On Mon, Oct 26, 2020 at 4:23 PM Bartosz Golaszewski <brgl@xxxxxxxx> wrote: > > From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx> > > Provide and use helpers for calculating the register address and bit > offset instead of hand coding it in every function. Can you check code generation on x86, for example? Sometimes compilers are eager to use idiv assembly instruction which does simultaneously / and %. I dunno if a) it's used for / 8 and % 8 since 8 is 2^3, b) splitting to functions makes the above optimisation impossible. > Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx> > --- > drivers/gpio/gpio-exar.c | 40 ++++++++++++++++++++++++++++------------ > 1 file changed, 28 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c > index db366d85b6b4..629f4dad6919 100644 > --- a/drivers/gpio/gpio-exar.c > +++ b/drivers/gpio/gpio-exar.c > @@ -33,6 +33,26 @@ struct exar_gpio_chip { > unsigned int first_pin; > }; > > +static unsigned int > +exar_offset_to_sel_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset) > +{ > + return (offset + exar_gpio->first_pin) / 8 ? EXAR_OFFSET_MPIOSEL_HI > + : EXAR_OFFSET_MPIOSEL_LO; > +} > + > +static unsigned int > +exar_offset_to_lvl_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset) > +{ > + return (offset + exar_gpio->first_pin) / 8 ? EXAR_OFFSET_MPIOLVL_HI > + : EXAR_OFFSET_MPIOLVL_LO; > +} > + > +static unsigned int > +exar_offset_to_bit(struct exar_gpio_chip *exar_gpio, unsigned int offset) > +{ > + return (offset + exar_gpio->first_pin) % 8; > +} > + > static void exar_update(struct gpio_chip *chip, unsigned int reg, int val, > unsigned int offset) > { > @@ -52,9 +72,8 @@ static int exar_set_direction(struct gpio_chip *chip, int direction, > unsigned int offset) > { > struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); > - unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? > - EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; > - unsigned int bit = (offset + exar_gpio->first_pin) % 8; > + unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset); > + unsigned int bit = exar_offset_to_bit(exar_gpio, offset); > > exar_update(chip, addr, direction, bit); > return 0; > @@ -75,9 +94,8 @@ static int exar_get(struct gpio_chip *chip, unsigned int reg) > static int exar_get_direction(struct gpio_chip *chip, unsigned int offset) > { > struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); > - unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? > - EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; > - unsigned int bit = (offset + exar_gpio->first_pin) % 8; > + unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset); > + unsigned int bit = exar_offset_to_bit(exar_gpio, offset); > > if (exar_get(chip, addr) & BIT(bit)) > return GPIO_LINE_DIRECTION_IN; > @@ -88,9 +106,8 @@ static int exar_get_direction(struct gpio_chip *chip, unsigned int offset) > static int exar_get_value(struct gpio_chip *chip, unsigned int offset) > { > struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); > - unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? > - EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO; > - unsigned int bit = (offset + exar_gpio->first_pin) % 8; > + unsigned int addr = exar_offset_to_lvl_addr(exar_gpio, offset); > + unsigned int bit = exar_offset_to_bit(exar_gpio, offset); > > return !!(exar_get(chip, addr) & BIT(bit)); > } > @@ -99,9 +116,8 @@ static void exar_set_value(struct gpio_chip *chip, unsigned int offset, > int value) > { > struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); > - unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? > - EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO; > - unsigned int bit = (offset + exar_gpio->first_pin) % 8; > + unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset); > + unsigned int bit = exar_offset_to_bit(exar_gpio, offset); > > exar_update(chip, addr, value, bit); > } > -- > 2.29.1 > -- With Best Regards, Andy Shevchenko