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/*
* linux/arch/arm/mach-ebsa110/core.c
*
* Copyright (C) 1998-2001 Russell King
*
* 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.
*
* Extra MM routines for the EBSA-110 architecture
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/serial_8250.h>
#include <linux/init.h>
#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/setup.h>
#include <asm/mach-types.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/system.h>
#include <asm/mach/arch.h>
#include <asm/mach/irq.h>
#include <asm/mach/map.h>
#include <asm/mach/time.h>
#define IRQ_MASK 0xfe000000 /* read */
#define IRQ_MSET 0xfe000000 /* write */
#define IRQ_STAT 0xff000000 /* read */
#define IRQ_MCLR 0xff000000 /* write */
static void ebsa110_mask_irq(unsigned int irq)
{
__raw_writeb(1 << irq, IRQ_MCLR);
}
static void ebsa110_unmask_irq(unsigned int irq)
{
__raw_writeb(1 << irq, IRQ_MSET);
}
static struct irqchip ebsa110_irq_chip = {
.ack = ebsa110_mask_irq,
.mask = ebsa110_mask_irq,
.unmask = ebsa110_unmask_irq,
};
static void __init ebsa110_init_irq(void)
{
unsigned long flags;
unsigned int irq;
local_irq_save(flags);
__raw_writeb(0xff, IRQ_MCLR);
__raw_writeb(0x55, IRQ_MSET);
__raw_writeb(0x00, IRQ_MSET);
if (__raw_readb(IRQ_MASK) != 0x55)
while (1);
__raw_writeb(0xff, IRQ_MCLR); /* clear all interrupt enables */
local_irq_restore(flags);
for (irq = 0; irq < NR_IRQS; irq++) {
set_irq_chip(irq, &ebsa110_irq_chip);
set_irq_handler(irq, do_level_IRQ);
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
}
}
static struct map_desc ebsa110_io_desc[] __initdata = {
/*
* sparse external-decode ISAIO space
*/
{ IRQ_STAT, TRICK4_PHYS, PGDIR_SIZE, MT_DEVICE }, /* IRQ_STAT/IRQ_MCLR */
{ IRQ_MASK, TRICK3_PHYS, PGDIR_SIZE, MT_DEVICE }, /* IRQ_MASK/IRQ_MSET */
{ SOFT_BASE, TRICK1_PHYS, PGDIR_SIZE, MT_DEVICE }, /* SOFT_BASE */
{ PIT_BASE, TRICK0_PHYS, PGDIR_SIZE, MT_DEVICE }, /* PIT_BASE */
/*
* self-decode ISAIO space
*/
{ ISAIO_BASE, ISAIO_PHYS, ISAIO_SIZE, MT_DEVICE },
{ ISAMEM_BASE, ISAMEM_PHYS, ISAMEM_SIZE, MT_DEVICE }
};
static void __init ebsa110_map_io(void)
{
iotable_init(ebsa110_io_desc, ARRAY_SIZE(ebsa110_io_desc));
}
#define PIT_CTRL (PIT_BASE + 0x0d)
#define PIT_T2 (PIT_BASE + 0x09)
#define PIT_T1 (PIT_BASE + 0x05)
#define PIT_T0 (PIT_BASE + 0x01)
/*
* This is the rate at which your MCLK signal toggles (in Hz)
* This was measured on a 10 digit frequency counter sampling
* over 1 second.
*/
#define MCLK 47894000
/*
* This is the rate at which the PIT timers get clocked
*/
#define CLKBY7 (MCLK / 7)
/*
* This is the counter value. We tick at 200Hz on this platform.
*/
#define COUNT ((CLKBY7 + (HZ / 2)) / HZ)
/*
* Get the time offset from the system PIT. Note that if we have missed an
* interrupt, then the PIT counter will roll over (ie, be negative).
* This actually works out to be convenient.
*/
static unsigned long ebsa110_gettimeoffset(void)
{
unsigned long offset, count;
__raw_writeb(0x40, PIT_CTRL);
count = __raw_readb(PIT_T1);
count |= __raw_readb(PIT_T1) << 8;
/*
* If count > COUNT, make the number negative.
*/
if (count > COUNT)
count |= 0xffff0000;
offset = COUNT;
offset -= count;
/*
* `offset' is in units of timer counts. Convert
* offset to units of microseconds.
*/
offset = offset * (1000000 / HZ) / COUNT;
return offset;
}
static irqreturn_t
ebsa110_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
u32 count;
write_seqlock(&xtime_lock);
/* latch and read timer 1 */
__raw_writeb(0x40, PIT_CTRL);
count = __raw_readb(PIT_T1);
count |= __raw_readb(PIT_T1) << 8;
count += COUNT;
__raw_writeb(count & 0xff, PIT_T1);
__raw_writeb(count >> 8, PIT_T1);
timer_tick(regs);
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}
static struct irqaction ebsa110_timer_irq = {
.name = "EBSA110 Timer Tick",
.flags = SA_INTERRUPT | SA_TIMER,
.handler = ebsa110_timer_interrupt,
};
/*
* Set up timer interrupt.
*/
static void __init ebsa110_timer_init(void)
{
/*
* Timer 1, mode 2, LSB/MSB
*/
__raw_writeb(0x70, PIT_CTRL);
__raw_writeb(COUNT & 0xff, PIT_T1);
__raw_writeb(COUNT >> 8, PIT_T1);
setup_irq(IRQ_EBSA110_TIMER0, &ebsa110_timer_irq);
}
static struct sys_timer ebsa110_timer = {
.init = ebsa110_timer_init,
.offset = ebsa110_gettimeoffset,
};
static struct plat_serial8250_port serial_platform_data[] = {
{
.iobase = 0x3f8,
.irq = 1,
.uartclk = 1843200,
.regshift = 0,
.iotype = UPIO_PORT,
.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
},
{
.iobase = 0x2f8,
.irq = 2,
.uartclk = 1843200,
.regshift = 0,
.iotype = UPIO_PORT,
.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
},
{ },
};
static struct platform_device serial_device = {
.name = "serial8250",
.id = 0,
.dev = {
.platform_data = serial_platform_data,
},
};
static int __init ebsa110_init(void)
{
return platform_device_register(&serial_device);
}
arch_initcall(ebsa110_init);
MACHINE_START(EBSA110, "EBSA110")
MAINTAINER("Russell King")
BOOT_MEM(0x00000000, 0xe0000000, 0xe0000000)
BOOT_PARAMS(0x00000400)
DISABLE_PARPORT(0)
DISABLE_PARPORT(2)
SOFT_REBOOT
MAPIO(ebsa110_map_io)
INITIRQ(ebsa110_init_irq)
.timer = &ebsa110_timer,
MACHINE_END
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