[media] gspca/sn9c20x: Test if sensor is a OV sensor

Instead of just assuming a ov9650 sensor based on USB ID,
double-check it, by reading the sensor ID.

Acked-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/media/video/gspca/sn9c20x.c b/drivers/media/video/gspca/sn9c20x.c
index 6b155ae3a746..1e0f219188ac 100644
--- a/drivers/media/video/gspca/sn9c20x.c
+++ b/drivers/media/video/gspca/sn9c20x.c
@@ -1224,8 +1224,17 @@ static int i2c_r2(struct gspca_dev *gspca_dev, u8 reg, u16 *val)
 static int ov9650_init_sensor(struct gspca_dev *gspca_dev)
 {
         int i;
+        u16 id;
         struct sd *sd = (struct sd *) gspca_dev;
 
+        if (i2c_r2(gspca_dev, 0x1c, &id) < 0)
+                return -EINVAL;
+
+        if (id != 0x7fa2) {
+                err("sensor id for ov9650 doesn't match (0x%04x)", id);
+                return -ENODEV;
+        }
+
         for (i = 0; i < ARRAY_SIZE(ov9650_init); i++) {
                 if (i2c_w1(gspca_dev, ov9650_init[i].reg,
                                 ov9650_init[i].val) < 0) {