/*

   *  linux/arch/arm/plat-pxa/gpio.c

   *
   *  Generic PXA GPIO handling
   *
   *  Author:	Nicolas Pitre
   *  Created:	Jun 15, 2001
   *  Copyright:	MontaVista Software Inc.
   *
   *  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/clk.h>
  #include <linux/err.h>

  #include <linux/gpio.h>

  #include <linux/gpio-pxa.h>

  #include <linux/init.h>

  #include <linux/irq.h>

  #include <linux/io.h>

  #include <linux/platform_device.h>

  #include <linux/syscore_ops.h>

  #include <linux/slab.h>

  /*
   * We handle the GPIOs by banks, each bank covers up to 32 GPIOs with
   * one set of registers. The register offsets are organized below:
   *
   *           GPLR    GPDR    GPSR    GPCR    GRER    GFER    GEDR
   * BANK 0 - 0x0000  0x000C  0x0018  0x0024  0x0030  0x003C  0x0048
   * BANK 1 - 0x0004  0x0010  0x001C  0x0028  0x0034  0x0040  0x004C
   * BANK 2 - 0x0008  0x0014  0x0020  0x002C  0x0038  0x0044  0x0050
   *
   * BANK 3 - 0x0100  0x010C  0x0118  0x0124  0x0130  0x013C  0x0148
   * BANK 4 - 0x0104  0x0110  0x011C  0x0128  0x0134  0x0140  0x014C
   * BANK 5 - 0x0108  0x0114  0x0120  0x012C  0x0138  0x0144  0x0150
   *
   * NOTE:
   *   BANK 3 is only available on PXA27x and later processors.
   *   BANK 4 and 5 are only available on PXA935
   */
  
  #define GPLR_OFFSET	0x00
  #define GPDR_OFFSET	0x0C
  #define GPSR_OFFSET	0x18
  #define GPCR_OFFSET	0x24
  #define GRER_OFFSET	0x30
  #define GFER_OFFSET	0x3C
  #define GEDR_OFFSET	0x48
  #define GAFR_OFFSET	0x54

  #define ED_MASK_OFFSET	0x9C	/* GPIO edge detection for AP side */

  
  #define BANK_OFF(n)	(((n) < 3) ? (n) << 2 : 0x100 + (((n) - 3) << 2))

  int pxa_last_gpio;

  struct pxa_gpio_chip {
  	struct gpio_chip chip;

  	void __iomem	*regbase;
  	char label[10];
  
  	unsigned long	irq_mask;
  	unsigned long	irq_edge_rise;
  	unsigned long	irq_edge_fall;
  
  #ifdef CONFIG_PM
  	unsigned long	saved_gplr;
  	unsigned long	saved_gpdr;
  	unsigned long	saved_grer;
  	unsigned long	saved_gfer;
  #endif

  };

  enum {
  	PXA25X_GPIO = 0,
  	PXA26X_GPIO,
  	PXA27X_GPIO,
  	PXA3XX_GPIO,
  	PXA93X_GPIO,
  	MMP_GPIO = 0x10,
  	MMP2_GPIO,
  };

  static DEFINE_SPINLOCK(gpio_lock);
  static struct pxa_gpio_chip *pxa_gpio_chips;

  static int gpio_type;

  static void __iomem *gpio_reg_base;

  
  #define for_each_gpio_chip(i, c)			\
  	for (i = 0, c = &pxa_gpio_chips[0]; i <= pxa_last_gpio; i += 32, c++)
  
  static inline void __iomem *gpio_chip_base(struct gpio_chip *c)
  {
  	return container_of(c, struct pxa_gpio_chip, chip)->regbase;
  }

  static inline struct pxa_gpio_chip *gpio_to_pxachip(unsigned gpio)

  {
  	return &pxa_gpio_chips[gpio_to_bank(gpio)];
  }

  static inline int gpio_is_pxa_type(int type)
  {
  	return (type & MMP_GPIO) == 0;
  }
  
  static inline int gpio_is_mmp_type(int type)
  {
  	return (type & MMP_GPIO) != 0;
  }

  /* GPIO86/87/88/89 on PXA26x have their direction bits in PXA_GPDR(2 inverted,
   * as well as their Alternate Function value being '1' for GPIO in GAFRx.
   */
  static inline int __gpio_is_inverted(int gpio)
  {
  	if ((gpio_type == PXA26X_GPIO) && (gpio > 85))
  		return 1;
  	return 0;
  }
  
  /*
   * On PXA25x and PXA27x, GAFRx and GPDRx together decide the alternate
   * function of a GPIO, and GPDRx cannot be altered once configured. It
   * is attributed as "occupied" here (I know this terminology isn't
   * accurate, you are welcome to propose a better one :-)
   */
  static inline int __gpio_is_occupied(unsigned gpio)
  {
  	struct pxa_gpio_chip *pxachip;
  	void __iomem *base;
  	unsigned long gafr = 0, gpdr = 0;
  	int ret, af = 0, dir = 0;
  
  	pxachip = gpio_to_pxachip(gpio);
  	base = gpio_chip_base(&pxachip->chip);
  	gpdr = readl_relaxed(base + GPDR_OFFSET);
  
  	switch (gpio_type) {
  	case PXA25X_GPIO:
  	case PXA26X_GPIO:
  	case PXA27X_GPIO:
  		gafr = readl_relaxed(base + GAFR_OFFSET);
  		af = (gafr >> ((gpio & 0xf) * 2)) & 0x3;
  		dir = gpdr & GPIO_bit(gpio);
  
  		if (__gpio_is_inverted(gpio))
  			ret = (af != 1) || (dir == 0);
  		else
  			ret = (af != 0) || (dir != 0);
  		break;
  	default:
  		ret = gpdr & GPIO_bit(gpio);
  		break;
  	}
  	return ret;
  }

  #ifdef CONFIG_ARCH_PXA
  static inline int __pxa_gpio_to_irq(int gpio)
  {
  	if (gpio_is_pxa_type(gpio_type))
  		return PXA_GPIO_TO_IRQ(gpio);
  	return -1;
  }
  
  static inline int __pxa_irq_to_gpio(int irq)
  {
  	if (gpio_is_pxa_type(gpio_type))
  		return irq - PXA_GPIO_TO_IRQ(0);
  	return -1;
  }
  #else
  static inline int __pxa_gpio_to_irq(int gpio) { return -1; }
  static inline int __pxa_irq_to_gpio(int irq) { return -1; }
  #endif
  
  #ifdef CONFIG_ARCH_MMP
  static inline int __mmp_gpio_to_irq(int gpio)
  {
  	if (gpio_is_mmp_type(gpio_type))
  		return MMP_GPIO_TO_IRQ(gpio);
  	return -1;
  }
  
  static inline int __mmp_irq_to_gpio(int irq)
  {
  	if (gpio_is_mmp_type(gpio_type))
  		return irq - MMP_GPIO_TO_IRQ(0);
  	return -1;
  }
  #else
  static inline int __mmp_gpio_to_irq(int gpio) { return -1; }
  static inline int __mmp_irq_to_gpio(int irq) { return -1; }
  #endif
  
  static int pxa_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  {
  	int gpio, ret;
  
  	gpio = chip->base + offset;
  	ret = __pxa_gpio_to_irq(gpio);
  	if (ret >= 0)
  		return ret;
  	return __mmp_gpio_to_irq(gpio);
  }
  
  int pxa_irq_to_gpio(int irq)
  {
  	int ret;
  
  	ret = __pxa_irq_to_gpio(irq);
  	if (ret >= 0)
  		return ret;
  	return __mmp_irq_to_gpio(irq);
  }

  static int pxa_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
  {

  	void __iomem *base = gpio_chip_base(chip);
  	uint32_t value, mask = 1 << offset;
  	unsigned long flags;
  
  	spin_lock_irqsave(&gpio_lock, flags);

  	value = readl_relaxed(base + GPDR_OFFSET);

  	if (__gpio_is_inverted(chip->base + offset))
  		value |= mask;
  	else
  		value &= ~mask;

  	writel_relaxed(value, base + GPDR_OFFSET);

  	spin_unlock_irqrestore(&gpio_lock, flags);

  	return 0;
  }
  
  static int pxa_gpio_direction_output(struct gpio_chip *chip,

  				     unsigned offset, int value)

  {

  	void __iomem *base = gpio_chip_base(chip);
  	uint32_t tmp, mask = 1 << offset;
  	unsigned long flags;

  	writel_relaxed(mask, base + (value ? GPSR_OFFSET : GPCR_OFFSET));

  
  	spin_lock_irqsave(&gpio_lock, flags);

  	tmp = readl_relaxed(base + GPDR_OFFSET);

  	if (__gpio_is_inverted(chip->base + offset))
  		tmp &= ~mask;
  	else
  		tmp |= mask;

  	writel_relaxed(tmp, base + GPDR_OFFSET);

  	spin_unlock_irqrestore(&gpio_lock, flags);

  	return 0;
  }

  static int pxa_gpio_get(struct gpio_chip *chip, unsigned offset)
  {

  	return readl_relaxed(gpio_chip_base(chip) + GPLR_OFFSET) & (1 << offset);

  }

  static void pxa_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  {

  	writel_relaxed(1 << offset, gpio_chip_base(chip) +

  				(value ? GPSR_OFFSET : GPCR_OFFSET));

  }

  static int __devinit pxa_init_gpio_chip(int gpio_end)

  {

  	int i, gpio, nbanks = gpio_to_bank(gpio_end) + 1;
  	struct pxa_gpio_chip *chips;

  	chips = kzalloc(nbanks * sizeof(struct pxa_gpio_chip), GFP_KERNEL);

  	if (chips == NULL) {
  		pr_err("%s: failed to allocate GPIO chips
  ", __func__);
  		return -ENOMEM;

  	}

  	for (i = 0, gpio = 0; i < nbanks; i++, gpio += 32) {
  		struct gpio_chip *c = &chips[i].chip;

  		sprintf(chips[i].label, "gpio-%d", i);

  		chips[i].regbase = gpio_reg_base + BANK_OFF(i);

  
  		c->base  = gpio;
  		c->label = chips[i].label;
  
  		c->direction_input  = pxa_gpio_direction_input;
  		c->direction_output = pxa_gpio_direction_output;
  		c->get = pxa_gpio_get;
  		c->set = pxa_gpio_set;

  		c->to_irq = pxa_gpio_to_irq;

  
  		/* number of GPIOs on last bank may be less than 32 */
  		c->ngpio = (gpio + 31 > gpio_end) ? (gpio_end - gpio + 1) : 32;
  		gpiochip_add(c);
  	}
  	pxa_gpio_chips = chips;
  	return 0;
  }

  /* Update only those GRERx and GFERx edge detection register bits if those
   * bits are set in c->irq_mask
   */
  static inline void update_edge_detect(struct pxa_gpio_chip *c)
  {
  	uint32_t grer, gfer;

  	grer = readl_relaxed(c->regbase + GRER_OFFSET) & ~c->irq_mask;
  	gfer = readl_relaxed(c->regbase + GFER_OFFSET) & ~c->irq_mask;

  	grer |= c->irq_edge_rise & c->irq_mask;
  	gfer |= c->irq_edge_fall & c->irq_mask;

  	writel_relaxed(grer, c->regbase + GRER_OFFSET);
  	writel_relaxed(gfer, c->regbase + GFER_OFFSET);

  }

  static int pxa_gpio_irq_type(struct irq_data *d, unsigned int type)

  {

  	struct pxa_gpio_chip *c;

  	int gpio = pxa_irq_to_gpio(d->irq);

  	unsigned long gpdr, mask = GPIO_bit(gpio);

  	c = gpio_to_pxachip(gpio);

  
  	if (type == IRQ_TYPE_PROBE) {
  		/* Don't mess with enabled GPIOs using preconfigured edges or
  		 * GPIOs set to alternate function or to output during probe
  		 */

  		if ((c->irq_edge_rise | c->irq_edge_fall) & GPIO_bit(gpio))

  			return 0;

  
  		if (__gpio_is_occupied(gpio))

  			return 0;

  		type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
  	}

  	gpdr = readl_relaxed(c->regbase + GPDR_OFFSET);

  	if (__gpio_is_inverted(gpio))

  		writel_relaxed(gpdr | mask,  c->regbase + GPDR_OFFSET);

  	else

  		writel_relaxed(gpdr & ~mask, c->regbase + GPDR_OFFSET);

  
  	if (type & IRQ_TYPE_EDGE_RISING)

  		c->irq_edge_rise |= mask;

  	else

  		c->irq_edge_rise &= ~mask;

  
  	if (type & IRQ_TYPE_EDGE_FALLING)

  		c->irq_edge_fall |= mask;

  	else

  		c->irq_edge_fall &= ~mask;

  	update_edge_detect(c);

  	pr_debug("%s: IRQ%d (GPIO%d) - edge%s%s
  ", __func__, d->irq, gpio,

  		((type & IRQ_TYPE_EDGE_RISING)  ? " rising"  : ""),
  		((type & IRQ_TYPE_EDGE_FALLING) ? " falling" : ""));
  	return 0;
  }

  static void pxa_gpio_demux_handler(unsigned int irq, struct irq_desc *desc)
  {

  	struct pxa_gpio_chip *c;
  	int loop, gpio, gpio_base, n;
  	unsigned long gedr;

  
  	do {

  		loop = 0;

  		for_each_gpio_chip(gpio, c) {
  			gpio_base = c->chip.base;

  			gedr = readl_relaxed(c->regbase + GEDR_OFFSET);

  			gedr = gedr & c->irq_mask;

  			writel_relaxed(gedr, c->regbase + GEDR_OFFSET);

  			n = find_first_bit(&gedr, BITS_PER_LONG);
  			while (n < BITS_PER_LONG) {
  				loop = 1;

  				generic_handle_irq(gpio_to_irq(gpio_base + n));
  				n = find_next_bit(&gedr, BITS_PER_LONG, n + 1);
  			}

  		}
  	} while (loop);
  }

  static void pxa_ack_muxed_gpio(struct irq_data *d)

  {

  	int gpio = pxa_irq_to_gpio(d->irq);

  	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);

  	writel_relaxed(GPIO_bit(gpio), c->regbase + GEDR_OFFSET);

  }

  static void pxa_mask_muxed_gpio(struct irq_data *d)

  {

  	int gpio = pxa_irq_to_gpio(d->irq);

  	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);

  	uint32_t grer, gfer;
  
  	c->irq_mask &= ~GPIO_bit(gpio);

  	grer = readl_relaxed(c->regbase + GRER_OFFSET) & ~GPIO_bit(gpio);
  	gfer = readl_relaxed(c->regbase + GFER_OFFSET) & ~GPIO_bit(gpio);
  	writel_relaxed(grer, c->regbase + GRER_OFFSET);
  	writel_relaxed(gfer, c->regbase + GFER_OFFSET);

  }

  static void pxa_unmask_muxed_gpio(struct irq_data *d)

  {

  	int gpio = pxa_irq_to_gpio(d->irq);

  	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);

  
  	c->irq_mask |= GPIO_bit(gpio);

  	update_edge_detect(c);

  }
  
  static struct irq_chip pxa_muxed_gpio_chip = {
  	.name		= "GPIO",

  	.irq_ack	= pxa_ack_muxed_gpio,
  	.irq_mask	= pxa_mask_muxed_gpio,
  	.irq_unmask	= pxa_unmask_muxed_gpio,
  	.irq_set_type	= pxa_gpio_irq_type,

  };

  static int pxa_gpio_nums(void)
  {
  	int count = 0;
  
  #ifdef CONFIG_ARCH_PXA
  	if (cpu_is_pxa25x()) {
  #ifdef CONFIG_CPU_PXA26x
  		count = 89;
  		gpio_type = PXA26X_GPIO;
  #elif defined(CONFIG_PXA25x)
  		count = 84;
  		gpio_type = PXA26X_GPIO;
  #endif /* CONFIG_CPU_PXA26x */
  	} else if (cpu_is_pxa27x()) {
  		count = 120;
  		gpio_type = PXA27X_GPIO;
  	} else if (cpu_is_pxa93x() || cpu_is_pxa95x()) {
  		count = 191;
  		gpio_type = PXA93X_GPIO;
  	} else if (cpu_is_pxa3xx()) {
  		count = 127;
  		gpio_type = PXA3XX_GPIO;
  	}
  #endif /* CONFIG_ARCH_PXA */
  
  #ifdef CONFIG_ARCH_MMP
  	if (cpu_is_pxa168() || cpu_is_pxa910()) {
  		count = 127;
  		gpio_type = MMP_GPIO;
  	} else if (cpu_is_mmp2()) {
  		count = 191;
  		gpio_type = MMP2_GPIO;
  	}
  #endif /* CONFIG_ARCH_MMP */
  	return count;
  }

  static int __devinit pxa_gpio_probe(struct platform_device *pdev)

  {

  	struct pxa_gpio_chip *c;

  	struct resource *res;

  	struct clk *clk;
  	int gpio, irq, ret;

  	int irq0 = 0, irq1 = 0, irq_mux, gpio_offset = 0;

  	pxa_last_gpio = pxa_gpio_nums();
  	if (!pxa_last_gpio)

  		return -EINVAL;
  
  	irq0 = platform_get_irq_byname(pdev, "gpio0");
  	irq1 = platform_get_irq_byname(pdev, "gpio1");
  	irq_mux = platform_get_irq_byname(pdev, "gpio_mux");
  	if ((irq0 > 0 && irq1 <= 0) || (irq0 <= 0 && irq1 > 0)
  		|| (irq_mux <= 0))
  		return -EINVAL;
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res)
  		return -EINVAL;
  	gpio_reg_base = ioremap(res->start, resource_size(res));
  	if (!gpio_reg_base)
  		return -EINVAL;
  
  	if (irq0 > 0)
  		gpio_offset = 2;

  	clk = clk_get(&pdev->dev, NULL);
  	if (IS_ERR(clk)) {
  		dev_err(&pdev->dev, "Error %ld to get gpio clock
  ",
  			PTR_ERR(clk));
  		iounmap(gpio_reg_base);
  		return PTR_ERR(clk);
  	}
  	ret = clk_prepare(clk);
  	if (ret) {
  		clk_put(clk);
  		iounmap(gpio_reg_base);
  		return ret;
  	}
  	ret = clk_enable(clk);
  	if (ret) {
  		clk_unprepare(clk);
  		clk_put(clk);
  		iounmap(gpio_reg_base);
  		return ret;
  	}

  	/* Initialize GPIO chips */

  	pxa_init_gpio_chip(pxa_last_gpio);

  	/* clear all GPIO edge detects */

  	for_each_gpio_chip(gpio, c) {

  		writel_relaxed(0, c->regbase + GFER_OFFSET);
  		writel_relaxed(0, c->regbase + GRER_OFFSET);
  		writel_relaxed(~0,c->regbase + GEDR_OFFSET);

  		/* unmask GPIO edge detect for AP side */
  		if (gpio_is_mmp_type(gpio_type))
  			writel_relaxed(~0, c->regbase + ED_MASK_OFFSET);

  	}

  #ifdef CONFIG_ARCH_PXA
  	irq = gpio_to_irq(0);
  	irq_set_chip_and_handler(irq, &pxa_muxed_gpio_chip,
  				 handle_edge_irq);
  	set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
  	irq_set_chained_handler(IRQ_GPIO0, pxa_gpio_demux_handler);
  
  	irq = gpio_to_irq(1);
  	irq_set_chip_and_handler(irq, &pxa_muxed_gpio_chip,
  				 handle_edge_irq);
  	set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
  	irq_set_chained_handler(IRQ_GPIO1, pxa_gpio_demux_handler);
  #endif

  	for (irq  = gpio_to_irq(gpio_offset);
  		irq <= gpio_to_irq(pxa_last_gpio); irq++) {

  		irq_set_chip_and_handler(irq, &pxa_muxed_gpio_chip,
  					 handle_edge_irq);

  		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
  	}

  	irq_set_chained_handler(irq_mux, pxa_gpio_demux_handler);
  	return 0;
  }
  
  static struct platform_driver pxa_gpio_driver = {
  	.probe		= pxa_gpio_probe,
  	.driver		= {
  		.name	= "pxa-gpio",
  	},
  };
  
  static int __init pxa_gpio_init(void)
  {
  	return platform_driver_register(&pxa_gpio_driver);

  }

  postcore_initcall(pxa_gpio_init);

  
  #ifdef CONFIG_PM

  static int pxa_gpio_suspend(void)

  {

  	struct pxa_gpio_chip *c;
  	int gpio;

  	for_each_gpio_chip(gpio, c) {

  		c->saved_gplr = readl_relaxed(c->regbase + GPLR_OFFSET);
  		c->saved_gpdr = readl_relaxed(c->regbase + GPDR_OFFSET);
  		c->saved_grer = readl_relaxed(c->regbase + GRER_OFFSET);
  		c->saved_gfer = readl_relaxed(c->regbase + GFER_OFFSET);

  
  		/* Clear GPIO transition detect bits */

  		writel_relaxed(0xffffffff, c->regbase + GEDR_OFFSET);

  	}
  	return 0;
  }

  static void pxa_gpio_resume(void)

  {

  	struct pxa_gpio_chip *c;
  	int gpio;

  	for_each_gpio_chip(gpio, c) {

  		/* restore level with set/clear */

  		writel_relaxed( c->saved_gplr, c->regbase + GPSR_OFFSET);
  		writel_relaxed(~c->saved_gplr, c->regbase + GPCR_OFFSET);

  		writel_relaxed(c->saved_grer, c->regbase + GRER_OFFSET);
  		writel_relaxed(c->saved_gfer, c->regbase + GFER_OFFSET);
  		writel_relaxed(c->saved_gpdr, c->regbase + GPDR_OFFSET);

  	}

  }
  #else
  #define pxa_gpio_suspend	NULL
  #define pxa_gpio_resume		NULL
  #endif

  struct syscore_ops pxa_gpio_syscore_ops = {

  	.suspend	= pxa_gpio_suspend,
  	.resume		= pxa_gpio_resume,
  };

  
  static int __init pxa_gpio_sysinit(void)
  {
  	register_syscore_ops(&pxa_gpio_syscore_ops);
  	return 0;
  }
  postcore_initcall(pxa_gpio_sysinit);