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]>

---

Notes:
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    | 46 ++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt

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

new file mode 100644
index 000000000000..a857af0eb68c
@@ -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 {
+			compatible = "fsl,imx25-gcq";
+			reg = <0x50030800 0x60>;
+			...
+		};
+	};

Signature · 6 lines

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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]>

---

Notes:
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    | 46 ++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt

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

new file mode 100644
index 000000000000..a857af0eb68c

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +11 -0

+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>'.

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +18 -0

+		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>;
+			...
+		};
+	};

Quoted 18 lines · Markus Pargmann

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]>

---

Notes:
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    | 46 ++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt line 1

Quoted 7 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +1 -0

new file mode 100644
index 000000000000..a857af0eb68c
@@ -0,0 +1,46 @@
+Freescale mx25 ADC/TSC multifunction device

Prefer "MX25" and "MultiFunction Device (MFD)"

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt line 8

Quoted 7 lines

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

+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.

Not exactly. More like start location and size.

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt line 10

Quoted 2 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +2 -0

+ - interrupts: Interrupt for this device as described in
+   interrupts/interrupts.txt

No such file. In any case, I'd prefer:

"(See: ../interrupt-controller/interrupts.txt)".

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt line 11

Quoted 1 line

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +1 -0

+ - clocks: An 'ipg' clock defined as described in clocks/clock.txt

Didn't you check any of what you've written?

"(See: ../clock/clock-bindings.txt)"

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt line 17

Quoted 7 lines

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

+ - 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

?

Also, don't think think that this looks better/easier to read?

Quoted 12 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +11 -0

+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>'.

[...]

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt line 28

Quoted 10 lines

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

+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";

I don't think this is required, if you only have a single clock.

Quoted 19 lines

Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt new file +18 -0

+		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>;
+			...
+		};
+	};

The documentation describes the bindings for the imx25 GCQ unit which is essentially a generic conversion queue using the imx25 ADC.

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

---

Notes:
Changes in v6:
- Changed bindings to use adc-refp and adc-refn. Also a bit of cleanup in the setup routine.

Changes in v5:
- Fixed locking
- Removed module owner

 .../devicetree/bindings/iio/adc/fsl,imx25-gcq.txt  | 58 ++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt

Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt new file +0 -0

new file mode 100644
index 000000000000..b0866d36a307

Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt new file +17 -0

+
+Example:
+
+	adc: adc at 50030800 {
+		compatible = "fsl,imx25-gcq";
+		reg = <0x50030800 0x60>;
+		interrupt-parent = <&tscadc>;
+		interrupts = <1>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		inaux at 5 {
+			reg = <5>;
+			fsl,adc-refp = <MX25_ADC_REFP_INT>;
+			fsl,adc-refn = <MX25_ADC_REFN_NGND>;
+		};
+	};

Signature · 6 lines

2.6.1

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Quoted 24 lines · Markus Pargmann

The documentation describes the bindings for the imx25 GCQ unit which is essentially a generic conversion queue using the imx25 ADC.

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

---

Notes:
Changes in v6:
- Changed bindings to use adc-refp and adc-refn. Also a bit of cleanup in the setup routine.

Changes in v5:
- Fixed locking
- Removed module owner

 .../devicetree/bindings/iio/adc/fsl,imx25-gcq.txt  | 58 ++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt

Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt new file +0 -0

new file mode 100644
index 000000000000..b0866d36a307

Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt line 41

Quoted 5 lines

Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt new file +5 -0

+Optional properties for subnodes:
+ - fsl,adc-refp: specifies the positive reference input as defined in
+     <dt-bindings/iio/adc/fsl-imx25-gcq.h>
+ - fsl,adc-refn: specifies the negative reference input as defined in
+     <dt-bindings/iio/adc/fsl-imx25-gcq.h>

This header should be part of this commit.

Quoted 8 lines

Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt new file +7 -0

+
+Example:
+
+	adc: adc at 50030800 {
+		compatible = "fsl,imx25-gcq";
+		reg = <0x50030800 0x60>;
+		interrupt-parent = <&tscadc>;

Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt line 58

Quoted 10 lines

Documentation/devicetree/bindings/iio/adc/fsl,imx25-gcq.txt new file +10 -0

+		interrupts = <1>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		inaux at 5 {
+			reg = <5>;
+			fsl,adc-refp = <MX25_ADC_REFP_INT>;
+			fsl,adc-refn = <MX25_ADC_REFN_NGND>;
+		};
+	};

_______________________________________________
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linux-arm-kernel at lists.infradead.org
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This is the touchscreen conversion queue binding documentation. It uses the shared imx25 ADC.

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

---

Notes:
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    | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt new file +7 -0

new file mode 100644
index 000000000000..89ab47a3acc1
@@ -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".

Quoted 35 lines · Markus Pargmann

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

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

---

Notes:
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    | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt new file +12 -0

new file mode 100644
index 000000000000..89ab47a3acc1
@@ -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>'

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt line 17

Quoted 5 lines

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt new file +5 -0

+
+Optional properties:
+ - fsl,pen-debounce: Pen debounce time in nanoseconds.
+ - fsl,pen-threshold: Pen-down threshold for the touchscreen.
+ - fsl,settling-time: Settling time in nanoseconds.

Don't we have standard properties for these? If not, these should have units.

I don't understand the difference between debounce and settling times. Please make that clear in the doc.

Rob

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Quoted 34 lines · Markus Pargmann

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

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

---

Notes:
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    | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt new file +11 -0

new file mode 100644
index 000000000000..89ab47a3acc1
@@ -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.

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt line 17

Quoted 6 lines

Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt new file +6 -0

+ - fsl,wires: Should be '<4>' or '<5>'
+
+Optional properties:
+ - fsl,pen-debounce: Pen debounce time in nanoseconds.
+ - fsl,pen-threshold: Pen-down threshold for the touchscreen.
+ - fsl,settling-time: Settling time in nanoseconds.

Don't we have standard properties for these?

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]>

---

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

@Jonathan Cameron:
I left your acked-by on the patch as these were small changes. If it should be removed, please say so. Thanks

 drivers/mfd/Kconfig             |   9 ++
 drivers/mfd/Makefile            |   2 +
 drivers/mfd/fsl-imx25-tsadc.c   | 204 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h | 140 +++++++++++++++++++++++++++
 4 files changed, 355 insertions(+)
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

drivers/mfd/Kconfig +9 -0

index 4d92df6ef9fe..4222e202ad2b 100644
@@ -271,6 +271,15 @@ config MFD_MC13XXX_I2C
 	help
 	  Select this if your MC13xxx is connected via an I2C bus.
 
+config MFD_MX25_TSADC
+	tristate "Freescale i.MX25 integrated Touchscreen and ADC unit"
+	select REGMAP_MMIO
+	depends on (SOC_IMX25 && OF) || COMPILE_TEST
+	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_HI6421_PMIC
 	tristate "HiSilicon Hi6421 PMU/Codec IC"
 	depends on OF

drivers/mfd/Makefile +2 -0

index a8b76b81b467..5741be88c173 100644
@@ -81,6 +81,8 @@ 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 +93 -0

new file mode 100644
index 000000000000..e67d5ca81e10
@@ -0,0 +1,204 @@
+/*
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdesc.h>
+#include <linux/irqdomain.h>
+#include <linux/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>
+
+static struct regmap_config mx25_tsadc_regmap_config = {
+	.fast_io = true,
+	.max_register = 8,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static void mx25_tsadc_irq_handler(struct irq_desc *desc)
+{
+	struct mx25_tsadc *tsadc = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	u32 status;
+
+	chained_irq_enter(chip, desc);
+
+	regmap_read(tsadc->regs, MX25_TSC_TGSR, &status);
+
+	if (status & MX25_TGSR_GCQ_INT)
+		generic_handle_irq(irq_find_mapping(tsadc->domain, 1));
+
+	if (status & MX25_TGSR_TCQ_INT)
+		generic_handle_irq(irq_find_mapping(tsadc->domain, 0));
+
+	chained_irq_exit(chip, desc);
+}
+
+static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hwirq)
+{
+	struct mx25_tsadc *tsadc = d->host_data;
+
+	irq_set_chip_data(irq, tsadc);
+	irq_set_chip_and_handler(irq, &dummy_irq_chip,
+				 handle_level_irq);
+	irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
+
+	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 *tsadc)
+{
+	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;
+	}
+
+	tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
+					      tsadc);
+	if (!tsadc->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, tsadc);
+
+	return 0;
+}
+
+static void mx25_tsadc_setup_clk(struct platform_device *pdev,

drivers/mfd/fsl-imx25-tsadc.c new file +101 -0

+	 */
+
+	dev_dbg(&pdev->dev, "Found master clock at %lu Hz\n",
+		clk_get_rate(tsadc->clk));
+
+	clk_div = DIV_ROUND_UP(clk_get_rate(tsadc->clk), 1750000);
+	dev_dbg(&pdev->dev, "Setting up ADC clock divider to %u\n", clk_div);
+
+	/* adc clock = IPG clock / (2 * div + 2) */
+	clk_div -= 2;
+	clk_div /= 2;
+
+	/*
+	 * the ADC clock divider changes its behaviour when values below 4
+	 * are used: it is fixed to "/ 10" in this case
+	 */
+	clk_div = max_t(unsigned, 4, clk_div);
+
+	dev_dbg(&pdev->dev, "Resulting ADC conversion clock at %lu Hz\n",
+		clk_get_rate(tsadc->clk) / (2 * clk_div + 2));
+
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR,
+			   MX25_TGCR_ADCCLKCFG(0x1f),
+			   MX25_TGCR_ADCCLKCFG(clk_div));
+}
+
+static int mx25_tsadc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct mx25_tsadc *tsadc;
+	struct resource *res;
+	int ret;
+	void __iomem *iomem;
+
+	tsadc = devm_kzalloc(dev, sizeof(*tsadc), GFP_KERNEL);
+	if (!tsadc)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	iomem = devm_ioremap_resource(dev, res);
+	if (IS_ERR(iomem))
+		return PTR_ERR(iomem);
+
+	tsadc->regs = devm_regmap_init_mmio(dev, iomem,
+					    &mx25_tsadc_regmap_config);
+	if (IS_ERR(tsadc->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(tsadc->regs);
+	}
+
+	tsadc->clk = devm_clk_get(dev, "ipg");
+	if (IS_ERR(tsadc->clk)) {
+		dev_err(dev, "Failed to get ipg clock\n");
+		return PTR_ERR(tsadc->clk);
+	}
+
+	/* setup clock according to the datasheet */
+	mx25_tsadc_setup_clk(pdev, tsadc);
+
+	/* Enable clock and reset the component */
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
+			   MX25_TGCR_CLK_EN);
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
+			   MX25_TGCR_TSC_RST);
+
+	/* Setup powersaving mode, but enable internal reference voltage */
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
+			   MX25_TGCR_POWERMODE_SAVE);
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
+			   MX25_TGCR_INTREFEN);
+
+	ret = mx25_tsadc_setup_irq(pdev, tsadc);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, tsadc);
+
+	of_platform_populate(np, NULL, NULL, dev);
+
+	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",
+		.of_match_table = of_match_ptr(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 +140 -0

new file mode 100644
index 000000000000..7fe4b8c3baac
@@ -0,0 +1,140 @@
+#ifndef _LINUX_INCLUDE_MFD_IMX25_TSADC_H_
+#define _LINUX_INCLUDE_MFD_IMX25_TSADC_H_
+
+struct regmap;
+struct clk;
+
+struct mx25_tsadc {
+	struct regmap *regs;
+	struct irq_domain *domain;
+	struct clk *clk;
+};
+
+#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))
+
+#define MX25_ADCQ_MR_MASK		0xffffffff
+
+/* TGCR */
+#define MX25_TGCR_PDBTIME(x)		((x) << 25)
+#define MX25_TGCR_PDBTIME_MASK		GENMASK(31, 25)
+#define MX25_TGCR_PDBEN			BIT(24)
+#define MX25_TGCR_PDEN			BIT(23)
+#define MX25_TGCR_ADCCLKCFG(x)		((x) << 16)
+#define MX25_TGCR_GET_ADCCLK(x)		(((x) >> 16) & 0x1f)
+#define MX25_TGCR_INTREFEN		BIT(10)
+#define MX25_TGCR_POWERMODE_MASK	GENMASK(9, 8)
+#define MX25_TGCR_POWERMODE_SAVE	(1 << 8)
+#define MX25_TGCR_POWERMODE_ON		(2 << 8)
+#define MX25_TGCR_STLC			BIT(5)
+#define MX25_TGCR_SLPC			BIT(4)
+#define MX25_TGCR_FUNC_RST		BIT(2)
+#define MX25_TGCR_TSC_RST		BIT(1)
+#define MX25_TGCR_CLK_EN		BIT(0)
+
+/* TGSR */
+#define MX25_TGSR_SLP_INT		BIT(2)
+#define MX25_TGSR_GCQ_INT		BIT(1)
+#define MX25_TGSR_TCQ_INT		BIT(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	BIT(19)
+#define MX25_ADCQ_CR_PDMSK		BIT(18)
+#define MX25_ADCQ_CR_FRST		BIT(17)
+#define MX25_ADCQ_CR_QRST		BIT(16)
+#define MX25_ADCQ_CR_RWAIT_MASK		GENMASK(15, 12)
+#define MX25_ADCQ_CR_RWAIT(x)		((x) << 12)
+#define MX25_ADCQ_CR_WMRK_MASK		GENMASK(11, 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		BIT(3)
+#define MX25_ADCQ_CR_FQS		BIT(2)
+#define MX25_ADCQ_CR_QSM_MASK		GENMASK(1, 0)
+#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		BIT(15)
+#define MX25_ADCQ_SR_FULL		BIT(14)
+#define MX25_ADCQ_SR_EMPT		BIT(13)
+#define MX25_ADCQ_SR_FDN(x)		(((x) >> 8) & 0x1f)
+#define MX25_ADCQ_SR_FRR		BIT(6)
+#define MX25_ADCQ_SR_FUR		BIT(5)
+#define MX25_ADCQ_SR_FOR		BIT(4)
+#define MX25_ADCQ_SR_EOQ		BIT(1)
+#define MX25_ADCQ_SR_PD			BIT(0)
+
+/* ADCQ_MR (TCQMR and GCQMR) */
+#define MX25_ADCQ_MR_FDRY_DMA		BIT(31)
+#define MX25_ADCQ_MR_FER_DMA		BIT(22)
+#define MX25_ADCQ_MR_FUR_DMA		BIT(21)
+#define MX25_ADCQ_MR_FOR_DMA		BIT(20)
+#define MX25_ADCQ_MR_EOQ_DMA		BIT(17)
+#define MX25_ADCQ_MR_PD_DMA		BIT(16)
+#define MX25_ADCQ_MR_FDRY_IRQ		BIT(15)
+#define MX25_ADCQ_MR_FER_IRQ		BIT(6)
+#define MX25_ADCQ_MR_FUR_IRQ		BIT(5)
+#define MX25_ADCQ_MR_FOR_IRQ		BIT(4)
+#define MX25_ADCQ_MR_EOQ_IRQ		BIT(1)
+#define MX25_ADCQ_MR_PD_IRQ		BIT(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		GENMASK(19, 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 << 12)
+#define MX25_ADCQ_CFG_YPLL_OFF		(1 << 12)
+#define MX25_ADCQ_CFG_YPLL_LOW		(3 << 12)
+#define MX25_ADCQ_CFG_XNUR_HIGH		(0 << 10)
+#define MX25_ADCQ_CFG_XNUR_OFF		(1 << 10)
+#define MX25_ADCQ_CFG_XNUR_LOW		(3 << 10)
+#define MX25_ADCQ_CFG_XPUL_HIGH		(0 << 9)
+#define MX25_ADCQ_CFG_XPUL_OFF		(1 << 9)
+#define MX25_ADCQ_CFG_REFP(sel)		((sel) << 7)
+#define MX25_ADCQ_CFG_REFP_YP		MX25_ADCQ_CFG_REFP(0)
+#define MX25_ADCQ_CFG_REFP_XP		MX25_ADCQ_CFG_REFP(1)
+#define MX25_ADCQ_CFG_REFP_EXT		MX25_ADCQ_CFG_REFP(2)
+#define MX25_ADCQ_CFG_REFP_INT		MX25_ADCQ_CFG_REFP(3)
+#define MX25_ADCQ_CFG_REFP_MASK		GENMASK(8, 7)
+#define MX25_ADCQ_CFG_IN(sel)		((sel) << 4)
+#define MX25_ADCQ_CFG_IN_XP		MX25_ADCQ_CFG_IN(0)
+#define MX25_ADCQ_CFG_IN_YP		MX25_ADCQ_CFG_IN(1)
+#define MX25_ADCQ_CFG_IN_XN		MX25_ADCQ_CFG_IN(2)
+#define MX25_ADCQ_CFG_IN_YN		MX25_ADCQ_CFG_IN(3)
+#define MX25_ADCQ_CFG_IN_WIPER		MX25_ADCQ_CFG_IN(4)
+#define MX25_ADCQ_CFG_IN_AUX0		MX25_ADCQ_CFG_IN(5)
+#define MX25_ADCQ_CFG_IN_AUX1		MX25_ADCQ_CFG_IN(6)
+#define MX25_ADCQ_CFG_IN_AUX2		MX25_ADCQ_CFG_IN(7)
+#define MX25_ADCQ_CFG_REFN(sel)		((sel) << 2)
+#define MX25_ADCQ_CFG_REFN_XN		MX25_ADCQ_CFG_REFN(0)
+#define MX25_ADCQ_CFG_REFN_YN		MX25_ADCQ_CFG_REFN(1)
+#define MX25_ADCQ_CFG_REFN_NGND		MX25_ADCQ_CFG_REFN(2)
+#define MX25_ADCQ_CFG_REFN_NGND2	MX25_ADCQ_CFG_REFN(3)
+#define MX25_ADCQ_CFG_REFN_MASK		GENMASK(3, 2)
+#define MX25_ADCQ_CFG_PENIACK		(1 << 1)
+
+#endif  /* _LINUX_INCLUDE_MFD_IMX25_TSADC_H_ */

Quoted 9 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.

Quoted 5 lines

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]>

Looks good to me - one query on meaning of a comment inline.

Acked-by Jonathan Cameron <[email protected]>

I'm taking the view this series wants to go through the MFD tree but don't mind if it goes through IIO or input instead if there is a good reason to do so.

Jonathan

Quoted 157 lines

---

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

@Jonathan Cameron:
I left your acked-by on the patch as these were small changes. If it should be removed, please say so. Thanks

 drivers/mfd/Kconfig             |   9 ++
 drivers/mfd/Makefile            |   2 +
 drivers/mfd/fsl-imx25-tsadc.c   | 204 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h | 140 +++++++++++++++++++++++++++
 4 files changed, 355 insertions(+)
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

drivers/mfd/Kconfig +9 -0

index 4d92df6ef9fe..4222e202ad2b 100644
@@ -271,6 +271,15 @@ config MFD_MC13XXX_I2C
 	help
 	  Select this if your MC13xxx is connected via an I2C bus.
 
+config MFD_MX25_TSADC
+	tristate "Freescale i.MX25 integrated Touchscreen and ADC unit"
+	select REGMAP_MMIO
+	depends on (SOC_IMX25 && OF) || COMPILE_TEST
+	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_HI6421_PMIC
 	tristate "HiSilicon Hi6421 PMU/Codec IC"
 	depends on OF

drivers/mfd/Makefile +2 -0

index a8b76b81b467..5741be88c173 100644
@@ -81,6 +81,8 @@ 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 +93 -0

new file mode 100644
index 000000000000..e67d5ca81e10
@@ -0,0 +1,204 @@
+/*
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdesc.h>
+#include <linux/irqdomain.h>
+#include <linux/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>
+
+static struct regmap_config mx25_tsadc_regmap_config = {
+	.fast_io = true,
+	.max_register = 8,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static void mx25_tsadc_irq_handler(struct irq_desc *desc)
+{
+	struct mx25_tsadc *tsadc = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	u32 status;
+
+	chained_irq_enter(chip, desc);
+
+	regmap_read(tsadc->regs, MX25_TSC_TGSR, &status);
+
+	if (status & MX25_TGSR_GCQ_INT)
+		generic_handle_irq(irq_find_mapping(tsadc->domain, 1));
+
+	if (status & MX25_TGSR_TCQ_INT)
+		generic_handle_irq(irq_find_mapping(tsadc->domain, 0));
+
+	chained_irq_exit(chip, desc);
+}
+
+static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hwirq)
+{
+	struct mx25_tsadc *tsadc = d->host_data;
+
+	irq_set_chip_data(irq, tsadc);
+	irq_set_chip_and_handler(irq, &dummy_irq_chip,
+				 handle_level_irq);
+	irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
+
+	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 *tsadc)
+{
+	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;
+	}
+
+	tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
+					      tsadc);
+	if (!tsadc->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, tsadc);
+
+	return 0;
+}
+
+static void mx25_tsadc_setup_clk(struct platform_device *pdev,

drivers/mfd/fsl-imx25-tsadc.c line 103

Quoted 10 lines

drivers/mfd/fsl-imx25-tsadc.c new file +10 -0

+				 struct mx25_tsadc *tsadc)
+{
+	unsigned clk_div;
+
+	/*
+	 * According to the datasheet the ADC clock should never
+	 * exceed 1,75 MHz. Base clock is the IPG and the ADC unit uses
+	 * a funny clock divider. To keep the time constant the ADC needs to do
+	 * one conversion, adapt the ADC internal clock divider to
+	 * the available IPG

I'm not entirely following this explanation...
maybe

...one conversion, then adapt the ADC...

Quoted 238 lines

drivers/mfd/fsl-imx25-tsadc.c new file +101 -0

+	 */
+
+	dev_dbg(&pdev->dev, "Found master clock at %lu Hz\n",
+		clk_get_rate(tsadc->clk));
+
+	clk_div = DIV_ROUND_UP(clk_get_rate(tsadc->clk), 1750000);
+	dev_dbg(&pdev->dev, "Setting up ADC clock divider to %u\n", clk_div);
+
+	/* adc clock = IPG clock / (2 * div + 2) */
+	clk_div -= 2;
+	clk_div /= 2;
+
+	/*
+	 * the ADC clock divider changes its behaviour when values below 4
+	 * are used: it is fixed to "/ 10" in this case
+	 */
+	clk_div = max_t(unsigned, 4, clk_div);
+
+	dev_dbg(&pdev->dev, "Resulting ADC conversion clock at %lu Hz\n",
+		clk_get_rate(tsadc->clk) / (2 * clk_div + 2));
+
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR,
+			   MX25_TGCR_ADCCLKCFG(0x1f),
+			   MX25_TGCR_ADCCLKCFG(clk_div));
+}
+
+static int mx25_tsadc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct mx25_tsadc *tsadc;
+	struct resource *res;
+	int ret;
+	void __iomem *iomem;
+
+	tsadc = devm_kzalloc(dev, sizeof(*tsadc), GFP_KERNEL);
+	if (!tsadc)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	iomem = devm_ioremap_resource(dev, res);
+	if (IS_ERR(iomem))
+		return PTR_ERR(iomem);
+
+	tsadc->regs = devm_regmap_init_mmio(dev, iomem,
+					    &mx25_tsadc_regmap_config);
+	if (IS_ERR(tsadc->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(tsadc->regs);
+	}
+
+	tsadc->clk = devm_clk_get(dev, "ipg");
+	if (IS_ERR(tsadc->clk)) {
+		dev_err(dev, "Failed to get ipg clock\n");
+		return PTR_ERR(tsadc->clk);
+	}
+
+	/* setup clock according to the datasheet */
+	mx25_tsadc_setup_clk(pdev, tsadc);
+
+	/* Enable clock and reset the component */
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
+			   MX25_TGCR_CLK_EN);
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
+			   MX25_TGCR_TSC_RST);
+
+	/* Setup powersaving mode, but enable internal reference voltage */
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
+			   MX25_TGCR_POWERMODE_SAVE);
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
+			   MX25_TGCR_INTREFEN);
+
+	ret = mx25_tsadc_setup_irq(pdev, tsadc);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, tsadc);
+
+	of_platform_populate(np, NULL, NULL, dev);
+
+	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",
+		.of_match_table = of_match_ptr(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 +130 -0

new file mode 100644
index 000000000000..7fe4b8c3baac
@@ -0,0 +1,140 @@
+#ifndef _LINUX_INCLUDE_MFD_IMX25_TSADC_H_
+#define _LINUX_INCLUDE_MFD_IMX25_TSADC_H_
+
+struct regmap;
+struct clk;
+
+struct mx25_tsadc {
+	struct regmap *regs;
+	struct irq_domain *domain;
+	struct clk *clk;
+};
+
+#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))
+
+#define MX25_ADCQ_MR_MASK		0xffffffff
+
+/* TGCR */
+#define MX25_TGCR_PDBTIME(x)		((x) << 25)
+#define MX25_TGCR_PDBTIME_MASK		GENMASK(31, 25)
+#define MX25_TGCR_PDBEN			BIT(24)
+#define MX25_TGCR_PDEN			BIT(23)
+#define MX25_TGCR_ADCCLKCFG(x)		((x) << 16)
+#define MX25_TGCR_GET_ADCCLK(x)		(((x) >> 16) & 0x1f)
+#define MX25_TGCR_INTREFEN		BIT(10)
+#define MX25_TGCR_POWERMODE_MASK	GENMASK(9, 8)
+#define MX25_TGCR_POWERMODE_SAVE	(1 << 8)
+#define MX25_TGCR_POWERMODE_ON		(2 << 8)
+#define MX25_TGCR_STLC			BIT(5)
+#define MX25_TGCR_SLPC			BIT(4)
+#define MX25_TGCR_FUNC_RST		BIT(2)
+#define MX25_TGCR_TSC_RST		BIT(1)
+#define MX25_TGCR_CLK_EN		BIT(0)
+
+/* TGSR */
+#define MX25_TGSR_SLP_INT		BIT(2)
+#define MX25_TGSR_GCQ_INT		BIT(1)
+#define MX25_TGSR_TCQ_INT		BIT(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	BIT(19)
+#define MX25_ADCQ_CR_PDMSK		BIT(18)
+#define MX25_ADCQ_CR_FRST		BIT(17)
+#define MX25_ADCQ_CR_QRST		BIT(16)
+#define MX25_ADCQ_CR_RWAIT_MASK		GENMASK(15, 12)
+#define MX25_ADCQ_CR_RWAIT(x)		((x) << 12)
+#define MX25_ADCQ_CR_WMRK_MASK		GENMASK(11, 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		BIT(3)
+#define MX25_ADCQ_CR_FQS		BIT(2)
+#define MX25_ADCQ_CR_QSM_MASK		GENMASK(1, 0)
+#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		BIT(15)
+#define MX25_ADCQ_SR_FULL		BIT(14)
+#define MX25_ADCQ_SR_EMPT		BIT(13)
+#define MX25_ADCQ_SR_FDN(x)		(((x) >> 8) & 0x1f)
+#define MX25_ADCQ_SR_FRR		BIT(6)
+#define MX25_ADCQ_SR_FUR		BIT(5)
+#define MX25_ADCQ_SR_FOR		BIT(4)
+#define MX25_ADCQ_SR_EOQ		BIT(1)
+#define MX25_ADCQ_SR_PD			BIT(0)
+
+/* ADCQ_MR (TCQMR and GCQMR) */
+#define MX25_ADCQ_MR_FDRY_DMA		BIT(31)
+#define MX25_ADCQ_MR_FER_DMA		BIT(22)
+#define MX25_ADCQ_MR_FUR_DMA		BIT(21)
+#define MX25_ADCQ_MR_FOR_DMA		BIT(20)
+#define MX25_ADCQ_MR_EOQ_DMA		BIT(17)
+#define MX25_ADCQ_MR_PD_DMA		BIT(16)
+#define MX25_ADCQ_MR_FDRY_IRQ		BIT(15)
+#define MX25_ADCQ_MR_FER_IRQ		BIT(6)
+#define MX25_ADCQ_MR_FUR_IRQ		BIT(5)
+#define MX25_ADCQ_MR_FOR_IRQ		BIT(4)
+#define MX25_ADCQ_MR_EOQ_IRQ		BIT(1)
+#define MX25_ADCQ_MR_PD_IRQ		BIT(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		GENMASK(19, 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 << 12)
+#define MX25_ADCQ_CFG_YPLL_OFF		(1 << 12)
+#define MX25_ADCQ_CFG_YPLL_LOW		(3 << 12)
+#define MX25_ADCQ_CFG_XNUR_HIGH		(0 << 10)
+#define MX25_ADCQ_CFG_XNUR_OFF		(1 << 10)
+#define MX25_ADCQ_CFG_XNUR_LOW		(3 << 10)
+#define MX25_ADCQ_CFG_XPUL_HIGH		(0 << 9)
+#define MX25_ADCQ_CFG_XPUL_OFF		(1 << 9)
+#define MX25_ADCQ_CFG_REFP(sel)		((sel) << 7)
+#define MX25_ADCQ_CFG_REFP_YP		MX25_ADCQ_CFG_REFP(0)
+#define MX25_ADCQ_CFG_REFP_XP		MX25_ADCQ_CFG_REFP(1)
+#define MX25_ADCQ_CFG_REFP_EXT		MX25_ADCQ_CFG_REFP(2)
+#define MX25_ADCQ_CFG_REFP_INT		MX25_ADCQ_CFG_REFP(3)
+#define MX25_ADCQ_CFG_REFP_MASK		GENMASK(8, 7)
+#define MX25_ADCQ_CFG_IN(sel)		((sel) << 4)
+#define MX25_ADCQ_CFG_IN_XP		MX25_ADCQ_CFG_IN(0)
+#define MX25_ADCQ_CFG_IN_YP		MX25_ADCQ_CFG_IN(1)
+#define MX25_ADCQ_CFG_IN_XN		MX25_ADCQ_CFG_IN(2)
+#define MX25_ADCQ_CFG_IN_YN		MX25_ADCQ_CFG_IN(3)
+#define MX25_ADCQ_CFG_IN_WIPER		MX25_ADCQ_CFG_IN(4)
+#define MX25_ADCQ_CFG_IN_AUX0		MX25_ADCQ_CFG_IN(5)
+#define MX25_ADCQ_CFG_IN_AUX1		MX25_ADCQ_CFG_IN(6)

include/linux/mfd/imx25-tsadc.h line 140

Quoted 10 lines

include/linux/mfd/imx25-tsadc.h new file +10 -0

+#define MX25_ADCQ_CFG_IN_AUX2		MX25_ADCQ_CFG_IN(7)
+#define MX25_ADCQ_CFG_REFN(sel)		((sel) << 2)
+#define MX25_ADCQ_CFG_REFN_XN		MX25_ADCQ_CFG_REFN(0)
+#define MX25_ADCQ_CFG_REFN_YN		MX25_ADCQ_CFG_REFN(1)
+#define MX25_ADCQ_CFG_REFN_NGND		MX25_ADCQ_CFG_REFN(2)
+#define MX25_ADCQ_CFG_REFN_NGND2	MX25_ADCQ_CFG_REFN(3)
+#define MX25_ADCQ_CFG_REFN_MASK		GENMASK(3, 2)
+#define MX25_ADCQ_CFG_PENIACK		(1 << 1)
+
+#endif  /* _LINUX_INCLUDE_MFD_IMX25_TSADC_H_ */

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Quoted 9 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.

Quoted 5 lines

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]>

Looks good to me - one query on meaning of a comment inline.

Acked-by Jonathan Cameron <[email protected]>

I'm taking the view this series wants to go through the MFD tree but don't mind if it goes through IIO or input instead if there is a good reason to do so.

Jonathan

Quoted 161 lines

---

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

@Jonathan Cameron:
I left your acked-by on the patch as these were small changes. If it should be removed, please say so. Thanks

 drivers/mfd/Kconfig             |   9 ++
 drivers/mfd/Makefile            |   2 +
 drivers/mfd/fsl-imx25-tsadc.c   | 204 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/imx25-tsadc.h | 140 +++++++++++++++++++++++++++
 4 files changed, 355 insertions(+)
 create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
 create mode 100644 include/linux/mfd/imx25-tsadc.h

drivers/mfd/Kconfig +9 -0

index 4d92df6ef9fe..4222e202ad2b 100644
@@ -271,6 +271,15 @@ config MFD_MC13XXX_I2C
 	help
 	  Select this if your MC13xxx is connected via an I2C bus.
 
+config MFD_MX25_TSADC
+	tristate "Freescale i.MX25 integrated Touchscreen and ADC unit"
+	select REGMAP_MMIO
+	depends on (SOC_IMX25 && OF) || COMPILE_TEST
+	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_HI6421_PMIC
 	tristate "HiSilicon Hi6421 PMU/Codec IC"
 	depends on OF

drivers/mfd/Makefile +2 -0

index a8b76b81b467..5741be88c173 100644
@@ -81,6 +81,8 @@ 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 +97 -0

new file mode 100644
index 000000000000..e67d5ca81e10
@@ -0,0 +1,204 @@
+/*
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdesc.h>
+#include <linux/irqdomain.h>
+#include <linux/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>
+
+static struct regmap_config mx25_tsadc_regmap_config = {
+	.fast_io = true,
+	.max_register = 8,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static void mx25_tsadc_irq_handler(struct irq_desc *desc)
+{
+	struct mx25_tsadc *tsadc = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	u32 status;
+
+	chained_irq_enter(chip, desc);
+
+	regmap_read(tsadc->regs, MX25_TSC_TGSR, &status);
+
+	if (status & MX25_TGSR_GCQ_INT)
+		generic_handle_irq(irq_find_mapping(tsadc->domain, 1));
+
+	if (status & MX25_TGSR_TCQ_INT)
+		generic_handle_irq(irq_find_mapping(tsadc->domain, 0));
+
+	chained_irq_exit(chip, desc);
+}
+
+static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hwirq)
+{
+	struct mx25_tsadc *tsadc = d->host_data;
+
+	irq_set_chip_data(irq, tsadc);
+	irq_set_chip_and_handler(irq, &dummy_irq_chip,
+				 handle_level_irq);
+	irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
+
+	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 *tsadc)
+{
+	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;
+	}
+
+	tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
+					      tsadc);
+	if (!tsadc->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, tsadc);
+
+	return 0;
+}
+
+static void mx25_tsadc_setup_clk(struct platform_device *pdev,
+				 struct mx25_tsadc *tsadc)
+{
+	unsigned clk_div;
+

drivers/mfd/fsl-imx25-tsadc.c line 103

Quoted 6 lines

drivers/mfd/fsl-imx25-tsadc.c new file +6 -0

+	/*
+	 * According to the datasheet the ADC clock should never
+	 * exceed 1,75 MHz. Base clock is the IPG and the ADC unit uses
+	 * a funny clock divider. To keep the time constant the ADC needs to do
+	 * one conversion, adapt the ADC internal clock divider to
+	 * the available IPG

I'm not entirely following this explanation...
maybe

...one conversion, then adapt the ADC...

Quoted 238 lines

drivers/mfd/fsl-imx25-tsadc.c new file +101 -0

+	 */
+
+	dev_dbg(&pdev->dev, "Found master clock at %lu Hz\n",
+		clk_get_rate(tsadc->clk));
+
+	clk_div = DIV_ROUND_UP(clk_get_rate(tsadc->clk), 1750000);
+	dev_dbg(&pdev->dev, "Setting up ADC clock divider to %u\n", clk_div);
+
+	/* adc clock = IPG clock / (2 * div + 2) */
+	clk_div -= 2;
+	clk_div /= 2;
+
+	/*
+	 * the ADC clock divider changes its behaviour when values below 4
+	 * are used: it is fixed to "/ 10" in this case
+	 */
+	clk_div = max_t(unsigned, 4, clk_div);
+
+	dev_dbg(&pdev->dev, "Resulting ADC conversion clock at %lu Hz\n",
+		clk_get_rate(tsadc->clk) / (2 * clk_div + 2));
+
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR,
+			   MX25_TGCR_ADCCLKCFG(0x1f),
+			   MX25_TGCR_ADCCLKCFG(clk_div));
+}
+
+static int mx25_tsadc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct mx25_tsadc *tsadc;
+	struct resource *res;
+	int ret;
+	void __iomem *iomem;
+
+	tsadc = devm_kzalloc(dev, sizeof(*tsadc), GFP_KERNEL);
+	if (!tsadc)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	iomem = devm_ioremap_resource(dev, res);
+	if (IS_ERR(iomem))
+		return PTR_ERR(iomem);
+
+	tsadc->regs = devm_regmap_init_mmio(dev, iomem,
+					    &mx25_tsadc_regmap_config);
+	if (IS_ERR(tsadc->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(tsadc->regs);
+	}
+
+	tsadc->clk = devm_clk_get(dev, "ipg");
+	if (IS_ERR(tsadc->clk)) {
+		dev_err(dev, "Failed to get ipg clock\n");
+		return PTR_ERR(tsadc->clk);
+	}
+
+	/* setup clock according to the datasheet */
+	mx25_tsadc_setup_clk(pdev, tsadc);
+
+	/* Enable clock and reset the component */
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
+			   MX25_TGCR_CLK_EN);
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
+			   MX25_TGCR_TSC_RST);
+
+	/* Setup powersaving mode, but enable internal reference voltage */
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
+			   MX25_TGCR_POWERMODE_SAVE);
+	regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
+			   MX25_TGCR_INTREFEN);
+
+	ret = mx25_tsadc_setup_irq(pdev, tsadc);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, tsadc);
+
+	of_platform_populate(np, NULL, NULL, dev);
+
+	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",
+		.of_match_table = of_match_ptr(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 +130 -0

new file mode 100644
index 000000000000..7fe4b8c3baac
@@ -0,0 +1,140 @@
+#ifndef _LINUX_INCLUDE_MFD_IMX25_TSADC_H_
+#define _LINUX_INCLUDE_MFD_IMX25_TSADC_H_
+
+struct regmap;
+struct clk;
+
+struct mx25_tsadc {
+	struct regmap *regs;
+	struct irq_domain *domain;
+	struct clk *clk;
+};
+
+#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))
+
+#define MX25_ADCQ_MR_MASK		0xffffffff
+
+/* TGCR */
+#define MX25_TGCR_PDBTIME(x)		((x) << 25)
+#define MX25_TGCR_PDBTIME_MASK		GENMASK(31, 25)
+#define MX25_TGCR_PDBEN			BIT(24)
+#define MX25_TGCR_PDEN			BIT(23)
+#define MX25_TGCR_ADCCLKCFG(x)		((x) << 16)
+#define MX25_TGCR_GET_ADCCLK(x)		(((x) >> 16) & 0x1f)
+#define MX25_TGCR_INTREFEN		BIT(10)
+#define MX25_TGCR_POWERMODE_MASK	GENMASK(9, 8)
+#define MX25_TGCR_POWERMODE_SAVE	(1 << 8)
+#define MX25_TGCR_POWERMODE_ON		(2 << 8)
+#define MX25_TGCR_STLC			BIT(5)
+#define MX25_TGCR_SLPC			BIT(4)
+#define MX25_TGCR_FUNC_RST		BIT(2)
+#define MX25_TGCR_TSC_RST		BIT(1)
+#define MX25_TGCR_CLK_EN		BIT(0)
+
+/* TGSR */
+#define MX25_TGSR_SLP_INT		BIT(2)
+#define MX25_TGSR_GCQ_INT		BIT(1)
+#define MX25_TGSR_TCQ_INT		BIT(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	BIT(19)
+#define MX25_ADCQ_CR_PDMSK		BIT(18)
+#define MX25_ADCQ_CR_FRST		BIT(17)
+#define MX25_ADCQ_CR_QRST		BIT(16)
+#define MX25_ADCQ_CR_RWAIT_MASK		GENMASK(15, 12)
+#define MX25_ADCQ_CR_RWAIT(x)		((x) << 12)
+#define MX25_ADCQ_CR_WMRK_MASK		GENMASK(11, 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		BIT(3)
+#define MX25_ADCQ_CR_FQS		BIT(2)
+#define MX25_ADCQ_CR_QSM_MASK		GENMASK(1, 0)
+#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		BIT(15)
+#define MX25_ADCQ_SR_FULL		BIT(14)
+#define MX25_ADCQ_SR_EMPT		BIT(13)
+#define MX25_ADCQ_SR_FDN(x)		(((x) >> 8) & 0x1f)
+#define MX25_ADCQ_SR_FRR		BIT(6)
+#define MX25_ADCQ_SR_FUR		BIT(5)
+#define MX25_ADCQ_SR_FOR		BIT(4)
+#define MX25_ADCQ_SR_EOQ		BIT(1)
+#define MX25_ADCQ_SR_PD			BIT(0)
+
+/* ADCQ_MR (TCQMR and GCQMR) */
+#define MX25_ADCQ_MR_FDRY_DMA		BIT(31)
+#define MX25_ADCQ_MR_FER_DMA		BIT(22)
+#define MX25_ADCQ_MR_FUR_DMA		BIT(21)
+#define MX25_ADCQ_MR_FOR_DMA		BIT(20)
+#define MX25_ADCQ_MR_EOQ_DMA		BIT(17)
+#define MX25_ADCQ_MR_PD_DMA		BIT(16)
+#define MX25_ADCQ_MR_FDRY_IRQ		BIT(15)
+#define MX25_ADCQ_MR_FER_IRQ		BIT(6)
+#define MX25_ADCQ_MR_FUR_IRQ		BIT(5)
+#define MX25_ADCQ_MR_FOR_IRQ		BIT(4)
+#define MX25_ADCQ_MR_EOQ_IRQ		BIT(1)
+#define MX25_ADCQ_MR_PD_IRQ		BIT(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		GENMASK(19, 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 << 12)
+#define MX25_ADCQ_CFG_YPLL_OFF		(1 << 12)
+#define MX25_ADCQ_CFG_YPLL_LOW		(3 << 12)
+#define MX25_ADCQ_CFG_XNUR_HIGH		(0 << 10)
+#define MX25_ADCQ_CFG_XNUR_OFF		(1 << 10)
+#define MX25_ADCQ_CFG_XNUR_LOW		(3 << 10)
+#define MX25_ADCQ_CFG_XPUL_HIGH		(0 << 9)
+#define MX25_ADCQ_CFG_XPUL_OFF		(1 << 9)
+#define MX25_ADCQ_CFG_REFP(sel)		((sel) << 7)
+#define MX25_ADCQ_CFG_REFP_YP		MX25_ADCQ_CFG_REFP(0)
+#define MX25_ADCQ_CFG_REFP_XP		MX25_ADCQ_CFG_REFP(1)
+#define MX25_ADCQ_CFG_REFP_EXT		MX25_ADCQ_CFG_REFP(2)
+#define MX25_ADCQ_CFG_REFP_INT		MX25_ADCQ_CFG_REFP(3)
+#define MX25_ADCQ_CFG_REFP_MASK		GENMASK(8, 7)
+#define MX25_ADCQ_CFG_IN(sel)		((sel) << 4)
+#define MX25_ADCQ_CFG_IN_XP		MX25_ADCQ_CFG_IN(0)
+#define MX25_ADCQ_CFG_IN_YP		MX25_ADCQ_CFG_IN(1)
+#define MX25_ADCQ_CFG_IN_XN		MX25_ADCQ_CFG_IN(2)
+#define MX25_ADCQ_CFG_IN_YN		MX25_ADCQ_CFG_IN(3)
+#define MX25_ADCQ_CFG_IN_WIPER		MX25_ADCQ_CFG_IN(4)
+#define MX25_ADCQ_CFG_IN_AUX0		MX25_ADCQ_CFG_IN(5)
+#define MX25_ADCQ_CFG_IN_AUX1		MX25_ADCQ_CFG_IN(6)

include/linux/mfd/imx25-tsadc.h line 140

Quoted 10 lines

include/linux/mfd/imx25-tsadc.h new file +10 -0

+#define MX25_ADCQ_CFG_IN_AUX2		MX25_ADCQ_CFG_IN(7)
+#define MX25_ADCQ_CFG_REFN(sel)		((sel) << 2)
+#define MX25_ADCQ_CFG_REFN_XN		MX25_ADCQ_CFG_REFN(0)
+#define MX25_ADCQ_CFG_REFN_YN		MX25_ADCQ_CFG_REFN(1)
+#define MX25_ADCQ_CFG_REFN_NGND		MX25_ADCQ_CFG_REFN(2)
+#define MX25_ADCQ_CFG_REFN_NGND2	MX25_ADCQ_CFG_REFN(3)
+#define MX25_ADCQ_CFG_REFN_MASK		GENMASK(3, 2)
+#define MX25_ADCQ_CFG_PENIACK		(1 << 1)
+
+#endif  /* _LINUX_INCLUDE_MFD_IMX25_TSADC_H_ */

_______________________________________________
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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 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         |   6 +
 drivers/input/touchscreen/Makefile        |   1 +
 drivers/input/touchscreen/fsl-imx25-tcq.c | 600 ++++++++++++++++++++++++++++++
 3 files changed, 607 insertions(+)
 create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c

drivers/input/touchscreen/Kconfig +0 -0

index ae33da7ab51f..b44651d33080 100644

drivers/input/touchscreen/Kconfig +0 -0

 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 +229 -0

new file mode 100644
index 000000000000..c833cd814972
@@ -0,0 +1,600 @@
+/*
+ * 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;
+};
+
+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,

drivers/input/touchscreen/fsl-imx25-tcq.c new file +24 -0

+					   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;
+	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;

drivers/input/touchscreen/fsl-imx25-tcq.c new file +66 -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);
+		}
+	}
+
+	return ret;
+}
+
+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 = 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);
+

drivers/input/touchscreen/fsl-imx25-tcq.c new file +157 -0

+
+	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_cnt;
+	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 = 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;
+
+	ret = imx25_setup_queue_4wire(priv, settling_cnt, &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_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));
+
+	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_open(struct input_dev *idev)
+{
+	struct device *dev = &idev->dev;
+	struct mx25_tcq_priv *priv = dev_get_drvdata(dev);
+	int ret;
+
+	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");
+		clk_disable_unprepare(priv->clk);
+		return ret;
+	}
+
+	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);
+}

drivers/input/touchscreen/fsl-imx25-tcq.c new file +17 -0

+		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);
+	}
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (priv->irq <= 0) {
+		dev_err(dev, "Failed to get IRQ\n");
+		return priv->irq;
+	}

drivers/input/touchscreen/fsl-imx25-tcq.c new file +23 -0

+	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);
+
+	ret = input_register_device(idev);
+	if (ret) {
+		dev_err(dev, "Failed to register input device\n");

drivers/input/touchscreen/fsl-imx25-tcq.c new file +16 -0

+
+	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

2.6.1

Quoted 36 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]>

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 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         |   6 +
 drivers/input/touchscreen/Makefile        |   1 +
 drivers/input/touchscreen/fsl-imx25-tcq.c | 600 ++++++++++++++++++++++++++++++
 3 files changed, 607 insertions(+)
 create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c

drivers/input/touchscreen/Kconfig +0 -0

index ae33da7ab51f..b44651d33080 100644

drivers/input/touchscreen/Kconfig config TOUCHSCREEN_USB_COMPOSITE · line 819

Quoted 9 lines

drivers/input/touchscreen/Kconfig +6 -0

@@ -811,6 +811,12 @@ 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.
+

To compile this driver as a module...

Quoted 254 lines

drivers/input/touchscreen/Kconfig +0 -0

 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 +233 -0

new file mode 100644
index 000000000000..c833cd814972
@@ -0,0 +1,600 @@
+/*
+ * 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;
+};
+
+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);

drivers/input/touchscreen/fsl-imx25-tcq.c line 239

Quoted 6 lines

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

Why not void? What callers are supposed to do with the value?

Quoted 29 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +28 -0

+					   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;
+	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:

drivers/input/touchscreen/fsl-imx25-tcq.c line 273

Quoted 6 lines

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

+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	if (ret == 0 && samples != 0) {

Where do we set ret to anything other than 0?

Quoted 71 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +70 -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);
+		}
+	}
+
+	return ret;
+}
+
+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 = 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)

drivers/input/touchscreen/fsl-imx25-tcq.c line 349

Quoted 6 lines

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

+{
+	struct mx25_tcq_priv *priv = dev_id;
+	u32 stat;
+	int ret = IRQ_HANDLED;
+
+	regmap_read(priv->regs, MX25_ADCQ_SR, &stat);

Is there any concern that these reads will fail?

Quoted 164 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +163 -0

+
+	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_cnt;
+	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 = 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;
+
+	ret = imx25_setup_queue_4wire(priv, settling_cnt, &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_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));
+
+	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_open(struct input_dev *idev)
+{
+	struct device *dev = &idev->dev;
+	struct mx25_tcq_priv *priv = dev_get_drvdata(dev);
+	int ret;
+
+	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");
+		clk_disable_unprepare(priv->clk);
+		return ret;
+	}
+
+	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;

drivers/input/touchscreen/fsl-imx25-tcq.c line 516

Quoted 4 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +4 -0

+	struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent);
+	struct resource *res;
+	void __iomem *mem;
+	int ret;

Personal preference: can we call variables that hold error codes and not returned in success path (i.e. when we do explicit "return 0:' for success) be called "error"?

drivers/input/touchscreen/fsl-imx25-tcq.c line 524

Quoted 8 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +8 -0

+
+	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)

devm_ioremap_resource() returns ERR_PTR-encoded pointer, you should not test it for NULL bit rather for IS_ERR.

Quoted 18 lines

drivers/input/touchscreen/fsl-imx25-tcq.c new file +17 -0

+		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);
+	}
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (priv->irq <= 0) {
+		dev_err(dev, "Failed to get IRQ\n");
+		return priv->irq;
+	}

drivers/input/touchscreen/fsl-imx25-tcq.c line 551

Quoted 10 lines

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

Replace the 2 lines above with: