/* arch/arm/plat-s3c64xx/gpiolib.c
 *
 * Copyright 2008 Openmoko, Inc.
 * Copyright 2008 Simtec Electronics
 *      Ben Dooks <ben@simtec.co.uk>
 *      http://armlinux.simtec.co.uk/
 *
 * S3C64XX - GPIOlib support 
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/io.h>

#include <mach/map.h>
#include <mach/gpio.h>
#include <mach/gpio-core.h>

#include <plat/gpio-cfg.h>
#include <plat/gpio-cfg-helpers.h>
#include <plat/regs-gpio.h>

/* GPIO bank summary:
 *
 * Bank	GPIOs	Style	SlpCon	ExtInt Group
 * A	8	4Bit	Yes	1
 * B	7	4Bit	Yes	1
 * C	8	4Bit	Yes	2
 * D	5	4Bit	Yes	3
 * E	5	4Bit	Yes	None
 * F	16	2Bit	Yes	4 [1]
 * G	7	4Bit	Yes	5
 * H	10	4Bit[2]	Yes	6
 * I	16	2Bit	Yes	None
 * J	12	2Bit	Yes	None
 * K	16	4Bit[2]	No	None
 * L	15	4Bit[2] No	None
 * M	6	4Bit	No	IRQ_EINT
 * N	16	2Bit	No	IRQ_EINT
 * O	16	2Bit	Yes	7
 * P	15	2Bit	Yes	8
 * Q	9	2Bit	Yes	9
 *
 * [1] BANKF pins 14,15 do not form part of the external interrupt sources
 * [2] BANK has two control registers, GPxCON0 and GPxCON1
 */

#define OFF_GPCON	(0x00)
#define OFF_GPDAT	(0x04)

#define con_4bit_shift(__off) ((__off) * 4)

#if 1
#define gpio_dbg(x...) do { } while(0)
#else
#define gpio_dbg(x...) printk(KERN_DEBUG ## x)
#endif

/* The s3c64xx_gpiolib_4bit routines are to control the gpio banks where
 * the gpio configuration register (GPxCON) has 4 bits per GPIO, as the
 * following example:
 *
 * base + 0x00: Control register, 4 bits per gpio
 *	        gpio n: 4 bits starting at (4*n)
 *		0000 = input, 0001 = output, others mean special-function
 * base + 0x04: Data register, 1 bit per gpio
 *		bit n: data bit n
 *
 * Note, since the data register is one bit per gpio and is at base + 0x4
 * we can use s3c_gpiolib_get and s3c_gpiolib_set to change the state of
 * the output.
*/

static int s3c64xx_gpiolib_4bit_input(struct gpio_chip *chip, unsigned offset)
{
	struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
	void __iomem *base = ourchip->base;
	unsigned long con;

	con = __raw_readl(base + OFF_GPCON);
	con &= ~(0xf << con_4bit_shift(offset));
	__raw_writel(con, base + OFF_GPCON);

	gpio_dbg("%s: %p: CON now %08lx\n", __func__, base, con);

	return 0;
}

static int s3c64xx_gpiolib_4bit_output(struct gpio_chip *chip,
				       unsigned offset, int value)
{
	struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
	void __iomem *base = ourchip->base;
	unsigned long con;
	unsigned long dat;

	con = __raw_readl(base + OFF_GPCON);
	con &= ~(0xf << con_4bit_shift(offset));
	con |= 0x1 << con_4bit_shift(offset);

	dat = __raw_readl(base + OFF_GPDAT);
	if (value)
		dat |= 1 << offset;
	else
		dat &= ~(1 << offset);

	__raw_writel(dat, base + OFF_GPDAT);
	__raw_writel(con, base + OFF_GPCON);
	__raw_writel(dat, base + OFF_GPDAT);

	gpio_dbg("%s: %p: CON %08lx, DAT %08lx\n", __func__, base, con, dat);

	return 0;
}

/* The next set of routines are for the case where the GPIO configuration
 * registers are 4 bits per GPIO but there is more than one register (the
 * bank has more than 8 GPIOs.
 *
 * This case is the similar to the 4 bit case, but the registers are as
 * follows:
 *
 * base + 0x00: Control register, 4 bits per gpio (lower 8 GPIOs)
 *	        gpio n: 4 bits starting at (4*n)
 *		0000 = input, 0001 = output, others mean special-function
 * base + 0x04: Control register, 4 bits per gpio (up to 8 additions GPIOs)
 *	        gpio n: 4 bits starting at (4*n)
 *		0000 = input, 0001 = output, others mean special-function
 * base + 0x08: Data register, 1 bit per gpio
 *		bit n: data bit n
 *
 * To allow us to use the s3c_gpiolib_get and s3c_gpiolib_set routines we
 * store the 'base + 0x4' address so that these routines see the data
 * register at ourchip->base + 0x04.
*/

static int s3c64xx_gpiolib_4bit2_input(struct gpio_chip *chip, unsigned offset)
{
	struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
	void __iomem *base = ourchip->base;
	void __iomem *regcon = base;
	unsigned long con;

	if (offset > 7)
		offset -= 8;
	else
		regcon -= 4;

	con = __raw_readl(regcon);
	con &= ~(0xf << con_4bit_shift(offset));
	__raw_writel(con, regcon);

	gpio_dbg("%s: %p: CON %08lx\n", __func__, base, con);

	return 0;

}

static int s3c64xx_gpiolib_4bit2_output(struct gpio_chip *chip,
				       unsigned offset, int value)
{
	struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
	void __iomem *base = ourchip->base;
	void __iomem *regcon = base;
	unsigned long con;
	unsigned long dat;

	if (offset > 7)
		offset -= 8;
	else
		regcon -= 4;

	con = __raw_readl(regcon);
	con &= ~(0xf << con_4bit_shift(offset));
	con |= 0x1 << con_4bit_shift(offset);

	dat = __raw_readl(base + OFF_GPDAT);
	if (value)
		dat |= 1 << offset;
	else
		dat &= ~(1 << offset);

	__raw_writel(dat, base + OFF_GPDAT);
	__raw_writel(con, regcon);
	__raw_writel(dat, base + OFF_GPDAT);

	gpio_dbg("%s: %p: CON %08lx, DAT %08lx\n", __func__, base, con, dat);

	return 0;
}

static struct s3c_gpio_cfg gpio_4bit_cfg_noint = {
	.set_config	= s3c_gpio_setcfg_s3c64xx_4bit,
	.set_pull	= s3c_gpio_setpull_updown,
	.get_pull	= s3c_gpio_getpull_updown,
};

static struct s3c_gpio_cfg gpio_4bit_cfg_eint0111 = {
	.cfg_eint	= 7,
	.set_config	= s3c_gpio_setcfg_s3c64xx_4bit,
	.set_pull	= s3c_gpio_setpull_updown,
	.get_pull	= s3c_gpio_getpull_updown,
};

static struct s3c_gpio_cfg gpio_4bit_cfg_eint0011 = {
	.cfg_eint	= 3,
	.set_config	= s3c_gpio_setcfg_s3c64xx_4bit,
	.set_pull	= s3c_gpio_setpull_updown,
	.get_pull	= s3c_gpio_getpull_updown,
};

static struct s3c_gpio_chip gpio_4bit[] = {
	{
		.base	= S3C64XX_GPA_BASE,
		.config	= &gpio_4bit_cfg_eint0111,
		.chip	= {
			.base	= S3C64XX_GPA(0),
			.ngpio	= S3C64XX_GPIO_A_NR,
			.label	= "GPA",
		},
	}, {
		.base	= S3C64XX_GPB_BASE,
		.config	= &gpio_4bit_cfg_eint0111,
		.chip	= {
			.base	= S3C64XX_GPB(0),
			.ngpio	= S3C64XX_GPIO_B_NR,
			.label	= "GPB",
		},
	}, {
		.base	= S3C64XX_GPC_BASE,
		.config	= &gpio_4bit_cfg_eint0111,
		.chip	= {
			.base	= S3C64XX_GPC(0),
			.ngpio	= S3C64XX_GPIO_C_NR,
			.label	= "GPC",
		},
	}, {
		.base	= S3C64XX_GPD_BASE,
		.config	= &gpio_4bit_cfg_eint0111,
		.chip	= {
			.base	= S3C64XX_GPD(0),
			.ngpio	= S3C64XX_GPIO_D_NR,
			.label	= "GPD",
		},
	}, {
		.base	= S3C64XX_GPE_BASE,
		.config	= &gpio_4bit_cfg_noint,
		.chip	= {
			.base	= S3C64XX_GPE(0),
			.ngpio	= S3C64XX_GPIO_E_NR,
			.label	= "GPE",
		},
	}, {
		.base	= S3C64XX_GPG_BASE,
		.config	= &gpio_4bit_cfg_eint0111,
		.chip	= {
			.base	= S3C64XX_GPG(0),
			.ngpio	= S3C64XX_GPIO_G_NR,
			.label	= "GPG",
		},
	}, {
		.base	= S3C64XX_GPM_BASE,
		.config	= &gpio_4bit_cfg_eint0011,
		.chip	= {
			.base	= S3C64XX_GPM(0),
			.ngpio	= S3C64XX_GPIO_M_NR,
			.label	= "GPM",
		},
	},
};

static struct s3c_gpio_chip gpio_4bit2[] = {
	{
		.base	= S3C64XX_GPH_BASE + 0x4,
		.config	= &gpio_4bit_cfg_eint0111,
		.chip	= {
			.base	= S3C64XX_GPH(0),
			.ngpio	= S3C64XX_GPIO_H_NR,
			.label	= "GPH",
		},
	}, {
		.base	= S3C64XX_GPK_BASE + 0x4,
		.config	= &gpio_4bit_cfg_noint,
		.chip	= {
			.base	= S3C64XX_GPK(0),
			.ngpio	= S3C64XX_GPIO_K_NR,
			.label	= "GPK",
		},
	}, {
		.base	= S3C64XX_GPL_BASE + 0x4,
		.config	= &gpio_4bit_cfg_eint0011,
		.chip	= {
			.base	= S3C64XX_GPL(0),
			.ngpio	= S3C64XX_GPIO_L_NR,
			.label	= "GPL",
		},
	},
};

static struct s3c_gpio_cfg gpio_2bit_cfg_noint = {
	.set_config	= s3c_gpio_setcfg_s3c24xx,
	.set_pull	= s3c_gpio_setpull_updown,
	.get_pull	= s3c_gpio_getpull_updown,
};

static struct s3c_gpio_cfg gpio_2bit_cfg_eint10 = {
	.cfg_eint	= 2,
	.set_config	= s3c_gpio_setcfg_s3c24xx,
	.set_pull	= s3c_gpio_setpull_updown,
	.get_pull	= s3c_gpio_getpull_updown,
};

static struct s3c_gpio_cfg gpio_2bit_cfg_eint11 = {
	.cfg_eint	= 3,
	.set_config	= s3c_gpio_setcfg_s3c24xx,
	.set_pull	= s3c_gpio_setpull_updown,
	.get_pull	= s3c_gpio_getpull_updown,
};

static struct s3c_gpio_chip gpio_2bit[] = {
	{
		.base	= S3C64XX_GPF_BASE,
		.config	= &gpio_2bit_cfg_eint11,
		.chip	= {
			.base	= S3C64XX_GPF(0),
			.ngpio	= S3C64XX_GPIO_F_NR,
			.label	= "GPF",
		},
	}, {
		.base	= S3C64XX_GPI_BASE,
		.config	= &gpio_2bit_cfg_noint,
		.chip	= {
			.base	= S3C64XX_GPI(0),
			.ngpio	= S3C64XX_GPIO_I_NR,
			.label	= "GPI",
		},
	}, {
		.base	= S3C64XX_GPJ_BASE,
		.config	= &gpio_2bit_cfg_noint,
		.chip	= {
			.base	= S3C64XX_GPJ(0),
			.ngpio	= S3C64XX_GPIO_J_NR,
			.label	= "GPJ",
		},
	}, {
		.base	= S3C64XX_GPN_BASE,
		.config	= &gpio_2bit_cfg_eint10,
		.chip	= {
			.base	= S3C64XX_GPN(0),
			.ngpio	= S3C64XX_GPIO_N_NR,
			.label	= "GPN",
		},
	}, {
		.base	= S3C64XX_GPO_BASE,
		.config	= &gpio_2bit_cfg_eint11,
		.chip	= {
			.base	= S3C64XX_GPO(0),
			.ngpio	= S3C64XX_GPIO_O_NR,
			.label	= "GPO",
		},
	}, {
		.base	= S3C64XX_GPP_BASE,
		.config	= &gpio_2bit_cfg_eint11,
		.chip	= {
			.base	= S3C64XX_GPP(0),
			.ngpio	= S3C64XX_GPIO_P_NR,
			.label	= "GPP",
		},
	}, {
		.base	= S3C64XX_GPQ_BASE,
		.config	= &gpio_2bit_cfg_eint11,
		.chip	= {
			.base	= S3C64XX_GPQ(0),
			.ngpio	= S3C64XX_GPIO_Q_NR,
			.label	= "GPQ",
		},
	},
};

static __init void s3c64xx_gpiolib_add_4bit(struct s3c_gpio_chip *chip)
{
	chip->chip.direction_input = s3c64xx_gpiolib_4bit_input;
	chip->chip.direction_output = s3c64xx_gpiolib_4bit_output;
}

static __init void s3c64xx_gpiolib_add_4bit2(struct s3c_gpio_chip *chip)
{
	chip->chip.direction_input = s3c64xx_gpiolib_4bit2_input;
	chip->chip.direction_output = s3c64xx_gpiolib_4bit2_output;
}

static __init void s3c64xx_gpiolib_add(struct s3c_gpio_chip *chips,
				       int nr_chips,
				       void (*fn)(struct s3c_gpio_chip *))
{
	for (; nr_chips > 0; nr_chips--, chips++) {
		if (fn)
			(fn)(chips);
		s3c_gpiolib_add(chips);
	}
}

static __init int s3c64xx_gpiolib_init(void)
{
	s3c64xx_gpiolib_add(gpio_4bit, ARRAY_SIZE(gpio_4bit),
			    s3c64xx_gpiolib_add_4bit);

	s3c64xx_gpiolib_add(gpio_4bit2, ARRAY_SIZE(gpio_4bit2),
			    s3c64xx_gpiolib_add_4bit2);

	s3c64xx_gpiolib_add(gpio_2bit, ARRAY_SIZE(gpio_2bit), NULL);

	return 0;
}

arch_initcall(s3c64xx_gpiolib_init);
