Re: [PATCH v2 6/8] input: goodix: add power management support

Dmitry Torokhov
2015-06-09T18:16:12Z

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@intel.com>
> Signed-off-by: Irina Tirdea <irina.tirdea@intel.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