Hi Stefan,
On Wed, Apr 17, 2024 at 11:05:24AM +0200, Stefan Eichenberger wrote:
> From: Stefan Eichenberger <stefan.eichenberger@xxxxxxxxxxx>
>
> Add a separate function for power off and power on instead of calling
> regulator_bulk_enable and regulator_bulk_disable directly.
>
> Signed-off-by: Stefan Eichenberger <stefan.eichenberger@xxxxxxxxxxx>
> ---
> drivers/input/touchscreen/atmel_mxt_ts.c | 59 +++++++++++++++---------
> 1 file changed, 37 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
> index 542a31448c8f..52867ce3b9b6 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -1307,6 +1307,38 @@ static int mxt_soft_reset(struct mxt_data *data)
> return 0;
> }
>
> +static int mxt_power_on(struct mxt_data *data)
> +{
> + int error;
> +
> + error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
> + data->regulators);
> + if (error) {
> + dev_err(&data->client->dev, "failed to enable regulators: %d\n",
> + error);
> + return error;
> + }
> +
> + msleep(MXT_BACKUP_TIME);
> +
> + if (data->reset_gpio) {
> + /* Wait a while and then de-assert the RESET GPIO line */
> + msleep(MXT_RESET_GPIO_TIME);
> + gpiod_set_value(data->reset_gpio, 0);
> + msleep(MXT_RESET_INVALID_CHG);
> + }
> +
> + return 0;
> +}
> +
> +static void mxt_power_off(struct mxt_data *data)
> +{
> + if (data->reset_gpio)
> + gpiod_set_value(data->reset_gpio, 1);
> +
> + regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
> +}
> +
> static void mxt_update_crc(struct mxt_data *data, u8 cmd, u8 value)
> {
> /*
> @@ -3305,25 +3337,9 @@ static int mxt_probe(struct i2c_client *client)
> return error;
> }
>
> - error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
> - data->regulators);
> - if (error) {
> - dev_err(&client->dev, "failed to enable regulators: %d\n",
> - error);
> + error = mxt_power_on(data);
> + if (error)
> return error;
> - }
> - /*
> - * The device takes 40ms to come up after power-on according
> - * to the mXT224 datasheet, page 13.
> - */
> - msleep(MXT_BACKUP_TIME);
> -
> - if (data->reset_gpio) {
> - /* Wait a while and then de-assert the RESET GPIO line */
> - msleep(MXT_RESET_GPIO_TIME);
> - gpiod_set_value(data->reset_gpio, 0);
> - msleep(MXT_RESET_INVALID_CHG);
> - }
>
> /*
> * Controllers like mXT1386 have a dedicated WAKE line that could be
> @@ -3361,8 +3377,8 @@ static int mxt_probe(struct i2c_client *client)
> mxt_free_input_device(data);
> mxt_free_object_table(data);
> err_disable_regulators:
> - regulator_bulk_disable(ARRAY_SIZE(data->regulators),
> - data->regulators);
> + mxt_power_off(data);
> +
> return error;
> }
>
> @@ -3374,8 +3390,7 @@ static void mxt_remove(struct i2c_client *client)
> sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
> mxt_free_input_device(data);
> mxt_free_object_table(data);
> - regulator_bulk_disable(ARRAY_SIZE(data->regulators),
> - data->regulators);
> + mxt_power_off(data);
This change means that on unbind we will leave with GPIO line asserted.
Won't this potentially cause some current leakage? Why do we need to
have reset asserted here?
Thanks.
--
Dmitry
