path: root/arch/arm/mach-ixp4xx/common.c

/*
 * 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 <linux/bitops.h>
#include <mach/udc.h>
#include <mach/hardware.h>
#include <mach/io.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/exception.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 struct irq_domain *ixp4xx_irqdomain;
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->hwirq];
	u32 int_style;
	enum ixp4xx_irq_type irq_type;
	volatile u32 *int_reg;

	/*
	 * Only for GPIO IRQs
	 * all other IRQs are simply active low
	 */
	if (line < 0)
		return 0;

	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->hwirq);
	else
		ixp4xx_irq_edge &= ~(1 << d->hwirq);

	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 << (