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linux/arch/arm/mach-ixp4xx/common.c
Kevin Hilman 84904d0ead [ARM] 3856/1: Add clocksource for Intel IXP4xx platforms 
Enables the ixp4xx platforms to use Generic time-of-day.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-28 20:59:25 +01:00

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/*
* 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/sched.h>
#include <linux/tty.h>
#include <linux/platform_device.h>
#include <linux/serial_core.h>
#include <linux/bootmem.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/clocksource.h>
#include <asm/hardware.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/irq.h>
#include <asm/mach/map.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
/*************************************************************************
* IXP4xx chipset I/O mapping
*************************************************************************/
static struct map_desc ixp4xx_io_desc[] __initdata = {
{ /* UART, Interrupt ctrl, GPIO, timers, NPEs, MACs, USB .... */
.virtual = 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 = 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 = IXP4XX_PCI_CFG_BASE_VIRT,
.pfn = __phys_to_pfn(IXP4XX_PCI_CFG_BASE_PHYS),
.length = IXP4XX_PCI_CFG_REGION_SIZE,
.type = MT_DEVICE
},
#ifdef CONFIG_DEBUG_LL
{ /* Debug UART mapping */
.virtual = IXP4XX_DEBUG_UART_BASE_VIRT,
.pfn = __phys_to_pfn(IXP4XX_DEBUG_UART_BASE_PHYS),
.length = IXP4XX_DEBUG_UART_REGION_SIZE,
.type = MT_DEVICE
}
#endif
};
void __init ixp4xx_map_io(void)
{
iotable_init(ixp4xx_io_desc, ARRAY_SIZE(ixp4xx_io_desc));
}
/*************************************************************************
* 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
};
static void ixp4xx_config_irq(unsigned irq, enum ixp4xx_irq_type type);
/*
* 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_set_irq_type(unsigned int irq, unsigned int type)
{
int line = irq2gpio[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 IRQT_BOTHEDGE:
int_style = IXP4XX_GPIO_STYLE_TRANSITIONAL;
irq_type = IXP4XX_IRQ_EDGE;
break;
case IRQT_RISING:
int_style = IXP4XX_GPIO_STYLE_RISING_EDGE;
irq_type = IXP4XX_IRQ_EDGE;
break;
case IRQT_FALLING:
int_style = IXP4XX_GPIO_STYLE_FALLING_EDGE;
irq_type = IXP4XX_IRQ_EDGE;
break;
case IRQT_HIGH:
int_style = IXP4XX_GPIO_STYLE_ACTIVE_HIGH;
irq_type = IXP4XX_IRQ_LEVEL;
break;
case IRQT_LOW:
int_style = IXP4XX_GPIO_STYLE_ACTIVE_LOW;
irq_type = IXP4XX_IRQ_LEVEL;
break;
default:
return -EINVAL;
}
ixp4xx_config_irq(irq, irq_type);
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(line, IXP4XX_GPIO_IN);
return 0;
}
static void ixp4xx_irq_mask(unsigned int irq)
{
if (cpu_is_ixp46x() && irq >= 32)
*IXP4XX_ICMR2 &= ~(1 << (irq - 32));
else
*IXP4XX_ICMR &= ~(1 << irq);
}
static void ixp4xx_irq_unmask(unsigned int irq)
{
if (cpu_is_ixp46x() && irq >= 32)
*IXP4XX_ICMR2 |= (1 << (irq - 32));
else
*IXP4XX_ICMR |= (1 << irq);
}
static void ixp4xx_irq_ack(unsigned int irq)
{
int line = (irq < 32) ? irq2gpio[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_level_unmask(unsigned int irq)
{
ixp4xx_irq_ack(irq);
ixp4xx_irq_unmask(irq);
}
static struct irqchip ixp4xx_irq_level_chip = {
.ack = ixp4xx_irq_mask,
.mask = ixp4xx_irq_mask,
.unmask = ixp4xx_irq_level_unmask,
.set_type = ixp4xx_set_irq_type,
};
static struct irqchip ixp4xx_irq_edge_chip = {
.ack = ixp4xx_irq_ack,
.mask = ixp4xx_irq_mask,
.unmask = ixp4xx_irq_unmask,
.set_type = ixp4xx_set_irq_type,
};
static void ixp4xx_config_irq(unsigned irq, enum ixp4xx_irq_type type)
{
switch (type) {
case IXP4XX_IRQ_LEVEL:
set_irq_chip(irq, &ixp4xx_irq_level_chip);
set_irq_handler(irq, do_level_IRQ);
break;
case IXP4XX_IRQ_EDGE:
set_irq_chip(irq, &ixp4xx_irq_edge_chip);
set_irq_handler(irq, do_edge_IRQ);
break;
}
set_irq_flags(irq, IRQF_VALID);
}
void __init ixp4xx_init_irq(void)
{
int i = 0;
/* Route all sources to IRQ instead of FIQ */
*IXP4XX_ICLR = 0x0;
/* Disable all interrupt */
*IXP4XX_ICMR = 0x0;
if (cpu_is_ixp46x()) {
/* 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++)
ixp4xx_config_irq(i, IXP4XX_IRQ_LEVEL);
}
/*************************************************************************
* 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 unsigned volatile last_jiffy_time;
#define CLOCK_TICKS_PER_USEC ((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC)
static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
write_seqlock(&xtime_lock);
/* Clear Pending Interrupt by writing '1' to it */
*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
/*
* Catch up with the real idea of time
*/
while ((signed long)(*IXP4XX_OSTS - last_jiffy_time) >= LATCH) {
timer_tick(regs);
last_jiffy_time += LATCH;
}
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}
static struct irqaction ixp4xx_timer_irq = {
.name = "IXP4xx Timer Tick",
.flags = IRQF_DISABLED | IRQF_TIMER,
.handler = ixp4xx_timer_interrupt,
};
static void __init ixp4xx_timer_init(void)
{
/* Clear Pending Interrupt by writing '1' to it */
*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
/* Setup the Timer counter value */
*IXP4XX_OSRT1 = (LATCH & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE;
/* Reset time-stamp counter */
*IXP4XX_OSTS = 0;
last_jiffy_time = 0;
/* Connect the interrupt handler and enable the interrupt */
setup_irq(IRQ_IXP4XX_TIMER1, &ixp4xx_timer_irq);
}
struct sys_timer ixp4xx_timer = {
.init = ixp4xx_timer_init,
};
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);
void __init ixp4xx_sys_init(void)
{
ixp4xx_exp_bus_size = SZ_16M;
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);
}
cycle_t ixp4xx_get_cycles(void)
{
return *IXP4XX_OSTS;
}
static struct clocksource clocksource_ixp4xx = {
.name = "OSTS",
.rating = 200,
.read = ixp4xx_get_cycles,
.mask = CLOCKSOURCE_MASK(32),
.shift = 20,
.is_continuous = 1,
};
unsigned long ixp4xx_timer_freq = FREQ;
static int __init ixp4xx_clocksource_init(void)
{
clocksource_ixp4xx.mult =
clocksource_hz2mult(ixp4xx_timer_freq,
clocksource_ixp4xx.shift);
clocksource_register(&clocksource_ixp4xx);
return 0;
}
device_initcall(ixp4xx_clocksource_init);
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