diff options
Diffstat (limited to 'arch/arm/mach-at91rm9200/gpio.c')
-rw-r--r-- | arch/arm/mach-at91rm9200/gpio.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/arch/arm/mach-at91rm9200/gpio.c b/arch/arm/mach-at91rm9200/gpio.c new file mode 100644 index 00000000000..2fd2ef583e4 --- /dev/null +++ b/arch/arm/mach-at91rm9200/gpio.c @@ -0,0 +1,302 @@ +/* + * linux/arch/arm/mach-at91rm9200/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/errno.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> + +#include <asm/io.h> +#include <asm/mach/irq.h> +#include <asm/arch/hardware.h> +#include <asm/arch/gpio.h> + +static const u32 pio_controller_offset[4] = { + AT91_PIOA, + AT91_PIOB, + AT91_PIOC, + AT91_PIOD, +}; + +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 < BGA_GPIO_BANKS)) + return sys_base + pio_controller_offset[pin]; + + 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 "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); + +/*--------------------------------------------------------------------------*/ + + +/* + * 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); + +/*--------------------------------------------------------------------------*/ + + +/* 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 irqchip gpio_irqchip = { + .mask = gpio_irq_mask, + .unmask = gpio_irq_unmask, + .set_type = gpio_irq_type, +}; + +static void gpio_irq_handler(unsigned irq, struct irqdesc *desc, struct pt_regs *regs) +{ + unsigned pin; + struct irqdesc *gpio; + void __iomem *pio; + u32 isr; + + pio = (void __force __iomem *) desc->chipdata; + + /* temporarily mask (level sensitive) parent IRQ */ + desc->chip->ack(irq); + for (;;) { + isr = __raw_readl(pio + PIO_ISR) & __raw_readl(pio + PIO_IMR); + if (!isr) + break; + + pin = (unsigned) desc->data; + gpio = &irq_desc[pin]; + + while (isr) { + if (isr & 1) + gpio->handle(pin, gpio, regs); + pin++; + gpio++; + isr >>= 1; + } + } + desc->chip->unmask(irq); + /* now it may re-trigger */ +} + +/* call this from board-specific init_irq */ +void __init at91_gpio_irq_setup(unsigned banks) +{ + unsigned pioc, pin, id; + + if (banks > 4) + banks = 4; + for (pioc = 0, pin = PIN_BASE, id = AT91_ID_PIOA; + pioc < banks; + pioc++, id++) { + void __iomem *controller; + unsigned i; + + controller = (void __iomem *) AT91_VA_BASE_SYS + pio_controller_offset[pioc]; + __raw_writel(~0, controller + PIO_IDR); + + set_irq_data(id, (void *) pin); + set_irq_chipdata(id, (void __force *) controller); + + for (i = 0; i < 32; i++, pin++) { + 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); +} |