[PATCH v2 5/5] gpio: pca953x: refactor pca953x_read_regs()

Bartosz Golaszewski
2016-09-07T09:25:28Z

Avoid the unnecessary if-else in pca953x_read_regs() by spltting the
routine into smaller, specialized functions and calling the right one
via a function pointer held in struct pca953x.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
drivers/gpio/gpio-pca953x.c | 55 ++++++++++++++++++++++++++++++++-------------
1 file changed, 39 insertions(+), 16 deletions(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 00bb2ea..e417c42 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -134,6 +134,7 @@ struct pca953x_chip {
const struct pca953x_offset *offset;

int (*write_regs)(struct pca953x_chip *, int, u8 *);
+ int (*read_regs)(struct pca953x_chip *, int, u8 *);
};

static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
@@ -219,24 +220,41 @@ static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
return 0;
}

-static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
+static int pca953x_read_regs_8(struct pca953x_chip *chip, int reg, u8 *val)
{
int ret;

- if (chip->gpio_chip.ngpio <= 8) {
- ret = i2c_smbus_read_byte_data(chip->client, reg);
- *val = ret;
- } else if (chip->gpio_chip.ngpio >= 24) {
- int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+ ret = i2c_smbus_read_byte_data(chip->client, reg);
+ *val = ret;

- ret = i2c_smbus_read_i2c_block_data(chip->client,
- (reg << bank_shift) | REG_ADDR_AI,
- NBANK(chip), val);
- } else {
- ret = i2c_smbus_read_word_data(chip->client, reg << 1);
- val[0] = (u16)ret & 0xFF;
- val[1] = (u16)ret >> 8;
- }
+ return ret;
+}
+
+static int pca953x_read_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
+{
+ int ret;
+
+ ret = i2c_smbus_read_word_data(chip->client, reg << 1);
+ val[0] = (u16)ret & 0xFF;
+ val[1] = (u16)ret >> 8;
+
+ return ret;
+}
+
+static int pca953x_read_regs_24(struct pca953x_chip *chip, int reg, u8 *val)
+{
+ int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+
+ return i2c_smbus_read_i2c_block_data(chip->client,
+ (reg << bank_shift) | REG_ADDR_AI,
+ NBANK(chip), val);
+}
+
+static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
+{
+ int ret;
+
+ ret = chip->read_regs(chip, reg, val);
if (ret < 0) {
dev_err(&chip->client->dev, "failed reading register\n");
return ret;
@@ -766,10 +784,15 @@ static int pca953x_probe(struct i2c_client *client,
*/
pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);

- if (chip->gpio_chip.ngpio <= 8)
+ if (chip->gpio_chip.ngpio <= 8) {
chip->write_regs = pca953x_write_regs_8;
- else if (chip->gpio_chip.ngpio >= 24)
+ chip->read_regs = pca953x_read_regs_8;
+ } else if (chip->gpio_chip.ngpio >= 24) {
chip->write_regs = pca953x_write_regs_24;
+ chip->read_regs = pca953x_read_regs_24;
+ } else {
+ chip->read_regs = pca953x_read_regs_16;
+ }

if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
ret = device_pca953x_init(chip, invert);
--
2.7.4