diff options
| author |   Linus Walleij <linus.walleij@linaro.org> | 2018-06-27 10:52:07 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2018-07-02 16:00:49 +0200 |
| commit | 4a2398d7211f8f750b717ce4a2b0d117385f2a4a (patch) | |
| tree | 9021ac59e3a8a9268c964ea14dee0f7acbf56683 /drivers/gpio/gpio-sch311x.c | |
| parent | gpio: sch311x: Implement .get_direction() (diff) | |
| download | linux-dev-4a2398d7211f8f750b717ce4a2b0d117385f2a4a.tar.xz linux-dev-4a2398d7211f8f750b717ce4a2b0d117385f2a4a.zip | |
gpio: sch311x: Use RMW to change direction
Bit 0 in the config register obviously controls the direction
of the GPIO so instead of hammering 0x0/0x1 into that register,
use read-modify-write so that we can also alter the other bits
in the register.
Cc: Bruno Randolf <br1@einfach.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpio-sch311x.c')
| -rw-r--r-- | drivers/gpio/gpio-sch311x.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/drivers/gpio/gpio-sch311x.c b/drivers/gpio/gpio-sch311x.c index ed64f7fa23b1..faf44178f97b 100644 --- a/drivers/gpio/gpio-sch311x.c +++ b/drivers/gpio/gpio-sch311x.c @@ -23,10 +23,9 @@ #define DRV_NAME "gpio-sch311x" -#define SCH311X_GPIO_CONF_OUT 0x00 -#define SCH311X_GPIO_CONF_IN 0x01 -#define SCH311X_GPIO_CONF_INVERT 0x02 -#define SCH311X_GPIO_CONF_OPEN_DRAIN 0x80 +#define SCH311X_GPIO_CONF_DIR BIT(0) +#define SCH311X_GPIO_CONF_INVERT BIT(1) +#define SCH311X_GPIO_CONF_OPEN_DRAIN BIT(7) #define SIO_CONFIG_KEY_ENTER 0x55 #define SIO_CONFIG_KEY_EXIT 0xaa @@ -196,10 +195,12 @@ static void sch311x_gpio_set(struct gpio_chip *chip, unsigned offset, static int sch311x_gpio_direction_in(struct gpio_chip *chip, unsigned offset) { struct sch311x_gpio_block *block = gpiochip_get_data(chip); + unsigned char data; spin_lock(&block->lock); - outb(SCH311X_GPIO_CONF_IN, block->runtime_reg + - block->config_regs[offset]); + data = inb(block->runtime_reg + block->config_regs[offset]); + data |= SCH311X_GPIO_CONF_DIR; + outb(data, block->runtime_reg + block->config_regs[offset]); spin_unlock(&block->lock); return 0; @@ -209,12 +210,13 @@ static int sch311x_gpio_direction_out(struct gpio_chip *chip, unsigned offset, int value) { struct sch311x_gpio_block *block = gpiochip_get_data(chip); + unsigned char data; spin_lock(&block->lock); - outb(SCH311X_GPIO_CONF_OUT, block->runtime_reg + - block->config_regs[offset]); - + data = inb(block->runtime_reg + block->config_regs[offset]); + data &= ~SCH311X_GPIO_CONF_DIR; + outb(data, block->runtime_reg + block->config_regs[offset]); __sch311x_gpio_set(block, offset, value); spin_unlock(&block->lock); @@ -230,7 +232,7 @@ static int sch311x_gpio_get_direction(struct gpio_chip *chip, unsigned offset) data = inb(block->runtime_reg + block->config_regs[offset]); spin_unlock(&block->lock); - return !!(data & SCH311X_GPIO_CONF_IN); + return !!(data & SCH311X_GPIO_CONF_DIR); } static int sch311x_gpio_probe(struct platform_device *pdev) |