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

From: [email-masked] (Dmitry Torokhov)
Date: Sat, 14 Jan 2017 23:11:10 -0800

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 <[email-masked]>

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 <[email-masked]>
Signed-off-by: Jaechul Lee <[email-masked]>
Reviewed-by: Javier Martinez Canillas <[email-masked]>
Reviewed-by: Andi Shyti <[email-masked]>
Acked-by: Krzysztof Kozlowski <[email-masked]>
Patchwork-Id: 9504149
Signed-off-by: Dmitry Torokhov <[email-masked]>
---
 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 <[email-masked]>
+ * Author: Jaechul Lee <[email-masked]>
+ *
+ * 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 <[email-masked]>");
+MODULE_AUTHOR("Jaechul Lee <[email-masked]>");
+MODULE_DESCRIPTION("Samsung touchkey driver");
+MODULE_LICENSE("GPL v2");