/*
   * Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
   * Copyright (C) 2010 Jason Wang <jason77.wang@gmail.com>
   *
   * The code contained herein is licensed under the GNU General Public
   * License. You may obtain a copy of the GNU General Public License
   * Version 2 or later at the following locations:
   *
   * http://www.opensource.org/licenses/gpl-license.html
   * http://www.gnu.org/copyleft/gpl.html
   */
  
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  #include <linux/io.h>
  #include <linux/platform_device.h>
  #include <linux/gpio.h>
  #include <linux/smsc911x.h>
  
  #include <mach/hardware.h>
  
  /* LAN9217 ethernet base address */
  #define LAN9217_BASE_ADDR(n)	(n + 0x0)
  /* External UART */
  #define UARTA_BASE_ADDR(n)	(n + 0x8000)
  #define UARTB_BASE_ADDR(n)	(n + 0x10000)
  
  #define BOARD_IO_ADDR(n)	(n + 0x20000)
  /* LED switchs */
  #define LED_SWITCH_REG		0x00
  /* buttons */
  #define SWITCH_BUTTONS_REG	0x08
  /* status, interrupt */
  #define INTR_STATUS_REG	0x10
  #define INTR_MASK_REG		0x38
  #define INTR_RESET_REG		0x20
  /* magic word for debug CPLD */
  #define MAGIC_NUMBER1_REG	0x40
  #define MAGIC_NUMBER2_REG	0x48
  /* CPLD code version */
  #define CPLD_CODE_VER_REG	0x50
  /* magic word for debug CPLD */
  #define MAGIC_NUMBER3_REG	0x58
  /* module reset register*/
  #define MODULE_RESET_REG	0x60
  /* CPU ID and Personality ID */
  #define MCU_BOARD_ID_REG	0x68
  
  #define MXC_IRQ_TO_EXPIO(irq)   ((irq) - MXC_BOARD_IRQ_START)
  #define MXC_IRQ_TO_GPIO(irq)	((irq) - MXC_INTERNAL_IRQS)
  
  #define MXC_EXP_IO_BASE		(MXC_BOARD_IRQ_START)
  #define MXC_MAX_EXP_IO_LINES	16
  
  /* interrupts like external uart , external ethernet etc*/
  #define EXPIO_INT_ENET		(MXC_BOARD_IRQ_START + 0)
  #define EXPIO_INT_XUART_A	(MXC_BOARD_IRQ_START + 1)
  #define EXPIO_INT_XUART_B	(MXC_BOARD_IRQ_START + 2)
  #define EXPIO_INT_BUTTON_A	(MXC_BOARD_IRQ_START + 3)
  #define EXPIO_INT_BUTTON_B	(MXC_BOARD_IRQ_START + 4)
  
  static void __iomem *brd_io;

  
  static struct resource smsc911x_resources[] = {
  	{
  		.flags = IORESOURCE_MEM,
  	} , {
  		.start = EXPIO_INT_ENET,
  		.end = EXPIO_INT_ENET,
  		.flags = IORESOURCE_IRQ,
  	},
  };
  
  static struct smsc911x_platform_config smsc911x_config = {
  	.irq_polarity = SMSC911X_IRQ_POLARITY_ACTIVE_LOW,
  	.flags = SMSC911X_USE_32BIT | SMSC911X_FORCE_INTERNAL_PHY,
  };
  
  static struct platform_device smsc_lan9217_device = {
  	.name = "smsc911x",
  	.id = 0,
  	.dev = {
  		.platform_data = &smsc911x_config,
  	},
  	.num_resources = ARRAY_SIZE(smsc911x_resources),
  	.resource = smsc911x_resources,
  };
  
  static void mxc_expio_irq_handler(u32 irq, struct irq_desc *desc)
  {
  	u32 imr_val;
  	u32 int_valid;
  	u32 expio_irq;

  	/* irq = gpio irq number */
  	desc->irq_data.chip->irq_mask(&desc->irq_data);

  
  	imr_val = __raw_readw(brd_io + INTR_MASK_REG);
  	int_valid = __raw_readw(brd_io + INTR_STATUS_REG) & ~imr_val;
  
  	expio_irq = MXC_BOARD_IRQ_START;
  	for (; int_valid != 0; int_valid >>= 1, expio_irq++) {

  		if ((int_valid & 1) == 0)
  			continue;

  		generic_handle_irq(expio_irq);

  	}

  	desc->irq_data.chip->irq_ack(&desc->irq_data);
  	desc->irq_data.chip->irq_unmask(&desc->irq_data);

  }
  
  /*
   * Disable an expio pin's interrupt by setting the bit in the imr.
   * Irq is an expio virtual irq number
   */

  static void expio_mask_irq(struct irq_data *d)

  {
  	u16 reg;

  	u32 expio = MXC_IRQ_TO_EXPIO(d->irq);

  
  	reg = __raw_readw(brd_io + INTR_MASK_REG);
  	reg |= (1 << expio);
  	__raw_writew(reg, brd_io + INTR_MASK_REG);
  }

  static void expio_ack_irq(struct irq_data *d)

  {

  	u32 expio = MXC_IRQ_TO_EXPIO(d->irq);

  
  	__raw_writew(1 << expio, brd_io + INTR_RESET_REG);
  	__raw_writew(0, brd_io + INTR_RESET_REG);

  	expio_mask_irq(d);

  }

  static void expio_unmask_irq(struct irq_data *d)

  {
  	u16 reg;

  	u32 expio = MXC_IRQ_TO_EXPIO(d->irq);

  
  	reg = __raw_readw(brd_io + INTR_MASK_REG);
  	reg &= ~(1 << expio);
  	__raw_writew(reg, brd_io + INTR_MASK_REG);
  }
  
  static struct irq_chip expio_irq_chip = {

  	.irq_ack = expio_ack_irq,
  	.irq_mask = expio_mask_irq,
  	.irq_unmask = expio_unmask_irq,

  };
  
  int __init mxc_expio_init(u32 base, u32 p_irq)
  {
  	int i;
  
  	brd_io = ioremap(BOARD_IO_ADDR(base), SZ_4K);
  	if (brd_io == NULL)
  		return -ENOMEM;
  
  	if ((__raw_readw(brd_io + MAGIC_NUMBER1_REG) != 0xAAAA) ||
  	    (__raw_readw(brd_io + MAGIC_NUMBER2_REG) != 0x5555) ||
  	    (__raw_readw(brd_io + MAGIC_NUMBER3_REG) != 0xCAFE)) {
  		pr_info("3-Stack Debug board not detected
  ");
  		iounmap(brd_io);
  		brd_io = NULL;
  		return -ENODEV;
  	}
  
  	pr_info("3-Stack Debug board detected, rev = 0x%04X
  ",
  		readw(brd_io + CPLD_CODE_VER_REG));
  
  	/*
  	 * Configure INT line as GPIO input
  	 */
  	gpio_request(MXC_IRQ_TO_GPIO(p_irq), "expio_pirq");
  	gpio_direction_input(MXC_IRQ_TO_GPIO(p_irq));
  
  	/* disable the interrupt and clear the status */
  	__raw_writew(0, brd_io + INTR_MASK_REG);
  	__raw_writew(0xFFFF, brd_io + INTR_RESET_REG);
  	__raw_writew(0, brd_io + INTR_RESET_REG);
  	__raw_writew(0x1F, brd_io + INTR_MASK_REG);
  	for (i = MXC_EXP_IO_BASE;
  	     i < (MXC_EXP_IO_BASE + MXC_MAX_EXP_IO_LINES); i++) {

  		irq_set_chip_and_handler(i, &expio_irq_chip, handle_level_irq);

  		set_irq_flags(i, IRQF_VALID);
  	}

  	irq_set_irq_type(p_irq, IRQF_TRIGGER_LOW);
  	irq_set_chained_handler(p_irq, mxc_expio_irq_handler);

  
  	/* Register Lan device on the debugboard */
  	smsc911x_resources[0].start = LAN9217_BASE_ADDR(base);
  	smsc911x_resources[0].end = LAN9217_BASE_ADDR(base) + 0x100 - 1;
  	platform_device_register(&smsc_lan9217_device);
  
  	return 0;
  }