Input: ad7879 - convert to use regmap

Instead of rolling our own infrastructure to provide uniform access to I2C
and SPI buses, let's switch to using regmap.

Reviewed-by: Michael Hennerich <michael.hennerich@analog.com>
Tested-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/touchscreen/ad7879-i2c.c b/drivers/input/touchscreen/ad7879-i2c.c
index 58f72e0..25aa9b8 100644
--- a/drivers/input/touchscreen/ad7879-i2c.c
+++ b/drivers/input/touchscreen/ad7879-i2c.c
@@ -12,53 +12,23 @@
 #include <linux/types.h>
 #include <linux/of.h>
 #include <linux/pm.h>
+#include <linux/regmap.h>
 
 #include "ad7879.h"
 
 #define AD7879_DEVID		0x79	/* AD7879-1/AD7889-1 */
 
-/* All registers are word-sized.
- * AD7879 uses a high-byte first convention.
- */
-static int ad7879_i2c_read(struct device *dev, u8 reg)
-{
-	struct i2c_client *client = to_i2c_client(dev);
-
-	return i2c_smbus_read_word_swapped(client, reg);
-}
-
-static int ad7879_i2c_multi_read(struct device *dev,
-				 u8 first_reg, u8 count, u16 *buf)
-{
-	struct i2c_client *client = to_i2c_client(dev);
-	u8 idx;
-
-	i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);
-
-	for (idx = 0; idx < count; ++idx)
-		buf[idx] = swab16(buf[idx]);
-
-	return 0;
-}
-
-static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
-{
-	struct i2c_client *client = to_i2c_client(dev);
-
-	return i2c_smbus_write_word_swapped(client, reg, val);
-}
-
-static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
-	.bustype	= BUS_I2C,
-	.read		= ad7879_i2c_read,
-	.multi_read	= ad7879_i2c_multi_read,
-	.write		= ad7879_i2c_write,
+static const struct regmap_config ad7879_i2c_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+	.max_register = 15,
 };
 
 static int ad7879_i2c_probe(struct i2c_client *client,
 				      const struct i2c_device_id *id)
 {
 	struct ad7879 *ts;
+	struct regmap *regmap;
 
 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_WORD_DATA)) {
@@ -66,8 +36,12 @@ static int ad7879_i2c_probe(struct i2c_client *client,
 		return -EIO;
 	}
 
-	ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
-			  &ad7879_i2c_bus_ops);
+	regmap = devm_regmap_init_i2c(client, &ad7879_i2c_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	ts = ad7879_probe(&client->dev, regmap, client->irq,
+			  BUS_I2C, AD7879_DEVID);
 	if (IS_ERR(ts))
 		return PTR_ERR(ts);