Input: pixcir_i2c_ts - add RESET gpio

The controller has a RESET pin which is usually controlled over
a GPIO line. If such a GPIO is provided, perform a RESET
during probe.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt b/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt
index 6e551090f4653ed6a3438be90d18b4afba310f47..8eb240a287c8aec13881a395eaa25a3da06c7194 100644 (file)
--- a/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt
@@ -8,6 +8,9 @@ Required properties:
 - touchscreen-size-x: horizontal resolution of touchscreen (in pixels)
 - touchscreen-size-y: vertical resolution of touchscreen (in pixels)
 
+Optional properties:
+- reset-gpio: GPIO connected to the RESET line of the chip
+
 Example:
 
        i2c@00000000 {

diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c b/drivers/input/touchscreen/pixcir_i2c_ts.c
index 5330c044654008fd8ab6bc3af625a53cdd722877..a5a83139aad05c7cc975ea14eafd9f0f1609cddf 100644 (file)
--- a/drivers/input/touchscreen/pixcir_i2c_ts.c
+++ b/drivers/input/touchscreen/pixcir_i2c_ts.c
@@ -36,6 +36,7 @@ struct pixcir_i2c_ts_data {
        struct i2c_client *client;
        struct input_dev *input;
        struct gpio_desc *gpio_attb;
+       struct gpio_desc *gpio_reset;
        const struct pixcir_ts_platform_data *pdata;
        bool running;
        int max_fingers;        /* Max fingers supported in this instance */
@@ -189,6 +190,17 @@ static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
        return IRQ_HANDLED;
 }
 
+static void pixcir_reset(struct pixcir_i2c_ts_data *tsdata)
+{
+       if (!IS_ERR_OR_NULL(tsdata->gpio_reset)) {
+               gpiod_set_value_cansleep(tsdata->gpio_reset, 1);
+               ndelay(100);    /* datasheet section 1.2.3 says 80ns min. */
+               gpiod_set_value_cansleep(tsdata->gpio_reset, 0);
+               /* wait for controller ready. 100ms guess. */
+               msleep(100);
+       }
+}
+
 static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
                                 enum pixcir_power_mode mode)
 {
@@ -529,6 +541,14 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
                return error;
        }
 
+       tsdata->gpio_reset = devm_gpiod_get_optional(dev, "reset",
+                                                    GPIOD_OUT_LOW);
+       if (IS_ERR(tsdata->gpio_reset)) {
+               error = PTR_ERR(tsdata->gpio_reset);
+               dev_err(dev, "Failed to request RESET gpio: %d\n", error);
+               return error;
+       }
+
        error = devm_request_threaded_irq(dev, client->irq, NULL, pixcir_ts_isr,
                                          IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                                          client->name, tsdata);
@@ -537,6 +557,8 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
                return error;
        }
 
+       pixcir_reset(tsdata);
+
        /* Always be in IDLE mode to save power, device supports auto wake */
        error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
        if (error) {