Provide support for controlling reset pin. If this is not driven correctly the device will be held in reset and will not respond.
Acked-by: Rob Herring <[email protected]> Signed-off-by: Sebastian Reichel <[email protected]> --- .../devicetree/bindings/input/atmel,maxtouch.txt | 2 ++ drivers/input/touchscreen/atmel_mxt_ts.c | 22 ++++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/Documentation/devicetree/bindings/input/atmel,maxtouch.txt b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt index 1852906517ab..23e3abc3fdef 100644 --- a/Documentation/devicetree/bindings/input/atmel,maxtouch.txt +++ b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt @@ -22,6 +22,8 @@ Optional properties for main touchpad device: experiment to determine which bit corresponds to which input. Use KEY_RESERVED for unused padding values. +- reset-gpios: GPIO specifier for the touchscreen's reset pin (active low) + Example: touch@4b { diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c index 9a7b8eba64a6..599f92363188 100644 --- a/drivers/input/touchscreen/atmel_mxt_ts.c +++ b/drivers/input/touchscreen/atmel_mxt_ts.c @@ -28,6 +28,7 @@ #include <linux/interrupt.h> #include <linux/of.h> #include <linux/slab.h> +#include <linux/gpio/consumer.h> #include <asm/unaligned.h> #include <media/v4l2-device.h> #include <media/v4l2-ioctl.h> @@ -300,6 +301,7 @@ struct mxt_data { u8 multitouch; struct t7_config t7_cfg; struct mxt_dbg dbg; + struct gpio_desc *reset_gpio; /* Cached parameters from object table */ u16 T5_address; @@ -3133,6 +3135,14 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id) init_completion(&data->reset_completion); init_completion(&data->crc_completion); + data->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", + GPIOD_OUT_LOW); + if (IS_ERR(data->reset_gpio)) { + error = PTR_ERR(data->reset_gpio); + dev_err(&client->dev, "Failed to get reset gpio: %d\n", error); + return error; + } + error = devm_request_threaded_irq(&client->dev, client->irq, NULL, mxt_interrupt, pdata->irqflags | IRQF_ONESHOT, @@ -3142,6 +3152,18 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id) return error; } + if (data->reset_gpio) { + data->in_bootloader = true; + msleep(MXT_RESET_TIME); + reinit_completion(&data->bl_completion); + gpiod_set_value(data->reset_gpio, 1); + error = mxt_wait_for_completion(data, &data->bl_completion, + MXT_RESET_TIMEOUT); + if (error) + return error; + data->in_bootloader = false; + } + disable_irq(client->irq); error = mxt_initialize(data); -- 2.13.2
