The function i2c_match_id() is used to fetch the matching ID from
the i2c_device_id table. This is often used to then retrieve the
matching driver_data. This can be done in one step with the helper
i2c_get_match_data().

This helper has a couple other benefits:
 * It doesn't need the i2c_device_id passed in so we do not need
   to have that forward declared, allowing us to remove those or
   move the i2c_device_id table down to its more natural spot
   with the other module info.
 * It also checks for device match data, which allows for OF and
   ACPI based probing. That means we do not have to manually check
   those first and can remove those checks.

Signed-off-by: Andrew Davis <afd@ti.com>
---
 drivers/rtc/rtc-pcf2127.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index bb4fe81d3d62c..e4785c5a55d03 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -1449,10 +1449,10 @@ static const struct regmap_bus pcf2127_i2c_regmap = {
 static struct i2c_driver pcf2127_i2c_driver;
 
 static const struct i2c_device_id pcf2127_i2c_id[] = {
-	{ "pcf2127", PCF2127 },
-	{ "pcf2129", PCF2129 },
-	{ "pca2129", PCF2129 },
-	{ "pcf2131", PCF2131 },
+	{ "pcf2127", (kernel_ulong_t)&pcf21xx_cfg[PCF2127] },
+	{ "pcf2129", (kernel_ulong_t)&pcf21xx_cfg[PCF2129] },
+	{ "pca2129", (kernel_ulong_t)&pcf21xx_cfg[PCF2129] },
+	{ "pcf2131", (kernel_ulong_t)&pcf21xx_cfg[PCF2131] },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id);
@@ -1469,18 +1469,9 @@ static int pcf2127_i2c_probe(struct i2c_client *client)
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 		return -ENODEV;
 
-	if (client->dev.of_node) {
-		variant = of_device_get_match_data(&client->dev);
-		if (!variant)
-			return -ENODEV;
-	} else {
-		enum pcf21xx_type type =
-			i2c_match_id(pcf2127_i2c_id, client)->driver_data;
-
-		if (type >= PCF21XX_LAST_ID)
-			return -ENODEV;
-		variant = &pcf21xx_cfg[type];
-	}
+	variant = i2c_get_match_data(client);
+	if (!variant)
+		return -ENODEV;
 
 	config.max_register = variant->max_register,
 
-- 
2.39.2