linux/arch/arm/plat-pxa/gpio.c

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/*
* linux/arch/arm/plat-pxa/gpio.c
*
* Generic PXA GPIO handling
*
* Author: Nicolas Pitre
* Created: Jun 15, 2001
* Copyright: MontaVista Software Inc.
*
* 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/init.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/sysdev.h>
#include <linux/bootmem.h>
#include <mach/gpio.h>
int pxa_last_gpio;
struct pxa_gpio_chip {
struct gpio_chip chip;
void __iomem *regbase;
char label[10];
unsigned long irq_mask;
unsigned long irq_edge_rise;
unsigned long irq_edge_fall;
#ifdef CONFIG_PM
unsigned long saved_gplr;
unsigned long saved_gpdr;
unsigned long saved_grer;
unsigned long saved_gfer;
#endif
};
static DEFINE_SPINLOCK(gpio_lock);
static struct pxa_gpio_chip *pxa_gpio_chips;
#define for_each_gpio_chip(i, c) \
for (i = 0, c = &pxa_gpio_chips[0]; i <= pxa_last_gpio; i += 32, c++)
static inline void __iomem *gpio_chip_base(struct gpio_chip *c)
{
return container_of(c, struct pxa_gpio_chip, chip)->regbase;
}
static inline struct pxa_gpio_chip *gpio_to_chip(unsigned gpio)
{
return &pxa_gpio_chips[gpio_to_bank(gpio)];
}
static int pxa_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
void __iomem *base = gpio_chip_base(chip);
uint32_t value, mask = 1 << offset;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
value = __raw_readl(base + GPDR_OFFSET);
if (__gpio_is_inverted(chip->base + offset))
value |= mask;
else
value &= ~mask;
__raw_writel(value, base + GPDR_OFFSET);
spin_unlock_irqrestore(&gpio_lock, flags);
return 0;
}
static int pxa_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
void __iomem *base = gpio_chip_base(chip);
uint32_t tmp, mask = 1 << offset;
unsigned long flags;
__raw_writel(mask, base + (value ? GPSR_OFFSET : GPCR_OFFSET));
spin_lock_irqsave(&gpio_lock, flags);
tmp = __raw_readl(base + GPDR_OFFSET);
if (__gpio_is_inverted(chip->base + offset))
tmp &= ~mask;
else
tmp |= mask;
__raw_writel(tmp, base + GPDR_OFFSET);
spin_unlock_irqrestore(&gpio_lock, flags);
return 0;
}
static int pxa_gpio_get(struct gpio_chip *chip, unsigned offset)
{
return __raw_readl(gpio_chip_base(chip) + GPLR_OFFSET) & (1 << offset);
}
static void pxa_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
__raw_writel(1 << offset, gpio_chip_base(chip) +
(value ? GPSR_OFFSET : GPCR_OFFSET));
}
static int __init pxa_init_gpio_chip(int gpio_end)
{
int i, gpio, nbanks = gpio_to_bank(gpio_end) + 1;
struct pxa_gpio_chip *chips;
/* this is early, we have to use bootmem allocator, and we really
* want this to be allocated dynamically for different 'gpio_end'
*/
chips = alloc_bootmem_low(nbanks * sizeof(struct pxa_gpio_chip));
if (chips == NULL) {
pr_err("%s: failed to allocate GPIO chips\n", __func__);
return -ENOMEM;
}
memset(chips, 0, nbanks * sizeof(struct pxa_gpio_chip));
for (i = 0, gpio = 0; i < nbanks; i++, gpio += 32) {
struct gpio_chip *c = &chips[i].chip;
sprintf(chips[i].label, "gpio-%d", i);
chips[i].regbase = (void __iomem *)GPIO_BANK(i);
c->base = gpio;
c->label = chips[i].label;
c->direction_input = pxa_gpio_direction_input;
c->direction_output = pxa_gpio_direction_output;
c->get = pxa_gpio_get;
c->set = pxa_gpio_set;
/* number of GPIOs on last bank may be less than 32 */
c->ngpio = (gpio + 31 > gpio_end) ? (gpio_end - gpio + 1) : 32;
gpiochip_add(c);
}
pxa_gpio_chips = chips;
return 0;
}
/* Update only those GRERx and GFERx edge detection register bits if those
* bits are set in c->irq_mask
*/
static inline void update_edge_detect(struct pxa_gpio_chip *c)
{
uint32_t grer, gfer;
grer = __raw_readl(c->regbase + GRER_OFFSET) & ~c->irq_mask;
gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~c->irq_mask;
grer |= c->irq_edge_rise & c->irq_mask;
gfer |= c->irq_edge_fall & c->irq_mask;
__raw_writel(grer, c->regbase + GRER_OFFSET);
__raw_writel(gfer, c->regbase + GFER_OFFSET);
}
static int pxa_gpio_irq_type(unsigned int irq, unsigned int type)
{
struct pxa_gpio_chip *c;
int gpio = irq_to_gpio(irq);
unsigned long gpdr, mask = GPIO_bit(gpio);
c = gpio_to_chip(gpio);
if (type == IRQ_TYPE_PROBE) {
/* Don't mess with enabled GPIOs using preconfigured edges or
* GPIOs set to alternate function or to output during probe
*/
if ((c->irq_edge_rise | c->irq_edge_fall) & GPIO_bit(gpio))
return 0;
if (__gpio_is_occupied(gpio))
return 0;
type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
}
gpdr = __raw_readl(c->regbase + GPDR_OFFSET);
if (__gpio_is_inverted(gpio))
__raw_writel(gpdr | mask, c->regbase + GPDR_OFFSET);
else
__raw_writel(gpdr & ~mask, c->regbase + GPDR_OFFSET);
if (type & IRQ_TYPE_EDGE_RISING)
c->irq_edge_rise |= mask;
else
c->irq_edge_rise &= ~mask;
if (type & IRQ_TYPE_EDGE_FALLING)
c->irq_edge_fall |= mask;
else
c->irq_edge_fall &= ~mask;
update_edge_detect(c);
pr_debug("%s: IRQ%d (GPIO%d) - edge%s%s\n", __func__, irq, gpio,
((type & IRQ_TYPE_EDGE_RISING) ? " rising" : ""),
((type & IRQ_TYPE_EDGE_FALLING) ? " falling" : ""));
return 0;
}
static void pxa_gpio_demux_handler(unsigned int irq, struct irq_desc *desc)
{
struct pxa_gpio_chip *c;
int loop, gpio, gpio_base, n;
unsigned long gedr;
do {
loop = 0;
for_each_gpio_chip(gpio, c) {
gpio_base = c->chip.base;
gedr = __raw_readl(c->regbase + GEDR_OFFSET);
gedr = gedr & c->irq_mask;
__raw_writel(gedr, c->regbase + GEDR_OFFSET);
n = find_first_bit(&gedr, BITS_PER_LONG);
while (n < BITS_PER_LONG) {
loop = 1;
generic_handle_irq(gpio_to_irq(gpio_base + n));
n = find_next_bit(&gedr, BITS_PER_LONG, n + 1);
}
}
} while (loop);
}
static void pxa_ack_muxed_gpio(unsigned int irq)
{
int gpio = irq_to_gpio(irq);
struct pxa_gpio_chip *c = gpio_to_chip(gpio);
__raw_writel(GPIO_bit(gpio), c->regbase + GEDR_OFFSET);
}
static void pxa_mask_muxed_gpio(unsigned int irq)
{
int gpio = irq_to_gpio(irq);
struct pxa_gpio_chip *c = gpio_to_chip(gpio);
uint32_t grer, gfer;
c->irq_mask &= ~GPIO_bit(gpio);
grer = __raw_readl(c->regbase + GRER_OFFSET) & ~GPIO_bit(gpio);
gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~GPIO_bit(gpio);
__raw_writel(grer, c->regbase + GRER_OFFSET);
__raw_writel(gfer, c->regbase + GFER_OFFSET);
}
static void pxa_unmask_muxed_gpio(unsigned int irq)
{
int gpio = irq_to_gpio(irq);
struct pxa_gpio_chip *c = gpio_to_chip(gpio);
c->irq_mask |= GPIO_bit(gpio);
update_edge_detect(c);
}
static struct irq_chip pxa_muxed_gpio_chip = {
.name = "GPIO",
.ack = pxa_ack_muxed_gpio,
.mask = pxa_mask_muxed_gpio,
.unmask = pxa_unmask_muxed_gpio,
.set_type = pxa_gpio_irq_type,
};
void __init pxa_init_gpio(int mux_irq, int start, int end, set_wake_t fn)
{
struct pxa_gpio_chip *c;
int gpio, irq;
pxa_last_gpio = end;
/* Initialize GPIO chips */
pxa_init_gpio_chip(end);
/* clear all GPIO edge detects */
for_each_gpio_chip(gpio, c) {
__raw_writel(0, c->regbase + GFER_OFFSET);
__raw_writel(0, c->regbase + GRER_OFFSET);
__raw_writel(~0,c->regbase + GEDR_OFFSET);
}
for (irq = gpio_to_irq(start); irq <= gpio_to_irq(end); irq++) {
set_irq_chip(irq, &pxa_muxed_gpio_chip);
set_irq_handler(irq, handle_edge_irq);
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
}
/* Install handler for GPIO>=2 edge detect interrupts */
set_irq_chained_handler(mux_irq, pxa_gpio_demux_handler);
pxa_muxed_gpio_chip.set_wake = fn;
}
#ifdef CONFIG_PM
static int pxa_gpio_suspend(struct sys_device *dev, pm_message_t state)
{
struct pxa_gpio_chip *c;
int gpio;
for_each_gpio_chip(gpio, c) {
c->saved_gplr = __raw_readl(c->regbase + GPLR_OFFSET);
c->saved_gpdr = __raw_readl(c->regbase + GPDR_OFFSET);
c->saved_grer = __raw_readl(c->regbase + GRER_OFFSET);
c->saved_gfer = __raw_readl(c->regbase + GFER_OFFSET);
/* Clear GPIO transition detect bits */
__raw_writel(0xffffffff, c->regbase + GEDR_OFFSET);
}
return 0;
}
static int pxa_gpio_resume(struct sys_device *dev)
{
struct pxa_gpio_chip *c;
int gpio;
for_each_gpio_chip(gpio, c) {
/* restore level with set/clear */
__raw_writel( c->saved_gplr, c->regbase + GPSR_OFFSET);
__raw_writel(~c->saved_gplr, c->regbase + GPCR_OFFSET);
__raw_writel(c->saved_grer, c->regbase + GRER_OFFSET);
__raw_writel(c->saved_gfer, c->regbase + GFER_OFFSET);
__raw_writel(c->saved_gpdr, c->regbase + GPDR_OFFSET);
}
return 0;
}
#else
#define pxa_gpio_suspend NULL
#define pxa_gpio_resume NULL
#endif
struct sysdev_class pxa_gpio_sysclass = {
.name = "gpio",
.suspend = pxa_gpio_suspend,
.resume = pxa_gpio_resume,
};
static int __init pxa_gpio_init(void)
{
return sysdev_class_register(&pxa_gpio_sysclass);
}
core_initcall(pxa_gpio_init);