On Thu, Dec 20, 2018 at 09:43:01PM +0100, Marek Vasut wrote:
> The touchscreen can have a reset GPIO connected to it, add support
> for such an arrangement.
>
> Signed-off-by: Marek Vasut <marex@xxxxxxx>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> Cc: Henrik Rydberg <rydberg@xxxxxxxxxxx>
> Cc: Olivier Sobrie <olivier@xxxxxxxxx>
> Cc: Philipp Puschmann <pp@xxxxxxxxx>
> To: linux-input@xxxxxxxxxxxxxxx
> ---
> V2: No change
> ---
> drivers/input/touchscreen/ili210x.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c
> index 04d75d4ecb20..a84ca555829e 100644
> --- a/drivers/input/touchscreen/ili210x.c
> +++ b/drivers/input/touchscreen/ili210x.c
> @@ -5,6 +5,7 @@
> #include <linux/input.h>
> #include <linux/input/mt.h>
> #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
>
> #define MAX_TOUCHES 2
> #define DEFAULT_POLL_PERIOD 20
> @@ -44,6 +45,7 @@ struct ili210x {
> struct input_dev *input;
> unsigned int poll_period;
> struct delayed_work dwork;
> + struct gpio_desc *reset_gpio;
> };
>
> static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
> @@ -172,6 +174,7 @@ static int ili210x_i2c_probe(struct i2c_client *client,
> {
> struct device *dev = &client->dev;
> struct ili210x *priv;
> + struct gpio_desc *reset_gpio;
> struct input_dev *input;
> struct panel_info panel;
> struct firmware_version firmware;
> @@ -185,6 +188,17 @@ static int ili210x_i2c_probe(struct i2c_client *client,
> return -EINVAL;
> }
>
> + reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> + if (IS_ERR(reset_gpio))
> + return PTR_ERR(reset_gpio);
> +
> + if (reset_gpio) {
> + gpiod_set_value_cansleep(reset_gpio, 1);
> + usleep_range(50, 100);
> + gpiod_set_value_cansleep(reset_gpio, 0);
> + mdelay(100);
> + }
> +
> /* Get firmware version */
> error = ili210x_read_reg(client, REG_FIRMWARE_VERSION,
> &firmware, sizeof(firmware));
> @@ -214,6 +228,7 @@ static int ili210x_i2c_probe(struct i2c_client *client,
> priv->input = input;
> priv->poll_period = DEFAULT_POLL_PERIOD;
> INIT_DELAYED_WORK(&priv->dwork, ili210x_work);
> + priv->reset_gpio = reset_gpio;
>
> /* Setup input device */
> input->name = "ILI210x Touchscreen";
> @@ -277,6 +292,8 @@ static int ili210x_i2c_remove(struct i2c_client *client)
> sysfs_remove_group(&client->dev.kobj, &ili210x_attr_group);
> cancel_delayed_work_sync(&priv->dwork);
> input_unregister_device(priv->input);
> + if (priv->reset_gpio)
> + gpiod_set_value_cansleep(priv->reset_gpio, 1);
Can you install this as devm action (devm_add_action_or_reset())? Then
it will play well with other devm interfaces instead of resetting chip
out of order (for example, devm-managed ISR may fire up and run with
chip in reset).
Thanks.
--
Dmitry
