/*
   *  linux/arch/arm/mach-pxa/mfp-pxa2xx.c
   *
   *  PXA2xx pin mux configuration support
   *
   *  The GPIOs on PXA2xx can be configured as one of many alternate
   *  functions, this is by concept samilar to the MFP configuration
   *  on PXA3xx,  what's more important, the low power pin state and
   *  wakeup detection are also supported by the same framework.
   *
   *  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/gpio.h>
  #include <linux/gpio-pxa.h>
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/io.h>
  #include <linux/syscore_ops.h>
  
  #include <mach/pxa2xx-regs.h>
  #include <mach/mfp-pxa2xx.h>
  
  #include "generic.h"
  
  #define PGSR(x)		__REG2(0x40F00020, (x) << 2)
  #define __GAFR(u, x)	__REG2((u) ? 0x40E00058 : 0x40E00054, (x) << 3)
  #define GAFR_L(x)	__GAFR(0, x)
  #define GAFR_U(x)	__GAFR(1, x)
  
  #define BANK_OFF(n)	(((n) < 3) ? (n) << 2 : 0x100 + (((n) - 3) << 2))
  #define GPLR(x)		__REG2(0x40E00000, BANK_OFF((x) >> 5))
  #define GPDR(x)		__REG2(0x40E00000, BANK_OFF((x) >> 5) + 0x0c)
  #define GPSR(x)		__REG2(0x40E00000, BANK_OFF((x) >> 5) + 0x18)
  #define GPCR(x)		__REG2(0x40E00000, BANK_OFF((x) >> 5) + 0x24)
  
  #define PWER_WE35	(1 << 24)
  
  struct gpio_desc {
  	unsigned	valid		: 1;
  	unsigned	can_wakeup	: 1;
  	unsigned	keypad_gpio	: 1;
  	unsigned	dir_inverted	: 1;
  	unsigned int	mask; /* bit mask in PWER or PKWR */
  	unsigned int	mux_mask; /* bit mask of muxed gpio bits, 0 if no mux */
  	unsigned long	config;
  };
  
  static struct gpio_desc gpio_desc[MFP_PIN_GPIO127 + 1];
  
  static unsigned long gpdr_lpm[4];
  
  static int __mfp_config_gpio(unsigned gpio, unsigned long c)
  {
  	unsigned long gafr, mask = GPIO_bit(gpio);
  	int bank = gpio_to_bank(gpio);
  	int uorl = !!(gpio & 0x10); /* GAFRx_U or GAFRx_L ? */
  	int shft = (gpio & 0xf) << 1;
  	int fn = MFP_AF(c);
  	int is_out = (c & MFP_DIR_OUT) ? 1 : 0;
  
  	if (fn > 3)
  		return -EINVAL;
  
  	/* alternate function and direction at run-time */
  	gafr = (uorl == 0) ? GAFR_L(bank) : GAFR_U(bank);
  	gafr = (gafr & ~(0x3 << shft)) | (fn << shft);
  
  	if (uorl == 0)
  		GAFR_L(bank) = gafr;
  	else
  		GAFR_U(bank) = gafr;
  
  	if (is_out ^ gpio_desc[gpio].dir_inverted)
  		GPDR(gpio) |= mask;
  	else
  		GPDR(gpio) &= ~mask;
  
  	/* alternate function and direction at low power mode */
  	switch (c & MFP_LPM_STATE_MASK) {
  	case MFP_LPM_DRIVE_HIGH:
  		PGSR(bank) |= mask;
  		is_out = 1;
  		break;
  	case MFP_LPM_DRIVE_LOW:
  		PGSR(bank) &= ~mask;
  		is_out = 1;
  		break;
  	case MFP_LPM_INPUT:
  	case MFP_LPM_DEFAULT:
  		break;
  	default:
  		/* warning and fall through, treat as MFP_LPM_DEFAULT */
  		pr_warning("%s: GPIO%d: unsupported low power mode
  ",
  				__func__, gpio);
  		break;
  	}
  
  	if (is_out ^ gpio_desc[gpio].dir_inverted)
  		gpdr_lpm[bank] |= mask;
  	else
  		gpdr_lpm[bank] &= ~mask;
  
  	/* give early warning if MFP_LPM_CAN_WAKEUP is set on the
  	 * configurations of those pins not able to wakeup
  	 */
  	if ((c & MFP_LPM_CAN_WAKEUP) && !gpio_desc[gpio].can_wakeup) {
  		pr_warning("%s: GPIO%d unable to wakeup
  ",
  				__func__, gpio);
  		return -EINVAL;
  	}
  
  	if ((c & MFP_LPM_CAN_WAKEUP) && is_out) {
  		pr_warning("%s: output GPIO%d unable to wakeup
  ",
  				__func__, gpio);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static inline int __mfp_validate(int mfp)
  {
  	int gpio = mfp_to_gpio(mfp);
  
  	if ((mfp > MFP_PIN_GPIO127) || !gpio_desc[gpio].valid) {
  		pr_warning("%s: GPIO%d is invalid pin
  ", __func__, gpio);
  		return -1;
  	}
  
  	return gpio;
  }
  
  void pxa2xx_mfp_config(unsigned long *mfp_cfgs, int num)
  {
  	unsigned long flags;
  	unsigned long *c;
  	int i, gpio;
  
  	for (i = 0, c = mfp_cfgs; i < num; i++, c++) {
  
  		gpio = __mfp_validate(MFP_PIN(*c));
  		if (gpio < 0)
  			continue;
  
  		local_irq_save(flags);
  
  		gpio_desc[gpio].config = *c;
  		__mfp_config_gpio(gpio, *c);
  
  		local_irq_restore(flags);
  	}
  }
  
  void pxa2xx_mfp_set_lpm(int mfp, unsigned long lpm)
  {
  	unsigned long flags, c;
  	int gpio;
  
  	gpio = __mfp_validate(mfp);
  	if (gpio < 0)
  		return;
  
  	local_irq_save(flags);
  
  	c = gpio_desc[gpio].config;
  	c = (c & ~MFP_LPM_STATE_MASK) | lpm;
  	__mfp_config_gpio(gpio, c);
  
  	local_irq_restore(flags);
  }
  
  int gpio_set_wake(unsigned int gpio, unsigned int on)
  {
  	struct gpio_desc *d;
  	unsigned long c, mux_taken;
  
  	if (gpio > mfp_to_gpio(MFP_PIN_GPIO127))
  		return -EINVAL;
  
  	d = &gpio_desc[gpio];
  	c = d->config;
  
  	if (!d->valid)
  		return -EINVAL;
  
  	/* Allow keypad GPIOs to wakeup system when
  	 * configured as generic GPIOs.
  	 */
  	if (d->keypad_gpio && (MFP_AF(d->config) == 0) &&
  	    (d->config & MFP_LPM_CAN_WAKEUP)) {
  		if (on)
  			PKWR |= d->mask;
  		else
  			PKWR &= ~d->mask;
  		return 0;
  	}
  
  	mux_taken = (PWER & d->mux_mask) & (~d->mask);
  	if (on && mux_taken)
  		return -EBUSY;
  
  	if (d->can_wakeup && (c & MFP_LPM_CAN_WAKEUP)) {
  		if (on) {
  			PWER = (PWER & ~d->mux_mask) | d->mask;
  
  			if (c & MFP_LPM_EDGE_RISE)
  				PRER |= d->mask;
  			else
  				PRER &= ~d->mask;
  
  			if (c & MFP_LPM_EDGE_FALL)
  				PFER |= d->mask;
  			else
  				PFER &= ~d->mask;
  		} else {
  			PWER &= ~d->mask;
  			PRER &= ~d->mask;
  			PFER &= ~d->mask;
  		}
  	}
  	return 0;
  }
  
  #ifdef CONFIG_PXA25x
  static void __init pxa25x_mfp_init(void)
  {
  	int i;
  
  	/* running before pxa_gpio_probe() */
  #ifdef CONFIG_CPU_PXA26x
  	pxa_last_gpio = 89;
  #else
  	pxa_last_gpio = 84;
  #endif
  	for (i = 0; i <= pxa_last_gpio; i++)
  		gpio_desc[i].valid = 1;
  
  	for (i = 0; i <= 15; i++) {
  		gpio_desc[i].can_wakeup = 1;
  		gpio_desc[i].mask = GPIO_bit(i);
  	}
  
  	/* PXA26x has additional 4 GPIOs (86/87/88/89) which has the
  	 * direction bit inverted in GPDR2. See PXA26x DM 4.1.1.
  	 */
  	for (i = 86; i <= pxa_last_gpio; i++)
  		gpio_desc[i].dir_inverted = 1;
  }
  #else
  static inline void pxa25x_mfp_init(void) {}
  #endif /* CONFIG_PXA25x */
  
  #ifdef CONFIG_PXA27x
  static int pxa27x_pkwr_gpio[] = {
  	13, 16, 17, 34, 36, 37, 38, 39, 90, 91, 93, 94,
  	95, 96, 97, 98, 99, 100, 101, 102
  };
  
  int keypad_set_wake(unsigned int on)
  {
  	unsigned int i, gpio, mask = 0;
  	struct gpio_desc *d;
  
  	for (i = 0; i < ARRAY_SIZE(pxa27x_pkwr_gpio); i++) {
  
  		gpio = pxa27x_pkwr_gpio[i];
  		d = &gpio_desc[gpio];
  
  		/* skip if configured as generic GPIO */
  		if (MFP_AF(d->config) == 0)
  			continue;
  
  		if (d->config & MFP_LPM_CAN_WAKEUP)
  			mask |= gpio_desc[gpio].mask;
  	}
  
  	if (on)
  		PKWR |= mask;
  	else
  		PKWR &= ~mask;
  	return 0;
  }
  
  #define PWER_WEMUX2_GPIO38	(1 << 16)
  #define PWER_WEMUX2_GPIO53	(2 << 16)
  #define PWER_WEMUX2_GPIO40	(3 << 16)
  #define PWER_WEMUX2_GPIO36	(4 << 16)
  #define PWER_WEMUX2_MASK	(7 << 16)
  #define PWER_WEMUX3_GPIO31	(1 << 19)
  #define PWER_WEMUX3_GPIO113	(2 << 19)
  #define PWER_WEMUX3_MASK	(3 << 19)
  
  #define INIT_GPIO_DESC_MUXED(mux, gpio)				\
  do {								\
  	gpio_desc[(gpio)].can_wakeup = 1;			\
  	gpio_desc[(gpio)].mask = PWER_ ## mux ## _GPIO ##gpio;	\
  	gpio_desc[(gpio)].mux_mask = PWER_ ## mux ## _MASK;	\
  } while (0)
  
  static void __init pxa27x_mfp_init(void)
  {
  	int i, gpio;
  
  	pxa_last_gpio = 120;	/* running before pxa_gpio_probe() */
  	for (i = 0; i <= pxa_last_gpio; i++) {
  		/* skip GPIO2, 5, 6, 7, 8, they are not
  		 * valid pins allow configuration
  		 */
  		if (i == 2 || i == 5 || i == 6 || i == 7 || i == 8)
  			continue;
  
  		gpio_desc[i].valid = 1;
  	}
  
  	/* Keypad GPIOs */
  	for (i = 0; i < ARRAY_SIZE(pxa27x_pkwr_gpio); i++) {
  		gpio = pxa27x_pkwr_gpio[i];
  		gpio_desc[gpio].can_wakeup = 1;
  		gpio_desc[gpio].keypad_gpio = 1;
  		gpio_desc[gpio].mask = 1 << i;
  	}
  
  	/* Overwrite GPIO13 as a PWER wakeup source */
  	for (i = 0; i <= 15; i++) {
  		/* skip GPIO2, 5, 6, 7, 8 */
  		if (GPIO_bit(i) & 0x1e4)
  			continue;
  
  		gpio_desc[i].can_wakeup = 1;
  		gpio_desc[i].mask = GPIO_bit(i);
  	}
  
  	gpio_desc[35].can_wakeup = 1;
  	gpio_desc[35].mask = PWER_WE35;
  
  	INIT_GPIO_DESC_MUXED(WEMUX3, 31);
  	INIT_GPIO_DESC_MUXED(WEMUX3, 113);
  	INIT_GPIO_DESC_MUXED(WEMUX2, 38);
  	INIT_GPIO_DESC_MUXED(WEMUX2, 53);
  	INIT_GPIO_DESC_MUXED(WEMUX2, 40);
  	INIT_GPIO_DESC_MUXED(WEMUX2, 36);
  }
  #else
  static inline void pxa27x_mfp_init(void) {}
  #endif /* CONFIG_PXA27x */
  
  #ifdef CONFIG_PM
  static unsigned long saved_gafr[2][4];
  static unsigned long saved_gpdr[4];
  static unsigned long saved_gplr[4];
  static unsigned long saved_pgsr[4];
  
  static int pxa2xx_mfp_suspend(void)
  {
  	int i;
  
  	/* set corresponding PGSR bit of those marked MFP_LPM_KEEP_OUTPUT */
  	for (i = 0; i < pxa_last_gpio; i++) {
  		if ((gpio_desc[i].config & MFP_LPM_KEEP_OUTPUT) &&
  		    (GPDR(i) & GPIO_bit(i))) {
  			if (GPLR(i) & GPIO_bit(i))
  				PGSR(gpio_to_bank(i)) |= GPIO_bit(i);
  			else
  				PGSR(gpio_to_bank(i)) &= ~GPIO_bit(i);
  		}
  	}
  
  	for (i = 0; i <= gpio_to_bank(pxa_last_gpio); i++) {
  		saved_gafr[0][i] = GAFR_L(i);
  		saved_gafr[1][i] = GAFR_U(i);
  		saved_gpdr[i] = GPDR(i * 32);
  		saved_gplr[i] = GPLR(i * 32);
  		saved_pgsr[i] = PGSR(i);
  
  		GPSR(i * 32) = PGSR(i);
  		GPCR(i * 32) = ~PGSR(i);
  	}
  
  	/* set GPDR bits taking into account MFP_LPM_KEEP_OUTPUT */
  	for (i = 0; i < pxa_last_gpio; i++) {
  		if ((gpdr_lpm[gpio_to_bank(i)] & GPIO_bit(i)) ||
  		    ((gpio_desc[i].config & MFP_LPM_KEEP_OUTPUT) &&
  		     (saved_gpdr[gpio_to_bank(i)] & GPIO_bit(i))))
  			GPDR(i) |= GPIO_bit(i);
  		else
  			GPDR(i) &= ~GPIO_bit(i);
  	}
  
  	return 0;
  }
  
  static void pxa2xx_mfp_resume(void)
  {
  	int i;
  
  	for (i = 0; i <= gpio_to_bank(pxa_last_gpio); i++) {
  		GAFR_L(i) = saved_gafr[0][i];
  		GAFR_U(i) = saved_gafr[1][i];
  		GPSR(i * 32) = saved_gplr[i];
  		GPCR(i * 32) = ~saved_gplr[i];
  		GPDR(i * 32) = saved_gpdr[i];
  		PGSR(i) = saved_pgsr[i];
  	}
  	PSSR = PSSR_RDH | PSSR_PH;
  }
  #else
  #define pxa2xx_mfp_suspend	NULL
  #define pxa2xx_mfp_resume	NULL
  #endif
  
  struct syscore_ops pxa2xx_mfp_syscore_ops = {
  	.suspend	= pxa2xx_mfp_suspend,
  	.resume		= pxa2xx_mfp_resume,
  };
  
  static int __init pxa2xx_mfp_init(void)
  {
  	int i;
  
  	if (!cpu_is_pxa2xx())
  		return 0;
  
  	if (cpu_is_pxa25x())
  		pxa25x_mfp_init();
  
  	if (cpu_is_pxa27x())
  		pxa27x_mfp_init();
  
  	/* clear RDH bit to enable GPIO receivers after reset/sleep exit */
  	PSSR = PSSR_RDH;
  
  	/* initialize gafr_run[], pgsr_lpm[] from existing values */
  	for (i = 0; i <= gpio_to_bank(pxa_last_gpio); i++)
  		gpdr_lpm[i] = GPDR(i * 32);
  
  	return 0;
  }
  postcore_initcall(pxa2xx_mfp_init);