Some gpio controllers ignores pin value writing when that pin is configured as input mode. As a result, bgpio_dir_out should set pin to output before configuring pin values or gpio pin values can't be set up properly. Introduce two variants of bgpio_dir_out: bgpio_dir_out_val_first and bgpio_dir_out_dir_first, and assign direction_output according to a new flag: BGPIOF_NO_SET_ON_INPUT. Signed-off-by: Chuanhong Guo <gch981213@xxxxxxxxx> --- drivers/gpio/gpio-mmio.c | 23 +++++++++++++++++++---- include/linux/gpio/driver.h | 1 + 2 files changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpio-mmio.c b/drivers/gpio/gpio-mmio.c index f729e3e9e983..b778f33cc6af 100644 --- a/drivers/gpio/gpio-mmio.c +++ b/drivers/gpio/gpio-mmio.c @@ -389,12 +389,10 @@ static int bgpio_get_dir(struct gpio_chip *gc, unsigned int gpio) return GPIO_LINE_DIRECTION_IN; } -static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) +static void bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) { unsigned long flags; - gc->set(gc, gpio, val); - spin_lock_irqsave(&gc->bgpio_lock, flags); gc->bgpio_dir |= bgpio_line2mask(gc, gpio); @@ -405,7 +403,21 @@ static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) gc->write_reg(gc->reg_dir_out, gc->bgpio_dir); spin_unlock_irqrestore(&gc->bgpio_lock, flags); +} +static int bgpio_dir_out_dir_first(struct gpio_chip *gc, unsigned int gpio, + int val) +{ + bgpio_dir_out(gc, gpio, val); + gc->set(gc, gpio, val); + return 0; +} + +static int bgpio_dir_out_val_first(struct gpio_chip *gc, unsigned int gpio, + int val) +{ + gc->set(gc, gpio, val); + bgpio_dir_out(gc, gpio, val); return 0; } @@ -538,7 +550,10 @@ static int bgpio_setup_direction(struct gpio_chip *gc, if (dirout || dirin) { gc->reg_dir_out = dirout; gc->reg_dir_in = dirin; - gc->direction_output = bgpio_dir_out; + if (flags & BGPIOF_NO_SET_ON_INPUT) + gc->direction_output = bgpio_dir_out_dir_first; + else + gc->direction_output = bgpio_dir_out_val_first; gc->direction_input = bgpio_dir_in; gc->get_direction = bgpio_get_dir; } else { diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 6ef05bccc0a6..ed65e00ee977 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -572,6 +572,7 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev, #define BGPIOF_BIG_ENDIAN_BYTE_ORDER BIT(3) #define BGPIOF_READ_OUTPUT_REG_SET BIT(4) /* reg_set stores output value */ #define BGPIOF_NO_OUTPUT BIT(5) /* only input */ +#define BGPIOF_NO_SET_ON_INPUT BIT(6) int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hwirq); -- 2.24.1