Commit d19d2de6 authored by Chuanhong Guo's avatar Chuanhong Guo Committed by Bartosz Golaszewski
Browse files

gpio: mmio: introduce BGPIOF_NO_SET_ON_INPUT 



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: default avatarChuanhong Guo <gch981213@gmail.com>
Tested-by: default avatarRené van Dorst <opensource@vdorst.com>
Reviewed-by: default avatarSergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
parent d1ee7e1f

drivers/gpio/gpio-mmio.c

+19 −4
Original line number Diff line number Diff line
@@ -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 {

include/linux/gpio/driver.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

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