Input: ad7879 - use device core to create driver-specific device attributes

Instead of creating driver-specific device attributes with
devm_device_add_group() have device core do this by setting up dev_groups
pointer in the driver structure.

Acked-by: Michael Hennerich <[e-mail]>
Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/touchscreen/ad7879-i2c.c

···
 
 static struct i2c_driver ad7879_i2c_driver = {
 	.driver = {
-		.name	= "ad7879",
-		.pm	= &ad7879_pm_ops,
-		.of_match_table = of_match_ptr(ad7879_i2c_dt_ids),
+		.name		= "ad7879",
+		.dev_groups	= ad7879_groups,
+		.pm		= &ad7879_pm_ops,
+		.of_match_table	= of_match_ptr(ad7879_i2c_dt_ids),
 	},
 	.probe		= ad7879_i2c_probe,
 	.id_table	= ad7879_id,

drivers/input/touchscreen/ad7879-spi.c

···
 
 static struct spi_driver ad7879_spi_driver = {
 	.driver = {
-		.name	= "ad7879",
-		.pm	= &ad7879_pm_ops,
-		.of_match_table = of_match_ptr(ad7879_spi_dt_ids),
+		.name		= "ad7879",
+		.dev_groups	= ad7879_groups,
+		.pm		= &ad7879_pm_ops,
+		.of_match_table	= of_match_ptr(ad7879_spi_dt_ids),
 	},
 	.probe		= ad7879_spi_probe,
 };

drivers/input/touchscreen/ad7879.c

···
 	.attrs = ad7879_attributes,
 };
 
+const struct attribute_group *ad7879_groups[] = {
+	&ad7879_attr_group,
+	NULL
+};
+EXPORT_SYMBOL_GPL(ad7879_groups);
+
 #ifdef CONFIG_GPIOLIB
 static int ad7879_gpio_direction_input(struct gpio_chip *chip,
 					unsigned gpio)
···
 	}
 
 	__ad7879_disable(ts);
-
-	err = devm_device_add_group(dev, &ad7879_attr_group);
-	if (err)
-		return err;
 
 	err = ad7879_gpio_add(ts);
 	if (err)

drivers/input/touchscreen/ad7879.h

···
 #ifndef _AD7879_H_
 #define _AD7879_H_
 
+#include <linux/pm.h>
 #include <linux/types.h>
 
+struct attribute_group;
 struct device;
 struct regmap;
 
+extern const struct attribute_group *ad7879_groups[];
 extern const struct dev_pm_ops ad7879_pm_ops;
 
 int ad7879_probe(struct device *dev, struct regmap *regmap,