imx25 adc and touchscreen driver

This documentation describes the devicetree bindings for the ADC/Touchscreen unit of the i.MX25 SoC.

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

Acked-by Jonathan Cameron <[email protected]>

Acked-by Rob Herring <[email protected]>

---

Notes:
Changes in v9:
- Fixed some style things.

Changes in v6:
- Removed adc-ref property and replaced it with refp and refn for positive and negative references. The properties are optional now as the default behaviour is a positive internal reference voltage and ADC GND as negative reference.

 .../devicetree/bindings/mfd/fsl-imx25-tsadc.txt    | 47 ++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +47 -0

new file mode 100644
index 000000000000..b03505286997
@@ -0,0 +1,47 @@
+Freescale MX25 ADC/TSC MultiFunction Device (MFD)
+
+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:				Start address and size of the memory area of
+ 					the device
+ - interrupts:			Interrupt for this device
+					(See: ../interrupt-controller/interrupts.txt)
+ - clocks:			An 'ipg' clock (See: ../clock/clock-bindings.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>'.
+
+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 {
+			compatible = "fsl,imx25-gcq";
+			reg = <0x50030800 0x60>;
+			...
+		};
+	};

This is the touchscreen conversion queue binding documentation. It uses the shared imx25 ADC.

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

---

Notes:
Changes in v9:
- Updated binding descriptions

Changes in v5:
- Fix signed/unsigned comparison
- Fix unused variable settling_time by putting it in the correct argument list
- Use continous conversion queue with the repeat feature and a proper repeat-wait. Previously the touchscreen caused massive number of interrupts.

 .../bindings/input/touchscreen/fsl-mx25-tcq.txt    | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt

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]>

[ensure correct ADC clock depending on the IPG clock]

Signed-off-by Juergen Borleis <[email protected]>

Acked-by Jonathan Cameron <[email protected]>

---

Notes:
Changes in v7:
- Cleanup bit defines in header files to be more readable
- Fix irq check to return with an error for irq <= 0
- Add COMPILE_TEST in Kconfig file

Changes in v5:
- Remove ifdef CONFIG_OF as this driver is only for DT usage
- Remove module owner
- Add Kconfig dependencies ARCH_MX25 and OF

 drivers/mfd/Kconfig             |   9 ++
 drivers/mfd/Makefile            |   2 +
 drivers/mfd/fsl-imx25-tsadc.c   | 203 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h | 140 +++++++++++++++++++++++++++
 4 files changed, 354 insertions(+)
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

Quoted 28 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]>

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

[ensure correct ADC clock depending on the IPG clock]

Signed-off-by Juergen Borleis <[email protected]>

Acked-by Jonathan Cameron <[email protected]>

---

Notes:
Changes in v7:
- Cleanup bit defines in header files to be more readable
- Fix irq check to return with an error for irq <= 0
- Add COMPILE_TEST in Kconfig file

Changes in v5:
- Remove ifdef CONFIG_OF as this driver is only for DT usage
- Remove module owner
- Add Kconfig dependencies ARCH_MX25 and OF

Quoted 7 lines

 drivers/mfd/Kconfig             |   9 ++
 drivers/mfd/Makefile            |   2 +
 drivers/mfd/fsl-imx25-tsadc.c   | 203 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h | 140 +++++++++++++++++++++++++++
 4 files changed, 354 insertions(+)
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

For my own reference:

Acked-by Lee Jones <[email protected]>

I will apply this and sent out pull-requests to the relevant maintainers once -rc1 is out.

Hi,

Quoted 38 lines · Lee Jones

Quoted 35 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]>

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

[ensure correct ADC clock depending on the IPG clock]

Signed-off-by Juergen Borleis <[email protected]>

Acked-by Jonathan Cameron <[email protected]>

---

Notes:
Changes in v7:
- Cleanup bit defines in header files to be more readable
- Fix irq check to return with an error for irq <= 0
- Add COMPILE_TEST in Kconfig file

Changes in v5:
- Remove ifdef CONFIG_OF as this driver is only for DT usage
- Remove module owner
- Add Kconfig dependencies ARCH_MX25 and OF

 drivers/mfd/Kconfig             |   9 ++
 drivers/mfd/Makefile            |   2 +
 drivers/mfd/fsl-imx25-tsadc.c   | 203 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h | 140 +++++++++++++++++++++++++++
 4 files changed, 354 insertions(+)
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

Quoted 5 lines

For my own reference:

Acked-by Lee Jones <[email protected]>

I will apply this and sent out pull-requests to the relevant maintainers once -rc1 is out.

Thanks. Do you mean just this patch or the whole series?

Shall I resend the whole series to fix the commit title of the first patch?

Quoted 41 lines · Markus Pargmann

Hi,

Quoted 38 lines · Lee Jones

Quoted 35 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]>

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

[ensure correct ADC clock depending on the IPG clock]

Signed-off-by Juergen Borleis <[email protected]>

Acked-by Jonathan Cameron <[email protected]>

---

Notes:
Changes in v7:
- Cleanup bit defines in header files to be more readable
- Fix irq check to return with an error for irq <= 0
- Add COMPILE_TEST in Kconfig file

Changes in v5:
- Remove ifdef CONFIG_OF as this driver is only for DT usage
- Remove module owner
- Add Kconfig dependencies ARCH_MX25 and OF

 drivers/mfd/Kconfig             |   9 ++
 drivers/mfd/Makefile            |   2 +
 drivers/mfd/fsl-imx25-tsadc.c   | 203 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h | 140 +++++++++++++++++++++++++++
 4 files changed, 354 insertions(+)
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

Quoted 7 lines

Quoted 5 lines

For my own reference:

Acked-by Lee Jones <[email protected]>

I will apply this and sent out pull-requests to the relevant maintainers once -rc1 is out.

Thanks. Do you mean just this patch or the whole series?

I will take all of the /driver patches. The ARM patches need to go in through ARM-SoC via the relevant sub-arch maintainer(s).

Quoted 2 lines

Shall I resend the whole series to fix the commit title of the first patch?

No, that's fine. I'll handle that *this time*.

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]>

[fix clock's period calculation]

[fix calculation of the 'settling' value]

Signed-off-by Juergen Borleis <[email protected]>

---

Notes:
Changes in v10:
- Renamed devicetree properties

Changes in v9:
- Added module description to Kconfig item
- Fixed devm_ioremap_resource() return value check to use IS_ERR()
- Removed return value of mx25_tcq_create_event_for_4wire()
- Renamed most 'ret' variables through 'error'
- Removed IRQF_ONESHOT
- Rearranged threaded handler to not mix up samples from multiple measurements

Changes in v7:
- Moved clk_prepare_enable() and mx25_tcq_init() into mx25_tcq_open(). This was done to be able to use devm_request_threaded_irq().
- Cleanup of the probe function through above change
- Removed mx25_tcq_remove(), not necessary now

 drivers/input/touchscreen/Kconfig         |   9 +
 drivers/input/touchscreen/Makefile        |   1 +
 drivers/input/touchscreen/fsl-imx25-tcq.c | 596 ++++++++++++++++++++++++++++++
 3 files changed, 606 insertions(+)
 create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c

drivers/input/touchscreen/Kconfig +9 -0

index ae33da7ab51f..873bf3697e35 100644
@@ -811,6 +811,15 @@ 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.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called fsl-imx25-tcq.
+
 config TOUCHSCREEN_MC13783
 	tristate "Freescale MC13783 touchscreen input driver"
 	depends on MFD_MC13XXX

drivers/input/touchscreen/Makefile +1 -0

index cbaa6abb08da..77a2ac54101a 100644
@@ -45,6 +45,7 @@ obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)	+= intel-mid-touch.o
 obj-$(CONFIG_TOUCHSCREEN_IPROC)		+= bcm_iproc_tsc.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 +596 -0

new file mode 100644
index 000000000000..fe9877a6af9e
@@ -0,0 +1,596 @@
+/*
+ * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ *
+ * Based on driver from 2011:
+ *   Juergen Beisert, Pengutronix <[email protected]>
+ *
+ * This is the driver for the imx25 TCQ (Touchscreen Conversion Queue)
+ * connected to the imx25 ADC.
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/interrupt.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;
+	int irq;
+	struct device *dev;
+};
+
+static struct regmap_config mx25_tcq_regconfig = {
+	.fast_io = true,
+	.max_register = 0x5c,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static const struct of_device_id mx25_tcq_ids[] = {
+	{ .compatible = "fsl,imx25-tcq", },
+	{ /* Sentinel */ }
+};
+
+#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
+
+#define MX25_TSC_REPEAT_WAIT 14
+
+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_cnt)
+{
+	u32 precharge_cfg =
+			MX25_PRECHARGE_VALUE |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt);
+	u32 touch_detect_cfg =
+			MX25_TOUCH_DETECT_VALUE |
+			MX25_ADCQ_CFG_NOS(1) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt);
+
+	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_cnt));
+
+	/* 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_cnt));
+
+	/* 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_cnt, int *items)
+{
+	imx25_setup_queue_cfgs(priv, settling_cnt);
+
+	/* 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);
+}
+
+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 void mx25_tcq_create_event_for_4wire(struct mx25_tcq_priv *priv,
+					    u32 *sample_buf,
+					    unsigned int samples)
+{
+	unsigned int x_pos = 0;
+	unsigned int y_pos = 0;
+	unsigned int touch_pre = 0;
+	unsigned int touch_post = 0;
+	unsigned int i;
+
+	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:
+			dev_dbg(priv->dev, "Dropped samples because of invalid index %d\n",
+				index);
+			return;
+		}
+	}
+
+	if (samples != 0) {
+		/*
+		 * only if both touch measures are below a threshold,
+		 * 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, 1);
+			input_sync(priv->idev);
+
+			/* get next sample */
+			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_enable_fifo_irq(priv);
+		}
+	}
+}
+
+static irqreturn_t mx25_tcq_irq_thread(int irq, void *dev_id)
+{
+	struct mx25_tcq_priv *priv = dev_id;
+	u32 sample_buf[TSC_MAX_SAMPLES];
+	unsigned int samples;
+	u32 stats;
+	unsigned int i;
+
+	/*
+	 * Check how many samples are available. We always have to read exactly
+	 * sample_count samples from the fifo, or a multiple of sample_count.
+	 * Otherwise we mixup samples into different touch events.
+	 */
+	regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+	samples = MX25_ADCQ_SR_FDN(stats);
+	samples -= samples % priv->sample_count;
+
+	if (!samples)
+		return IRQ_HANDLED;
+
+	for (i = 0; i != samples; ++i)
+		regmap_read(priv->regs, MX25_ADCQ_FIFO, &sample_buf[i]);
+
+	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 = 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_re_enable_touch_detection(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_FRR | MX25_ADCQ_SR_FUR |
+			   MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD);
+
+	return ret;
+}
+
+/* configure the state machine 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_cnt;
+	int itemct;
+	int error;
+
+	regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr);
+	ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr));
+	adc_period = USEC_PER_SEC * ipg_div * 2 + 2;
+	adc_period /= clk_get_rate(priv->clk) / 1000 + 1;
+	debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1;
+	settling_cnt = DIV_ROUND_UP(priv->settling_time, adc_period * 8) - 1;
+
+	/* 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;
+
+	/* up to 255 * 8 ADC clocks are possible */
+	if (settling_cnt > 255)
+		settling_cnt = 255;
+
+	error = imx25_setup_queue_4wire(priv, settling_cnt, &itemct);
+	if (error)
+		return error;
+
+	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_MASK,
+			   MX25_ADCQ_CR_QSM_FQS);
+
+	/* Enable repeat and repeat wait */
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+			   MX25_ADCQ_CR_RPT | MX25_ADCQ_CR_RWAIT_MASK,
+			   MX25_ADCQ_CR_RPT |
+			   MX25_ADCQ_CR_RWAIT(MX25_TSC_REPEAT_WAIT));
+
+	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 error;
+
+	/* Setup defaults */
+	priv->pen_threshold = 500;
+	priv->sample_count = 3;
+	priv->pen_debounce = 1000000;
+	priv->settling_time = 250000;
+
+	error = of_property_read_u32(np, "fsl,wires", &wires);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to find fsl,wires properties\n");
+		return error;
+	}
+
+	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-ns", &priv->settling_time);
+	of_property_read_u32(np, "fsl,pen-debounce-ns", &priv->pen_debounce);
+
+	return 0;
+}
+
+static int mx25_tcq_open(struct input_dev *idev)
+{
+	struct device *dev = &idev->dev;
+	struct mx25_tcq_priv *priv = dev_get_drvdata(dev);
+	int error;
+
+	error = clk_prepare_enable(priv->clk);
+	if (error) {
+		dev_err(dev, "Failed to enable ipg clock\n");
+		return error;
+	}
+
+	error = mx25_tcq_init(priv);
+	if (error) {
+		dev_err(dev, "Failed to init tcq\n");
+		clk_disable_unprepare(priv->clk);
+		return error;
+	}
+
+	mx25_tcq_re_enable_touch_detection(priv);
+
+	return 0;
+}
+
+static void mx25_tcq_close(struct input_dev *idev)
+{
+	struct mx25_tcq_priv *priv = input_get_drvdata(idev);
+
+	mx25_tcq_force_queue_stop(priv);
+	mx25_tcq_disable_touch_irq(priv);
+	mx25_tcq_disable_fifo_irq(priv);
+	clk_disable_unprepare(priv->clk);
+}
+
+static int mx25_tcq_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct input_dev *idev;
+	struct mx25_tcq_priv *priv;
+	struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent);
+	struct resource *res;
+	void __iomem *mem;
+	int error;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	priv->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mem = devm_ioremap_resource(dev, res);
+	if (IS_ERR(mem))
+		return PTR_ERR(mem);
+
+	error = mx25_tcq_parse_dt(pdev, priv);
+	if (error)
+		return error;
+
+	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);
+	}
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (priv->irq <= 0) {
+		dev_err(dev, "Failed to get IRQ\n");
+		return priv->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;
+	input_set_capability(idev, EV_KEY, 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;
+	idev->open = mx25_tcq_open;
+	idev->close = mx25_tcq_close;
+
+	priv->idev = idev;
+	input_set_drvdata(idev, priv);
+
+	priv->core_regs = tsadc->regs;
+	if (!priv->core_regs)
+		return -EINVAL;
+
+	priv->clk = tsadc->clk;
+	if (!priv->clk)
+		return -EINVAL;
+
+	platform_set_drvdata(pdev, priv);
+
+	error = devm_request_threaded_irq(dev, priv->irq, mx25_tcq_irq,
+					  mx25_tcq_irq_thread, 0, pdev->name,
+					  priv);
+	if (error) {
+		dev_err(dev, "Failed requesting IRQ\n");
+		return error;
+	}
+
+	error = input_register_device(idev);
+	if (error) {
+		dev_err(dev, "Failed to register input device\n");
+		return error;
+	}
+
+	return 0;
+}
+
+static struct platform_driver mx25_tcq_driver = {
+	.driver		= {
+		.name	= "mx25-tcq",
+		.of_match_table = mx25_tcq_ids,
+	},
+	.probe		= mx25_tcq_probe,
+};
+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

2.6.2

From: Denis Carikli <[email protected]>

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

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

Enjoy!

The following changes since commit 36f90b0a2ddd60823fe193a85e60ff1906c2a9b3:

Linux 4.5-rc2 (2016-01-31 18:12:16 -0800)

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git tags/ib-mfd-input-iio-v4.6

for you to fetch changes up to 4f7ed234f2a5dcc26fc56a6e8324d34bbc9afe23:

Input: touchscreen: Add imx25 TCQ driver (2016-02-11 15:40:42 +0000)

----------------------------------------------------------------
Immutable branch between MFD, Input and IIO due for v4.6

----------------------------------------------------------------
Markus Pargmann (6):
mfd: Add DT binding documentation for imx25 ADC/TSC
iio: Add binding documentation for imx25 GCQ
Input: add binding documentation for imx25 touchscreen controller
mfd: fsl-imx25-tsadc: Register touchscreen ADC driver
iio: adc: Add imx25-gcq ADC driver
Input: touchscreen: Add imx25 TCQ driver

 .../devicetree/bindings/iio/adc/fsl,imx25-gcq.txt  |  58 ++
 .../bindings/input/touchscreen/fsl-mx25-tcq.txt    |  35 ++
 .../devicetree/bindings/mfd/fsl-imx25-tsadc.txt    |  47 ++
 drivers/iio/adc/Kconfig                            |   7 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/fsl-imx25-gcq.c                    | 417 ++++++++++++++
 drivers/input/touchscreen/Kconfig                  |   9 +
 drivers/input/touchscreen/Makefile                 |   1 +
 drivers/input/touchscreen/fsl-imx25-tcq.c          | 596 +++++++++++++++++++++
 drivers/mfd/Kconfig                                |   9 +
 drivers/mfd/Makefile                               |   2 +
 drivers/mfd/fsl-imx25-tsadc.c                      | 203 +++++++
 include/dt-bindings/iio/adc/fsl-imx25-gcq.h        |  18 +
 include/linux/mfd/imx25-tsadc.h                    | 140 +++++
 14 files changed, 1543 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
 create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt
 create mode 100644 drivers/iio/adc/fsl-imx25-gcq.c
 create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/dt-bindings/iio/adc/fsl-imx25-gcq.h
 create mode 100644 include/linux/mfd/imx25-tsadc.h