Re: [PATCH v5 4/5] input: tm2-touchkey: Add touchkey driver support for TM2

From: Chanwoo Choi
Date: Fri Jan 06 2017 - 17:14:07 EST


Hi,

I have a question. In this patch, the compatible name includes the
specific h/w board name(TM2). Usually, when developing the device
driver, we prefer to use the original h/w name of each device.
- "samsung,tm2-touchkey"

If this touchkey device is used on other h/w board, you should add new
compatible name.
Why don't you use the original device name?

And I have a minor comment.

2017-01-06 22:43 GMT+09:00 Andi Shyti <andi.shyti@xxxxxxxxxxx>:
> From: Jaechul Lee <jcsing.lee@xxxxxxxxxxx>
>
> 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@xxxxxxxxxxx>
> Signed-off-by: Jaechul Lee <jcsing.lee@xxxxxxxxxxx>
> Reviewed-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>
> Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxx>
> Acked-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxx>
> ---
> drivers/input/keyboard/Kconfig | 11 ++
> drivers/input/keyboard/Makefile | 1 +
> drivers/input/keyboard/tm2-touchkey.c | 280 ++++++++++++++++++++++++++++++++++
> 3 files changed, 292 insertions(+)
> create mode 100644 drivers/input/keyboard/tm2-touchkey.c
>
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index cbd75cf44739..e6e98585b4b0 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..92eacb62f8e7
> --- /dev/null
> +++ b/drivers/input/keyboard/tm2-touchkey.c
> @@ -0,0 +1,280 @@
> +/*
> + * TM2 touchkey device driver
> + *
> + * Copyright 2005 Phil Blundell
> + * Copyright 2016 Samsung Electronics Co., Ltd.
> + *
> + * Author: Beomho Seo <beomho.seo@xxxxxxxxxxx>
> + * Author: Jaechul Lee <jcsing.lee@xxxxxxxxxxx>
> + *
> + * 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_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[1].consumer, volt, volt);

I don't force the modification. It is minor comment.
In the case, when handling the regulator, you better to use the
definition because the integer index is difficult to understand what
does this mean.

> + 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[0].supply = "vcc";
> + touchkey->regulators[1].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 = "samsung,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@xxxxxxxxxxx>");
> +MODULE_AUTHOR("Jaechul Lee <jcsing.lee@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Samsung touchkey driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.11.0
>
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--
Best Regards,
Chanwoo Choi