Input: ar1021_i2c - enable touch mode during open

The device could as well be in command mode, in which this driver cannot
handle the device. When opening the device, let's make sure the device
will be in the mode we expect it to be for this driver.

Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/ar1021_i2c.c b/drivers/input/touchscreen/ar1021_i2c.c
index 1a94d8bfec54..21c74ee59341 100644
--- a/drivers/input/touchscreen/ar1021_i2c.c
+++ b/drivers/input/touchscreen/ar1021_i2c.c
@@ -18,6 +18,10 @@
 #define AR1021_MAX_X    4095
 #define AR1021_MAX_Y    4095
 
+#define AR1021_CMD      0x55
+
+#define AR1021_CMD_ENABLE_TOUCH         0x12
+
 struct ar1021_i2c {
         struct i2c_client *client;
         struct input_dev *input;
@@ -56,8 +60,19 @@ out:
 
 static int ar1021_i2c_open(struct input_dev *dev)
 {
+        static const u8 cmd_enable_touch[] = {
+                AR1021_CMD,
+                0x01, /* number of bytes after this */
+                AR1021_CMD_ENABLE_TOUCH
+        };
         struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
         struct i2c_client *client = ar1021->client;
+        int error;
+
+        error = i2c_master_send(ar1021->client, cmd_enable_touch,
+                                sizeof(cmd_enable_touch));
+        if (error < 0)
+                return error;
 
         enable_irq(client->irq);