Input: tsc2007 - make sure that X plate resistance is specified

Abort driver initialization if X plate resistance was not specified in
platform data as it will cause pressure to be always calculated as 0,
and making userspace ignore touch coordinates.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

2 files changed, 7 insertions, 1 deletions

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index 0acca68cc52b..1f674cb6c55b 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -310,6 +310,12 @@ static int __devinit tsc2007_probe(struct i2c_client *client,
         ts->get_pendown_state = pdata->get_pendown_state;
         ts->clear_penirq      = pdata->clear_penirq;
 
+        if (pdata->x_plate_ohms == 0) {
+                dev_err(&client->dev, "x_plate_ohms is not set up in platform data");
+                err = -EINVAL;
+                goto err_free_mem;
+        }
+
         snprintf(ts->phys, sizeof(ts->phys),
                  "%s/input0", dev_name(&client->dev));
 
diff --git a/include/linux/i2c/tsc2007.h b/include/linux/i2c/tsc2007.h
index 591427a63b06..506a9f7af51e 100644
--- a/include/linux/i2c/tsc2007.h
+++ b/include/linux/i2c/tsc2007.h
@@ -5,7 +5,7 @@
 
 struct tsc2007_platform_data {
         u16     model;                          /* 2007. */
-        u16     x_plate_ohms;
+        u16     x_plate_ohms;   /* must be non-zero value */
         u16     max_rt; /* max. resistance above which samples are ignored */
         unsigned long poll_delay; /* delay (in ms) after pen-down event
                                      before polling starts */