[PATCH v2 3/5] gpio: pca953x: refactor pca953x_write_regs()

Bartosz Golaszewski
2016-09-07T09:25:45Z

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>
---
drivers/gpio/gpio-pca953x.c | 75 ++++++++++++++++++++++++++++-----------------
1 file changed, 47 insertions(+), 28 deletions(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 195944b..6b62898 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -133,6 +133,8 @@ struct pca953x_chip {
unsigned long driver_data;

const struct pca953x_offset *offset;
+
+ int (*write_regs)(struct pca953x_chip *, int, u8 *);
};

static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
@@ -172,38 +174,44 @@ 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;
@@ -645,6 +653,9 @@ static int device_pca953x_init(struct pca953x_chip *chip, u32 invert)

chip->offset = &pca953x_offsets;

+ if (!chip->write_regs)
+ chip->write_regs = pca953x_write_regs_16;
+
ret = pca953x_read_regs(chip, PCA953X_OUTPUT, chip->reg_output);
if (ret)
goto out;
@@ -672,6 +683,9 @@ static int device_pca957x_init(struct pca953x_chip *chip, u32 invert)

chip->offset = &pca957x_offsets;

+ if (!chip->write_regs)
+ chip->write_regs = pca957x_write_regs_16;
+
ret = pca953x_read_regs(chip, PCA957X_OUT, chip->reg_output);
if (ret)
goto out;
@@ -755,6 +769,11 @@ 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;
+
if (chip->chip_type == PCA953X_TYPE)
ret = device_pca953x_init(chip, invert);
else
--
2.7.4