linux/arch/arm/mach-ns9xxx/gpio.c

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/*
* arch/arm/mach-ns9xxx/gpio.c
*
* Copyright (C) 2006 by Digi International Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <asm/arch-ns9xxx/gpio.h>
#include <asm/arch-ns9xxx/processor.h>
#include <asm/arch-ns9xxx/regs-bbu.h>
#include <asm/io.h>
#include <asm/bug.h>
#include <asm/types.h>
#include <asm/bitops.h>
#if defined(CONFIG_PROCESSOR_NS9360)
#define GPIO_MAX 72
#elif defined(CONFIG_PROCESSOR_NS9750)
#define GPIO_MAX 49
#endif
/* protects BBU_GCONFx and BBU_GCTRLx */
static spinlock_t gpio_lock = __SPIN_LOCK_UNLOCKED(gpio_lock);
/* only access gpiores with atomic ops */
static DECLARE_BITMAP(gpiores, GPIO_MAX);
static inline int ns9xxx_valid_gpio(unsigned gpio)
{
#if defined(CONFIG_PROCESSOR_NS9360)
if (processor_is_ns9360())
return gpio <= 72;
else
#endif
#if defined(CONFIG_PROCESSOR_NS9750)
if (processor_is_ns9750())
return gpio <= 49;
else
#endif
BUG();
}
static inline void __iomem *ns9xxx_gpio_get_gconfaddr(unsigned gpio)
{
if (gpio < 56)
return BBU_GCONFb1(gpio / 8);
else
/*
* this could be optimised away on
* ns9750 only builds, but it isn't ...
*/
return BBU_GCONFb2((gpio - 56) / 8);
}
static inline void __iomem *ns9xxx_gpio_get_gctrladdr(unsigned gpio)
{
if (gpio < 32)
return BBU_GCTRL1;
else if (gpio < 64)
return BBU_GCTRL2;
else
/* this could be optimised away on ns9750 only builds */
return BBU_GCTRL3;
}
static inline void __iomem *ns9xxx_gpio_get_gstataddr(unsigned gpio)
{
if (gpio < 32)
return BBU_GSTAT1;
else if (gpio < 64)
return BBU_GSTAT2;
else
/* this could be optimised away on ns9750 only builds */
return BBU_GSTAT3;
}
int gpio_request(unsigned gpio, const char *label)
{
if (likely(ns9xxx_valid_gpio(gpio)))
return test_and_set_bit(gpio, gpiores) ? -EBUSY : 0;
else
return -EINVAL;
}
EXPORT_SYMBOL(gpio_request);
void gpio_free(unsigned gpio)
{
clear_bit(gpio, gpiores);
return;
}
EXPORT_SYMBOL(gpio_free);
/*
* each gpio can serve for 4 different purposes [0..3]. These are called
* "functions" and passed in the parameter func. Functions 0-2 are always some
* special things, function 3 is GPIO. If func == 3 dir specifies input or
* output, and with inv you can enable an inverter (independent of func).
*/
static int __ns9xxx_gpio_configure(unsigned gpio, int dir, int inv, int func)
{
void __iomem *conf = ns9xxx_gpio_get_gconfaddr(gpio);
u32 confval;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
confval = __raw_readl(conf);
REGSETIM_IDX(confval, BBU_GCONFx, DIR, gpio & 7, dir);
REGSETIM_IDX(confval, BBU_GCONFx, INV, gpio & 7, inv);
REGSETIM_IDX(confval, BBU_GCONFx, FUNC, gpio & 7, func);
__raw_writel(confval, conf);
spin_unlock_irqrestore(&gpio_lock, flags);
return 0;
}
int ns9xxx_gpio_configure(unsigned gpio, int inv, int func)
{
if (likely(ns9xxx_valid_gpio(gpio))) {
if (func == 3) {
printk(KERN_WARNING "use gpio_direction_input "
"or gpio_direction_output\n");
return -EINVAL;
} else
return __ns9xxx_gpio_configure(gpio, 0, inv, func);
} else
return -EINVAL;
}
EXPORT_SYMBOL(ns9xxx_gpio_configure);
int gpio_direction_input(unsigned gpio)
{
if (likely(ns9xxx_valid_gpio(gpio))) {
return __ns9xxx_gpio_configure(gpio, 0, 0, 3);
} else
return -EINVAL;
}
EXPORT_SYMBOL(gpio_direction_input);
int gpio_direction_output(unsigned gpio, int value)
{
if (likely(ns9xxx_valid_gpio(gpio))) {
gpio_set_value(gpio, value);
return __ns9xxx_gpio_configure(gpio, 1, 0, 3);
} else
return -EINVAL;
}
EXPORT_SYMBOL(gpio_direction_output);
int gpio_get_value(unsigned gpio)
{
void __iomem *stat = ns9xxx_gpio_get_gstataddr(gpio);
int ret;
ret = 1 & (__raw_readl(stat) >> (gpio & 31));
return ret;
}
EXPORT_SYMBOL(gpio_get_value);
void gpio_set_value(unsigned gpio, int value)
{
void __iomem *ctrl = ns9xxx_gpio_get_gctrladdr(gpio);
u32 ctrlval;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
ctrlval = __raw_readl(ctrl);
if (value)
ctrlval |= 1 << (gpio & 31);
else
ctrlval &= ~(1 << (gpio & 31));
__raw_writel(ctrlval, ctrl);
spin_unlock_irqrestore(&gpio_lock, flags);
}
EXPORT_SYMBOL(gpio_set_value);