media: i2c: ov9281: Read chip ID via 2 reads

Vision Components have made an OV9281 module which blocks reading
back the majority of registers to comply with NDAs, and in doing
so doesn't allow auto-increment register reading as used when
reading the chip ID.

Use two reads and manually combine the results.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
This commit is contained in:
Dave Stevenson
2020-07-06 17:51:32 +01:00
committed by Dom Cobley
parent 8995361380
commit 20855581e0

View File

@@ -904,13 +904,17 @@ static int ov9281_check_sensor_id(struct ov9281 *ov9281,
struct i2c_client *client)
{
struct device *dev = &ov9281->client->dev;
u32 id = 0;
u32 id = 0, id_msb;
int ret;
ret = ov9281_read_reg(client, OV9281_REG_CHIP_ID + 1,
OV9281_REG_VALUE_08BIT, &id);
if (!ret)
ret = ov9281_read_reg(client, OV9281_REG_CHIP_ID,
OV9281_REG_VALUE_16BIT, &id);
if (id != CHIP_ID) {
dev_err(dev, "Unexpected sensor id(%06x), ret(%d)\n", id, ret);
OV9281_REG_VALUE_08BIT, &id_msb);
id |= (id_msb << 8);
if (ret || id != CHIP_ID) {
dev_err(dev, "Unexpected sensor id(%04x), ret(%d)\n", id, ret);
return -ENODEV;
}