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/*
* 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/irqs.h>
#include <mach/common.h>
#define DAVINCI_GPIO_BASE 0x01C67000
enum davinci_gpio_type {
GPIO_TYPE_DAVINCI = 0,
};
/*
* 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;
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.
*
* 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);
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 */
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