HI, On 16-11-16 18:51, Dmitry Torokhov wrote:
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)?
We already put the device in low-power mode using the power pin. Of the 20 or so different tablets I've with this touchscreen controller only 2 actually have a separate regulator for the controller, so I do not believe that powering down the regulator will be a big win, otherwise all tablets would have had this. > Does it take too long? It is a couple of kB written one 32-bit word at a time over i2c, so it's not fast. Regards, Hans
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
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