Input: exc3000 - add reset gpio support

Add basic support for an optional reset gpio.

Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200805160520.456570-4-sebastian.reichel@collabora.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/Documentation/devicetree/bindings/input/touchscreen/eeti,exc3000.yaml b/Documentation/devicetree/bindings/input/touchscreen/eeti,exc3000.yaml
index 7e6e23f..007adbc 100644 (file)
--- a/Documentation/devicetree/bindings/input/touchscreen/eeti,exc3000.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/eeti,exc3000.yaml
@@ -22,6 +22,8 @@ properties:
     const: 0x2a
   interrupts:
     maxItems: 1
+  reset-gpios:
+    maxItems: 1
   touchscreen-size-x: true
   touchscreen-size-y: true
   touchscreen-inverted-x: true

diff --git a/drivers/input/touchscreen/exc3000.c b/drivers/input/touchscreen/exc3000.c
index b497bd2..203f50a 100644 (file)
--- a/drivers/input/touchscreen/exc3000.c
+++ b/drivers/input/touchscreen/exc3000.c
@@ -8,7 +8,9 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
 #include <linux/input/mt.h>
@@ -30,6 +32,9 @@
 
 #define EXC3000_TIMEOUT_MS             100
 
+#define EXC3000_RESET_MS               10
+#define EXC3000_READY_MS               100
+
 static const struct i2c_device_id exc3000_id[];
 
 struct eeti_dev_info {
@@ -63,6 +68,7 @@ struct exc3000_data {
        const struct eeti_dev_info *info;
        struct input_dev *input;
        struct touchscreen_properties prop;
+       struct gpio_desc *reset;
        struct timer_list timer;
        u8 buf[2 * EXC3000_LEN_FRAME];
 };
@@ -204,6 +210,17 @@ static int exc3000_probe(struct i2c_client *client)
        }
        timer_setup(&data->timer, exc3000_timer, 0);
 
+       data->reset = devm_gpiod_get_optional(&client->dev, "reset",
+                                             GPIOD_OUT_HIGH);
+       if (IS_ERR(data->reset))
+               return PTR_ERR(data->reset);
+
+       if (data->reset) {
+               msleep(EXC3000_RESET_MS);
+               gpiod_set_value_cansleep(data->reset, 0);
+               msleep(EXC3000_READY_MS);
+       }
+
        input = devm_input_allocate_device(&client->dev);
        if (!input)
                return -ENOMEM;