Re: [PATCH v3 3/5] gpio: pca953x: refactor pca953x_read_regs()

[Andy Shevchenko]

On Wed, 2016-09-07 at 15:37 +0200, Bartosz Golaszewski wrote:
> 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@xxxxxxxxxxxx>
> ---
> Âdrivers/gpio/gpio-pca953x.c | 56 +++++++++++++++++++++++++++++++-----
> ---------
> Â1 file changed, 39 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index b3020ee..018bd18 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -135,6 +135,7 @@ struct pca953x_chip {
> Â	const struct pca953x_offset *offset;
> Â
> Â	int (*write_regs)(struct pca953x_chip *, int, u8 *);
> +	int (*read_regs)(struct pca953x_chip *, int, u8 *);
> Â};
> Â
> Âstatic int pca953x_read_single(struct pca953x_chip *chip, int reg,
> u32 *val,
> @@ -220,24 +221,41 @@ static int pca953x_write_regs(struct
> pca953x_chip *chip, int reg, u8 *val)
> Â	return 0;
> Â}
> Â
> -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)
> Â{
> Â	int ret;
> Â
> -	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;

It's probably of out scope of this series, but looks like

if (ret < 0)
Âreturn ret;

*val = ret;
return 0 (?);

> @@ -762,14 +780,18 @@ static int pca953x_probe(struct i2c_client
> *client,
> Â	Â*/
> Â	pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);
> Â
> -	if (chip->gpio_chip.ngpio <= 8)
> +	if (chip->gpio_chip.ngpio <= 8) {
> Â		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) {
> Â		chip->write_regs = pca953x_write_regs_24;
> -	else
> +		chip->read_regs = pca953x_read_regs_24;
> +	} else {
> Â		chip->write_regs = chip->chip_type == PCA953X_TYPE ?
> Â					pca953x_write_regs_16 :
> Â					pca957x_write_regs_16;
> +		chip->read_regs = pca953x_read_regs_16;
> +	}

Would you move {} to the previous patch?

-- 
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy