/*
   * arch/arm/mach-ks8695/gpio.c
   *
   * Copyright (C) 2006 Andrew Victor

   * Updated to GPIOLIB, Copyright 2008 Simtec Electronics
   *                     Daniel Silverstone <dsilvers@simtec.co.uk>

   *
   * 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.
   *
   * 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 <linux/gpio.h>

  #include <linux/kernel.h>
  #include <linux/mm.h>
  #include <linux/init.h>

  #include <linux/debugfs.h>
  #include <linux/seq_file.h>

  #include <linux/module.h>

  #include <linux/io.h>

  #include <mach/hardware.h>

  #include <asm/mach/irq.h>

  #include <mach/regs-gpio.h>

  #include <mach/gpio-ks8695.h>

  
  /*
   * Configure a GPIO line for either GPIO function, or its internal
   * function (Interrupt, Timer, etc).
   */

  static void ks8695_gpio_mode(unsigned int pin, short gpio)

  {
  	unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
  	unsigned long x, flags;
  
  	if (pin > KS8695_GPIO_5)	/* only GPIO 0..5 have internal functions */
  		return;
  
  	local_irq_save(flags);
  
  	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
  	if (gpio)			/* GPIO: set bit to 0 */
  		x &= ~enable[pin];
  	else				/* Internal function: set bit to 1 */
  		x |= enable[pin];
  	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPC);
  
  	local_irq_restore(flags);
  }
  
  
  static unsigned short gpio_irq[] = { KS8695_IRQ_EXTERN0, KS8695_IRQ_EXTERN1, KS8695_IRQ_EXTERN2, KS8695_IRQ_EXTERN3 };
  
  /*
   * Configure GPIO pin as external interrupt source.
   */

  int ks8695_gpio_interrupt(unsigned int pin, unsigned int type)

  {
  	unsigned long x, flags;
  
  	if (pin > KS8695_GPIO_3)	/* only GPIO 0..3 can generate IRQ */
  		return -EINVAL;
  
  	local_irq_save(flags);
  
  	/* set pin as input */
  	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);

  	x &= ~IOPM(pin);

  	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
  
  	local_irq_restore(flags);
  
  	/* Set IRQ triggering type */

  	irq_set_irq_type(gpio_irq[pin], type);

  
  	/* enable interrupt mode */
  	ks8695_gpio_mode(pin, 0);
  
  	return 0;
  }
  EXPORT_SYMBOL(ks8695_gpio_interrupt);
  
  
  
  /* .... Generic GPIO interface .............................................. */
  
  /*
   * Configure the GPIO line as an input.
   */

  static int ks8695_gpio_direction_input(struct gpio_chip *gc, unsigned int pin)

  {
  	unsigned long x, flags;
  
  	if (pin > KS8695_GPIO_15)
  		return -EINVAL;
  
  	/* set pin to GPIO mode */
  	ks8695_gpio_mode(pin, 1);
  
  	local_irq_save(flags);
  
  	/* set pin as input */
  	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);

  	x &= ~IOPM(pin);

  	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
  
  	local_irq_restore(flags);
  
  	return 0;
  }

  
  
  /*
   * Configure the GPIO line as an output, with default state.
   */

  static int ks8695_gpio_direction_output(struct gpio_chip *gc,
  					unsigned int pin, int state)

  {
  	unsigned long x, flags;
  
  	if (pin > KS8695_GPIO_15)
  		return -EINVAL;
  
  	/* set pin to GPIO mode */
  	ks8695_gpio_mode(pin, 1);
  
  	local_irq_save(flags);
  
  	/* set line state */
  	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
  	if (state)

  		x |= IOPD(pin);

  	else

  		x &= ~IOPD(pin);

  	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);
  
  	/* set pin as output */
  	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);

  	x |= IOPM(pin);

  	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
  
  	local_irq_restore(flags);
  
  	return 0;
  }

  
  
  /*
   * Set the state of an output GPIO line.
   */

  static void ks8695_gpio_set_value(struct gpio_chip *gc,
  				  unsigned int pin, int state)

  {
  	unsigned long x, flags;
  
  	if (pin > KS8695_GPIO_15)
  		return;
  
  	local_irq_save(flags);
  
  	/* set output line state */
  	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
  	if (state)

  		x |= IOPD(pin);

  	else

  		x &= ~IOPD(pin);

  	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);
  
  	local_irq_restore(flags);
  }

  
  
  /*
   * Read the state of a GPIO line.
   */

  static int ks8695_gpio_get_value(struct gpio_chip *gc, unsigned int pin)

  {
  	unsigned long x;
  
  	if (pin > KS8695_GPIO_15)
  		return -EINVAL;
  
  	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);

  	return (x & IOPD(pin)) != 0;

  }

  
  
  /*
   * Map GPIO line to IRQ number.
   */

  static int ks8695_gpio_to_irq(struct gpio_chip *gc, unsigned int pin)

  {
  	if (pin > KS8695_GPIO_3)	/* only GPIO 0..3 can generate IRQ */
  		return -EINVAL;
  
  	return gpio_irq[pin];
  }

  
  /*
   * Map IRQ number to GPIO line.
   */
  int irq_to_gpio(unsigned int irq)
  {
  	if ((irq < KS8695_IRQ_EXTERN0) || (irq > KS8695_IRQ_EXTERN3))
  		return -EINVAL;
  
  	return (irq - KS8695_IRQ_EXTERN0);
  }
  EXPORT_SYMBOL(irq_to_gpio);

  /* GPIOLIB interface */
  
  static struct gpio_chip ks8695_gpio_chip = {
  	.label			= "KS8695",
  	.direction_input	= ks8695_gpio_direction_input,
  	.direction_output	= ks8695_gpio_direction_output,
  	.get			= ks8695_gpio_get_value,
  	.set			= ks8695_gpio_set_value,

  	.to_irq			= ks8695_gpio_to_irq,

  	.base			= 0,
  	.ngpio			= 16,
  	.can_sleep		= 0,
  };
  
  /* Register the GPIOs */
  void ks8695_register_gpios(void)
  {
  	if (gpiochip_add(&ks8695_gpio_chip))
  		printk(KERN_ERR "Unable to register core GPIOs
  ");
  }

  
  /* .... Debug interface ..................................................... */
  
  #ifdef CONFIG_DEBUG_FS
  
  static int ks8695_gpio_show(struct seq_file *s, void *unused)
  {
  	unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
  	unsigned int intmask[] = { IOPC_IOEINT0TM, IOPC_IOEINT1TM, IOPC_IOEINT2TM, IOPC_IOEINT3TM };
  	unsigned long mode, ctrl, data;
  	int i;
  
  	mode = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
  	ctrl = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
  	data = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
  
  	seq_printf(s, "Pin\tI/O\tFunction\tState
  
  ");
  
  	for (i = KS8695_GPIO_0; i <= KS8695_GPIO_15 ; i++) {
  		seq_printf(s, "%i:\t", i);

  		seq_printf(s, "%s\t", (mode & IOPM(i)) ? "Output" : "Input");

  
  		if (i <= KS8695_GPIO_3) {
  			if (ctrl & enable[i]) {
  				seq_printf(s, "EXT%i ", i);
  
  				switch ((ctrl & intmask[i]) >> (4 * i)) {
  					case IOPC_TM_LOW:
  						seq_printf(s, "(Low)");		break;
  					case IOPC_TM_HIGH:
  						seq_printf(s, "(High)");	break;
  					case IOPC_TM_RISING:
  						seq_printf(s, "(Rising)");	break;
  					case IOPC_TM_FALLING:
  						seq_printf(s, "(Falling)");	break;
  					case IOPC_TM_EDGE:
  						seq_printf(s, "(Edges)");	break;
  				}
  			}
  			else
  				seq_printf(s, "GPIO\t");
  		}
  		else if (i <= KS8695_GPIO_5) {
  			if (ctrl & enable[i])
  				seq_printf(s, "TOUT%i\t", i - KS8695_GPIO_4);
  			else
  				seq_printf(s, "GPIO\t");
  		}
  		else
  			seq_printf(s, "GPIO\t");
  
  		seq_printf(s, "\t");

  		seq_printf(s, "%i
  ", (data & IOPD(i)) ? 1 : 0);

  	}
  	return 0;
  }
  
  static int ks8695_gpio_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, ks8695_gpio_show, NULL);
  }
  
  static const struct file_operations ks8695_gpio_operations = {
  	.open		= ks8695_gpio_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= single_release,
  };
  
  static int __init ks8695_gpio_debugfs_init(void)
  {
  	/* /sys/kernel/debug/ks8695_gpio */
  	(void) debugfs_create_file("ks8695_gpio", S_IFREG | S_IRUGO, NULL, NULL, &ks8695_gpio_operations);
  	return 0;
  }
  postcore_initcall(ks8695_gpio_debugfs_init);
  
  #endif