[PATCH v6 0/3] Add touch key driver support for TM2

[PATCH v6 0/3] Add touch key driver support for TM2

[Jaechul Lee]

Hi,

This patch is last three patch from https://lkml.org/lkml/2017/1/6/277.
because 1 and 2 patches have already been merged by Krzysztof.

This patchset adds support for the tm2 touchkey device.

The driver has been ported from Tizen Kernel, originally written
by Beomho. I ported it to the latest mainline Kernel.

Best Regard,
Jaechul

Changes in v6:
 - changed compatible name from samsaung to cypress. 
 - updated commit tags.
 - removed first two patches from the original patchset.
 
Changes in v5:
 - patch 1: removed a spurious regulator-always-off inherited from
   a different patch. Thanks Krzysztof.
 - patch 2: fixed a slip on  the model, thanks Javier (this patch
   confuses me quite a lot, this was all right some patches ago
   and re appeared on this one).
 - patch 2: removed 'regulator' label and used the original ldo3x
   labels. Krzysztof: it looks better indeed.
 - added Javier's reviews and Krzysztof's acks on the related
   patches.

Changes in v4:
 - patch 1 has been rebased on top of 7c294e002641 (arm64: dts:
   exynos: Remove unsupported regulator-always-off property from
   TM2E)
 - patch 2 has been generated with -B50% diff option using git
   2.11

Changes in v3:
 - Changed the commit ordering, the tm2-touchkey related patches
   are the last 3.
 - Added Chanwoo's patch which fixes the wrong voltage of ldo23
   and ldo25.
 - Andi (patch 3) moves the ldo31 and ldo38 in the tm2 and tm2e
   files as they have different values.

Changes in v2:
 - fixed reviews from Javier, Dmitry
 - refactored power enable/disable functions.
 - reordered signed-offs in patch 2, while patch 4 is left as it
   was as Andi copy pasted the node to the new tm2.dts file
 - added Jarvier's (patch 1,2,4) and Krzysztof's (patch 4)
   reviews
   and Rob's Ack
 - patch 3 diff has been generated with -B50%

Jaechul Lee (3):
  input: Add support for the tm2 touchkey device driver
  input: tm2-touchkey: Add touchkey driver support for TM2
  arm64: dts: exynos: Add tm2 touchkey node

 .../bindings/input/cypress,tm2-touchkey.txt        |  27 ++
 arch/arm64/boot/dts/exynos/exynos5433-tm2.dts      |  13 +
 drivers/input/keyboard/Kconfig                     |  11 +
 drivers/input/keyboard/Makefile                    |   1 +
 drivers/input/keyboard/tm2-touchkey.c              | 287 +++++++++++++++++++++
 5 files changed, 339 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/cypress,tm2-touchkey.txt
 create mode 100644 drivers/input/keyboard/tm2-touchkey.c

-- 
2.7.4

[PATCH v6 1/3] input: Add support for the tm2 touchkey device driver

[Jaechul Lee]

This patch adds the binding description of the tm2 touchkey
device driver.

Signed-off-by: Jaechul Lee <jcsing.lee@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 .../bindings/input/cypress,tm2-touchkey.txt        | 27 ++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/cypress,tm2-touchkey.txt

diff --git a/Documentation/devicetree/bindings/input/cypress,tm2-touchkey.txt b/Documentation/devicetree/bindings/input/cypress,tm2-touchkey.txt
new file mode 100644
index 0000000..635f62c
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/cypress,tm2-touchkey.txt
@@ -0,0 +1,27 @@
+Samsung tm2-touchkey
+
+Required properties:
+- compatible: must be "cypress,tm2-touchkey"
+- reg: I2C address of the chip.
+- interrupt-parent: a phandle for the interrupt controller (see interrupt
+	binding[0]).
+- interrupts: interrupt to which the chip is connected (see interrupt
+	binding[0]).
+- vcc-supply : internal regulator output. 1.8V
+- vdd-supply : power supply for IC 3.3V
+
+[0]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+
+Example:
+	&i2c0 {
+		/* ... */
+
+		touchkey@20 {
+			compatible = "cypress,tm2-touchkey";
+			reg = <0x20>;
+			interrupt-parent = <&gpa3>;
+			interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
+			vcc-supply=<&ldo32_reg>;
+			vdd-supply=<&ldo33_reg>;
+		};
+	};
-- 
2.7.4

[PATCH v6 2/3] input: tm2-touchkey: Add touchkey driver support for TM2

[Jaechul Lee]

This patch adds support for the TM2 touch key and led
functionality.

The driver interfaces with userspace through an input device and
reports KEY_PHONE and KEY_BACK event types. LED brightness can be
controlled by "/sys/class/leds/tm2-touchkey/brightness".

Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
Signed-off-by: Jaechul Lee <jcsing.lee@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/input/keyboard/Kconfig        |  11 ++
 drivers/input/keyboard/Makefile       |   1 +
 drivers/input/keyboard/tm2-touchkey.c | 287 ++++++++++++++++++++++++++++++++++
 3 files changed, 299 insertions(+)
 create mode 100644 drivers/input/keyboard/tm2-touchkey.c

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index cbd75cf..97acd65 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -666,6 +666,17 @@ config KEYBOARD_TC3589X
 	  To compile this driver as a module, choose M here: the
 	  module will be called tc3589x-keypad.
 
+config KEYBOARD_TM2_TOUCHKEY
+	tristate "TM2 touchkey support"
+	depends on I2C
+	depends on LEDS_CLASS
+	help
+	  Say Y here to enable device driver for tm2-touchkey with
+	  LED control for the Exynos5433 TM2 board.
+
+	  To compile this driver as a module, choose M here.
+	  module will be called tm2-touchkey.
+
 config KEYBOARD_TWL4030
 	tristate "TI TWL4030/TWL5030/TPS659x0 keypad support"
 	depends on TWL4030_CORE
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index d9f4cfc..7d9acff 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_KEYBOARD_SUN4I_LRADC)	+= sun4i-lradc-keys.o
 obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
 obj-$(CONFIG_KEYBOARD_TC3589X)		+= tc3589x-keypad.o
 obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
+obj-$(CONFIG_KEYBOARD_TM2_TOUCHKEY)	+= tm2-touchkey.o
 obj-$(CONFIG_KEYBOARD_TWL4030)		+= twl4030_keypad.o
 obj-$(CONFIG_KEYBOARD_XTKBD)		+= xtkbd.o
 obj-$(CONFIG_KEYBOARD_W90P910)		+= w90p910_keypad.o
diff --git a/drivers/input/keyboard/tm2-touchkey.c b/drivers/input/keyboard/tm2-touchkey.c
new file mode 100644
index 0000000..e927d06
--- /dev/null
+++ b/drivers/input/keyboard/tm2-touchkey.c
@@ -0,0 +1,287 @@
+/*
+ * TM2 touchkey device driver
+ *
+ * Copyright 2005 Phil Blundell
+ * Copyright 2016 Samsung Electronics Co., Ltd.
+ *
+ * Author: Beomho Seo <beomho.seo@samsung.com>
+ * Author: Jaechul Lee <jcsing.lee@samsung.com>
+ *
+ * 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/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+
+#define TM2_TOUCHKEY_DEV_NAME		"tm2-touchkey"
+#define TM2_TOUCHKEY_KEYCODE_REG	0x03
+#define TM2_TOUCHKEY_BASE_REG		0x00
+#define TM2_TOUCHKEY_CMD_LED_ON		0x10
+#define TM2_TOUCHKEY_CMD_LED_OFF	0x20
+#define TM2_TOUCHKEY_BIT_PRESS_EV	BIT(3)
+#define TM2_TOUCHKEY_BIT_KEYCODE	GENMASK(2, 0)
+#define TM2_TOUCHKEY_LED_VOLTAGE_MIN	2500000
+#define TM2_TOUCHKEY_LED_VOLTAGE_MAX	3300000
+
+enum {
+	TM2_TOUCHKEY_KEY_MENU = 0x1,
+	TM2_TOUCHKEY_KEY_BACK,
+};
+
+enum {
+	TM2_TOUCHKEY_SUPPLIES_VCC,
+	TM2_TOUCHKEY_SUPPLIES_VDD,
+};
+
+struct tm2_touchkey_data {
+	struct i2c_client *client;
+	struct input_dev *input_dev;
+	struct led_classdev led_dev;
+	struct regulator_bulk_data regulators[2];
+
+	u8 keycode_type;
+	u8 pressed;
+};
+
+static void tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
+						enum led_brightness brightness)
+{
+	struct tm2_touchkey_data *touchkey =
+	    container_of(led_dev, struct tm2_touchkey_data, led_dev);
+	u32 volt;
+	u8 data;
+
+	if (brightness == LED_OFF) {
+		volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
+		data = TM2_TOUCHKEY_CMD_LED_OFF;
+	} else {
+		volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
+		data = TM2_TOUCHKEY_CMD_LED_ON;
+	}
+
+	regulator_set_voltage(
+		touchkey->regulators[TM2_TOUCHKEY_SUPPLIES_VDD].consumer,
+		volt, volt);
+	i2c_smbus_write_byte_data(touchkey->client,
+						TM2_TOUCHKEY_BASE_REG, data);
+}
+
+static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
+{
+	int ret = 0;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
+						touchkey->regulators);
+	if (ret)
+		return ret;
+
+	/* waiting for device initialization, at least 150ms */
+	msleep(150);
+
+	return 0;
+}
+
+static void tm2_touchkey_power_disable(void *data)
+{
+	struct tm2_touchkey_data *touchkey = data;
+
+	regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
+						touchkey->regulators);
+}
+
+static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
+{
+	struct tm2_touchkey_data *touchkey = devid;
+	u32 data;
+
+	data = i2c_smbus_read_byte_data(touchkey->client,
+					TM2_TOUCHKEY_KEYCODE_REG);
+
+	if (data < 0) {
+		dev_err(&touchkey->client->dev, "Failed to read i2c data\n");
+		return IRQ_HANDLED;
+	}
+
+	touchkey->keycode_type = data & TM2_TOUCHKEY_BIT_KEYCODE;
+	touchkey->pressed = !(data & TM2_TOUCHKEY_BIT_PRESS_EV);
+
+	if (touchkey->keycode_type != TM2_TOUCHKEY_KEY_MENU &&
+	    touchkey->keycode_type != TM2_TOUCHKEY_KEY_BACK) {
+		dev_warn(&touchkey->client->dev, "Skip unhandled keycode(%d)\n",
+							touchkey->keycode_type);
+		return IRQ_HANDLED;
+	}
+
+	if (!touchkey->pressed) {
+		input_report_key(touchkey->input_dev, KEY_PHONE, 0);
+		input_report_key(touchkey->input_dev, KEY_BACK, 0);
+	} else {
+		if (touchkey->keycode_type == TM2_TOUCHKEY_KEY_MENU)
+			input_report_key(touchkey->input_dev,
+					 KEY_PHONE, 1);
+		else
+			input_report_key(touchkey->input_dev,
+					 KEY_BACK, 1);
+	}
+	input_sync(touchkey->input_dev);
+
+	return IRQ_HANDLED;
+}
+
+static int tm2_touchkey_probe(struct i2c_client *client,
+					const struct i2c_device_id *id)
+{
+	struct tm2_touchkey_data *touchkey;
+	int ret;
+
+	ret = i2c_check_functionality(client->adapter,
+				      I2C_FUNC_SMBUS_BYTE |
+				      I2C_FUNC_SMBUS_BYTE_DATA);
+	if (!ret) {
+		dev_err(&client->dev, "No I2C functionality found\n");
+		return -ENODEV;
+	}
+
+	touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
+	if (!touchkey)
+		return -ENOMEM;
+
+	touchkey->client = client;
+	i2c_set_clientdata(client, touchkey);
+
+	/* regulators */
+	touchkey->regulators[TM2_TOUCHKEY_SUPPLIES_VCC].supply = "vcc";
+	touchkey->regulators[TM2_TOUCHKEY_SUPPLIES_VDD].supply = "vdd";
+	ret = devm_regulator_bulk_get(&client->dev,
+					ARRAY_SIZE(touchkey->regulators),
+					touchkey->regulators);
+	if (ret) {
+		dev_err(&client->dev, "Failed to get regulators\n");
+		return ret;
+	}
+
+	/* power */
+	ret = tm2_touchkey_power_enable(touchkey);
+	if (ret) {
+		dev_err(&client->dev, "Failed to enable power\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&client->dev,
+					tm2_touchkey_power_disable, touchkey);
+	if (ret)
+		return ret;
+
+	/* input device */
+	touchkey->input_dev = devm_input_allocate_device(&client->dev);
+	if (!touchkey->input_dev) {
+		dev_err(&client->dev, "Failed to alloc input device\n");
+		return -ENOMEM;
+	}
+	touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
+	touchkey->input_dev->id.bustype = BUS_I2C;
+
+	set_bit(EV_KEY, touchkey->input_dev->evbit);
+	input_set_capability(touchkey->input_dev, EV_KEY, KEY_PHONE);
+	input_set_capability(touchkey->input_dev, EV_KEY, KEY_BACK);
+
+	input_set_drvdata(touchkey->input_dev, touchkey);
+
+	ret = input_register_device(touchkey->input_dev);
+	if (ret) {
+		dev_err(&client->dev, "Failed to register input device\n");
+		return ret;
+	}
+
+	/* irq */
+	ret = devm_request_threaded_irq(&client->dev,
+					client->irq, NULL,
+					tm2_touchkey_irq_handler,
+					IRQF_ONESHOT, TM2_TOUCHKEY_DEV_NAME,
+					touchkey);
+	if (ret) {
+		dev_err(&client->dev, "Failed to request threaded irq\n");
+		return ret;
+	}
+
+	/* led device */
+	touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
+	touchkey->led_dev.brightness = LED_FULL;
+	touchkey->led_dev.max_brightness = LED_FULL;
+	touchkey->led_dev.brightness_set = tm2_touchkey_led_brightness_set;
+
+	ret = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to register touchkey led\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
+{
+	struct tm2_touchkey_data *touchkey = dev_get_drvdata(dev);
+
+	disable_irq(touchkey->client->irq);
+	tm2_touchkey_power_disable(touchkey);
+
+	return 0;
+}
+
+static int __maybe_unused tm2_touchkey_resume(struct device *dev)
+{
+	struct tm2_touchkey_data *touchkey = dev_get_drvdata(dev);
+	int ret;
+
+	enable_irq(touchkey->client->irq);
+	ret = tm2_touchkey_power_enable(touchkey);
+	if (ret)
+		dev_err(dev, "Failed to enable power\n");
+
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops, tm2_touchkey_suspend,
+							tm2_touchkey_resume);
+
+static const struct i2c_device_id tm2_touchkey_id_table[] = {
+	{TM2_TOUCHKEY_DEV_NAME, 0},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
+
+static const struct of_device_id tm2_touchkey_of_match[] = {
+	{.compatible = "cypress,tm2-touchkey",},
+	{},
+};
+MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
+
+static struct i2c_driver tm2_touchkey_driver = {
+	.driver = {
+		.name = TM2_TOUCHKEY_DEV_NAME,
+		.pm = &tm2_touchkey_pm_ops,
+		.of_match_table = of_match_ptr(tm2_touchkey_of_match),
+	},
+	.probe = tm2_touchkey_probe,
+	.id_table = tm2_touchkey_id_table,
+};
+
+module_i2c_driver(tm2_touchkey_driver);
+
+MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
+MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
+MODULE_DESCRIPTION("Samsung touchkey driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

[PATCH v6 3/3] arm64: dts: exynos: Add tm2 touchkey node

[Jaechul Lee]

Add DT node support for TM2 touchkey device.

Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
Signed-off-by: Jaechul Lee <jcsing.lee@samsung.com>
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
---
 arch/arm64/boot/dts/exynos/exynos5433-tm2.dts | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts b/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts
index 2449266..ddba2f8 100644
--- a/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts
+++ b/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts
@@ -18,6 +18,19 @@
 	compatible = "samsung,tm2", "samsung,exynos5433";
 };
 
+&hsi2c_9 {
+	status = "okay";
+
+	touchkey@20 {
+		compatible = "cypress,tm2-touchkey";
+		reg = <0x20>;
+		interrupt-parent = <&gpa3>;
+		interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
+		vcc-supply = <&ldo32_reg>;
+		vdd-supply = <&ldo33_reg>;
+	};
+};
+
 &ldo31_reg {
 	regulator-name = "TSP_VDD_1.85V_AP";
 	regulator-min-microvolt = <1850000>;
-- 
2.7.4

Re: [PATCH v6 2/3] input: tm2-touchkey: Add touchkey driver support for TM2

[Chanwoo Choi]

Hi Jaechul,

Looks good to me. I tested this patch on TM2 board.
It is well working.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>

Best Regards,
Chanwoo Choi

On 2017년 01월 09일 16:22, Jaechul Lee wrote:
> This patch adds support for the TM2 touch key and led
> functionality.
> 
> The driver interfaces with userspace through an input device and
> reports KEY_PHONE and KEY_BACK event types. LED brightness can be
> controlled by "/sys/class/leds/tm2-touchkey/brightness".
> 
> Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
> Signed-off-by: Jaechul Lee <jcsing.lee@samsung.com>
> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
> Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
> Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
> ---
>  drivers/input/keyboard/Kconfig        |  11 ++
>  drivers/input/keyboard/Makefile       |   1 +
>  drivers/input/keyboard/tm2-touchkey.c | 287 ++++++++++++++++++++++++++++++++++
>  3 files changed, 299 insertions(+)
>  create mode 100644 drivers/input/keyboard/tm2-touchkey.c
> 
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index cbd75cf..97acd65 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -666,6 +666,17 @@ config KEYBOARD_TC3589X
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called tc3589x-keypad.
>  
> +config KEYBOARD_TM2_TOUCHKEY
> +	tristate "TM2 touchkey support"
> +	depends on I2C
> +	depends on LEDS_CLASS
> +	help
> +	  Say Y here to enable device driver for tm2-touchkey with
> +	  LED control for the Exynos5433 TM2 board.
> +
> +	  To compile this driver as a module, choose M here.
> +	  module will be called tm2-touchkey.
> +
>  config KEYBOARD_TWL4030
>  	tristate "TI TWL4030/TWL5030/TPS659x0 keypad support"
>  	depends on TWL4030_CORE
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index d9f4cfc..7d9acff 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -61,6 +61,7 @@ obj-$(CONFIG_KEYBOARD_SUN4I_LRADC)	+= sun4i-lradc-keys.o
>  obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
>  obj-$(CONFIG_KEYBOARD_TC3589X)		+= tc3589x-keypad.o
>  obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
> +obj-$(CONFIG_KEYBOARD_TM2_TOUCHKEY)	+= tm2-touchkey.o
>  obj-$(CONFIG_KEYBOARD_TWL4030)		+= twl4030_keypad.o
>  obj-$(CONFIG_KEYBOARD_XTKBD)		+= xtkbd.o
>  obj-$(CONFIG_KEYBOARD_W90P910)		+= w90p910_keypad.o
> diff --git a/drivers/input/keyboard/tm2-touchkey.c b/drivers/input/keyboard/tm2-touchkey.c
> new file mode 100644
> index 0000000..e927d06
> --- /dev/null
> +++ b/drivers/input/keyboard/tm2-touchkey.c
> @@ -0,0 +1,287 @@
> +/*
> + * TM2 touchkey device driver
> + *
> + * Copyright 2005 Phil Blundell
> + * Copyright 2016 Samsung Electronics Co., Ltd.
> + *
> + * Author: Beomho Seo <beomho.seo@samsung.com>
> + * Author: Jaechul Lee <jcsing.lee@samsung.com>
> + *
> + * 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/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/i2c.h>
> +#include <linux/input.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/pm.h>
> +#include <linux/regulator/consumer.h>
> +
> +#define TM2_TOUCHKEY_DEV_NAME		"tm2-touchkey"
> +#define TM2_TOUCHKEY_KEYCODE_REG	0x03
> +#define TM2_TOUCHKEY_BASE_REG		0x00
> +#define TM2_TOUCHKEY_CMD_LED_ON		0x10
> +#define TM2_TOUCHKEY_CMD_LED_OFF	0x20
> +#define TM2_TOUCHKEY_BIT_PRESS_EV	BIT(3)
> +#define TM2_TOUCHKEY_BIT_KEYCODE	GENMASK(2, 0)
> +#define TM2_TOUCHKEY_LED_VOLTAGE_MIN	2500000
> +#define TM2_TOUCHKEY_LED_VOLTAGE_MAX	3300000
> +
> +enum {
> +	TM2_TOUCHKEY_KEY_MENU = 0x1,
> +	TM2_TOUCHKEY_KEY_BACK,
> +};
> +
> +enum {
> +	TM2_TOUCHKEY_SUPPLIES_VCC,
> +	TM2_TOUCHKEY_SUPPLIES_VDD,
> +};
> +
> +struct tm2_touchkey_data {
> +	struct i2c_client *client;
> +	struct input_dev *input_dev;
> +	struct led_classdev led_dev;
> +	struct regulator_bulk_data regulators[2];
> +
> +	u8 keycode_type;
> +	u8 pressed;
> +};
> +
> +static void tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
> +						enum led_brightness brightness)
> +{
> +	struct tm2_touchkey_data *touchkey =
> +	    container_of(led_dev, struct tm2_touchkey_data, led_dev);
> +	u32 volt;
> +	u8 data;
> +
> +	if (brightness == LED_OFF) {
> +		volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
> +		data = TM2_TOUCHKEY_CMD_LED_OFF;
> +	} else {
> +		volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
> +		data = TM2_TOUCHKEY_CMD_LED_ON;
> +	}
> +
> +	regulator_set_voltage(
> +		touchkey->regulators[TM2_TOUCHKEY_SUPPLIES_VDD].consumer,
> +		volt, volt);
> +	i2c_smbus_write_byte_data(touchkey->client,
> +						TM2_TOUCHKEY_BASE_REG, data);
> +}
> +
> +static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
> +{
> +	int ret = 0;
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
> +						touchkey->regulators);
> +	if (ret)
> +		return ret;
> +
> +	/* waiting for device initialization, at least 150ms */
> +	msleep(150);
> +
> +	return 0;
> +}
> +
> +static void tm2_touchkey_power_disable(void *data)
> +{
> +	struct tm2_touchkey_data *touchkey = data;
> +
> +	regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
> +						touchkey->regulators);
> +}
> +
> +static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
> +{
> +	struct tm2_touchkey_data *touchkey = devid;
> +	u32 data;
> +
> +	data = i2c_smbus_read_byte_data(touchkey->client,
> +					TM2_TOUCHKEY_KEYCODE_REG);
> +
> +	if (data < 0) {
> +		dev_err(&touchkey->client->dev, "Failed to read i2c data\n");
> +		return IRQ_HANDLED;
> +	}
> +
> +	touchkey->keycode_type = data & TM2_TOUCHKEY_BIT_KEYCODE;
> +	touchkey->pressed = !(data & TM2_TOUCHKEY_BIT_PRESS_EV);
> +
> +	if (touchkey->keycode_type != TM2_TOUCHKEY_KEY_MENU &&
> +	    touchkey->keycode_type != TM2_TOUCHKEY_KEY_BACK) {
> +		dev_warn(&touchkey->client->dev, "Skip unhandled keycode(%d)\n",
> +							touchkey->keycode_type);
> +		return IRQ_HANDLED;
> +	}
> +
> +	if (!touchkey->pressed) {
> +		input_report_key(touchkey->input_dev, KEY_PHONE, 0);
> +		input_report_key(touchkey->input_dev, KEY_BACK, 0);
> +	} else {
> +		if (touchkey->keycode_type == TM2_TOUCHKEY_KEY_MENU)
> +			input_report_key(touchkey->input_dev,
> +					 KEY_PHONE, 1);
> +		else
> +			input_report_key(touchkey->input_dev,
> +					 KEY_BACK, 1);
> +	}
> +	input_sync(touchkey->input_dev);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int tm2_touchkey_probe(struct i2c_client *client,
> +					const struct i2c_device_id *id)
> +{
> +	struct tm2_touchkey_data *touchkey;
> +	int ret;
> +
> +	ret = i2c_check_functionality(client->adapter,
> +				      I2C_FUNC_SMBUS_BYTE |
> +				      I2C_FUNC_SMBUS_BYTE_DATA);
> +	if (!ret) {
> +		dev_err(&client->dev, "No I2C functionality found\n");
> +		return -ENODEV;
> +	}
> +
> +	touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
> +	if (!touchkey)
> +		return -ENOMEM;
> +
> +	touchkey->client = client;
> +	i2c_set_clientdata(client, touchkey);
> +
> +	/* regulators */
> +	touchkey->regulators[TM2_TOUCHKEY_SUPPLIES_VCC].supply = "vcc";
> +	touchkey->regulators[TM2_TOUCHKEY_SUPPLIES_VDD].supply = "vdd";
> +	ret = devm_regulator_bulk_get(&client->dev,
> +					ARRAY_SIZE(touchkey->regulators),
> +					touchkey->regulators);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to get regulators\n");
> +		return ret;
> +	}
> +
> +	/* power */
> +	ret = tm2_touchkey_power_enable(touchkey);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to enable power\n");
> +		return ret;
> +	}
> +
> +	ret = devm_add_action_or_reset(&client->dev,
> +					tm2_touchkey_power_disable, touchkey);
> +	if (ret)
> +		return ret;
> +
> +	/* input device */
> +	touchkey->input_dev = devm_input_allocate_device(&client->dev);
> +	if (!touchkey->input_dev) {
> +		dev_err(&client->dev, "Failed to alloc input device\n");
> +		return -ENOMEM;
> +	}
> +	touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
> +	touchkey->input_dev->id.bustype = BUS_I2C;
> +
> +	set_bit(EV_KEY, touchkey->input_dev->evbit);
> +	input_set_capability(touchkey->input_dev, EV_KEY, KEY_PHONE);
> +	input_set_capability(touchkey->input_dev, EV_KEY, KEY_BACK);
> +
> +	input_set_drvdata(touchkey->input_dev, touchkey);
> +
> +	ret = input_register_device(touchkey->input_dev);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to register input device\n");
> +		return ret;
> +	}
> +
> +	/* irq */
> +	ret = devm_request_threaded_irq(&client->dev,
> +					client->irq, NULL,
> +					tm2_touchkey_irq_handler,
> +					IRQF_ONESHOT, TM2_TOUCHKEY_DEV_NAME,
> +					touchkey);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to request threaded irq\n");
> +		return ret;
> +	}
> +
> +	/* led device */
> +	touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
> +	touchkey->led_dev.brightness = LED_FULL;
> +	touchkey->led_dev.max_brightness = LED_FULL;
> +	touchkey->led_dev.brightness_set = tm2_touchkey_led_brightness_set;
> +
> +	ret = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "Failed to register touchkey led\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
> +{
> +	struct tm2_touchkey_data *touchkey = dev_get_drvdata(dev);
> +
> +	disable_irq(touchkey->client->irq);
> +	tm2_touchkey_power_disable(touchkey);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused tm2_touchkey_resume(struct device *dev)
> +{
> +	struct tm2_touchkey_data *touchkey = dev_get_drvdata(dev);
> +	int ret;
> +
> +	enable_irq(touchkey->client->irq);
> +	ret = tm2_touchkey_power_enable(touchkey);
> +	if (ret)
> +		dev_err(dev, "Failed to enable power\n");
> +
> +	return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops, tm2_touchkey_suspend,
> +							tm2_touchkey_resume);
> +
> +static const struct i2c_device_id tm2_touchkey_id_table[] = {
> +	{TM2_TOUCHKEY_DEV_NAME, 0},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
> +
> +static const struct of_device_id tm2_touchkey_of_match[] = {
> +	{.compatible = "cypress,tm2-touchkey",},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
> +
> +static struct i2c_driver tm2_touchkey_driver = {
> +	.driver = {
> +		.name = TM2_TOUCHKEY_DEV_NAME,
> +		.pm = &tm2_touchkey_pm_ops,
> +		.of_match_table = of_match_ptr(tm2_touchkey_of_match),
> +	},
> +	.probe = tm2_touchkey_probe,
> +	.id_table = tm2_touchkey_id_table,
> +};
> +
> +module_i2c_driver(tm2_touchkey_driver);
> +
> +MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
> +MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
> +MODULE_DESCRIPTION("Samsung touchkey driver");
> +MODULE_LICENSE("GPL v2");
> 

Re: [PATCH v6 3/3] arm64: dts: exynos: Add tm2 touchkey node

[Chanwoo Choi]

Hi Jaechul,

I tested this patch on TM2 board. It is well working
with platform.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>

Best Regards,
Chanwoo Choi

On 2017년 01월 09일 16:22, Jaechul Lee wrote:
> Add DT node support for TM2 touchkey device.
> 
> Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
> Signed-off-by: Jaechul Lee <jcsing.lee@samsung.com>
> Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
> ---
>  arch/arm64/boot/dts/exynos/exynos5433-tm2.dts | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts b/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts
> index 2449266..ddba2f8 100644
> --- a/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts
> +++ b/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts
> @@ -18,6 +18,19 @@
>  	compatible = "samsung,tm2", "samsung,exynos5433";
>  };
>  
> +&hsi2c_9 {
> +	status = "okay";
> +
> +	touchkey@20 {
> +		compatible = "cypress,tm2-touchkey";
> +		reg = <0x20>;
> +		interrupt-parent = <&gpa3>;
> +		interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
> +		vcc-supply = <&ldo32_reg>;
> +		vdd-supply = <&ldo33_reg>;
> +	};
> +};
> +
>  &ldo31_reg {
>  	regulator-name = "TSP_VDD_1.85V_AP";
>  	regulator-min-microvolt = <1850000>;
> 

Re: [PATCH v6 2/3] input: tm2-touchkey: Add touchkey driver support for TM2

[Dmitry Torokhov]

Hi Jaechul,

On Mon, Jan 09, 2017 at 04:22:14PM +0900, Jaechul Lee wrote:
> +static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
> +{
> +	struct tm2_touchkey_data *touchkey = devid;
> +	u32 data;
> +
> +	data = i2c_smbus_read_byte_data(touchkey->client,
> +					TM2_TOUCHKEY_KEYCODE_REG);
> +
> +	if (data < 0) {

You declared data as u32 so it will never be negative.

> +		dev_err(&touchkey->client->dev, "Failed to read i2c data\n");
> +		return IRQ_HANDLED;
> +	}
> +
> +	touchkey->keycode_type = data & TM2_TOUCHKEY_BIT_KEYCODE;
> +	touchkey->pressed = !(data & TM2_TOUCHKEY_BIT_PRESS_EV);

There is no need to store this in touchkey structure as you are not
going to use it past this function.

Does the version of the patch below work for you?

Thanks.

-- 
Dmitry


Input: tm2-touchkey - add touchkey driver support for TM2

From: Jaechul Lee <jcsing.lee@samsung.com>

This patch adds support for the TM2 touch key and led functionality.

The driver interfaces with userspace through an input device and
reports KEY_PHONE and KEY_BACK event types. LED brightness can be
controlled by "/sys/class/leds/tm2-touchkey/brightness".

Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
Signed-off-by: Jaechul Lee <jcsing.lee@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Patchwork-Id: 9504149
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/keyboard/Kconfig        |   11 +
 drivers/input/keyboard/Makefile       |    1 
 drivers/input/keyboard/tm2-touchkey.c |  286 +++++++++++++++++++++++++++++++++
 3 files changed, 298 insertions(+)
 create mode 100644 drivers/input/keyboard/tm2-touchkey.c

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index cbd75cf44739..97acd6524ad7 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -666,6 +666,17 @@ config KEYBOARD_TC3589X
 	  To compile this driver as a module, choose M here: the
 	  module will be called tc3589x-keypad.
 
+config KEYBOARD_TM2_TOUCHKEY
+	tristate "TM2 touchkey support"
+	depends on I2C
+	depends on LEDS_CLASS
+	help
+	  Say Y here to enable device driver for tm2-touchkey with
+	  LED control for the Exynos5433 TM2 board.
+
+	  To compile this driver as a module, choose M here.
+	  module will be called tm2-touchkey.
+
 config KEYBOARD_TWL4030
 	tristate "TI TWL4030/TWL5030/TPS659x0 keypad support"
 	depends on TWL4030_CORE
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index d9f4cfcf3410..7d9acff819a7 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_KEYBOARD_SUN4I_LRADC)	+= sun4i-lradc-keys.o
 obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
 obj-$(CONFIG_KEYBOARD_TC3589X)		+= tc3589x-keypad.o
 obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
+obj-$(CONFIG_KEYBOARD_TM2_TOUCHKEY)	+= tm2-touchkey.o
 obj-$(CONFIG_KEYBOARD_TWL4030)		+= twl4030_keypad.o
 obj-$(CONFIG_KEYBOARD_XTKBD)		+= xtkbd.o
 obj-$(CONFIG_KEYBOARD_W90P910)		+= w90p910_keypad.o
diff --git a/drivers/input/keyboard/tm2-touchkey.c b/drivers/input/keyboard/tm2-touchkey.c
new file mode 100644
index 000000000000..79bc2d2bd4b9
--- /dev/null
+++ b/drivers/input/keyboard/tm2-touchkey.c
@@ -0,0 +1,286 @@
+/*
+ * TM2 touchkey device driver
+ *
+ * Copyright 2005 Phil Blundell
+ * Copyright 2016 Samsung Electronics Co., Ltd.
+ *
+ * Author: Beomho Seo <beomho.seo@samsung.com>
+ * Author: Jaechul Lee <jcsing.lee@samsung.com>
+ *
+ * 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/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+
+#define TM2_TOUCHKEY_DEV_NAME		"tm2-touchkey"
+#define TM2_TOUCHKEY_KEYCODE_REG	0x03
+#define TM2_TOUCHKEY_BASE_REG		0x00
+#define TM2_TOUCHKEY_CMD_LED_ON		0x10
+#define TM2_TOUCHKEY_CMD_LED_OFF	0x20
+#define TM2_TOUCHKEY_BIT_PRESS_EV	BIT(3)
+#define TM2_TOUCHKEY_BIT_KEYCODE	GENMASK(2, 0)
+#define TM2_TOUCHKEY_LED_VOLTAGE_MIN	2500000
+#define TM2_TOUCHKEY_LED_VOLTAGE_MAX	3300000
+
+enum {
+	TM2_TOUCHKEY_KEY_MENU = 0x1,
+	TM2_TOUCHKEY_KEY_BACK,
+};
+
+struct tm2_touchkey_data {
+	struct i2c_client *client;
+	struct input_dev *input_dev;
+	struct led_classdev led_dev;
+	struct regulator *vdd;
+	struct regulator_bulk_data regulators[2];
+};
+
+static void tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
+					    enum led_brightness brightness)
+{
+	struct tm2_touchkey_data *touchkey =
+		container_of(led_dev, struct tm2_touchkey_data, led_dev);
+	u32 volt;
+	u8 data;
+
+	if (brightness == LED_OFF) {
+		volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
+		data = TM2_TOUCHKEY_CMD_LED_OFF;
+	} else {
+		volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
+		data = TM2_TOUCHKEY_CMD_LED_ON;
+	}
+
+	regulator_set_voltage(touchkey->vdd, volt, volt);
+	i2c_smbus_write_byte_data(touchkey->client,
+				  TM2_TOUCHKEY_BASE_REG, data);
+}
+
+static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
+{
+	int error;
+
+	error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
+				      touchkey->regulators);
+	if (error)
+		return error;
+
+	/* waiting for device initialization, at least 150ms */
+	msleep(150);
+
+	return 0;
+}
+
+static void tm2_touchkey_power_disable(void *data)
+{
+	struct tm2_touchkey_data *touchkey = data;
+
+	regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
+			       touchkey->regulators);
+}
+
+static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
+{
+	struct tm2_touchkey_data *touchkey = devid;
+	int data;
+	int key;
+
+	data = i2c_smbus_read_byte_data(touchkey->client,
+					TM2_TOUCHKEY_KEYCODE_REG);
+	if (data < 0) {
+		dev_err(&touchkey->client->dev,
+			"failed to read i2c data: %d\n", data);
+		goto out;
+	}
+
+	switch (data & TM2_TOUCHKEY_BIT_KEYCODE) {
+	case TM2_TOUCHKEY_KEY_MENU:
+		key = KEY_PHONE;
+		break;
+
+	case TM2_TOUCHKEY_KEY_BACK:
+		key = KEY_BACK;
+		break;
+
+	default:
+		dev_warn(&touchkey->client->dev,
+			 "unhandled keycode, data %#02x\n", data);
+		goto out;
+	}
+
+	if (data & TM2_TOUCHKEY_BIT_PRESS_EV) {
+		input_report_key(touchkey->input_dev, key, 1);
+	} else {
+		input_report_key(touchkey->input_dev, KEY_PHONE, 0);
+		input_report_key(touchkey->input_dev, KEY_BACK, 0);
+	}
+
+	input_sync(touchkey->input_dev);
+
+out:
+	return IRQ_HANDLED;
+}
+
+static int tm2_touchkey_probe(struct i2c_client *client,
+			      const struct i2c_device_id *id)
+{
+	struct tm2_touchkey_data *touchkey;
+	int error;
+
+	if (!i2c_check_functionality(client->adapter,
+			I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) {
+		dev_err(&client->dev, "incompatible I2C adapter\n");
+		return -EIO;
+	}
+
+	touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
+	if (!touchkey)
+		return -ENOMEM;
+
+	touchkey->client = client;
+	i2c_set_clientdata(client, touchkey);
+
+	touchkey->regulators[0].supply = "vcc";
+	touchkey->regulators[1].supply = "vdd";
+	error = devm_regulator_bulk_get(&client->dev,
+					ARRAY_SIZE(touchkey->regulators),
+					touchkey->regulators);
+	if (error) {
+		dev_err(&client->dev, "failed to get regulators: %d\n", error);
+		return error;
+	}
+
+	/* Save VDD for easy access */
+	touchkey->vdd = touchkey->regulators[1].consumer;
+
+	error = tm2_touchkey_power_enable(touchkey);
+	if (error) {
+		dev_err(&client->dev, "failed to power up device: %d\n", error);
+		return error;
+	}
+
+	error = devm_add_action_or_reset(&client->dev,
+					 tm2_touchkey_power_disable, touchkey);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to install poweroff handler: %d\n", error);
+		return error;
+	}
+
+	/* input device */
+	touchkey->input_dev = devm_input_allocate_device(&client->dev);
+	if (!touchkey->input_dev) {
+		dev_err(&client->dev, "failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
+	touchkey->input_dev->id.bustype = BUS_I2C;
+
+	input_set_capability(touchkey->input_dev, EV_KEY, KEY_PHONE);
+	input_set_capability(touchkey->input_dev, EV_KEY, KEY_BACK);
+
+	input_set_drvdata(touchkey->input_dev, touchkey);
+
+	error = input_register_device(touchkey->input_dev);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to register input device: %d\n", error);
+		return error;
+	}
+
+	error = devm_request_threaded_irq(&client->dev, client->irq,
+					  NULL, tm2_touchkey_irq_handler,
+					  IRQF_ONESHOT,
+					  TM2_TOUCHKEY_DEV_NAME, touchkey);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to request threaded irq: %d\n", error);
+		return error;
+	}
+
+	/* led device */
+	touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
+	touchkey->led_dev.brightness = LED_FULL;
+	touchkey->led_dev.max_brightness = LED_FULL;
+	touchkey->led_dev.brightness_set = tm2_touchkey_led_brightness_set;
+
+	error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to register touchkey led: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
+
+	disable_irq(client->irq);
+	tm2_touchkey_power_disable(touchkey);
+
+	return 0;
+}
+
+static int __maybe_unused tm2_touchkey_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
+	int ret;
+
+	enable_irq(client->irq);
+
+	ret = tm2_touchkey_power_enable(touchkey);
+	if (ret)
+		dev_err(dev, "failed to enable power: %d\n", ret);
+
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops,
+			 tm2_touchkey_suspend, tm2_touchkey_resume);
+
+static const struct i2c_device_id tm2_touchkey_id_table[] = {
+	{ TM2_TOUCHKEY_DEV_NAME, 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
+
+static const struct of_device_id tm2_touchkey_of_match[] = {
+	{ .compatible = "cypress,tm2-touchkey", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
+
+static struct i2c_driver tm2_touchkey_driver = {
+	.driver = {
+		.name = TM2_TOUCHKEY_DEV_NAME,
+		.pm = &tm2_touchkey_pm_ops,
+		.of_match_table = of_match_ptr(tm2_touchkey_of_match),
+	},
+	.probe = tm2_touchkey_probe,
+	.id_table = tm2_touchkey_id_table,
+};
+module_i2c_driver(tm2_touchkey_driver);
+
+MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
+MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
+MODULE_DESCRIPTION("Samsung touchkey driver");
+MODULE_LICENSE("GPL v2");

Re: [PATCH v6 2/3] input: tm2-touchkey: Add touchkey driver support for TM2

[Jaechul Lee]

Dear Dmitry Torokhov,

On Sat, Jan 14, 2017 at 11:11:10PM -0800, Dmitry Torokhov wrote:
> Hi Jaechul,
> 
> On Mon, Jan 09, 2017 at 04:22:14PM +0900, Jaechul Lee wrote:
> > +static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
> > +{
> > +	struct tm2_touchkey_data *touchkey = devid;
> > +	u32 data;
> > +
> > +	data = i2c_smbus_read_byte_data(touchkey->client,
> > +					TM2_TOUCHKEY_KEYCODE_REG);
> > +
> > +	if (data < 0) {
> 
> You declared data as u32 so it will never be negative.

Yes, it won't be negative.

> 
> > +		dev_err(&touchkey->client->dev, "Failed to read i2c data\n");
> > +		return IRQ_HANDLED;
> > +	}
> > +
> > +	touchkey->keycode_type = data & TM2_TOUCHKEY_BIT_KEYCODE;
> > +	touchkey->pressed = !(data & TM2_TOUCHKEY_BIT_PRESS_EV);
> 
> There is no need to store this in touchkey structure as you are not
> going to use it past this function.

I agree with you. it doesn't need to store variables in touchkey structure.

> 
> Does the version of the patch below work for you?

I found that the condition is inverted.
if data & TM2_TOUCHKEY_BIT_PRESS_EV is true, it means touchkey is released.

it should be changed like this.

	if (data & TM2_TOUCHKEY_BIT_PRESS_EV) {
		input_report_key(touchkey->input_dev, KEY_PHONE, 0);
		input_report_key(touchkey->input_dev, KEY_BACK, 0);
	} else {
		input_report_key(touchkey->input_dev, key, 1);
	}

I will prepare for patch v7 based on your modifications.
Thank you very much for your reviews.

Best Regards,
Jaechul

> 
> Thanks.
> 
> -- 
> Dmitry
> 
> 
> Input: tm2-touchkey - add touchkey driver support for TM2
> 
> From: Jaechul Lee <jcsing.lee@samsung.com>
> 
> This patch adds support for the TM2 touch key and led functionality.
> 
> The driver interfaces with userspace through an input device and
> reports KEY_PHONE and KEY_BACK event types. LED brightness can be
> controlled by "/sys/class/leds/tm2-touchkey/brightness".
> 
> Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
> Signed-off-by: Jaechul Lee <jcsing.lee@samsung.com>
> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
> Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
> Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
> Patchwork-Id: 9504149
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
>  drivers/input/keyboard/Kconfig        |   11 +
>  drivers/input/keyboard/Makefile       |    1 
>  drivers/input/keyboard/tm2-touchkey.c |  286 +++++++++++++++++++++++++++++++++
>  3 files changed, 298 insertions(+)
>  create mode 100644 drivers/input/keyboard/tm2-touchkey.c
> 
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index cbd75cf44739..97acd6524ad7 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -666,6 +666,17 @@ config KEYBOARD_TC3589X
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called tc3589x-keypad.
>  
> +config KEYBOARD_TM2_TOUCHKEY
> +	tristate "TM2 touchkey support"
> +	depends on I2C
> +	depends on LEDS_CLASS
> +	help
> +	  Say Y here to enable device driver for tm2-touchkey with
> +	  LED control for the Exynos5433 TM2 board.
> +
> +	  To compile this driver as a module, choose M here.
> +	  module will be called tm2-touchkey.
> +
>  config KEYBOARD_TWL4030
>  	tristate "TI TWL4030/TWL5030/TPS659x0 keypad support"
>  	depends on TWL4030_CORE
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index d9f4cfcf3410..7d9acff819a7 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -61,6 +61,7 @@ obj-$(CONFIG_KEYBOARD_SUN4I_LRADC)	+= sun4i-lradc-keys.o
>  obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
>  obj-$(CONFIG_KEYBOARD_TC3589X)		+= tc3589x-keypad.o
>  obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
> +obj-$(CONFIG_KEYBOARD_TM2_TOUCHKEY)	+= tm2-touchkey.o
>  obj-$(CONFIG_KEYBOARD_TWL4030)		+= twl4030_keypad.o
>  obj-$(CONFIG_KEYBOARD_XTKBD)		+= xtkbd.o
>  obj-$(CONFIG_KEYBOARD_W90P910)		+= w90p910_keypad.o
> diff --git a/drivers/input/keyboard/tm2-touchkey.c b/drivers/input/keyboard/tm2-touchkey.c
> new file mode 100644
> index 000000000000..79bc2d2bd4b9
> --- /dev/null
> +++ b/drivers/input/keyboard/tm2-touchkey.c
> @@ -0,0 +1,286 @@
> +/*
> + * TM2 touchkey device driver
> + *
> + * Copyright 2005 Phil Blundell
> + * Copyright 2016 Samsung Electronics Co., Ltd.
> + *
> + * Author: Beomho Seo <beomho.seo@samsung.com>
> + * Author: Jaechul Lee <jcsing.lee@samsung.com>
> + *
> + * 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/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/i2c.h>
> +#include <linux/input.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/pm.h>
> +#include <linux/regulator/consumer.h>
> +
> +#define TM2_TOUCHKEY_DEV_NAME		"tm2-touchkey"
> +#define TM2_TOUCHKEY_KEYCODE_REG	0x03
> +#define TM2_TOUCHKEY_BASE_REG		0x00
> +#define TM2_TOUCHKEY_CMD_LED_ON		0x10
> +#define TM2_TOUCHKEY_CMD_LED_OFF	0x20
> +#define TM2_TOUCHKEY_BIT_PRESS_EV	BIT(3)
> +#define TM2_TOUCHKEY_BIT_KEYCODE	GENMASK(2, 0)
> +#define TM2_TOUCHKEY_LED_VOLTAGE_MIN	2500000
> +#define TM2_TOUCHKEY_LED_VOLTAGE_MAX	3300000
> +
> +enum {
> +	TM2_TOUCHKEY_KEY_MENU = 0x1,
> +	TM2_TOUCHKEY_KEY_BACK,
> +};
> +
> +struct tm2_touchkey_data {
> +	struct i2c_client *client;
> +	struct input_dev *input_dev;
> +	struct led_classdev led_dev;
> +	struct regulator *vdd;
> +	struct regulator_bulk_data regulators[2];
> +};
> +
> +static void tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
> +					    enum led_brightness brightness)
> +{
> +	struct tm2_touchkey_data *touchkey =
> +		container_of(led_dev, struct tm2_touchkey_data, led_dev);
> +	u32 volt;
> +	u8 data;
> +
> +	if (brightness == LED_OFF) {
> +		volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
> +		data = TM2_TOUCHKEY_CMD_LED_OFF;
> +	} else {
> +		volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
> +		data = TM2_TOUCHKEY_CMD_LED_ON;
> +	}
> +
> +	regulator_set_voltage(touchkey->vdd, volt, volt);
> +	i2c_smbus_write_byte_data(touchkey->client,
> +				  TM2_TOUCHKEY_BASE_REG, data);
> +}
> +
> +static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
> +{
> +	int error;
> +
> +	error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
> +				      touchkey->regulators);
> +	if (error)
> +		return error;
> +
> +	/* waiting for device initialization, at least 150ms */
> +	msleep(150);
> +
> +	return 0;
> +}
> +
> +static void tm2_touchkey_power_disable(void *data)
> +{
> +	struct tm2_touchkey_data *touchkey = data;
> +
> +	regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
> +			       touchkey->regulators);
> +}
> +
> +static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
> +{
> +	struct tm2_touchkey_data *touchkey = devid;
> +	int data;
> +	int key;
> +
> +	data = i2c_smbus_read_byte_data(touchkey->client,
> +					TM2_TOUCHKEY_KEYCODE_REG);
> +	if (data < 0) {
> +		dev_err(&touchkey->client->dev,
> +			"failed to read i2c data: %d\n", data);
> +		goto out;
> +	}
> +
> +	switch (data & TM2_TOUCHKEY_BIT_KEYCODE) {
> +	case TM2_TOUCHKEY_KEY_MENU:
> +		key = KEY_PHONE;
> +		break;
> +
> +	case TM2_TOUCHKEY_KEY_BACK:
> +		key = KEY_BACK;
> +		break;
> +
> +	default:
> +		dev_warn(&touchkey->client->dev,
> +			 "unhandled keycode, data %#02x\n", data);
> +		goto out;
> +	}
> +
> +	if (data & TM2_TOUCHKEY_BIT_PRESS_EV) {
> +		input_report_key(touchkey->input_dev, key, 1);
> +	} else {
> +		input_report_key(touchkey->input_dev, KEY_PHONE, 0);
> +		input_report_key(touchkey->input_dev, KEY_BACK, 0);
> +	}
> +
> +	input_sync(touchkey->input_dev);
> +
> +out:
> +	return IRQ_HANDLED;
> +}
> +
> +static int tm2_touchkey_probe(struct i2c_client *client,
> +			      const struct i2c_device_id *id)
> +{
> +	struct tm2_touchkey_data *touchkey;
> +	int error;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +			I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) {
> +		dev_err(&client->dev, "incompatible I2C adapter\n");
> +		return -EIO;
> +	}
> +
> +	touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
> +	if (!touchkey)
> +		return -ENOMEM;
> +
> +	touchkey->client = client;
> +	i2c_set_clientdata(client, touchkey);
> +
> +	touchkey->regulators[0].supply = "vcc";
> +	touchkey->regulators[1].supply = "vdd";
> +	error = devm_regulator_bulk_get(&client->dev,
> +					ARRAY_SIZE(touchkey->regulators),
> +					touchkey->regulators);
> +	if (error) {
> +		dev_err(&client->dev, "failed to get regulators: %d\n", error);
> +		return error;
> +	}
> +
> +	/* Save VDD for easy access */
> +	touchkey->vdd = touchkey->regulators[1].consumer;
> +
> +	error = tm2_touchkey_power_enable(touchkey);
> +	if (error) {
> +		dev_err(&client->dev, "failed to power up device: %d\n", error);
> +		return error;
> +	}
> +
> +	error = devm_add_action_or_reset(&client->dev,
> +					 tm2_touchkey_power_disable, touchkey);
> +	if (error) {
> +		dev_err(&client->dev,
> +			"failed to install poweroff handler: %d\n", error);
> +		return error;
> +	}
> +
> +	/* input device */
> +	touchkey->input_dev = devm_input_allocate_device(&client->dev);
> +	if (!touchkey->input_dev) {
> +		dev_err(&client->dev, "failed to allocate input device\n");
> +		return -ENOMEM;
> +	}
> +
> +	touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
> +	touchkey->input_dev->id.bustype = BUS_I2C;
> +
> +	input_set_capability(touchkey->input_dev, EV_KEY, KEY_PHONE);
> +	input_set_capability(touchkey->input_dev, EV_KEY, KEY_BACK);
> +
> +	input_set_drvdata(touchkey->input_dev, touchkey);
> +
> +	error = input_register_device(touchkey->input_dev);
> +	if (error) {
> +		dev_err(&client->dev,
> +			"failed to register input device: %d\n", error);
> +		return error;
> +	}
> +
> +	error = devm_request_threaded_irq(&client->dev, client->irq,
> +					  NULL, tm2_touchkey_irq_handler,
> +					  IRQF_ONESHOT,
> +					  TM2_TOUCHKEY_DEV_NAME, touchkey);
> +	if (error) {
> +		dev_err(&client->dev,
> +			"failed to request threaded irq: %d\n", error);
> +		return error;
> +	}
> +
> +	/* led device */
> +	touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
> +	touchkey->led_dev.brightness = LED_FULL;
> +	touchkey->led_dev.max_brightness = LED_FULL;
> +	touchkey->led_dev.brightness_set = tm2_touchkey_led_brightness_set;
> +
> +	error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
> +	if (error) {
> +		dev_err(&client->dev,
> +			"failed to register touchkey led: %d\n", error);
> +		return error;
> +	}
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
> +
> +	disable_irq(client->irq);
> +	tm2_touchkey_power_disable(touchkey);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused tm2_touchkey_resume(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
> +	int ret;
> +
> +	enable_irq(client->irq);
> +
> +	ret = tm2_touchkey_power_enable(touchkey);
> +	if (ret)
> +		dev_err(dev, "failed to enable power: %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops,
> +			 tm2_touchkey_suspend, tm2_touchkey_resume);
> +
> +static const struct i2c_device_id tm2_touchkey_id_table[] = {
> +	{ TM2_TOUCHKEY_DEV_NAME, 0 },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
> +
> +static const struct of_device_id tm2_touchkey_of_match[] = {
> +	{ .compatible = "cypress,tm2-touchkey", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
> +
> +static struct i2c_driver tm2_touchkey_driver = {
> +	.driver = {
> +		.name = TM2_TOUCHKEY_DEV_NAME,
> +		.pm = &tm2_touchkey_pm_ops,
> +		.of_match_table = of_match_ptr(tm2_touchkey_of_match),
> +	},
> +	.probe = tm2_touchkey_probe,
> +	.id_table = tm2_touchkey_id_table,
> +};
> +module_i2c_driver(tm2_touchkey_driver);
> +
> +MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
> +MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
> +MODULE_DESCRIPTION("Samsung touchkey driver");
> +MODULE_LICENSE("GPL v2");
> --
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