u-boot/drivers/gpio/mxs_gpio.c
Michael Heimpold ac135f6699 mxs_gpio: fix the handling in gpio_direction_output()
Setting the direction and an output value should be done by
1) set the desired output value,
2) switch to output.

If this is done in the inverse order, there can be a glitch on
the GPIO line.

This patch fixes this by using the order as described above.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>
Acked-by: Stefano Babic <sbabic@denx.de>
2013-11-13 10:09:09 +01:00

117 lines
2.8 KiB
C

/*
* Freescale i.MX28 GPIO control code
*
* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
* on behalf of DENX Software Engineering GmbH
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <netdev.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/arch/iomux.h>
#include <asm/arch/imx-regs.h>
#if defined(CONFIG_MX23)
#define PINCTRL_BANKS 3
#define PINCTRL_DOUT(n) (0x0500 + ((n) * 0x10))
#define PINCTRL_DIN(n) (0x0600 + ((n) * 0x10))
#define PINCTRL_DOE(n) (0x0700 + ((n) * 0x10))
#define PINCTRL_PIN2IRQ(n) (0x0800 + ((n) * 0x10))
#define PINCTRL_IRQEN(n) (0x0900 + ((n) * 0x10))
#define PINCTRL_IRQSTAT(n) (0x0c00 + ((n) * 0x10))
#elif defined(CONFIG_MX28)
#define PINCTRL_BANKS 5
#define PINCTRL_DOUT(n) (0x0700 + ((n) * 0x10))
#define PINCTRL_DIN(n) (0x0900 + ((n) * 0x10))
#define PINCTRL_DOE(n) (0x0b00 + ((n) * 0x10))
#define PINCTRL_PIN2IRQ(n) (0x1000 + ((n) * 0x10))
#define PINCTRL_IRQEN(n) (0x1100 + ((n) * 0x10))
#define PINCTRL_IRQSTAT(n) (0x1400 + ((n) * 0x10))
#else
#error "Please select CONFIG_MX23 or CONFIG_MX28"
#endif
#define GPIO_INT_FALL_EDGE 0x0
#define GPIO_INT_LOW_LEV 0x1
#define GPIO_INT_RISE_EDGE 0x2
#define GPIO_INT_HIGH_LEV 0x3
#define GPIO_INT_LEV_MASK (1 << 0)
#define GPIO_INT_POL_MASK (1 << 1)
void mxs_gpio_init(void)
{
int i;
for (i = 0; i < PINCTRL_BANKS; i++) {
writel(0, MXS_PINCTRL_BASE + PINCTRL_PIN2IRQ(i));
writel(0, MXS_PINCTRL_BASE + PINCTRL_IRQEN(i));
/* Use SCT address here to clear the IRQSTAT bits */
writel(0xffffffff, MXS_PINCTRL_BASE + PINCTRL_IRQSTAT(i) + 8);
}
}
int gpio_get_value(unsigned gpio)
{
uint32_t bank = PAD_BANK(gpio);
uint32_t offset = PINCTRL_DIN(bank);
struct mxs_register_32 *reg =
(struct mxs_register_32 *)(MXS_PINCTRL_BASE + offset);
return (readl(&reg->reg) >> PAD_PIN(gpio)) & 1;
}
void gpio_set_value(unsigned gpio, int value)
{
uint32_t bank = PAD_BANK(gpio);
uint32_t offset = PINCTRL_DOUT(bank);
struct mxs_register_32 *reg =
(struct mxs_register_32 *)(MXS_PINCTRL_BASE + offset);
if (value)
writel(1 << PAD_PIN(gpio), &reg->reg_set);
else
writel(1 << PAD_PIN(gpio), &reg->reg_clr);
}
int gpio_direction_input(unsigned gpio)
{
uint32_t bank = PAD_BANK(gpio);
uint32_t offset = PINCTRL_DOE(bank);
struct mxs_register_32 *reg =
(struct mxs_register_32 *)(MXS_PINCTRL_BASE + offset);
writel(1 << PAD_PIN(gpio), &reg->reg_clr);
return 0;
}
int gpio_direction_output(unsigned gpio, int value)
{
uint32_t bank = PAD_BANK(gpio);
uint32_t offset = PINCTRL_DOE(bank);
struct mxs_register_32 *reg =
(struct mxs_register_32 *)(MXS_PINCTRL_BASE + offset);
gpio_set_value(gpio, value);
writel(1 << PAD_PIN(gpio), &reg->reg_set);
return 0;
}
int gpio_request(unsigned gpio, const char *label)
{
if (PAD_BANK(gpio) >= PINCTRL_BANKS)
return -1;
return 0;
}
int gpio_free(unsigned gpio)
{
return 0;
}