linux/arch/avr32/mach-at32ap/intc.c
Haavard Skinnemoen 02a00cf672 avr32: Power Management support ("standby" and "mem" modes)
Implement Standby support. In this mode, we'll suspend all drivers,
put the SDRAM in self-refresh mode and switch off the HSB bus
("frozen" mode.)

Implement Suspend-to-mem support. In this mode, we suspend all
drivers, put the SDRAM into self-refresh mode and switch off all
internal clocks except the 32 kHz oscillator ("stop" mode.)

The lowest-level suspend code runs from a small portion of SRAM
allocated at startup time. This gets rid of a small potential race
with the SDRAM where we might try to enter self-refresh mode in the
middle of an icache burst. We also relocate all interrupt and
exception handlers to SRAM during the small window when we enter and
exit the low-power modes.

We don't need to do any special tricks to start and stop the PLL. The
main clock is automatically gated by hardware until the PLL is stable.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-07-02 11:05:01 +02:00

218 lines
4.5 KiB
C

/*
* Copyright (C) 2006, 2008 Atmel Corporation
*
* 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.
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/sysdev.h>
#include <asm/io.h>
#include "intc.h"
struct intc {
void __iomem *regs;
struct irq_chip chip;
struct sys_device sysdev;
#ifdef CONFIG_PM
unsigned long suspend_ipr;
unsigned long saved_ipr[64];
#endif
};
extern struct platform_device at32_intc0_device;
/*
* TODO: We may be able to implement mask/unmask by setting IxM flags
* in the status register.
*/
static void intc_mask_irq(unsigned int irq)
{
}
static void intc_unmask_irq(unsigned int irq)
{
}
static struct intc intc0 = {
.chip = {
.name = "intc",
.mask = intc_mask_irq,
.unmask = intc_unmask_irq,
},
};
/*
* All interrupts go via intc at some point.
*/
asmlinkage void do_IRQ(int level, struct pt_regs *regs)
{
struct irq_desc *desc;
struct pt_regs *old_regs;
unsigned int irq;
unsigned long status_reg;
local_irq_disable();
old_regs = set_irq_regs(regs);
irq_enter();
irq = intc_readl(&intc0, INTCAUSE0 - 4 * level);
desc = irq_desc + irq;
desc->handle_irq(irq, desc);
/*
* Clear all interrupt level masks so that we may handle
* interrupts during softirq processing. If this is a nested
* interrupt, interrupts must stay globally disabled until we
* return.
*/
status_reg = sysreg_read(SR);
status_reg &= ~(SYSREG_BIT(I0M) | SYSREG_BIT(I1M)
| SYSREG_BIT(I2M) | SYSREG_BIT(I3M));
sysreg_write(SR, status_reg);
irq_exit();
set_irq_regs(old_regs);
}
void __init init_IRQ(void)
{
extern void _evba(void);
extern void irq_level0(void);
struct resource *regs;
struct clk *pclk;
unsigned int i;
u32 offset, readback;
regs = platform_get_resource(&at32_intc0_device, IORESOURCE_MEM, 0);
if (!regs) {
printk(KERN_EMERG "intc: no mmio resource defined\n");
goto fail;
}
pclk = clk_get(&at32_intc0_device.dev, "pclk");
if (IS_ERR(pclk)) {
printk(KERN_EMERG "intc: no clock defined\n");
goto fail;
}
clk_enable(pclk);
intc0.regs = ioremap(regs->start, regs->end - regs->start + 1);
if (!intc0.regs) {
printk(KERN_EMERG "intc: failed to map registers (0x%08lx)\n",
(unsigned long)regs->start);
goto fail;
}
/*
* Initialize all interrupts to level 0 (lowest priority). The
* priority level may be changed by calling
* irq_set_priority().
*
*/
offset = (unsigned long)&irq_level0 - (unsigned long)&_evba;
for (i = 0; i < NR_INTERNAL_IRQS; i++) {
intc_writel(&intc0, INTPR0 + 4 * i, offset);
readback = intc_readl(&intc0, INTPR0 + 4 * i);
if (readback == offset)
set_irq_chip_and_handler(i, &intc0.chip,
handle_simple_irq);
}
/* Unmask all interrupt levels */
sysreg_write(SR, (sysreg_read(SR)
& ~(SR_I3M | SR_I2M | SR_I1M | SR_I0M)));
return;
fail:
panic("Interrupt controller initialization failed!\n");
}
#ifdef CONFIG_PM
void intc_set_suspend_handler(unsigned long offset)
{
intc0.suspend_ipr = offset;
}
static int intc_suspend(struct sys_device *sdev, pm_message_t state)
{
struct intc *intc = container_of(sdev, struct intc, sysdev);
int i;
if (unlikely(!irqs_disabled())) {
pr_err("intc_suspend: called with interrupts enabled\n");
return -EINVAL;
}
if (unlikely(!intc->suspend_ipr)) {
pr_err("intc_suspend: suspend_ipr not initialized\n");
return -EINVAL;
}
for (i = 0; i < 64; i++) {
intc->saved_ipr[i] = intc_readl(intc, INTPR0 + 4 * i);
intc_writel(intc, INTPR0 + 4 * i, intc->suspend_ipr);
}
return 0;
}
static int intc_resume(struct sys_device *sdev)
{
struct intc *intc = container_of(sdev, struct intc, sysdev);
int i;
WARN_ON(!irqs_disabled());
for (i = 0; i < 64; i++)
intc_writel(intc, INTPR0 + 4 * i, intc->saved_ipr[i]);
return 0;
}
#else
#define intc_suspend NULL
#define intc_resume NULL
#endif
static struct sysdev_class intc_class = {
.name = "intc",
.suspend = intc_suspend,
.resume = intc_resume,
};
static int __init intc_init_sysdev(void)
{
int ret;
ret = sysdev_class_register(&intc_class);
if (ret)
return ret;
intc0.sysdev.id = 0;
intc0.sysdev.cls = &intc_class;
ret = sysdev_register(&intc0.sysdev);
return ret;
}
device_initcall(intc_init_sysdev);
unsigned long intc_get_pending(unsigned int group)
{
return intc_readl(&intc0, INTREQ0 + 4 * group);
}
EXPORT_SYMBOL_GPL(intc_get_pending);