On Wed, Nov 16, 2016 at 12:55:07PM +0100, Hans de Goede wrote:
> On some tablets the touchscreen controller is powered by separate
> regulators, add support for this.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> Changes in v2:
> -Use devm_regulator_bulk_get() and friends
> -Use devm_add_action_or_reset() to disable the regulator
> ---
> .../bindings/input/touchscreen/silead_gsl1680.txt | 2 ++
> drivers/input/touchscreen/silead.c | 29 ++++++++++++++++++++++
> 2 files changed, 31 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt b/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt
> index e844c3f..b726823 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt
> @@ -22,6 +22,8 @@ Optional properties:
> - touchscreen-inverted-y : See touchscreen.txt
> - touchscreen-swapped-x-y : See touchscreen.txt
> - silead,max-fingers : maximum number of fingers the touchscreen can detect
> +- vddio-supply : regulator phandle for controller VDDIO
> +- avdd-supply : regulator phandle for controller AVDD
>
> Example:
>
> diff --git a/drivers/input/touchscreen/silead.c b/drivers/input/touchscreen/silead.c
> index f502c84..404830a 100644
> --- a/drivers/input/touchscreen/silead.c
> +++ b/drivers/input/touchscreen/silead.c
> @@ -29,6 +29,7 @@
> #include <linux/input/touchscreen.h>
> #include <linux/pm.h>
> #include <linux/irq.h>
> +#include <linux/regulator/consumer.h>
>
> #include <asm/unaligned.h>
>
> @@ -73,6 +74,7 @@ struct silead_ts_data {
> struct i2c_client *client;
> struct gpio_desc *gpio_power;
> struct input_dev *input;
> + struct regulator_bulk_data regulators[2];
> char fw_name[64];
> struct touchscreen_properties prop;
> u32 max_fingers;
> @@ -433,6 +435,13 @@ static int silead_ts_set_default_fw_name(struct silead_ts_data *data,
> }
> #endif
>
> +static void silead_disable_regulator(void *arg)
> +{
> + struct silead_ts_data *data = arg;
> +
> + regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
> +}
> +
> static int silead_ts_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> @@ -465,6 +474,26 @@ static int silead_ts_probe(struct i2c_client *client,
> if (client->irq <= 0)
> return -ENODEV;
>
> + data->regulators[0].supply = "vddio";
> + data->regulators[1].supply = "avdd";
> + error = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->regulators),
> + data->regulators);
> + if (error)
> + return error;
> +
> + /*
> + * Enable regulators at probe and disable them at remove, we need
> + * to keep the chip powered otherwise it forgets its firmware.
> + */
Hmm, this burns power though. Why can't we reload firmware on resume (it
should be already cached)? Does it take too long?
Thanks.
> + error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
> + data->regulators);
> + if (error)
> + return error;
> +
> + error = devm_add_action_or_reset(dev, silead_disable_regulator, data);
> + if (error)
> + return error;
> +
> /* Power GPIO pin */
> data->gpio_power = devm_gpiod_get_optional(dev, "power", GPIOD_OUT_LOW);
> if (IS_ERR(data->gpio_power)) {
> --
> 2.9.3
>
--
Dmitry
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