Hi Alistair,
On Thu, Mar 25, 2021 at 09:52:27PM -0400, Alistair Francis wrote:
> From: Alistair Francis <alistair@xxxxxxxxxxxxx>
>
> Signed-off-by: Alistair Francis <alistair@xxxxxxxxxxxxx>
> ---
> v4:
> - Initial commit
>
> drivers/input/touchscreen/wacom_i2c.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
> index 84c7ccb737bd..28004b1180c9 100644
> --- a/drivers/input/touchscreen/wacom_i2c.c
> +++ b/drivers/input/touchscreen/wacom_i2c.c
> @@ -55,6 +55,7 @@ struct wacom_features {
> struct wacom_i2c {
> struct i2c_client *client;
> struct input_dev *input;
> + struct reset_control *rstc;
> struct touchscreen_properties props;
> u8 data[WACOM_QUERY_SIZE];
> bool prox;
> @@ -175,6 +176,8 @@ static int wacom_i2c_open(struct input_dev *dev)
> struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
> struct i2c_client *client = wac_i2c->client;
>
> + reset_control_reset(wac_i2c->rstc);
Why does this device need to be reset on every open compared to doing it
in probe?
> +
> enable_irq(client->irq);
>
> return 0;
> @@ -193,6 +196,7 @@ static int wacom_i2c_probe(struct i2c_client *client,
> {
> struct wacom_i2c *wac_i2c;
> struct input_dev *input;
> + struct reset_control *rstc;
> struct wacom_features features = { 0 };
> int error;
>
> @@ -201,6 +205,12 @@ static int wacom_i2c_probe(struct i2c_client *client,
> return -EIO;
> }
>
> + rstc = devm_reset_control_get_optional_exclusive(&client->dev, NULL);
> + if (IS_ERR(rstc)) {
> + dev_err(&client->dev, "Failed to get reset control before init\n");
> + return PTR_ERR(rstc);
> + }
I think majority users will have this controller reset line connected to
a GPIO. I briefly looked into reset controller code and I do not see it
supporting this case. How is this device connected on your board?
> +
> error = wacom_query_device(client, &features);
> if (error)
> return error;
> @@ -214,6 +224,7 @@ static int wacom_i2c_probe(struct i2c_client *client,
>
> wac_i2c->client = client;
> wac_i2c->input = input;
> + wac_i2c->rstc = rstc;
>
> input->name = "Wacom I2C Digitizer";
> input->id.bustype = BUS_I2C;
> --
> 2.31.0
>
Thanks.
--
Dmitry
