gpio: pca953x: Extract the register address mangling to single function

Instead of having the I2C register calculation function spread across
multiple accessor functions, pull it out into a single function which
returns the adjusted register address.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.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 b338681..7e66f46 100644 (file)
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -164,17 +164,37 @@ static int pca953x_bank_shift(struct pca953x_chip *chip)
        return fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
 }
 
+static u8 pca953x_recalc_addr(struct pca953x_chip *chip, int reg, int off,
+                             bool write, bool addrinc)
+{
+       int bank_shift = pca953x_bank_shift(chip);
+       int addr = (reg & PCAL_GPIO_MASK) << bank_shift;
+       int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1;
+       u8 regaddr = pinctrl | addr | (off / BANK_SZ);
+
+       /* Single byte read doesn't need AI bit set. */
+       if (!addrinc)
+               return regaddr;
+
+       /* Chips with 24 and more GPIOs always support Auto Increment */
+       if (write && NBANK(chip) > 2)
+               regaddr |= REG_ADDR_AI;
+
+       /* PCA9575 needs address-increment on multi-byte writes */
+       if (PCA_CHIP_TYPE(chip->driver_data) == PCA957X_TYPE)
+               regaddr |= REG_ADDR_AI;
+
+       return regaddr;
+}
+
 static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
                                int off)
 {
+       u8 regaddr = pca953x_recalc_addr(chip, reg, off, false, false);
        int ret;
-       int bank_shift = pca953x_bank_shift(chip);
-       int offset = off / BANK_SZ;
 
-       ret = i2c_smbus_read_byte_data(chip->client,
-                               (reg << bank_shift) + offset);
+       ret = i2c_smbus_read_byte_data(chip->client, regaddr);
        *val = ret;
-
        if (ret < 0) {
                dev_err(&chip->client->dev, "failed reading register\n");
                return ret;
@@ -186,13 +206,10 @@ static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
 static int pca953x_write_single(struct pca953x_chip *chip, int reg, u32 val,
                                int off)
 {
+       u8 regaddr = pca953x_recalc_addr(chip, reg, off, true, false);
        int ret;
-       int bank_shift = pca953x_bank_shift(chip);
-       int offset = off / BANK_SZ;
-
-       ret = i2c_smbus_write_byte_data(chip->client,
-                                       (reg << bank_shift) + offset, val);
 
+       ret = i2c_smbus_write_byte_data(chip->client, regaddr, val);
        if (ret < 0) {
                dev_err(&chip->client->dev, "failed writing register\n");
                return ret;
@@ -203,20 +220,9 @@ static int pca953x_write_single(struct pca953x_chip *chip, int reg, u32 val,
 
 static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
 {
-       int bank_shift = pca953x_bank_shift(chip);
-       int addr = (reg & PCAL_GPIO_MASK) << bank_shift;
-       int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1;
-       u8 regaddr = pinctrl | addr;
+       u8 regaddr = pca953x_recalc_addr(chip, reg, 0, true, true);
        int ret;
 
-       /* Chips with 24 and more GPIOs always support Auto Increment */
-       if (NBANK(chip) > 2)
-               regaddr |= REG_ADDR_AI;
-
-       /* PCA9575 needs address-increment on multi-byte writes */
-       if (PCA_CHIP_TYPE(chip->driver_data) == PCA957X_TYPE)
-               regaddr |= REG_ADDR_AI;
-
        ret = i2c_smbus_write_i2c_block_data(chip->client, regaddr,
                                             NBANK(chip), val);
        if (ret < 0) {
@@ -229,16 +235,9 @@ static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
 
 static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
 {
-       int bank_shift = pca953x_bank_shift(chip);
-       int addr = (reg & PCAL_GPIO_MASK) << bank_shift;
-       int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1;
-       u8 regaddr = pinctrl | addr;
+       u8 regaddr = pca953x_recalc_addr(chip, reg, 0, false, true);
        int ret;
 
-       /* Chips with 24 and more GPIOs always support Auto Increment */
-       if (NBANK(chip) > 2)
-               regaddr |= REG_ADDR_AI;
-
        ret = i2c_smbus_read_i2c_block_data(chip->client, regaddr,
                                            NBANK(chip), val);
        if (ret < 0) {