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Diffstat (limited to 'arch/arm/mach-davinci/include/mach/gpio.h')
| -rw-r--r-- | arch/arm/mach-davinci/include/mach/gpio.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/include/mach/gpio.h b/arch/arm/mach-davinci/include/mach/gpio.h new file mode 100644 index 00000000000..b3a2961f0f4 --- /dev/null +++ b/arch/arm/mach-davinci/include/mach/gpio.h @@ -0,0 +1,154 @@ +/* + * TI DaVinci GPIO Support + * + * Copyright (c) 2006 David Brownell + * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com> + * + * 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. + */ + +#ifndef __DAVINCI_GPIO_H +#define __DAVINCI_GPIO_H + +#include <linux/io.h> +#include <asm-generic/gpio.h> +#include <mach/hardware.h> + +/* + * basic gpio routines + * + * board-specific init should be done by arch/.../.../board-XXX.c (maybe + * initializing banks together) rather than boot loaders; kexec() won't + * go through boot loaders. + * + * the gpio clock will be turned on when gpios are used, and you may also + * need to pay attention to PINMUX0 and PINMUX1 to be sure those pins are + * used as gpios, not with other peripherals. + * + * On-chip GPIOs are numbered 0..(DAVINCI_N_GPIO-1). For documentation, + * and maybe for later updates, code should write GPIO(N) or: + * - GPIOV18(N) for 1.8V pins, N in 0..53; same as GPIO(0)..GPIO(53) + * - GPIOV33(N) for 3.3V pins, N in 0..17; same as GPIO(54)..GPIO(70) + * + * For GPIO IRQs use gpio_to_irq(GPIO(N)) or gpio_to_irq(GPIOV33(N)) etc + * for now, that's != GPIO(N) + * + * GPIOs can also be on external chips, numbered after the ones built-in + * to the DaVinci chip. For now, they won't be usable as IRQ sources. + */ +#define GPIO(X) (X) /* 0 <= X <= 70 */ +#define GPIOV18(X) (X) /* 1.8V i/o; 0 <= X <= 53 */ +#define GPIOV33(X) ((X)+54) /* 3.3V i/o; 0 <= X <= 17 */ + +struct gpio_controller { + u32 dir; + u32 out_data; + u32 set_data; + u32 clr_data; + u32 in_data; + u32 set_rising; + u32 clr_rising; + u32 set_falling; + u32 clr_falling; + u32 intstat; +}; + +/* The __gpio_to_controller() and __gpio_mask() functions inline to constants + * with constant parameters; or in outlined code they execute at runtime. + * + * You'd access the controller directly when reading or writing more than + * one gpio value at a time, and to support wired logic where the value + * being driven by the cpu need not match the value read back. + * + * These are NOT part of the cross-platform GPIO interface + */ +static inline struct gpio_controller *__iomem +__gpio_to_controller(unsigned gpio) +{ + void *__iomem ptr; + + if (gpio < 32) + ptr = IO_ADDRESS(DAVINCI_GPIO_BASE + 0x10); + else if (gpio < 64) + ptr = IO_ADDRESS(DAVINCI_GPIO_BASE + 0x38); + else if (gpio < DAVINCI_N_GPIO) + ptr = IO_ADDRESS(DAVINCI_GPIO_BASE + 0x60); + else + ptr = NULL; + return ptr; +} + +static inline u32 __gpio_mask(unsigned gpio) +{ + return 1 << (gpio % 32); +} + +/* The get/set/clear functions will inline when called with constant + * parameters referencing built-in GPIOs, for low-overhead bitbanging. + * + * Otherwise, calls with variable parameters or referencing external + * GPIOs (e.g. on GPIO expander chips) use outlined functions. + */ +static inline void gpio_set_value(unsigned gpio, int value) +{ + if (__builtin_constant_p(value) && gpio < DAVINCI_N_GPIO) { + struct gpio_controller *__iomem g; + u32 mask; + + g = __gpio_to_controller(gpio); + mask = __gpio_mask(gpio); + if (value) + __raw_writel(mask, &g->set_data); + else + __raw_writel(mask, &g->clr_data); + return; + } + + __gpio_set_value(gpio, value); +} + +/* Returns zero or nonzero; works for gpios configured as inputs OR + * as outputs, at least for built-in GPIOs. + * + * NOTE: for built-in GPIOs, changes in reported values are synchronized + * to the GPIO clock. This is easily seen after calling gpio_set_value() + * and then immediately gpio_get_value(), where the gpio_get_value() will + * return the old value until the GPIO clock ticks and the new value gets + * latched. + */ +static inline int gpio_get_value(unsigned gpio) +{ + struct gpio_controller *__iomem g; + + if (!__builtin_constant_p(gpio) || gpio >= DAVINCI_N_GPIO) + return __gpio_get_value(gpio); + + g = __gpio_to_controller(gpio); + return __gpio_mask(gpio) & __raw_readl(&g->in_data); +} + +static inline int gpio_cansleep(unsigned gpio) +{ + if (__builtin_constant_p(gpio) && gpio < DAVINCI_N_GPIO) + return 0; + else + return __gpio_cansleep(gpio); +} + +static inline int gpio_to_irq(unsigned gpio) +{ + if (gpio >= DAVINCI_N_GPIO) + return -EINVAL; + return DAVINCI_N_AINTC_IRQ + gpio; +} + +static inline int irq_to_gpio(unsigned irq) +{ + /* caller guarantees gpio_to_irq() succeeded */ + return irq - DAVINCI_N_AINTC_IRQ; +} + +#endif /* __DAVINCI_GPIO_H */ |