQ_CFG_NOS_MASK (0xf << 16)
+#define MX25_ADCQ_CFG_NOS(x) (((x) - 1) << 16)
+#define MX25_ADCQ_CFG_WIPER (1 << 15)
+#define MX25_ADCQ_CFG_YNLR (1 << 14)
+#define MX25_ADCQ_CFG_YPLL_HIGH 0
+#define MX25_ADCQ_CFG_YPLL_OFF (1 << 12)
+#define MX25_ADCQ_CFG_YPLL_LOW (3 << 12)
+#define MX25_ADCQ_CFG_XNUR_HIGH 0
+#define MX25_ADCQ_CFG_XNUR_OFF (1 << 10)
+#define MX25_ADCQ_CFG_XNUR_LOW (3 << 10)
+#define MX25_ADCQ_CFG_XPUL_OFF (1 << 9)
+#define MX25_ADCQ_CFG_XPUL_HIGH 0
+#define MX25_ADCQ_CFG_REFP_YP 0
+#define MX25_ADCQ_CFG_REFP_XP (1 << 7)
+#define MX25_ADCQ_CFG_REFP_EXT (2 << 7)
+#define MX25_ADCQ_CFG_REFP_INT (3 << 7)
+#define MX25_ADCQ_CFG_REFP_MASK (3 << 7)
+#define MX25_ADCQ_CFG_IN_XP 0
+#define MX25_ADCQ_CFG_IN_YP (1 << 4)
+#define MX25_ADCQ_CFG_IN_XN (2 << 4)
+#define MX25_ADCQ_CFG_IN_YN (3 << 4)
+#define MX25_ADCQ_CFG_IN_WIPER (4 << 4)
+#define MX25_ADCQ_CFG_IN_AUX0 (5 << 4)
+#define MX25_ADCQ_CFG_IN_AUX1 (6 << 4)
+#define MX25_ADCQ_CFG_IN_AUX2 (7 << 4)
+#define MX25_ADCQ_CFG_REFN_XN 0
+#define MX25_ADCQ_CFG_REFN_YN (1 << 2)
+#define MX25_ADCQ_CFG_REFN_NGND (2 << 2)
+#define MX25_ADCQ_CFG_REFN_NGND2 (3 << 2)
+#define MX25_ADCQ_CFG_REFN_MASK (3 << 2)
+#define MX25_ADCQ_CFG_PENIACK (1 << 1)
+
+
+#endif  /* _LINUX_INCLUDE_INPUT_IMX25_TSADC_H_ */

drivers/input/touchscreen/fsl-imx25-tcq.c new file +5 -0

+
+	if (ret == 0 && samples != 0) {
+		/*
+		 * only if both touch measures are below a treshold,
+		 * the position is valid

drivers/input/touchscreen/fsl-imx25-tcq.c new file +20 -0

+	u32 sample_buf[TSC_MAX_SAMPLES];
+	int samples = 0;
+
+	/* read all samples */
+	while (1) {
+		u32 stats;
+
+		regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+		if (stats & MX25_ADCQ_SR_EMPT)
+			break;
+
+		if (samples < TSC_MAX_SAMPLES) {
+			regmap_read(priv->regs, MX25_ADCQ_FIFO,
+							&sample_buf[samples]);
+			++samples;
+		} else {
+			u32 discarded;
+			/* discard samples */
+			regmap_read(priv->regs, MX25_ADCQ_FIFO, &discarded);
+		}

drivers/input/touchscreen/fsl-imx25-tcq.c new file +180 -0

+	u32 stat;
+	int ret = IRQ_HANDLED;
+
+	regmap_read(priv->regs, MX25_ADCQ_SR, &stat);
+
+	if (stat & (MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR))
+		mx25_tcq_fifo_reset(priv);
+
+	if (stat & MX25_ADCQ_SR_PD) {
+		mx25_tcq_disable_touch_irq(priv);
+		mx25_tcq_force_queue_start(priv);
+		mx25_tcq_enable_fifo_irq(priv);
+	}
+
+	if (stat & MX25_ADCQ_SR_FDRY) {
+		mx25_tcq_disable_fifo_irq(priv);
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
+			MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD |
+			MX25_ADCQ_SR_EOQ,
+			MX25_ADCQ_SR_FRR |
+			MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD |
+			MX25_ADCQ_SR_EOQ);
+
+	return ret;
+}
+
+/* configure the statemachine for a 4-wire touchscreen */
+static int mx25_tcq_init(struct mx25_tcq_priv *priv)
+{
+	u32 tgcr;
+	unsigned int ipg_div;
+	unsigned int adc_period;
+	unsigned int debounce_cnt;
+	unsigned int settling_time;
+	int itemct;
+	int ret;
+
+	regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr);
+	ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr));
+	adc_period = clk_get_rate(priv->clk) / (ipg_div * 2 + 2);
+	debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1;
+	settling_time = DIV_ROUND_UP(priv->settling_time, adc_period);
+
+
+	/* Reset */
+	regmap_write(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QRST |
+			MX25_ADCQ_CR_FRST);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QRST |
+			MX25_ADCQ_CR_FRST, 0);
+
+	/* up to 128 * 8 ADC clocks are possible */
+	if (debounce_cnt > 127)
+		debounce_cnt = 127;
+
+	ret = imx25_setup_queue_4wire(priv, 0x0, &itemct);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_LITEMID_MASK |
+			MX25_ADCQ_CR_WMRK_MASK,
+			MX25_ADCQ_CR_LITEMID(itemct - 1) |
+			MX25_ADCQ_CR_WMRK(priv->expected_samples - 1));
+
+	/* setup debounce count */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR,
+			MX25_TGCR_PDBTIME_MASK,
+			MX25_TGCR_PDBTIME(debounce_cnt));
+
+	/* enable debounce */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDBEN,
+			MX25_TGCR_PDBEN);
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDEN,
+			MX25_TGCR_PDEN);
+
+	/* enable the engine on demand */
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QSM_FQS,
+			MX25_ADCQ_CR_QSM_FQS);
+
+	mx25_tcq_re_enable_touch_detection(priv);
+
+	return 0;
+}
+
+static int mx25_tcq_parse_dt(struct platform_device *pdev,
+		struct mx25_tcq_priv *priv)
+{
+	struct device_node *np = pdev->dev.of_node;
+	u32 wires;
+	int ret;
+
+	/* Setup defaults */
+	priv->pen_threshold = 500;
+	priv->sample_count = 3;
+	priv->pen_debounce = 1000000;
+	priv->settling_time = 250000;
+
+	ret = of_property_read_u32(np, "fsl,wires", &wires);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to find fsl,wires properties\n");
+		return ret;
+	}
+
+	if (wires == 4) {
+		priv->mode = MX25_TS_4WIRE;
+	} else {
+		dev_err(&pdev->dev, "%u-wire mode not supported\n", wires);
+		return -EINVAL;
+	}
+
+	/* These are optional, we don't care about the return values */
+	of_property_read_u32(np, "fsl,pen-threshold", &priv->pen_threshold);
+	of_property_read_u32(np, "fsl,settling-time", &priv->settling_time);
+	of_property_read_u32(np, "fsl,pen-debounce", &priv->pen_debounce);
+
+	return 0;
+}
+
+static int mx25_tcq_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct input_dev *idev;
+	struct mx25_tcq_priv *priv;
+	struct resource *res;
+	void __iomem *mem;
+	int ret;
+	int irq;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mem = devm_ioremap_resource(dev, res);
+	if (!mem)
+		return -ENOMEM;
+
+	ret = mx25_tcq_parse_dt(pdev, priv);
+	if (ret)
+		return ret;
+
+	priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_tcq_regconfig);
+	if (IS_ERR(priv->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(priv->regs);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(dev, "Failed to get IRQ\n");
+		return irq;
+	}
+
+	idev = devm_input_allocate_device(dev);
+	if (!idev) {
+		dev_err(dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	idev->name = mx25_tcq_name;
+	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+	input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
+
+	idev->id.bustype = BUS_HOST;
+
+	ret = input_register_device(idev);
+	if (ret) {
+		dev_err(dev, "Failed to register input device\n");
+		return ret;
+	}
+
+	priv->idev = idev;
+
+	priv->core_regs = mx25_tsadc_get_regmap(pdev->dev.parent);
+	priv->clk = mx25_tsadc_get_ipg(pdev->dev.parent);
+

drivers/input/touchscreen/fsl-imx25-tcq.c new file +41 -0

+		return ret;
+	}
+
+	ret = mx25_tcq_init(priv);
+	if (ret) {
+		dev_err(dev, "Failed to init tcq\n");
+		goto error_tcq_init;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+
+error_tcq_init:
+	clk_disable_unprepare(priv->clk);
+	return ret;
+}
+
+static int mx25_tcq_remove(struct platform_device *pdev)
+{
+	struct mx25_tcq_priv *priv = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static struct platform_driver mx25_tcq_driver = {
+	.driver		= {
+		.name	= "mx25-tcq",
+		.owner	= THIS_MODULE,
+		.of_match_table = mx25_tcq_ids,
+	},
+	.probe		= mx25_tcq_probe,
+	.remove		= mx25_tcq_remove,
+};
+module_platform_driver(mx25_tcq_driver);
+
+MODULE_DESCRIPTION("TS input driver for Freescale mx25");
+MODULE_AUTHOR("Markus Pargmann <[email protected]>");
+MODULE_LICENSE("GPL v2");

Signature · 1 line

1.7.9.5

From: Markus Pargmann <[email protected]>

This is a driver for the imx25 ADC/TSC module. It controls the touchscreen conversion queue and creates a touchscreen input device. The driver currently only supports 4 wire touchscreens. The driver uses a simple conversion queue of precharge, touch detection, X measurement, Y measurement, precharge and another touch detection.

This driver uses the regmap from the parent to setup some touch specific settings in the core driver and setup a idle configuration with touch detection.

Signed-off-by Markus Pargmann <[email protected]>

Signed-off-by Denis Carikli <[email protected]>

---
  .../bindings/input/touchscreen/fsl-mx25-tcq.txt    |   29 +
  drivers/input/touchscreen/Kconfig                  |    6 +
  drivers/input/touchscreen/Makefile                 |    1 +
  drivers/input/touchscreen/fsl-imx25-tcq.c          |  576 ++++++++++++++++++++
  4 files changed, 612 insertions(+)

create mode 100644 Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt new file +29 -0

new file mode 100644
index 0000000..4214a99
@@ -0,0 +1,29 @@
+Freescale mx25 TS conversion queue module
+
+mx25 touchscreen conversion queue module which controls the ADC unit of the
+mx25 for attached touchscreens.
+
+Required properties:
+ - compatible: Should be "fsl,imx25-tcq".
+ - reg: Memory range of the device.
+ - interrupts: Should be the interrupt number associated with this module within
+   the tscadc unit (<0>).
+ - interrupt-parent: Should be a phandle to the tscadc unit.
+ - fsl,wires: Should be '<4>' or '<5>'
+
+Optional properties:
+ - fsl,pen-debounce: Pen debounce time.
+ - fsl,pen-threshold: Pen-down threshold for the touchscreen.
+ - fsl,settling-time: Settling time in nanoseconds.
+
+This device includes two conversion queues which can be added as subnodes.
+The first queue is for the touchscreen, the second for general purpose ADC.
+
+Example:
+	tsc: tcq@50030400 {
+		compatible = "fsl,imx25-tcq";
+		reg = <0x50030400 0x60>;
+		interrupt-parent = <&tscadc>;
+		interrupts = <0>;
+		fsl,wires = <4>;
+	};

drivers/input/touchscreen/Kconfig +6 -0

index a23a94b..a2290b9 100644
@@ -699,6 +699,12 @@ config TOUCHSCREEN_USB_COMPOSITE
  	  To compile this driver as a module, choose M here: the
  	  module will be called usbtouchscreen.
 
+config TOUCHSCREEN_MX25
+	tristate "Freescale i.MX25 touchscreen input driver"
+	depends on MFD_MX25_TSADC
+	help
+	  Enable support for touchscreen connected to your i.MX25.
+
  config TOUCHSCREEN_MC13783
  	tristate "Freescale MC13783 touchscreen input driver"
  	depends on MFD_MC13XXX

drivers/input/touchscreen/Makefile +1 -0

index 126479d..537d591 100644
@@ -38,6 +38,7 @@ obj-$(CONFIG_TOUCHSCREEN_INEXIO)	+= inexio.o
  obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)	+= intel-mid-touch.o
  obj-$(CONFIG_TOUCHSCREEN_LPC32XX)	+= lpc32xx_ts.o
  obj-$(CONFIG_TOUCHSCREEN_MAX11801)	+= max11801_ts.o
+obj-$(CONFIG_TOUCHSCREEN_MX25)		+= fsl-imx25-tcq.o
  obj-$(CONFIG_TOUCHSCREEN_MC13783)	+= mc13783_ts.o
  obj-$(CONFIG_TOUCHSCREEN_MCS5000)	+= mcs5000_ts.o
  obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o

drivers/input/touchscreen/fsl-imx25-tcq.c new file +470 -0

new file mode 100644
index 0000000..4ce576e
@@ -0,0 +1,576 @@
+/*
+ * Copyright 2014 Markus Pargmann, Pengutronix <[email protected]>
+ * Based on driver from 2011:
+ *   Juergen Beisert, Pengutronix <[email protected]>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * This is the driver for the imx25 TCQ (Touchscreen Conversion Queue)
+ * connected to the imx25 ADC.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/mfd/imx25-tsadc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static const char mx25_tcq_name[] = "mx25-tcq";
+
+enum mx25_tcq_mode {
+	MX25_TS_4WIRE,
+};
+
+struct mx25_tcq_priv {
+	struct regmap *regs;
+	struct regmap *core_regs;
+	struct input_dev *idev;
+	enum mx25_tcq_mode mode;
+	unsigned int pen_threshold;
+	unsigned int sample_count;
+	unsigned int expected_samples;
+	unsigned int pen_debounce;
+	unsigned int settling_time;
+	struct clk *clk;
+};
+
+static struct regmap_config mx25_tcq_regconfig = {
+	.fast_io = true,
+	.max_register = 0x5c,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static struct of_device_id mx25_tcq_ids[] = {
+	{ .compatible = "fsl,imx25-tcq", },
+	{ /* Senitel */ }
+};
+
+#define TSC_4WIRE_PRE_INDEX 0
+#define TSC_4WIRE_X_INDEX 1
+#define TSC_4WIRE_Y_INDEX 2
+#define TSC_4WIRE_POST_INDEX 3
+#define TSC_4WIRE_LEAVE 4
+
+#define MX25_TSC_DEF_THRESHOLD 80
+#define TSC_MAX_SAMPLES 16
+
+
+enum mx25_adc_configurations {
+	MX25_CFG_PRECHARGE = 0,
+	MX25_CFG_TOUCH_DETECT,
+	MX25_CFG_X_MEASUREMENT,
+	MX25_CFG_Y_MEASUREMENT,
+};
+
+#define MX25_PRECHARGE_VALUE (\
+			MX25_ADCQ_CFG_YPLL_OFF | \
+			MX25_ADCQ_CFG_XNUR_OFF | \
+			MX25_ADCQ_CFG_XPUL_HIGH | \
+			MX25_ADCQ_CFG_REFP_INT | \
+			MX25_ADCQ_CFG_IN_XP | \
+			MX25_ADCQ_CFG_REFN_NGND2 | \
+			MX25_ADCQ_CFG_IGS)
+
+#define MX25_TOUCH_DETECT_VALUE (\
+			MX25_ADCQ_CFG_YNLR | \
+			MX25_ADCQ_CFG_YPLL_OFF | \
+			MX25_ADCQ_CFG_XNUR_OFF | \
+			MX25_ADCQ_CFG_XPUL_OFF | \
+			MX25_ADCQ_CFG_REFP_INT | \
+			MX25_ADCQ_CFG_IN_XP | \
+			MX25_ADCQ_CFG_REFN_NGND2 | \
+			MX25_ADCQ_CFG_PENIACK)
+
+static void imx25_setup_queue_cfgs(struct mx25_tcq_priv *priv,
+		unsigned int settling_time)
+{
+	u32 precharge_cfg =
+			MX25_PRECHARGE_VALUE |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time);
+	u32 touch_detect_cfg =
+			MX25_TOUCH_DETECT_VALUE |
+			MX25_ADCQ_CFG_NOS(1) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time);
+
+	regmap_write(priv->core_regs, MX25_TSC_TICR, precharge_cfg);
+
+	/* PRECHARGE */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_PRECHARGE),
+			precharge_cfg);
+
+	/* TOUCH_DETECT */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_TOUCH_DETECT),
+			touch_detect_cfg);
+
+	/* X Measurement */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_X_MEASUREMENT),
+			MX25_ADCQ_CFG_YPLL_OFF |
+			MX25_ADCQ_CFG_XNUR_LOW |
+			MX25_ADCQ_CFG_XPUL_HIGH |
+			MX25_ADCQ_CFG_REFP_XP |
+			MX25_ADCQ_CFG_IN_YP |
+			MX25_ADCQ_CFG_REFN_XN |
+			MX25_ADCQ_CFG_NOS(priv->sample_count) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time));
+
+	/* Y Measurement */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_Y_MEASUREMENT),
+			MX25_ADCQ_CFG_YNLR |
+			MX25_ADCQ_CFG_YPLL_HIGH |
+			MX25_ADCQ_CFG_XNUR_OFF |
+			MX25_ADCQ_CFG_XPUL_OFF |
+			MX25_ADCQ_CFG_REFP_YP |
+			MX25_ADCQ_CFG_IN_XP |
+			MX25_ADCQ_CFG_REFN_YN |
+			MX25_ADCQ_CFG_NOS(priv->sample_count) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time));
+
+	/* Enable the touch detection right now */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, touch_detect_cfg |
+			MX25_ADCQ_CFG_IGS);
+}
+
+static int imx25_setup_queue_4wire(struct mx25_tcq_priv *priv,
+		unsigned settling_time, int *items)
+{
+	imx25_setup_queue_cfgs(priv, settling_time);
+
+	/* Setup the conversion queue */
+	regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
+			MX25_ADCQ_ITEM(0, MX25_CFG_PRECHARGE) |
+			MX25_ADCQ_ITEM(1, MX25_CFG_TOUCH_DETECT) |
+			MX25_ADCQ_ITEM(2, MX25_CFG_X_MEASUREMENT) |
+			MX25_ADCQ_ITEM(3, MX25_CFG_Y_MEASUREMENT) |
+			MX25_ADCQ_ITEM(4, MX25_CFG_PRECHARGE) |
+			MX25_ADCQ_ITEM(5, MX25_CFG_TOUCH_DETECT));
+
+	/* We measure X/Y with 'sample_count' number of samples and execute a
+	 * touch detection twice, with 1 sample each */
+	priv->expected_samples = priv->sample_count * 2 + 2;
+	*items = 6;
+
+	return 0;
+}
+
+static void mx25_tcq_disable_touch_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK,
+			MX25_ADCQ_CR_PDMSK);
+}
+
+static void mx25_tcq_enable_touch_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, 0);
+}
+
+static void mx25_tcq_disable_fifo_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ,
+			MX25_ADCQ_MR_FDRY_IRQ);
+}
+
+static void mx25_tcq_enable_fifo_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, 0);
+}
+
+static void mx25_tcq_force_queue_start(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS,
+			MX25_ADCQ_CR_FQS);
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS, 0);
+}
+
+static void mx25_tcq_force_queue_stop(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS, 0);
+}
+
+static void mx25_tcq_fifo_reset(struct mx25_tcq_priv *priv)
+{
+	u32 tcqcr;
+
+	regmap_read(priv->regs, MX25_ADCQ_CR, &tcqcr);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST,
+			MX25_ADCQ_CR_FRST);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST,
+			0);
+	regmap_write(priv->regs, MX25_ADCQ_CR, tcqcr);
+}
+
+static void mx25_tcq_re_enable_touch_detection(struct mx25_tcq_priv *priv)
+{
+	/* stop the queue from looping */
+	mx25_tcq_force_queue_stop(priv);
+
+	/* for a clean touch detection, preload the X plane */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_PRECHARGE_VALUE);
+
+	/* waste some time now to pre-load the X plate to high voltage */
+	mx25_tcq_fifo_reset(priv);
+
+	/* re-enable the detection right now */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_TOUCH_DETECT_VALUE |
+			MX25_ADCQ_CFG_IGS);
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_PD,
+			MX25_ADCQ_SR_PD);
+
+	/* enable the pen down event to be a source for the interrupt */
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_PD_IRQ, 0);
+
+	/* lets fire the next IRQ if someone touches the touchscreen */
+	mx25_tcq_enable_touch_irq(priv);
+}
+
+static int mx25_tcq_create_event_for_4wire(struct mx25_tcq_priv *priv,
+		u32 *sample_buf, int samples)
+{
+	unsigned int x_pos = 0;
+	unsigned int y_pos = 0;
+	unsigned int touch_pre = 0;
+	unsigned int touch_post = 0;
+	unsigned i;
+	int ret = 0;
+
+	for (i = 0; i < samples; i++) {
+		unsigned int index = MX25_ADCQ_FIFO_ID(sample_buf[i]);
+		unsigned int val = MX25_ADCQ_FIFO_DATA(sample_buf[i]);
+
+		switch (index) {
+		case 1:
+			touch_pre = val;
+			break;
+		case 2:
+			x_pos = val;
+			break;
+		case 3:
+			y_pos = val;
+			break;
+		case 5:
+			touch_post = val;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	if (ret == 0 && samples != 0) {
+		/*
+		 * only if both touch measures are below a treshold,
+		 * the position is valid
+		 */
+		if (touch_pre < priv->pen_threshold &&
+					touch_post < priv->pen_threshold) {
+			/* valid samples, generate a report */
+			x_pos /= priv->sample_count;
+			y_pos /= priv->sample_count;
+			input_report_abs(priv->idev, ABS_X, x_pos);
+			input_report_abs(priv->idev, ABS_Y, y_pos);
+			input_report_key(priv->idev, BTN_TOUCH,
+					0xfff - ((touch_pre + touch_post) / 2));
+			input_sync(priv->idev);
+
+			/* get next sample */
+			mx25_tcq_force_queue_start(priv);
+			mx25_tcq_enable_fifo_irq(priv);
+		} else if (touch_pre >= priv->pen_threshold &&
+				touch_post >= priv->pen_threshold) {
+			/*
+			 * if both samples are invalid,
+			 * generate a release report
+			 */
+			input_report_key(priv->idev, BTN_TOUCH, 0);
+			input_sync(priv->idev);
+			mx25_tcq_re_enable_touch_detection(priv);
+		} else {
+			/*
+			 * if only one of both touch measurements are
+			 * below the threshold, still some bouncing
+			 * happens. Take additional samples in this
+			 * case to be sure
+			 */
+			mx25_tcq_force_queue_start(priv);
+			mx25_tcq_enable_fifo_irq(priv);
+		}
+	}
+
+	return ret;
+}
+
+static irqreturn_t mx25_tcq_irq_thread(int irq, void *dev_id)
+{
+	struct mx25_tcq_priv *priv = (struct mx25_tcq_priv *) dev_id;
+	u32 sample_buf[TSC_MAX_SAMPLES];
+	int samples = 0;
+
+	/* read all samples */
+	while (1) {
+		u32 stats;
+
+		regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+		if (stats & MX25_ADCQ_SR_EMPT)
+			break;
+
+		if (samples < TSC_MAX_SAMPLES) {
+			regmap_read(priv->regs, MX25_ADCQ_FIFO,
+							&sample_buf[samples]);
+			++samples;
+		} else {
+			u32 discarded;
+			/* discard samples */
+			regmap_read(priv->regs, MX25_ADCQ_FIFO, &discarded);
+		}
+	}
+
+	mx25_tcq_create_event_for_4wire(priv, sample_buf, samples);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mx25_tcq_irq(int irq, void *dev_id)
+{
+	struct mx25_tcq_priv *priv = (struct mx25_tcq_priv *)dev_id;
+	u32 stat;
+	int ret = IRQ_HANDLED;
+
+	regmap_read(priv->regs, MX25_ADCQ_SR, &stat);
+
+	if (stat & (MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR))
+		mx25_tcq_fifo_reset(priv);
+
+	if (stat & MX25_ADCQ_SR_PD) {
+		mx25_tcq_disable_touch_irq(priv);
+		mx25_tcq_force_queue_start(priv);
+		mx25_tcq_enable_fifo_irq(priv);
+	}
+
+	if (stat & MX25_ADCQ_SR_FDRY) {
+		mx25_tcq_disable_fifo_irq(priv);
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
+			MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD |
+			MX25_ADCQ_SR_EOQ,
+			MX25_ADCQ_SR_FRR |
+			MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD |
+			MX25_ADCQ_SR_EOQ);
+
+	return ret;
+}
+
+/* configure the statemachine for a 4-wire touchscreen */
+static int mx25_tcq_init(struct mx25_tcq_priv *priv)
+{
+	u32 tgcr;
+	unsigned int ipg_div;
+	unsigned int adc_period;
+	unsigned int debounce_cnt;
+	unsigned int settling_time;
+	int itemct;
+	int ret;
+
+	regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr);
+	ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr));
+	adc_period = clk_get_rate(priv->clk) / (ipg_div * 2 + 2);
+	debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1;
+	settling_time = DIV_ROUND_UP(priv->settling_time, adc_period);
+
+
+	/* Reset */
+	regmap_write(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QRST |
+			MX25_ADCQ_CR_FRST);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QRST |
+			MX25_ADCQ_CR_FRST, 0);
+
+	/* up to 128 * 8 ADC clocks are possible */
+	if (debounce_cnt > 127)
+		debounce_cnt = 127;
+
+	ret = imx25_setup_queue_4wire(priv, 0x0, &itemct);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_LITEMID_MASK |
+			MX25_ADCQ_CR_WMRK_MASK,
+			MX25_ADCQ_CR_LITEMID(itemct - 1) |
+			MX25_ADCQ_CR_WMRK(priv->expected_samples - 1));
+
+	/* setup debounce count */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR,
+			MX25_TGCR_PDBTIME_MASK,
+			MX25_TGCR_PDBTIME(debounce_cnt));
+
+	/* enable debounce */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDBEN,
+			MX25_TGCR_PDBEN);
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDEN,
+			MX25_TGCR_PDEN);
+
+	/* enable the engine on demand */
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QSM_FQS,
+			MX25_ADCQ_CR_QSM_FQS);
+
+	mx25_tcq_re_enable_touch_detection(priv);
+
+	return 0;
+}
+
+static int mx25_tcq_parse_dt(struct platform_device *pdev,
+		struct mx25_tcq_priv *priv)
+{
+	struct device_node *np = pdev->dev.of_node;
+	u32 wires;
+	int ret;
+
+	/* Setup defaults */
+	priv->pen_threshold = 500;
+	priv->sample_count = 3;
+	priv->pen_debounce = 1000000;
+	priv->settling_time = 250000;
+
+	ret = of_property_read_u32(np, "fsl,wires", &wires);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to find fsl,wires properties\n");
+		return ret;
+	}
+
+	if (wires == 4) {
+		priv->mode = MX25_TS_4WIRE;
+	} else {
+		dev_err(&pdev->dev, "%u-wire mode not supported\n", wires);
+		return -EINVAL;
+	}
+
+	/* These are optional, we don't care about the return values */
+	of_property_read_u32(np, "fsl,pen-threshold", &priv->pen_threshold);
+	of_property_read_u32(np, "fsl,settling-time", &priv->settling_time);
+	of_property_read_u32(np, "fsl,pen-debounce", &priv->pen_debounce);
+
+	return 0;
+}
+
+static int mx25_tcq_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct input_dev *idev;
+	struct mx25_tcq_priv *priv;