Input: melfas_mip4 - ensure that device is present

Try a quick read from the device in mip4_query_device() to make sure
that the device is there, as we do not consider failures to retrieve
product name or resolution fatal.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Dmitry Torokhov 2017-03-24 16:50:28 -07:00
parent f5a28a7d48
commit 4896fb1348

View File

@ -253,10 +253,21 @@ static int mip4_get_fw_version(struct mip4_ts *ts)
*/
static int mip4_query_device(struct mip4_ts *ts)
{
union i2c_smbus_data dummy;
int error;
u8 cmd[2];
u8 buf[14];
/*
* Make sure there is something at this address as we do not
* consider subsequent failures as fatal.
*/
if (i2c_smbus_xfer(ts->client->adapter, ts->client->addr,
0, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
dev_err(&ts->client->dev, "nothing at this address\n");
return -ENXIO;
}
/* Product name */
cmd[0] = MIP4_R0_INFO;
cmd[1] = MIP4_R1_INFO_PRODUCT_NAME;