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>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index aeb46522073a..7659bc48f1db 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);