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avr32: Power Management support ("standby" and "mem" modes)

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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>
This commit is contained in:
Haavard Skinnemoen 2008-02-24 13:51:38 +01:00 • committed by Haavard Skinnemoen
parent aa8e87ca61
commit 02a00cf672
8 changed files with 496 additions and 1 deletions
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54
arch/avr32/mach-at32ap/intc.c
View file

@ -22,6 +22,10 @@ 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;
@ -138,8 +142,56 @@ 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",
.name = "intc",
.suspend = intc_suspend,
.resume = intc_resume,
};
static int __init intc_init_sysdev(void)