Input: elan_i2c - handle firmware not implementing "get pattern" command

Not all versions of firmware implement "get pattern" command. When
encountering those assume that the controllers use older pattern.

Signed-off-by: Jingle Wu <jingle.wu@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Jingle Wu 2020-07-15 17:40:27 -07:00 committed by Dmitry Torokhov
parent 3d77e6a880
commit 77da21c5d3

View file

@ -249,7 +249,13 @@ static int elan_i2c_get_pattern(struct i2c_client *client, u8 *pattern)
dev_err(&client->dev, "failed to get pattern: %d\n", error);
return error;
}
*pattern = val[1];
/*
* Not all versions of firmware implement "get pattern" command.
* When this command is not implemented the device will respond
* with 0xFF 0xFF, which we will treat as "old" pattern 0.
*/
*pattern = val[0] == 0xFF && val[1] == 0xFF ? 0 : val[1];
return 0;
}