linux-stable/drivers/bcma/driver_gpio.c
Hauke Mehrtens cf0936b06d bcma: add GPIO driver
Register a GPIO driver to access the GPIOs provided by the chip.
The GPIOs of the SoC should always start at 0 and the other GPIOs could
start at a random position. There is just one SoC in a system and when
they start at 0 the number is predictable.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4587
Acked-by: Florian Fainelli <florian@openwrt.org>
2012-11-21 21:55:52 +01:00

98 lines
2.4 KiB
C

/*
* Broadcom specific AMBA
* GPIO driver
*
* Copyright 2011, Broadcom Corporation
* Copyright 2012, Hauke Mehrtens <hauke@hauke-m.de>
*
* Licensed under the GNU/GPL. See COPYING for details.
*/
#include <linux/gpio.h>
#include <linux/export.h>
#include <linux/bcma/bcma.h>
#include "bcma_private.h"
static inline struct bcma_drv_cc *bcma_gpio_get_cc(struct gpio_chip *chip)
{
return container_of(chip, struct bcma_drv_cc, gpio);
}
static int bcma_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
return !!bcma_chipco_gpio_in(cc, 1 << gpio);
}
static void bcma_gpio_set_value(struct gpio_chip *chip, unsigned gpio,
int value)
{
struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
}
static int bcma_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
bcma_chipco_gpio_outen(cc, 1 << gpio, 0);
return 0;
}
static int bcma_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
int value)
{
struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
bcma_chipco_gpio_outen(cc, 1 << gpio, 1 << gpio);
bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
return 0;
}
static int bcma_gpio_request(struct gpio_chip *chip, unsigned gpio)
{
struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
bcma_chipco_gpio_control(cc, 1 << gpio, 0);
/* clear pulldown */
bcma_chipco_gpio_pulldown(cc, 1 << gpio, 0);
/* Set pullup */
bcma_chipco_gpio_pullup(cc, 1 << gpio, 1 << gpio);
return 0;
}
static void bcma_gpio_free(struct gpio_chip *chip, unsigned gpio)
{
struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
/* clear pullup */
bcma_chipco_gpio_pullup(cc, 1 << gpio, 0);
}
int bcma_gpio_init(struct bcma_drv_cc *cc)
{
struct gpio_chip *chip = &cc->gpio;
chip->label = "bcma_gpio";
chip->owner = THIS_MODULE;
chip->request = bcma_gpio_request;
chip->free = bcma_gpio_free;
chip->get = bcma_gpio_get_value;
chip->set = bcma_gpio_set_value;
chip->direction_input = bcma_gpio_direction_input;
chip->direction_output = bcma_gpio_direction_output;
chip->ngpio = 16;
/* There is just one SoC in one device and its GPIO addresses should be
* deterministic to address them more easily. The other buses could get
* a random base number. */
if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
chip->base = 0;
else
chip->base = -1;
return gpiochip_add(chip);
}