From 5d7b644aad721ecca20bd8976b38fb243fdc84f9 Mon Sep 17 00:00:00 2001 From: Chuanhong Guo Date: Sun, 15 Mar 2020 20:13:37 +0800 Subject: [PATCH] gpio: mmio: introduce BGPIOF_NO_SET_ON_INPUT MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Tested-by: René van Dorst Reviewed-by: Sergio Paracuellos Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-mmio.c | 23 +++++++++++++++++++---- include/linux/gpio/driver.h | 1 + 2 files changed, 20 insertions(+), 4 deletions(-) --- a/drivers/gpio/gpio-mmio.c +++ b/drivers/gpio/gpio-mmio.c @@ -381,12 +381,10 @@ static int bgpio_get_dir(struct gpio_chi return 1; } -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); @@ -397,7 +395,21 @@ static int bgpio_dir_out(struct gpio_chi 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; } @@ -530,7 +542,10 @@ static int bgpio_setup_direction(struct 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 { --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -567,6 +567,7 @@ int bgpio_init(struct gpio_chip *gc, str #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);