From 814138ffa488824393d2f49f2720dcd197a7d4cf Mon Sep 17 00:00:00 2001 From: Andrew Victor Date: Mon, 19 Jun 2006 15:26:54 +0100 Subject: [PATCH] [ARM] 3584/1: AT91RM9200 GPIO suspend/resume support Patch from Andrew Victor This patch adds suspend/resume/set_wake support for the AT91RM9200's GPIO interrupts. Original patch from David Brownell. Signed-off-by: Andrew Victor Signed-off-by: Russell King --- arch/arm/mach-at91rm9200/gpio.c | 87 +++++++++++++++++++++++++++++++-- 1 file changed, 84 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-at91rm9200/gpio.c b/arch/arm/mach-at91rm9200/gpio.c index 5ab46274e1a3..3430ea054662 100644 --- a/arch/arm/mach-at91rm9200/gpio.c +++ b/arch/arm/mach-at91rm9200/gpio.c @@ -213,6 +213,84 @@ EXPORT_SYMBOL(at91_get_gpio_value); /*--------------------------------------------------------------------------*/ +#ifdef CONFIG_PM + +static u32 wakeups[BGA_GPIO_BANKS]; +static u32 backups[BGA_GPIO_BANKS]; + +static int gpio_irq_set_wake(unsigned pin, unsigned state) +{ + unsigned mask = pin_to_mask(pin); + + pin -= PIN_BASE; + pin /= 32; + + if (unlikely(pin >= BGA_GPIO_BANKS)) + return -EINVAL; + + if (state) + wakeups[pin] |= mask; + else + wakeups[pin] &= ~mask; + + return 0; +} + +void at91_gpio_suspend(void) +{ + int i; + + for (i = 0; i < BGA_GPIO_BANKS; i++) { + u32 pio = pio_controller_offset[i]; + + /* + * Note: drivers should have disabled GPIO interrupts that + * aren't supposed to be wakeup sources. + * But that is not much good on ARM..... disable_irq() does + * not update the hardware immediately, so the hardware mask + * (IMR) has the wrong value (not current, too much is + * permitted). + * + * Our workaround is to disable all non-wakeup IRQs ... + * which is exactly what correct drivers asked for in the + * first place! + */ + backups[i] = at91_sys_read(pio + PIO_IMR); + at91_sys_write(pio_controller_offset[i] + PIO_IDR, backups[i]); + at91_sys_write(pio_controller_offset[i] + PIO_IER, wakeups[i]); + + if (!wakeups[i]) { + disable_irq_wake(AT91_ID_PIOA + i); + at91_sys_write(AT91_PMC_PCDR, 1 << (AT91_ID_PIOA + i)); + } else { + enable_irq_wake(AT91_ID_PIOA + i); +#ifdef CONFIG_PM_DEBUG + printk(KERN_DEBUG "GPIO-%c may wake for %08x\n", "ABCD"[i], wakeups[i]); +#endif + } + } +} + +void at91_gpio_resume(void) +{ + int i; + + for (i = 0; i < BGA_GPIO_BANKS; i++) { + at91_sys_write(pio_controller_offset[i] + PIO_IDR, wakeups[i]); + at91_sys_write(pio_controller_offset[i] + PIO_IER, backups[i]); + } + + at91_sys_write(AT91_PMC_PCER, + (1 << AT91_ID_PIOA) + | (1 << AT91_ID_PIOB) + | (1 << AT91_ID_PIOC) + | (1 << AT91_ID_PIOD)); +} + +#else +#define gpio_irq_set_wake NULL +#endif + /* Several AIC controller irqs are dispatched through this GPIO handler. * To use any AT91_PIN_* as an externally triggered IRQ, first call @@ -252,6 +330,7 @@ static struct irqchip gpio_irqchip = { .mask = gpio_irq_mask, .unmask = gpio_irq_unmask, .set_type = gpio_irq_type, + .set_wake = gpio_irq_set_wake, }; static void gpio_irq_handler(unsigned irq, struct irqdesc *desc, struct pt_regs *regs) @@ -266,6 +345,7 @@ static void gpio_irq_handler(unsigned irq, struct irqdesc *desc, struct pt_regs /* temporarily mask (level sensitive) parent IRQ */ desc->chip->ack(irq); for (;;) { + /* reading ISR acks the pending (edge triggered) GPIO interrupt */ isr = __raw_readl(pio + PIO_ISR) & __raw_readl(pio + PIO_IMR); if (!isr) break; @@ -315,15 +395,16 @@ void __init at91_gpio_irq_setup(unsigned banks) set_irq_chipdata(id, controller); for (i = 0; i < 32; i++, pin++) { + /* + * Can use the "simple" and not "edge" handler since it's + * shorter, and the AIC handles interupts sanely. + */ set_irq_chip(pin, &gpio_irqchip); set_irq_handler(pin, do_simple_IRQ); set_irq_flags(pin, IRQF_VALID); } set_irq_chained_handler(id, gpio_irq_handler); - - /* enable the PIO peripheral clock */ - at91_sys_write(AT91_PMC_PCER, 1 << id); } pr_info("AT91: %d gpio irqs in %d banks\n", pin - PIN_BASE, banks); }