Re: [PATCH 7/9] input: goodix: add power management support

Bastien Nocera
2015-06-04T13:01:27Z

On Thu, 2015-05-28 at 15:47 +0300, Irina Tirdea wrote:
> Implement suspend/resume for goodix driver.
>
> Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
> Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
> ---
> drivers/input/touchscreen/goodix.c | 81
> +++++++++++++++++++++++++++++++++++---
> 1 file changed, 76 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/input/touchscreen/goodix.c
> b/drivers/input/touchscreen/goodix.c
> index 22052c9..ce7e834 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -37,6 +37,7 @@ 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, 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;
> @@ -227,6 +236,18 @@ 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_get_cfg - Get device config from ACPI/DT.
> *
> @@ -562,7 +583,6 @@ 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;
>
> @@ -614,10 +634,8 @@ 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;
> @@ -626,6 +644,58 @@ static int goodix_ts_probe(struct i2c_client
> *client,
> return 0;
> }
>
> +#ifdef CONFIG_PM_SLEEP
> +static int goodix_suspend(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct goodix_ts_data *ts = i2c_get_clientdata(client);
> + int ret;
> +
> + goodix_free_irq(ts);
> + ret = gpiod_direction_output(ts->gpiod_int, 0);
> + if (ret) {
> + goodix_request_irq(ts);
> + return ret;
> + }
> + usleep_range(5000, 6000);

I'd appreciate some references and explanations for those magic
numbers.

> +
> + 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;
> + }
> +
> + /*
> + * To avoid waking up while is not sleeping,

You're missing a subject in that sentence.

> + * delay 58ms to ensure reliability
> + */
> + msleep(58);

Why 58ms?

> + return 0;
> +}
> +
> +static int goodix_resume(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct goodix_ts_data *ts = i2c_get_clientdata(client);
> + int ret;
> +
> + ret = gpiod_direction_output(ts->gpiod_int, 1);
> + if (ret)
> + return ret;
> + usleep_range(2000, 5000); /* 2ms~5ms */

Good comment, just missing a reference (anything that could help find
that information in the datasheets would be good).

> + 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 },
> { }
> @@ -663,6 +733,7 @@ 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);