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/*
* arch/arm/mach-ep93xx/core.c
* Core routines for Cirrus EP93xx chips.
*
* Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
* Copyright (C) 2007 Herbert Valerio Riedel <hvr@gnu.org>
*
* Thanks go to Michael Burian and Ray Lehtiniemi for their key
* role in the ep93xx linux community.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/serial.h>
#include <linux/tty.h>
#include <linux/bitops.h>
#include <linux/serial_8250.h>
#include <linux/serial_core.h>
#include <linux/device.h>
#include <linux/mm.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/delay.h>
#include <linux/termios.h>
#include <linux/amba/bus.h>
#include <linux/amba/serial.h>
#include <asm/types.h>
#include <asm/setup.h>
#include <asm/memory.h>
#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/tlbflush.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/mach/map.h>
#include <asm/mach/time.h>
#include <asm/mach/irq.h>
#include <asm/arch/gpio.h>
#include <asm/hardware/vic.h>
/*************************************************************************
* Static I/O mappings that are needed for all EP93xx platforms
*************************************************************************/
static struct map_desc ep93xx_io_desc[] __initdata = {
{
.virtual = EP93XX_AHB_VIRT_BASE,
.pfn = __phys_to_pfn(EP93XX_AHB_PHYS_BASE),
.length = EP93XX_AHB_SIZE,
.type = MT_DEVICE,
}, {
.virtual = EP93XX_APB_VIRT_BASE,
.pfn = __phys_to_pfn(EP93XX_APB_PHYS_BASE),
.length = EP93XX_APB_SIZE,
.type = MT_DEVICE,
},
};
void __init ep93xx_map_io(void)
{
iotable_init(ep93xx_io_desc, ARRAY_SIZE(ep93xx_io_desc));
}
/*************************************************************************
* Timer handling for EP93xx
*************************************************************************
* The ep93xx has four internal timers. Timers 1, 2 (both 16 bit) and
* 3 (32 bit) count down at 508 kHz, are self-reloading, and can generate
* an interrupt on underflow. Timer 4 (40 bit) counts down at 983.04 kHz,
* is free-running, and can't generate interrupts.
*
* The 508 kHz timers are ideal for use for the timer interrupt, as the
* most common values of HZ divide 508 kHz nicely. We pick one of the 16
* bit timers (timer 1) since we don't need more than 16 bits of reload
* value as long as HZ >= 8.
*
* The higher clock rate of timer 4 makes it a better choice than the
* other timers for use in gettimeoffset(), while the fact that it can't
* generate interrupts means we don't have to worry about not being able
* to use this timer for something else. We also use timer 4 for keeping
* track of lost jiffies.
*/
static unsigned int last_jiffy_time;
#define TIMER4_TICKS_PER_JIFFY ((CLOCK_TICK_RATE + (HZ/2)) / HZ)
static int ep93xx_timer_interrupt(int irq, void *dev_id)
{
__raw_writel(1, EP93XX_TIMER1_CLEAR);
while ((signed long)
(__raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time)
>= TIMER4_TICKS_PER_JIFFY) {
last_jiffy_time += TIMER4_TICKS_PER_JIFFY;
timer_tick();
}
return IRQ_HANDLED;
}
static struct irqaction ep93xx_timer_irq = {
.name = "ep93xx timer",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = ep93xx_timer_interrupt,
};
static void __init ep93xx_timer_init(void)
{
/* Enable periodic HZ timer. */
__raw_writel(0x48, EP93XX_TIMER1_CONTROL);
__raw_writel((508469 / HZ) - 1, EP93XX_TIMER1_LOAD);
__raw_writel(0xc8, EP93XX_TIMER1_CONTROL);
/* Enable lost jiffy timer. */
__raw_writel(0x100, EP93XX_TIMER4_VALUE_HIGH);
setup_irq(IRQ_EP93XX_TIMER1, &ep93xx_timer_irq);
}
static unsigned long ep93xx_gettimeoffset(void)
{
int offset;
offset = __raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time;
/* Calculate (1000000 / 983040) * offset. */
return offset + (53 * offset / 3072);
}
struct sys_timer ep93xx_timer = {
.init = ep93xx_timer_init,
.offset = ep93xx_gettimeoffset,
};
/*************************************************************************
* GPIO handling for EP93xx
*************************************************************************/
static unsigned char gpio_int_unmasked[3];
static unsigned char gpio_int_enabled[3];
static unsigned char gpio_int_type1[3];
static unsigned char gpio_int_type2[3];
/* Port ordering is: A B F */
static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c };
static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 };
static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 };
static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x5c };
void ep93xx_gpio_update_int_params(unsigned port)
{
BUG_ON(port > 2);
__raw_writeb(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
__raw_writeb(gpio_int_type2[port],
EP93XX_GPIO_REG(int_type2_register_offset[port]));
__raw_writeb(gpio_int_type1[port],
EP93XX_GPIO_REG(int_type1_register_offset[port]));
__raw_writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
EP93XX_GPIO_REG(int_en_register_offset[port]));
}
void ep93xx_gpio_int_mask(unsigned line)
{
gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7));
}
/*************************************************************************
* EP93xx IRQ handling
*************************************************************************/
static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
{
unsigned char status;
int i;
status = __raw_readb(EP93XX_GPIO_A_INT_STATUS);
for (i = 0; i < 8; i++) {
if (status & (1 << i)) {
int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
desc = irq_desc + gpio_irq;
desc_handle_irq(gpio_irq, desc);
}
}
status = __raw_readb(EP93XX_GPIO_B_INT_STATUS);
for (i = 0; i < 8; i++) {
if (status & (1 << i)) {
int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
desc = irq_desc + gpio_irq;
desc_handle_irq(gpio_irq, desc);
}
}
}
static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc)
{
/*
* map discontiguous hw irq range to continous sw irq range:
*
* IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
*/
int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;
desc_handle_irq(gpio_irq, irq_desc + gpio_irq);
}
static void ep93xx_gpio_irq_ack(unsigned int irq)
{
int line = irq_to_gpio(irq);
int port = line >> 3;
int port_mask = 1 << (line & 7);
if ((irq_desc[irq].status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE) {
gpio_int_type2[port] ^= port_mask; /* switch edge direction */
ep93xx_gpio_update_int_params(port);
}
__raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
}
static void ep93xx_gpio_irq_mask_ack(unsigned int irq)
{
int line = irq_to_gpio(irq);
int port = line >> 3;
int port_mask = 1 << (line & 7);
if ((irq_desc[irq].status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE)
gpio_int_type2[port] ^= port_mask; /* switch edge direction */
gpio_int_unmasked[port] &= ~port_mask;
ep93xx_gpio_update_int_params(port);
__raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
}
static void ep93xx_gpio_irq_mask(unsigned int irq)
{
int line = irq_to_gpio(irq);
int port = line >> 3;
gpio_int_unmasked[port] &= ~(1 << (line & 7));
ep93xx_gpio_update_int_params(port);
}
static void ep93xx_gpio_irq_unmask(unsigned int irq)
{
int line = irq_to_gpio(irq);
int port = line >> 3;
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