Input: atmel_mxt_ts - add support for reset line

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 <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Sebastian Reichel 2017-07-25 14:11:34 -07:00 committed by Dmitry Torokhov
parent 8cc8446b9b
commit f657b00df2
2 changed files with 24 additions and 0 deletions

View File

@ -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 {

View File

@ -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);