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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [arch/] [arm/] [mach-at91/] [gpio.c] - Rev 3
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/* * linux/arch/arm/mach-at91/gpio.c * * Copyright (C) 2005 HP Labs * * 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/clk.h> #include <linux/errno.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/module.h> #include <asm/io.h> #include <asm/hardware.h> #include <asm/arch/at91_pio.h> #include <asm/arch/gpio.h> #include "generic.h" static struct at91_gpio_bank *gpio; static int gpio_banks; static inline void __iomem *pin_to_controller(unsigned pin) { void __iomem *sys_base = (void __iomem *) AT91_VA_BASE_SYS; pin -= PIN_BASE; pin /= 32; if (likely(pin < gpio_banks)) return sys_base + gpio[pin].offset; return NULL; } static inline unsigned pin_to_mask(unsigned pin) { pin -= PIN_BASE; return 1 << (pin % 32); } /*--------------------------------------------------------------------------*/ /* Not all hardware capabilities are exposed through these calls; they * only encapsulate the most common features and modes. (So if you * want to change signals in groups, do it directly.) * * Bootloaders will usually handle some of the pin multiplexing setup. * The intent is certainly that by the time Linux is fully booted, all * pins should have been fully initialized. These setup calls should * only be used by board setup routines, or possibly in driver probe(). * * For bootloaders doing all that setup, these calls could be inlined * as NOPs so Linux won't duplicate any setup code */ /* * mux the pin to the "GPIO" peripheral role. */ int __init_or_module at91_set_GPIO_periph(unsigned pin, int use_pullup) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio) return -EINVAL; __raw_writel(mask, pio + PIO_IDR); __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR)); __raw_writel(mask, pio + PIO_PER); return 0; } EXPORT_SYMBOL(at91_set_GPIO_periph); /* * mux the pin to the "A" internal peripheral role. */ int __init_or_module at91_set_A_periph(unsigned pin, int use_pullup) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio) return -EINVAL; __raw_writel(mask, pio + PIO_IDR); __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR)); __raw_writel(mask, pio + PIO_ASR); __raw_writel(mask, pio + PIO_PDR); return 0; } EXPORT_SYMBOL(at91_set_A_periph); /* * mux the pin to the "B" internal peripheral role. */ int __init_or_module at91_set_B_periph(unsigned pin, int use_pullup) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio) return -EINVAL; __raw_writel(mask, pio + PIO_IDR); __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR)); __raw_writel(mask, pio + PIO_BSR); __raw_writel(mask, pio + PIO_PDR); return 0; } EXPORT_SYMBOL(at91_set_B_periph); /* * mux the pin to the gpio controller (instead of "A" or "B" peripheral), and * configure it for an input. */ int __init_or_module at91_set_gpio_input(unsigned pin, int use_pullup) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio) return -EINVAL; __raw_writel(mask, pio + PIO_IDR); __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR)); __raw_writel(mask, pio + PIO_ODR); __raw_writel(mask, pio + PIO_PER); return 0; } EXPORT_SYMBOL(at91_set_gpio_input); /* * mux the pin to the gpio controller (instead of "A" or "B" peripheral), * and configure it for an output. */ int __init_or_module at91_set_gpio_output(unsigned pin, int value) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio) return -EINVAL; __raw_writel(mask, pio + PIO_IDR); __raw_writel(mask, pio + PIO_PUDR); __raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR)); __raw_writel(mask, pio + PIO_OER); __raw_writel(mask, pio + PIO_PER); return 0; } EXPORT_SYMBOL(at91_set_gpio_output); /* * enable/disable the glitch filter; mostly used with IRQ handling. */ int __init_or_module at91_set_deglitch(unsigned pin, int is_on) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio) return -EINVAL; __raw_writel(mask, pio + (is_on ? PIO_IFER : PIO_IFDR)); return 0; } EXPORT_SYMBOL(at91_set_deglitch); /* * enable/disable the multi-driver; This is only valid for output and * allows the output pin to run as an open collector output. */ int __init_or_module at91_set_multi_drive(unsigned pin, int is_on) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio) return -EINVAL; __raw_writel(mask, pio + (is_on ? PIO_MDER : PIO_MDDR)); return 0; } EXPORT_SYMBOL(at91_set_multi_drive); /*--------------------------------------------------------------------------*/ /* new-style GPIO calls; these expect at91_set_GPIO_periph to have been * called, and maybe at91_set_multi_drive() for putout pins. */ int gpio_direction_input(unsigned pin) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio || !(__raw_readl(pio + PIO_PSR) & mask)) return -EINVAL; __raw_writel(mask, pio + PIO_ODR); return 0; } EXPORT_SYMBOL(gpio_direction_input); int gpio_direction_output(unsigned pin, int value) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio || !(__raw_readl(pio + PIO_PSR) & mask)) return -EINVAL; __raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR)); __raw_writel(mask, pio + PIO_OER); return 0; } EXPORT_SYMBOL(gpio_direction_output); /*--------------------------------------------------------------------------*/ /* * assuming the pin is muxed as a gpio output, set its value. */ int at91_set_gpio_value(unsigned pin, int value) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (!pio) return -EINVAL; __raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR)); return 0; } EXPORT_SYMBOL(at91_set_gpio_value); /* * read the pin's value (works even if it's not muxed as a gpio). */ int at91_get_gpio_value(unsigned pin) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); u32 pdsr; if (!pio) return -EINVAL; pdsr = __raw_readl(pio + PIO_PDSR); return (pdsr & mask) != 0; } EXPORT_SYMBOL(at91_get_gpio_value); /*--------------------------------------------------------------------------*/ #ifdef CONFIG_PM static u32 wakeups[MAX_GPIO_BANKS]; static u32 backups[MAX_GPIO_BANKS]; static int gpio_irq_set_wake(unsigned pin, unsigned state) { unsigned mask = pin_to_mask(pin); unsigned bank = (pin - PIN_BASE) / 32; if (unlikely(bank >= MAX_GPIO_BANKS)) return -EINVAL; if (state) wakeups[bank] |= mask; else wakeups[bank] &= ~mask; set_irq_wake(gpio[bank].id, state); return 0; } void at91_gpio_suspend(void) { int i; for (i = 0; i < gpio_banks; i++) { u32 pio = gpio[i].offset; backups[i] = at91_sys_read(pio + PIO_IMR); at91_sys_write(pio + PIO_IDR, backups[i]); at91_sys_write(pio + PIO_IER, wakeups[i]); if (!wakeups[i]) clk_disable(gpio[i].clock); else { #ifdef CONFIG_PM_DEBUG printk(KERN_DEBUG "GPIO-%c may wake for %08x\n", 'A'+i, wakeups[i]); #endif } } } void at91_gpio_resume(void) { int i; for (i = 0; i < gpio_banks; i++) { u32 pio = gpio[i].offset; if (!wakeups[i]) clk_enable(gpio[i].clock); at91_sys_write(pio + PIO_IDR, wakeups[i]); at91_sys_write(pio + PIO_IER, backups[i]); } } #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 * at91_set_gpio_input() then maybe enable its glitch filter. * Then just request_irq() with the pin ID; it works like any ARM IRQ * handler, though it always triggers on rising and falling edges. * * Alternatively, certain pins may be used directly as IRQ0..IRQ6 after * configuring them with at91_set_a_periph() or at91_set_b_periph(). * IRQ0..IRQ6 should be configurable, e.g. level vs edge triggering. */ static void gpio_irq_mask(unsigned pin) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (pio) __raw_writel(mask, pio + PIO_IDR); } static void gpio_irq_unmask(unsigned pin) { void __iomem *pio = pin_to_controller(pin); unsigned mask = pin_to_mask(pin); if (pio) __raw_writel(mask, pio + PIO_IER); } static int gpio_irq_type(unsigned pin, unsigned type) { return (type == IRQT_BOTHEDGE) ? 0 : -EINVAL; } static struct irq_chip gpio_irqchip = { .name = "GPIO", .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 irq_desc *desc) { unsigned pin; struct irq_desc *gpio; void __iomem *pio; u32 isr; pio = get_irq_chip_data(irq); /* 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; pin = (unsigned) get_irq_data(irq); gpio = &irq_desc[pin]; while (isr) { if (isr & 1) { if (unlikely(gpio->depth)) { /* * The core ARM interrupt handler lazily disables IRQs so * another IRQ must be generated before it actually gets * here to be disabled on the GPIO controller. */ gpio_irq_mask(pin); } else desc_handle_irq(pin, gpio); } pin++; gpio++; isr >>= 1; } } desc->chip->unmask(irq); /* now it may re-trigger */ } /*--------------------------------------------------------------------------*/ /* * Called from the processor-specific init to enable GPIO interrupt support. */ void __init at91_gpio_irq_setup(void) { unsigned pioc, pin; for (pioc = 0, pin = PIN_BASE; pioc < gpio_banks; pioc++) { void __iomem *controller; unsigned id = gpio[pioc].id; unsigned i; clk_enable(gpio[pioc].clock); /* enable PIO controller's clock */ controller = (void __iomem *) AT91_VA_BASE_SYS + gpio[pioc].offset; __raw_writel(~0, controller + PIO_IDR); set_irq_data(id, (void *) pin); set_irq_chip_data(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 interrupts sanely. */ set_irq_chip(pin, &gpio_irqchip); set_irq_handler(pin, handle_simple_irq); set_irq_flags(pin, IRQF_VALID); } set_irq_chained_handler(id, gpio_irq_handler); } pr_info("AT91: %d gpio irqs in %d banks\n", pin - PIN_BASE, gpio_banks); } /* * Called from the processor-specific init to enable GPIO pin support. */ void __init at91_gpio_init(struct at91_gpio_bank *data, int nr_banks) { BUG_ON(nr_banks > MAX_GPIO_BANKS); gpio = data; gpio_banks = nr_banks; }