Input: goodix - allow specifying the config filename

The config which needs to be send to the controller on some device-models
is model-specific. Allow specifying a model-specific filename through
a device-property, rather then always using a fixed filename.

Note the "goodix,config-name" device-property used by this is
*not* documented in the
Documentation/devicetree/bindings/input/touchscreen/goodix.yaml
device-tree bindings for now.

Not documenting these is intentional. This is done because this code has
only been tested on x86/ACPI so far, where devicetree is not used.
Instead these properties are set through a software-fwnode attached to the
device by the drivers/platform/x86/touchscreen_dmi.c code. This means that
the use of this property for now is purely a kernel-internal thing and
the name/working of the property may still be changed for now.
Reviewed-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210920150643.155872-6-hdegoede@redhat.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/goodix.c

@@ -1165,6 +1165,7 @@ static int goodix_ts_probe(struct i2c_client *client,
 			   const struct i2c_device_id *id)
 {
 	struct goodix_ts_data *ts;
+	const char *cfg_name;
 	int error;
 
 	dev_dbg(&client->dev, "I2C Address: 0x%02x\n", client->addr);
@@ -1238,10 +1239,15 @@ static int goodix_ts_probe(struct i2c_client *client,
 
 	if (ts->load_cfg_from_disk) {
 		/* update device config */
-		ts->cfg_name = devm_kasprintf(&client->dev, GFP_KERNEL,
-					      "goodix_%s_cfg.bin", ts->id);
-		if (!ts->cfg_name)
-			return -ENOMEM;
+		error = device_property_read_string(&client->dev,
+						    "goodix,config-name",
+						    &cfg_name);
+		if (!error)
+			snprintf(ts->cfg_name, sizeof(ts->cfg_name),
+				 "goodix/%s", cfg_name);
+		else
+			snprintf(ts->cfg_name, sizeof(ts->cfg_name),
+				 "goodix_%s_cfg.bin", ts->id);
 
 		error = request_firmware_nowait(THIS_MODULE, true, ts->cfg_name,
 						&client->dev, GFP_KERNEL, ts,

drivers/input/touchscreen/goodix.h

@@ -52,8 +52,8 @@ struct goodix_ts_data {
 	int gpio_count;
 	int gpio_int_idx;
 	char id[GOODIX_ID_MAX_LEN + 1];
+	char cfg_name[64];
 	u16 version;
-	const char *cfg_name;
 	bool reset_controller_at_probe;
 	bool load_cfg_from_disk;
 	struct completion firmware_loading_complete;