/*
 *
 * (c) 2008 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <linux/clk.h>
#include <errno.h>
#include <io.h>
#include <mach/gpio.h>
#include <gpio.h>

static int gpio_banks;
static struct at91_gpio_bank *gpio;

static inline void __iomem *pin_to_controller(unsigned pin)
{
	pin -= PIN_BASE;
	pin /= 32;
	if (likely(pin < gpio_banks))
		return gpio[pin].regbase;

	return NULL;
}

static inline unsigned pin_to_mask(unsigned pin)
{
	pin -= PIN_BASE;
	return 1 << (pin % 32);
}

/*
 * mux the pin to the "GPIO" peripheral role.
 */
int at91_set_GPIO_periph(unsigned pin, int use_pullup)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;
	__raw_writel(mask, pio + PIO_IDR);
	__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
	__raw_writel(mask, pio + PIO_PER);
	return 0;
}
EXPORT_SYMBOL(at91_set_GPIO_periph);

/*
 * mux the pin to the "A" internal peripheral role.
 */
int at91_set_A_periph(unsigned pin, int use_pullup)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + PIO_IDR);
	__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
	__raw_writel(mask, pio + PIO_ASR);
	__raw_writel(mask, pio + PIO_PDR);
	return 0;
}
EXPORT_SYMBOL(at91_set_A_periph);

/*
 * mux the pin to the "B" internal peripheral role.
 */
int at91_set_B_periph(unsigned pin, int use_pullup)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + PIO_IDR);
	__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
	__raw_writel(mask, pio + PIO_BSR);
	__raw_writel(mask, pio + PIO_PDR);
	return 0;
}
EXPORT_SYMBOL(at91_set_B_periph);

/*
 * mux the pin to the gpio controller (instead of "A" or "B" peripheral), and
 * configure it for an input.
 */
int at91_set_gpio_input(unsigned pin, int use_pullup)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + PIO_IDR);
	__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
	__raw_writel(mask, pio + PIO_ODR);
	__raw_writel(mask, pio + PIO_PER);
	return 0;
}
EXPORT_SYMBOL(at91_set_gpio_input);

/*
 * mux the pin to the gpio controller (instead of "A" or "B" peripheral),
 * and configure it for an output.
 */
int at91_set_gpio_output(unsigned pin, int value)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + PIO_IDR);
	__raw_writel(mask, pio + PIO_PUDR);
	__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
	__raw_writel(mask, pio + PIO_OER);
	__raw_writel(mask, pio + PIO_PER);
	return 0;
}
EXPORT_SYMBOL(at91_set_gpio_output);

/*
 * enable/disable the glitch filter; mostly used with IRQ handling.
 */
int at91_set_deglitch(unsigned pin, int is_on)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;
	__raw_writel(mask, pio + (is_on ? PIO_IFER : PIO_IFDR));
	return 0;
}
EXPORT_SYMBOL(at91_set_deglitch);

/*
 * enable/disable the multi-driver; This is only valid for output and
 * allows the output pin to run as an open collector output.
 */
int at91_set_multi_drive(unsigned pin, int is_on)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + (is_on ? PIO_MDER : PIO_MDDR));
	return 0;
}
EXPORT_SYMBOL(at91_set_multi_drive);

/*
 * assuming the pin is muxed as a gpio output, set its value.
 */
int at91_set_gpio_value(unsigned pin, int value)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;
	__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
	return 0;
}
EXPORT_SYMBOL(at91_set_gpio_value);

/*
 * read the pin's value (works even if it's not muxed as a gpio).
 */
int at91_get_gpio_value(unsigned pin)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);
	u32		pdsr;

	if (!pio)
		return -EINVAL;
	pdsr = __raw_readl(pio + PIO_PDSR);
	return (pdsr & mask) != 0;
}
EXPORT_SYMBOL(at91_get_gpio_value);

int gpio_direction_input(unsigned pin)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio || !(__raw_readl(pio + PIO_PSR) & mask))
		return -EINVAL;
	__raw_writel(mask, pio + PIO_ODR);
	return 0;
}
EXPORT_SYMBOL(gpio_direction_input);

int gpio_direction_output(unsigned pin, int value)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio || !(__raw_readl(pio + PIO_PSR) & mask))
		return -EINVAL;
	__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
	__raw_writel(mask, pio + PIO_OER);
	return 0;
}
EXPORT_SYMBOL(gpio_direction_output);

/*--------------------------------------------------------------------------*/

int at91_gpio_init(struct at91_gpio_bank *data, int nr_banks)
{
	unsigned i;

	gpio = data;
	gpio_banks = nr_banks;

	for (i = 0; i < nr_banks; i++, data++) {
		/* enable PIO controller's clock */
		clk_enable(data->clock);
	}

	return 0;
}