linux-hardened/include/linux/basic_mmio_gpio.h
Shawn Guo 3e11f7b840 gpio/generic: initialize basic_mmio_gpio shadow variables properly
It fixes the issue in gpio-generic that commit fb14921 (gpio/mxc: add
missing initialization of basic_mmio_gpio shadow variables) manged to
fix in gpio-mxc driver, so that other platform specific drivers do not
suffer from the same problem over and over again.

Changes since v1:
* Turn the last parameter of bgpio_init() "bool big_endian" into
  "unsigned long flags" and give those really quirky hardwares a
  chance to tell that reg_set and reg_dir are unreadable.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
[grant.likely: Fix big-endian usage to explicitly set BBGPIOF_BIG_ENDIAN]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-19 12:17:35 -06:00

76 lines
2 KiB
C

/*
* Basic memory-mapped GPIO controllers.
*
* Copyright 2008 MontaVista Software, Inc.
* Copyright 2008,2010 Anton Vorontsov <cbouatmailru@gmail.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 __BASIC_MMIO_GPIO_H
#define __BASIC_MMIO_GPIO_H
#include <linux/gpio.h>
#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/spinlock_types.h>
struct bgpio_pdata {
int base;
int ngpio;
};
struct device;
struct bgpio_chip {
struct gpio_chip gc;
unsigned long (*read_reg)(void __iomem *reg);
void (*write_reg)(void __iomem *reg, unsigned long data);
void __iomem *reg_dat;
void __iomem *reg_set;
void __iomem *reg_clr;
void __iomem *reg_dir;
/* Number of bits (GPIOs): <register width> * 8. */
int bits;
/*
* Some GPIO controllers work with the big-endian bits notation,
* e.g. in a 8-bits register, GPIO7 is the least significant bit.
*/
unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);
/*
* Used to lock bgpio_chip->data. Also, this is needed to keep
* shadowed and real data registers writes together.
*/
spinlock_t lock;
/* Shadowed data register to clear/set bits safely. */
unsigned long data;
/* Shadowed direction registers to clear/set direction safely. */
unsigned long dir;
};
static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
{
return container_of(gc, struct bgpio_chip, gc);
}
int bgpio_remove(struct bgpio_chip *bgc);
int bgpio_init(struct bgpio_chip *bgc, struct device *dev,
unsigned long sz, void __iomem *dat, void __iomem *set,
void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
unsigned long flags);
#define BGPIOF_BIG_ENDIAN BIT(0)
#define BGPIOF_UNREADABLE_REG_SET BIT(1) /* reg_set is unreadable */
#define BGPIOF_UNREADABLE_REG_DIR BIT(2) /* reg_dir is unreadable */
#endif /* __BASIC_MMIO_GPIO_H */