Message-ID: <20150609181556.GK6338@dtor-ws>
Date:	Tue, 9 Jun 2015 11:15:56 -0700
From:	Dmitry Torokhov <dmitry.torokhov@...il.com>
To:	Irina Tirdea <irina.tirdea@...el.com>
Cc:	Bastien Nocera <hadess@...ess.net>,
	Mark Rutland <mark.rutland@....com>,
	linux-input@...r.kernel.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Octavian Purdila <octavian.purdila@...el.com>
Subject: Re: [PATCH v2 6/8] input: goodix: add power management support

On Mon, Jun 08, 2015 at 05:37:51PM +0300, Irina Tirdea wrote:
> Implement suspend/resume for goodix driver.
> 
> This is based on Goodix datasheets for GT911 and GT9271
> and on Goodix driver gt9xx.c for Android (publicly available
> in Android kernel trees for various devices).
> 
> Signed-off-by: Octavian Purdila <octavian.purdila@...el.com>
> Signed-off-by: Irina Tirdea <irina.tirdea@...el.com>
> ---
>  drivers/input/touchscreen/goodix.c | 88 +++++++++++++++++++++++++++++++++++---
>  1 file changed, 83 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
> index 1ce9278..903c83d 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -38,6 +38,7 @@ struct goodix_ts_data {
>  	unsigned int int_trigger_type;
>  	struct gpio_desc *gpiod_int;
>  	struct gpio_desc *gpiod_rst;
> +	unsigned long irq_flags;
>  };
>  
>  #define GOODIX_GPIO_INT_NAME		"irq"
> @@ -52,6 +53,9 @@ struct goodix_ts_data {
>  #define GOODIX_CONFIG_MAX_LENGTH	240
>  
>  /* Register defines */
> +#define GOODIX_REG_COMMAND		0x8040
> +#define GOODIX_CMD_SCREEN_OFF		0x05
> +
>  #define GOODIX_READ_COOR_ADDR		0x814E
>  #define GOODIX_REG_CONFIG_DATA		0x8047
>  #define GOODIX_REG_ID			0x8140
> @@ -129,6 +133,11 @@ static int goodix_i2c_write(struct i2c_client *client, u16 reg, const u8 *buf,
>  	return ret < 0 ? ret : (ret != 1 ? -EIO : 0);
>  }
>  
> +static int goodix_i2c_write_u8(struct i2c_client *client, u16 reg, u8 value)
> +{
> +	return goodix_i2c_write(client, reg, &value, sizeof(value));
> +}
> +
>  static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
>  {
>  	int touch_num;
> @@ -226,6 +235,18 @@ static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id)
>  	return IRQ_HANDLED;
>  }
>  
> +static void goodix_free_irq(struct goodix_ts_data *ts)
> +{
> +	devm_free_irq(&ts->client->dev, ts->client->irq, ts);
> +}
> +
> +static int goodix_request_irq(struct goodix_ts_data *ts)
> +{
> +	return devm_request_threaded_irq(&ts->client->dev, ts->client->irq,
> +					 NULL, goodix_ts_irq_handler,
> +					 ts->irq_flags, ts->client->name, ts);
> +}
> +
>  /**
>   * goodix_check_cfg - Checks if config buffer is valid
>   *
> @@ -547,7 +568,6 @@ static int goodix_ts_probe(struct i2c_client *client,
>  			   const struct i2c_device_id *id)
>  {
>  	struct goodix_ts_data *ts;
> -	unsigned long irq_flags;
>  	int error;
>  	u16 version_info, id_info;
>  
> @@ -599,10 +619,8 @@ static int goodix_ts_probe(struct i2c_client *client,
>  	if (error)
>  		return error;
>  
> -	irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
> -	error = devm_request_threaded_irq(&ts->client->dev, client->irq,
> -					  NULL, goodix_ts_irq_handler,
> -					  irq_flags, client->name, ts);
> +	ts->irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
> +	error = goodix_request_irq(ts);
>  	if (error) {
>  		dev_err(&client->dev, "request IRQ failed: %d\n", error);
>  		return error;
> @@ -611,6 +629,65 @@ static int goodix_ts_probe(struct i2c_client *client,
>  	return 0;
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int goodix_suspend(struct device *dev)

Please drop #ifdef CONFIG_PM_SLEEP and annotate with __maybe_unused
instead.

> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct goodix_ts_data *ts = i2c_get_clientdata(client);
> +	int ret;
> +
> +	goodix_free_irq(ts);

Why do we need to free IRQ here?

> +	/* Output LOW on the INT pin for 5 ms */
> +	ret = gpiod_direction_output(ts->gpiod_int, 0);
> +	if (ret) {
> +		goodix_request_irq(ts);
> +		return ret;
> +	}
> +	usleep_range(5000, 6000);
> +
> +	ret = goodix_i2c_write_u8(ts->client, GOODIX_REG_COMMAND,
> +				  GOODIX_CMD_SCREEN_OFF);
> +	if (ret) {
> +		dev_err(&ts->client->dev, "Screen off command failed\n");
> +		gpiod_direction_input(ts->gpiod_int);
> +		goodix_request_irq(ts);
> +		return -EAGAIN;
> +	}
> +
> +	/*
> +	 * The datasheet specifies that the interval between sending screen-off
> +	 * command and wake-up should be longer than 58 ms. To avoid waking up
> +	 * sooner, delay 58ms here.
> +	 */
> +	msleep(58);
> +	return 0;
> +}
> +
> +static int goodix_resume(struct device *dev)

__maybe_unused

> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct goodix_ts_data *ts = i2c_get_clientdata(client);
> +	int ret;
> +
> +	/*
> +	 * Exit sleep mode by outputting HIGH level to INT pin
> +	 * for 2ms~5ms.
> +	 */
> +	ret = gpiod_direction_output(ts->gpiod_int, 1);
> +	if (ret)
> +		return ret;
> +	usleep_range(2000, 5000);
> +
> +	ret = goodix_int_sync(ts);
> +	if (ret)
> +		return ret;
> +
> +	return goodix_request_irq(ts);
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(goodix_pm_ops, goodix_suspend, goodix_resume);
> +
>  static const struct i2c_device_id goodix_ts_id[] = {
>  	{ "GDIX1001:00", 0 },
>  	{ }
> @@ -646,6 +723,7 @@ static struct i2c_driver goodix_ts_driver = {
>  		.owner = THIS_MODULE,
>  		.acpi_match_table = ACPI_PTR(goodix_acpi_match),
>  		.of_match_table = of_match_ptr(goodix_of_match),
> +		.pm = &goodix_pm_ops,
>  	},
>  };
>  module_i2c_driver(goodix_ts_driver);
> -- 
> 1.9.1
> 

Thanks.

-- 
Dmitry
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