Input: elants_i2c - fix NULL dereference at probing

The recent change in elants_i2c driver to support more chips
introduced a regression leading to Oops at probing.  The driver reads
id->driver_data, but the id may be NULL depending on the device type
the driver gets bound.

Replace the driver data extraction with the device_get_match_data()
helper, and define the driver data in OF table, too.

Fixes: 9517b95bdc46 ("Input: elants_i2c - add support for eKTF3624")
BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1186454
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210528071024.26450-1-tiwai@suse.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index 17540bdb1eaf7b03af79c009a34a3e659565ba18..0f9e3ec99aae187bc9f4bdcf2d8de2d6e96a36e3 100644 (file)
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -1396,7 +1396,7 @@ static int elants_i2c_probe(struct i2c_client *client,
        init_completion(&ts->cmd_done);
 
        ts->client = client;
-       ts->chip_id = (enum elants_chip_id)id->driver_data;
+       ts->chip_id = (enum elants_chip_id)(uintptr_t)device_get_match_data(&client->dev);
        i2c_set_clientdata(client, ts);
 
        ts->vcc33 = devm_regulator_get(&client->dev, "vcc33");
@@ -1636,8 +1636,8 @@ MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
 
 #ifdef CONFIG_OF
 static const struct of_device_id elants_of_match[] = {
-       { .compatible = "elan,ekth3500" },
-       { .compatible = "elan,ektf3624" },
+       { .compatible = "elan,ekth3500", .data = (void *)EKTH3500 },
+       { .compatible = "elan,ektf3624", .data = (void *)EKTF3624 },
        { /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, elants_of_match);