On 11/29/2017 09:11 AM, Hugues Fruchet wrote:
Verify that chip identifier is correct before starting streaming
Signed-off-by: Hugues Fruchet <hugues.fruchet@xxxxxx>
---
drivers/media/i2c/ov5640.c | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)
diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index 61071f5..a576d11 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -34,7 +34,8 @@
#define OV5640_DEFAULT_SLAVE_ID 0x3c
-#define OV5640_REG_CHIP_ID 0x300a
+#define OV5640_REG_CHIP_ID_HIGH 0x300a
+#define OV5640_REG_CHIP_ID_LOW 0x300b
There is no need to separate low and high byte addresses.
See below.
#define OV5640_REG_PAD_OUTPUT00 0x3019
#define OV5640_REG_SC_PLL_CTRL0 0x3034
#define OV5640_REG_SC_PLL_CTRL1 0x3035
@@ -926,6 +927,29 @@ static int ov5640_load_regs(struct ov5640_dev *sensor,
return ret;
}
+static int ov5640_check_chip_id(struct ov5640_dev *sensor)
+{
+ struct i2c_client *client = sensor->i2c_client;
+ int ret;
+ u8 chip_id_h, chip_id_l;
+
+ ret = ov5640_read_reg(sensor, OV5640_REG_CHIP_ID_HIGH, &chip_id_h);
+ if (ret)
+ return ret;
+
+ ret = ov5640_read_reg(sensor, OV5640_REG_CHIP_ID_LOW, &chip_id_l);
+ if (ret)
+ return ret;
+
+ if (!(chip_id_h == 0x56 && chip_id_l == 0x40)) {
+ dev_err(&client->dev, "%s: wrong chip identifier, expected 0x5640, got 0x%x%x\n",
+ __func__, chip_id_h, chip_id_l);
+ return -EINVAL;
+ }
+
This should all be be replaced by:
u16 chip_id;
ret = ov5640_read_reg16(sensor, OV5640_REG_CHIP_ID, &chip_id);
etc.
+ return 0;
+}
+
/* read exposure, in number of line periods */
static int ov5640_get_exposure(struct ov5640_dev *sensor)
{
@@ -1562,6 +1586,10 @@ static int ov5640_set_power(struct ov5640_dev *sensor, bool on)
ov5640_reset(sensor);
ov5640_power(sensor, true);
+ ret = ov5640_check_chip_id(sensor);
+ if (ret)
+ goto power_off;
+
ret = ov5640_init_slave_id(sensor);
if (ret)
goto power_off;
