gpio: pca953x: refactor pca953x_write_regs()

Avoid the unnecessary if-else in pca953x_write_regs() by splitting
the routine into smaller, specialized functions and calling the right
one via a function pointer held in struct pca953x_chip.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 5d65c9e8af25a8bd7577a63ea9de08feeb676606..e9defeb9c21275c9e5afd6c40fbd98e7e82bc16e 100644 (file)
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -135,6 +135,8 @@ struct pca953x_chip {
        struct regulator *regulator;
 
        const struct pca953x_reg_config *regs;
+
+       int (*write_regs)(struct pca953x_chip *, int, u8 *);
 };
 
 static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
@@ -174,38 +176,44 @@ static int pca953x_write_single(struct pca953x_chip *chip, int reg, u32 val,
        return 0;
 }
 
-static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
+static int pca953x_write_regs_8(struct pca953x_chip *chip, int reg, u8 *val)
 {
-       int ret = 0;
+       return i2c_smbus_write_byte_data(chip->client, reg, *val);
+}
 
-       if (chip->gpio_chip.ngpio <= 8)
-               ret = i2c_smbus_write_byte_data(chip->client, reg, *val);
-       else if (chip->gpio_chip.ngpio >= 24) {
-               int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
-               ret = i2c_smbus_write_i2c_block_data(chip->client,
-                                       (reg << bank_shift) | REG_ADDR_AI,
-                                       NBANK(chip), val);
-       } else {
-               switch (chip->chip_type) {
-               case PCA953X_TYPE: {
-                       __le16 word = cpu_to_le16(get_unaligned((u16 *)val));
+static int pca953x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
+{
+       __le16 word = cpu_to_le16(get_unaligned((u16 *)val));
 
-                       ret = i2c_smbus_write_word_data(chip->client, reg << 1,
-                                                       (__force u16)word);
-                       break;
-               }
-               case PCA957X_TYPE:
-                       ret = i2c_smbus_write_byte_data(chip->client, reg << 1,
-                                                       val[0]);
-                       if (ret < 0)
-                               break;
-                       ret = i2c_smbus_write_byte_data(chip->client,
-                                                       (reg << 1) + 1,
-                                                       val[1]);
-                       break;
-               }
-       }
+       return i2c_smbus_write_word_data(chip->client,
+                                        reg << 1, (__force u16)word);
+}
+
+static int pca957x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
+{
+       int ret;
+
+       ret = i2c_smbus_write_byte_data(chip->client, reg << 1, val[0]);
+       if (ret < 0)
+               return ret;
+
+       return i2c_smbus_write_byte_data(chip->client, (reg << 1) + 1, val[1]);
+}
 
+static int pca953x_write_regs_24(struct pca953x_chip *chip, int reg, u8 *val)
+{
+       int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+
+       return i2c_smbus_write_i2c_block_data(chip->client,
+                                             (reg << bank_shift) | REG_ADDR_AI,
+                                             NBANK(chip), val);
+}
+
+static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
+{
+       int ret = 0;
+
+       ret = chip->write_regs(chip, reg, val);
        if (ret < 0) {
                dev_err(&chip->client->dev, "failed writing register\n");
                return ret;
@@ -774,6 +782,17 @@ static int pca953x_probe(struct i2c_client *client,
         */
        pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);
 
+       if (chip->gpio_chip.ngpio <= 8) {
+               chip->write_regs = pca953x_write_regs_8;
+       } else if (chip->gpio_chip.ngpio >= 24) {
+               chip->write_regs = pca953x_write_regs_24;
+       } else {
+               if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
+                       chip->write_regs = pca953x_write_regs_16;
+               else
+                       chip->write_regs = pca957x_write_regs_16;
+       }
+
        if (chip->chip_type == PCA953X_TYPE)
                ret = device_pca953x_init(chip, invert);
        else