driver_gpio.c

/*
 * Sonics Silicon Backplane
 * 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/ssb/ssb.h>

#include "ssb_private.h"

static struct ssb_bus *ssb_gpio_get_bus(struct gpio_chip *chip)
{
	return container_of(chip, struct ssb_bus, gpio);
}

static int ssb_gpio_chipco_get_value(struct gpio_chip *chip, unsigned gpio)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	return !!ssb_chipco_gpio_in(&bus->chipco, 1 << gpio);
}

static void ssb_gpio_chipco_set_value(struct gpio_chip *chip, unsigned gpio,
				      int value)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	ssb_chipco_gpio_out(&bus->chipco, 1 << gpio, value ? 1 << gpio : 0);
}

static int ssb_gpio_chipco_direction_input(struct gpio_chip *chip,
					   unsigned gpio)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	ssb_chipco_gpio_outen(&bus->chipco, 1 << gpio, 0);
	return 0;
}

static int ssb_gpio_chipco_direction_output(struct gpio_chip *chip,
					    unsigned gpio, int value)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	ssb_chipco_gpio_outen(&bus->chipco, 1 << gpio, 1 << gpio);
	ssb_chipco_gpio_out(&bus->chipco, 1 << gpio, value ? 1 << gpio : 0);
	return 0;
}

static int ssb_gpio_chipco_request(struct gpio_chip *chip, unsigned gpio)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	ssb_chipco_gpio_control(&bus->chipco, 1 << gpio, 0);
	/* clear pulldown */
	ssb_chipco_gpio_pulldown(&bus->chipco, 1 << gpio, 0);
	/* Set pullup */
	ssb_chipco_gpio_pullup(&bus->chipco, 1 << gpio, 1 << gpio);

	return 0;
}

static void ssb_gpio_chipco_free(struct gpio_chip *chip, unsigned gpio)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	/* clear pullup */
	ssb_chipco_gpio_pullup(&bus->chipco, 1 << gpio, 0);
}

static int ssb_gpio_chipco_init(struct ssb_bus *bus)
{
	struct gpio_chip *chip = &bus->gpio;

	chip->label		= "ssb_chipco_gpio";
	chip->owner		= THIS_MODULE;
	chip->request		= ssb_gpio_chipco_request;
	chip->free		= ssb_gpio_chipco_free;
	chip->get		= ssb_gpio_chipco_get_value;
	chip->set		= ssb_gpio_chipco_set_value;
	chip->direction_input	= ssb_gpio_chipco_direction_input;
	chip->direction_output	= ssb_gpio_chipco_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 (bus->bustype == SSB_BUSTYPE_SSB)
		chip->base		= 0;
	else
		chip->base		= -1;

	return gpiochip_add(chip);
}

#ifdef CONFIG_SSB_DRIVER_EXTIF

static int ssb_gpio_extif_get_value(struct gpio_chip *chip, unsigned gpio)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	return !!ssb_extif_gpio_in(&bus->extif, 1 << gpio);
}

static void ssb_gpio_extif_set_value(struct gpio_chip *chip, unsigned gpio,
				     int value)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	ssb_extif_gpio_out(&bus->extif, 1 << gpio, value ? 1 << gpio : 0);
}

static int ssb_gpio_extif_direction_input(struct gpio_chip *chip,
					  unsigned gpio)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	ssb_extif_gpio_outen(&bus->extif, 1 << gpio, 0);
	return 0;
}

static int ssb_gpio_extif_direction_output(struct gpio_chip *chip,
					   unsigned gpio, int value)
{
	struct ssb_bus *bus = ssb_gpio_get_bus(chip);

	ssb_extif_gpio_outen(&bus->extif, 1 << gpio, 1 << gpio);
	ssb_extif_gpio_out(&bus->extif, 1 << gpio, value ? 1 << gpio : 0);
	return 0;
}

static int ssb_gpio_extif_init(struct ssb_bus *bus)
{
	struct gpio_chip *chip = &bus->gpio;

	chip->label		= "ssb_extif_gpio";
	chip->owner		= THIS_MODULE;
	chip->get		= ssb_gpio_extif_get_value;
	chip->set		= ssb_gpio_extif_set_value;
	chip->direction_input	= ssb_gpio_extif_direction_input;
	chip->direction_output	= ssb_gpio_extif_direction_output;
	chip->ngpio		= 5;
	/* 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 (bus->bustype == SSB_BUSTYPE_SSB)
		chip->base		= 0;
	else
		chip->base		= -1;

	return gpiochip_add(chip);
}

#else
static int ssb_gpio_extif_init(struct ssb_bus *bus)
{
	return -ENOTSUPP;
}
#endif

int ssb_gpio_init(struct ssb_bus *bus)
{
	if (ssb_chipco_available(&bus->chipco))
		return ssb_gpio_chipco_init(bus);
	else if (ssb_extif_available(&bus->extif))
		return ssb_gpio_extif_init(bus);
	else
		SSB_WARN_ON(1);

	return -1;
}

int ssb_gpio_unregister(struct ssb_bus *bus)
{
	if (ssb_chipco_available(&bus->chipco) ||
	    ssb_extif_available(&bus->extif)) {
		return gpiochip_remove(&bus->gpio);
	} else {
		SSB_WARN_ON(1);
	}

	return -1;
}