/*
 * arch/arm/mach-ixp4xx/common.c
 *
 * Generic code shared across all IXP4XX platforms
 *
 * Maintainer: Deepak Saxena <dsaxena@plexity.net>
 *
 * Copyright 2002 (c) Intel Corporation
 * Copyright 2003-2004 (c) MontaVista, Software, Inc. 
 * 
 * This file is licensed under  the terms of the GNU General Public 
 * License version 2. This program is licensed "as is" without any 
 * warranty of any kind, whether express or implied.
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/serial.h>
#include <linux/tty.h>
#include <linux/platform_device.h>
#include <linux/serial_core.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/time.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/io.h>
#include <linux/export.h>
#include <linux/gpio/driver.h>
#include <linux/cpu.h>
#include <linux/pci.h>
#include <linux/sched_clock.h>
#include <mach/udc.h>
#include <mach/hardware.h>
#include <mach/io.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/irq.h>
#include <asm/system_misc.h>
#include <asm/mach/map.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>

#define IXP4XX_TIMER_FREQ 66666000

/*
 * The timer register doesn't allow to specify the two least significant bits of
 * the timeout value and assumes them being zero. So make sure IXP4XX_LATCH is
 * the best value with the two least significant bits unset.
 */
#define IXP4XX_LATCH DIV_ROUND_CLOSEST(IXP4XX_TIMER_FREQ, \
				       (IXP4XX_OST_RELOAD_MASK + 1) * HZ) * \
			(IXP4XX_OST_RELOAD_MASK + 1)

static void __init ixp4xx_clocksource_init(void);
static void __init ixp4xx_clockevent_init(void);
static struct clock_event_device clockevent_ixp4xx;

/*************************************************************************
 * IXP4xx chipset I/O mapping
 *************************************************************************/
static struct map_desc ixp4xx_io_desc[] __initdata = {
	{	/* UART, Interrupt ctrl, GPIO, timers, NPEs, MACs, USB .... */
		.virtual	= (unsigned long)IXP4XX_PERIPHERAL_BASE_VIRT,
		.pfn		= __phys_to_pfn(IXP4XX_PERIPHERAL_BASE_PHYS),
		.length		= IXP4XX_PERIPHERAL_REGION_SIZE,
		.type		= MT_DEVICE
	}, {	/* Expansion Bus Config Registers */
		.virtual	= (unsigned long)IXP4XX_EXP_CFG_BASE_VIRT,
		.pfn		= __phys_to_pfn(IXP4XX_EXP_CFG_BASE_PHYS),
		.length		= IXP4XX_EXP_CFG_REGION_SIZE,
		.type		= MT_DEVICE
	}, {	/* PCI Registers */
		.virtual	= (unsigned long)IXP4XX_PCI_CFG_BASE_VIRT,
		.pfn		= __phys_to_pfn(IXP4XX_PCI_CFG_BASE_PHYS),
		.length		= IXP4XX_PCI_CFG_REGION_SIZE,
		.type		= MT_DEVICE
	}, {	/* Queue Manager */
		.virtual	= (unsigned long)IXP4XX_QMGR_BASE_VIRT,
		.pfn		= __phys_to_pfn(IXP4XX_QMGR_BASE_PHYS),
		.length		= IXP4XX_QMGR_REGION_SIZE,
		.type		= MT_DEVICE
	},
};

void __init ixp4xx_map_io(void)
{
  	iotable_init(ixp4xx_io_desc, ARRAY_SIZE(ixp4xx_io_desc));
}

/*
 * GPIO-functions
 */
/*
 * The following converted to the real HW bits the gpio_line_config
 */
/* GPIO pin types */
#define IXP4XX_GPIO_OUT 		0x1
#define IXP4XX_GPIO_IN  		0x2

/* GPIO signal types */
#define IXP4XX_GPIO_LOW			0
#define IXP4XX_GPIO_HIGH		1

/* GPIO Clocks */
#define IXP4XX_GPIO_CLK_0		14
#define IXP4XX_GPIO_CLK_1		15

static void gpio_line_config(u8 line, u32 direction)
{
	if (direction == IXP4XX_GPIO_IN)
		*IXP4XX_GPIO_GPOER |= (1 << line);
	else
		*IXP4XX_GPIO_GPOER &= ~(1 << line);
}

static void gpio_line_get(u8 line, int *value)
{
	*value = (*IXP4XX_GPIO_GPINR >> line) & 0x1;
}

static void gpio_line_set(u8 line, int value)
{
	if (value == IXP4XX_GPIO_HIGH)
	    *IXP4XX_GPIO_GPOUTR |= (1 << line);
	else if (value == IXP4XX_GPIO_LOW)
	    *IXP4XX_GPIO_GPOUTR &= ~(1 << line);
}

/*************************************************************************
 * IXP4xx chipset IRQ handling
 *
 * TODO: GPIO IRQs should be marked invalid until the user of the IRQ
 *       (be it PCI or something else) configures that GPIO line
 *       as an IRQ.
 **************************************************************************/
enum ixp4xx_irq_type {
	IXP4XX_IRQ_LEVEL, IXP4XX_IRQ_EDGE
};

/* Each bit represents an IRQ: 1: edge-triggered, 0: level triggered */
static unsigned long long ixp4xx_irq_edge = 0;

/*
 * IRQ -> GPIO mapping table
 */
static signed char irq2gpio[32] = {
	-1, -1, -1, -1, -1, -1,  0,  1,
	-1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1,  2,  3,  4,  5,  6,
	 7,  8,  9, 10, 11, 12, -1, -1,
};

static int ixp4xx_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
{
	int irq;

	for (irq = 0; irq < 32; irq++) {
		if (irq2gpio[irq] == gpio)
			return irq;
	}
	return -EINVAL;
}

static int ixp4xx_set_irq_type(struct irq_data *d, unsigned int type)
{
	int line = irq2gpio[d->irq];
	u32 int_style;
	enum ixp4xx_irq_type irq_type;
	volatile u32 *int_reg;

	/*
	 * Only for GPIO IRQs
	 */
	if (line < 0)
		return -EINVAL;

	switch (type){
	case IRQ_TYPE_EDGE_BOTH:
		int_style = IXP4XX_GPIO_STYLE_TRANSITIONAL;
		irq_type = IXP4XX_IRQ_EDGE;
		break;
	case IRQ_TYPE_EDGE_RISING:
		int_style = IXP4XX_GPIO_STYLE_RISING_EDGE;
		irq_type = IXP4XX_IRQ_EDGE;
		break;
	case IRQ_TYPE_EDGE_FALLING:
		int_style = IXP4XX_GPIO_STYLE_FALLING_EDGE;
		irq_type = IXP4XX_IRQ_EDGE;
		break;
	case IRQ_TYPE_LEVEL_HIGH:
		int_style = IXP4XX_GPIO_STYLE_ACTIVE_HIGH;
		irq_type = IXP4XX_IRQ_LEVEL;
		break;
	case IRQ_TYPE_LEVEL_LOW:
		int_style = IXP4XX_GPIO_STYLE_ACTIVE_LOW;
		irq_type = IXP4XX_IRQ_LEVEL;
		break;
	default:
		return -EINVAL;
	}

	if (irq_type == IXP4XX_IRQ_EDGE)
		ixp4xx_irq_edge |= (1 << d->irq);
	else
		ixp4xx_irq_edge &= ~(1 << d->irq);

	if (line >= 8) {	/* pins 8-15 */
		line -= 8;
		int_reg = IXP4XX_GPIO_GPIT2R;
	} else {		/* pins 0-7 */
		int_reg = IXP4XX_GPIO_GPIT1R;
	}

	/* Clear the style for the appropriate pin */
	*int_reg &= ~(IXP4XX_GPIO_STYLE_CLEAR <<
	    		(line * IXP4XX_GPIO_STYLE_SIZE));

	*IXP4XX_GPIO_GPISR = (1 << line);

	/* Set the new style */
	*int_reg |= (int_style << (line * IXP4XX_GPIO_STYLE_SIZE));

	/* Configure the line as an input */
	gpio_line_config(irq2gpio[d->irq], IXP4XX_GPIO_IN);

	return 0;
}

static void ixp4xx_irq_mask(struct irq_data *d)
{
	if ((cpu_is_ixp46x() || cpu_is_ixp43x()) && d->irq >= 32)
		*IXP4XX_ICMR2 &= ~(1 << (d->irq - 32));
	else
		*IXP4XX_ICMR &= ~(1 << d->irq);
}

static void ixp4xx_irq_ack(struct irq_data *d)
{
	int line = (d->irq < 32) ? irq2gpio[d->irq] : -1;

	if (line >= 0)
		*IXP4XX_GPIO_GPISR = (1 << line);
}

/*
 * Level triggered interrupts on GPIO lines can only be cleared when the
 * interrupt condition disappears.
 */
static void ixp4xx_irq_unmask(struct irq_data *d)
{
	if (!(ixp4xx_irq_edge & (1 << d->irq)))
		ixp4xx_irq_ack(d);

	if ((cpu_is_ixp46x() || cpu_is_ixp43x()) && d->irq >= 32)
		*IXP4XX_ICMR2 |= (1 << (d->irq - 32));
	else
		*IXP4XX_ICMR |= (1 << d->irq);
}

static struct irq_chip ixp4xx_irq_chip = {
	.name		= "IXP4xx",
	.irq_ack	= ixp4xx_irq_ack,
	.irq_mask	= ixp4xx_irq_mask,
	.irq_unmask	= ixp4xx_irq_unmask,
	.irq_set_type	= ixp4xx_set_irq_type,
};

void __init ixp4xx_init_irq(void)
{
	int i = 0;

	/*
	 * ixp4xx does not implement the XScale PWRMODE register
	 * so it must not call cpu_do_idle().
	 */
	cpu_idle_poll_ctrl(true);

	/* Route all sources to IRQ instead of FIQ */
	*IXP4XX_ICLR = 0x0;

	/* Disable all interrupt */
	*IXP4XX_ICMR = 0x0; 

	if (cpu_is_ixp46x() || cpu_is_ixp43x()) {
		/* Route upper 32 sources to IRQ instead of FIQ */
		*IXP4XX_ICLR2 = 0x00;

		/* Disable upper 32 interrupts */
		*IXP4XX_ICMR2 = 0x00;
	}

        /* Default to all level triggered */
	for(i = 0; i < NR_IRQS; i++) {
		irq_set_chip_and_handler(i, &ixp4xx_irq_chip,
					 handle_level_irq);
		irq_clear_status_flags(i, IRQ_NOREQUEST);
	}
}


/*************************************************************************
 * IXP4xx timer tick
 * We use OS timer1 on the CPU for the timer tick and the timestamp 
 * counter as a source of real clock ticks to account for missed jiffies.
 *************************************************************************/

static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *evt = dev_id;

	/* Clear Pending Interrupt by writing '1' to it */
	*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;

	evt->event_handler(evt);

	return IRQ_HANDLED;
}

static struct irqaction ixp4xx_timer_irq = {
	.name		= "timer1",
	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
	.handler	= ixp4xx_timer_interrupt,
	.dev_id		= &clockevent_ixp4xx,
};

void __init ixp4xx_timer_init(void)
{
	/* Reset/disable counter */
	*IXP4XX_OSRT1 = 0;

	/* Clear Pending Interrupt by writing '1' to it */
	*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;

	/* Reset time-stamp counter */
	*IXP4XX_OSTS = 0;

	/* Connect the interrupt handler and enable the interrupt */
	setup_irq(IRQ_IXP4XX_TIMER1, &ixp4xx_timer_irq);

	ixp4xx_clocksource_init();
	ixp4xx_clockevent_init();
}

static struct pxa2xx_udc_mach_info ixp4xx_udc_info;

void __init ixp4xx_set_udc_info(struct pxa2xx_udc_mach_info *info)
{
	memcpy(&ixp4xx_udc_info, info, sizeof *info);
}

static struct resource ixp4xx_udc_resources[] = {
	[0] = {
		.start  = 0xc800b000,
		.end    = 0xc800bfff,
		.flags  = IORESOURCE_MEM,
	},
	[1] = {
		.start  = IRQ_IXP4XX_USB,
		.end    = IRQ_IXP4XX_USB,
		.flags  = IORESOURCE_IRQ,
	},
};

/*
 * USB device controller. The IXP4xx uses the same controller as PXA25X,
 * so we just use the same device.
 */
static struct platform_device ixp4xx_udc_device = {
	.name           = "pxa25x-udc",
	.id             = -1,
	.num_resources  = 2,
	.resource       = ixp4xx_udc_resources,
	.dev            = {
		.platform_data = &ixp4xx_udc_info,
	},
};

static struct platform_device *ixp4xx_devices[] __initdata = {
	&ixp4xx_udc_device,
};

static struct resource ixp46x_i2c_resources[] = {
	[0] = {
		.start 	= 0xc8011000,
		.end	= 0xc801101c,
		.flags	= IORESOURCE_MEM,
	},
	[1] = {
		.start 	= IRQ_IXP4XX_I2C,
		.end	= IRQ_IXP4XX_I2C,
		.flags	= IORESOURCE_IRQ
	}
};

/*
 * I2C controller. The IXP46x uses the same block as the IOP3xx, so
 * we just use the same device name.
 */
static struct platform_device ixp46x_i2c_controller = {
	.name		= "IOP3xx-I2C",
	.id		= 0,
	.num_resources	= 2,
	.resource	= ixp46x_i2c_resources
};

static struct platform_device *ixp46x_devices[] __initdata = {
	&ixp46x_i2c_controller
};

unsigned long ixp4xx_exp_bus_size;
EXPORT_SYMBOL(ixp4xx_exp_bus_size);

static int ixp4xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
	gpio_line_config(gpio, IXP4XX_GPIO_IN);

	return 0;
}

static int ixp4xx_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
					int level)
{
	gpio_line_set(gpio, level);
	gpio_line_config(gpio, IXP4XX_GPIO_OUT);

	return 0;
}

static int ixp4xx_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
	int value;

	gpio_line_get(gpio, &value);

	return value;
}

static void ixp4xx_gpio_set_value(struct gpio_chip *chip, unsigned gpio,
				  int value)
{
	gpio_line_set(gpio, value);
}

static struct gpio_chip ixp4xx_gpio_chip = {
	.label			= "IXP4XX_GPIO_CHIP",
	.direction_input	= ixp4xx_gpio_direction_input,
	.direction_output	= ixp4xx_gpio_direction_output,
	.get			= ixp4xx_gpio_get_value,
	.set			= ixp4xx_gpio_set_value,
	.to_irq			= ixp4xx_gpio_to_irq,
	.base			= 0,
	.ngpio			= 16,
};

void __init ixp4xx_sys_init(void)
{
	ixp4xx_exp_bus_size = SZ_16M;

	platform_add_devices(ixp4xx_devices, ARRAY_SIZE(ixp4xx_devices));

	gpiochip_add_data(&ixp4xx_gpio_chip, NULL);

	if (cpu_is_ixp46x()) {
		int region;

		platform_add_devices(ixp46x_devices,
				ARRAY_SIZE(ixp46x_devices));

		for (region = 0; region < 7; region++) {
			if((*(IXP4XX_EXP_REG(0x4 * region)) & 0x200)) {
				ixp4xx_exp_bus_size = SZ_32M;
				break;
			}
		}
	}

	printk("IXP4xx: Using %luMiB expansion bus window size\n",
			ixp4xx_exp_bus_size >> 20);
}

/*
 * sched_clock()
 */
static u64 notrace ixp4xx_read_sched_clock(void)
{
	return *IXP4XX_OSTS;
}

/*
 * clocksource
 */

static cycle_t ixp4xx_clocksource_read(struct clocksource *c)
{
	return *IXP4XX_OSTS;
}

unsigned long ixp4xx_timer_freq = IXP4XX_TIMER_FREQ;
EXPORT_SYMBOL(ixp4xx_timer_freq);
static void __init ixp4xx_clocksource_init(void)
{
	sched_clock_register(ixp4xx_read_sched_clock, 32, ixp4xx_timer_freq);

	clocksource_mmio_init(NULL, "OSTS", ixp4xx_timer_freq, 200, 32,
			ixp4xx_clocksource_read);
}

/*
 * clockevents
 */
static int ixp4xx_set_next_event(unsigned long evt,
				 struct clock_event_device *unused)
{
	unsigned long opts = *IXP4XX_OSRT1 & IXP4XX_OST_RELOAD_MASK;

	*IXP4XX_OSRT1 = (evt & ~IXP4XX_OST_RELOAD_MASK) | opts;

	return 0;
}

static int ixp4xx_shutdown(struct clock_event_device *evt)
{
	unsigned long opts = *IXP4XX_OSRT1 & IXP4XX_OST_RELOAD_MASK;
	unsigned long osrt = *IXP4XX_OSRT1 & ~IXP4XX_OST_RELOAD_MASK;

	opts &= ~IXP4XX_OST_ENABLE;
	*IXP4XX_OSRT1 = osrt | opts;
	return 0;
}

static int ixp4xx_set_oneshot(struct clock_event_device *evt)
{
	unsigned long opts = IXP4XX_OST_ENABLE | IXP4XX_OST_ONE_SHOT;
	unsigned long osrt = 0;

	/* period set by 'set next_event' */
	*IXP4XX_OSRT1 = osrt | opts;
	return 0;
}

static int ixp4xx_set_periodic(struct clock_event_device *evt)
{
	unsigned long opts = IXP4XX_OST_ENABLE;
	unsigned long osrt = IXP4XX_LATCH & ~IXP4XX_OST_RELOAD_MASK;

	*IXP4XX_OSRT1 = osrt | opts;
	return 0;
}

static int ixp4xx_resume(struct clock_event_device *evt)
{
	unsigned long opts = *IXP4XX_OSRT1 & IXP4XX_OST_RELOAD_MASK;
	unsigned long osrt = *IXP4XX_OSRT1 & ~IXP4XX_OST_RELOAD_MASK;

	opts |= IXP4XX_OST_ENABLE;
	*IXP4XX_OSRT1 = osrt | opts;
	return 0;
}

static struct clock_event_device clockevent_ixp4xx = {
	.name			= "ixp4xx timer1",
	.features		= CLOCK_EVT_FEAT_PERIODIC |
				  CLOCK_EVT_FEAT_ONESHOT,
	.rating			= 200,
	.set_state_shutdown	= ixp4xx_shutdown,
	.set_state_periodic	= ixp4xx_set_periodic,
	.set_state_oneshot	= ixp4xx_set_oneshot,
	.tick_resume		= ixp4xx_resume,
	.set_next_event		= ixp4xx_set_next_event,
};

static void __init ixp4xx_clockevent_init(void)
{
	clockevent_ixp4xx.cpumask = cpumask_of(0);
	clockevents_config_and_register(&clockevent_ixp4xx, IXP4XX_TIMER_FREQ,
					0xf, 0xfffffffe);
}

void ixp4xx_restart(enum reboot_mode mode, const char *cmd)
{
	if (mode == REBOOT_SOFT) {
		/* Jump into ROM at address 0 */
		soft_restart(0);
	} else {
		/* Use on-chip reset capability */

		/* set the "key" register to enable access to
		 * "timer" and "enable" registers
		 */
		*IXP4XX_OSWK = IXP4XX_WDT_KEY;

		/* write 0 to the timer register for an immediate reset */
		*IXP4XX_OSWT = 0;

		*IXP4XX_OSWE = IXP4XX_WDT_RESET_ENABLE | IXP4XX_WDT_COUNT_ENABLE;
	}
}

#ifdef CONFIG_PCI
static int ixp4xx_needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
{
	return (dma_addr + size) > SZ_64M;
}

static int ixp4xx_platform_notify_remove(struct device *dev)
{
	if (dev_is_pci(dev))
		dmabounce_unregister_dev(dev);

	return 0;
}
#endif

/*
 * Setup DMA mask to 64MB on PCI devices and 4 GB on all other things.
 */
static int ixp4xx_platform_notify(struct device *dev)
{
	dev->dma_mask = &dev->coherent_dma_mask;

#ifdef CONFIG_PCI
	if (dev_is_pci(dev)) {
		dev->coherent_dma_mask = DMA_BIT_MASK(28); /* 64 MB */
		dmabounce_register_dev(dev, 2048, 4096, ixp4xx_needs_bounce);
		return 0;
	}
#endif

	dev->coherent_dma_mask = DMA_BIT_MASK(32);
	return 0;
}

int dma_set_coherent_mask(struct device *dev, u64 mask)
{
	if (dev_is_pci(dev))
		mask &= DMA_BIT_MASK(28); /* 64 MB */

	if ((mask & DMA_BIT_MASK(28)) == DMA_BIT_MASK(28)) {
		dev->coherent_dma_mask = mask;
		return 0;
	}

	return -EIO;		/* device wanted sub-64MB mask */
}
EXPORT_SYMBOL(dma_set_coherent_mask);

#ifdef CONFIG_IXP4XX_INDIRECT_PCI
/*
 * In the case of using indirect PCI, we simply return the actual PCI
 * address and our read/write implementation use that to drive the
 * access registers. If something outside of PCI is ioremap'd, we
 * fallback to the default.
 */

static void __iomem *ixp4xx_ioremap_caller(phys_addr_t addr, size_t size,
					   unsigned int mtype, void *caller)
{
	if (!is_pci_memory(addr))
		return __arm_ioremap_caller(addr, size, mtype, caller);

	return (void __iomem *)addr;
}

static void ixp4xx_iounmap(volatile void __iomem *addr)
{
	if (!is_pci_memory((__force u32)addr))
		__iounmap(addr);
}
#endif

void __init ixp4xx_init_early(void)
{
	platform_notify = ixp4xx_platform_notify;
#ifdef CONFIG_PCI
	platform_notify_remove = ixp4xx_platform_notify_remove;
#endif
#ifdef CONFIG_IXP4XX_INDIRECT_PCI
	arch_ioremap_caller = ixp4xx_ioremap_caller;
	arch_iounmap = ixp4xx_iounmap;
#endif
}