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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 | 161 |
1 files changed, 161 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 00000000..fbece126 --- /dev/null +++ b/arch/arm/mach-davinci/include/mach/gpio.h @@ -0,0 +1,161 @@ +/* + * 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 <linux/spinlock.h> + +#include <asm-generic/gpio.h> + +#include <mach/irqs.h> +#include <mach/common.h> + +#define DAVINCI_GPIO_BASE 0x01C67000 + +enum davinci_gpio_type { + GPIO_TYPE_DAVINCI = 0, + GPIO_TYPE_TNETV107X, +}; + +/* + * 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 PINMUX registers 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 may write GPIO(N). These may be + * all 1.8V signals, all 3.3V ones, or a mix of the two. A given chip + * may not support all the GPIOs in that range. + * + * 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 <= (DAVINCI_N_GPIO - 1) */ + +/* Convert GPIO signal to GPIO pin number */ +#define GPIO_TO_PIN(bank, gpio) (16 * (bank) + (gpio)) + +struct davinci_gpio_controller { + struct gpio_chip chip; + int irq_base; + spinlock_t lock; + void __iomem *regs; + void __iomem *set_data; + void __iomem *clr_data; + void __iomem *in_data; +}; + +/* 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 davinci_gpio_controller * +__gpio_to_controller(unsigned gpio) +{ + struct davinci_gpio_controller *ctlrs = davinci_soc_info.gpio_ctlrs; + int index = gpio / 32; + + if (!ctlrs || index >= davinci_soc_info.gpio_ctlrs_num) + return NULL; + + return ctlrs + index; +} + +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. + * + * gpio_set_value() will inline only on traditional Davinci style controllers + * with distinct set/clear registers. + * + * 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_soc_info.gpio_num) { + struct davinci_gpio_controller *ctlr; + u32 mask; + + ctlr = __gpio_to_controller(gpio); + + if (ctlr->set_data != ctlr->clr_data) { + mask = __gpio_mask(gpio); + if (value) + __raw_writel(mask, ctlr->set_data); + else + __raw_writel(mask, ctlr->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 davinci_gpio_controller *ctlr; + + if (!__builtin_constant_p(gpio) || gpio >= davinci_soc_info.gpio_num) + return __gpio_get_value(gpio); + + ctlr = __gpio_to_controller(gpio); + return __gpio_mask(gpio) & __raw_readl(ctlr->in_data); +} + +static inline int gpio_cansleep(unsigned gpio) +{ + if (__builtin_constant_p(gpio) && gpio < davinci_soc_info.gpio_num) + return 0; + else + return __gpio_cansleep(gpio); +} + +static inline int gpio_to_irq(unsigned gpio) +{ + return __gpio_to_irq(gpio); +} + +static inline int irq_to_gpio(unsigned irq) +{ + /* don't support the reverse mapping */ + return -ENOSYS; +} + +#endif /* __DAVINCI_GPIO_H */ |