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|
/*
* linux/drivers/gpio/pl061.c
*
* Copyright (C) 2008, 2009 Provigent Ltd.
*
* 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.
*
* Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061)
*
* Data sheet: ARM DDI 0190B, September 2000
*/
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/bitops.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
#include <linux/device.h>
#include <linux/amba/bus.h>
#include <linux/amba/pl061.h>
#include <linux/slab.h>
#define GPIODIR 0x400
#define GPIOIS 0x404
#define GPIOIBE 0x408
#define GPIOIEV 0x40C
#define GPIOIE 0x410
#define GPIORIS 0x414
#define GPIOMIS 0x418
#define GPIOIC 0x41C
#define PL061_GPIO_NR 8
struct pl061_gpio {
/* We use a list of pl061_gpio structs for each trigger IRQ in the main
* interrupts controller of the system. We need this to support systems
* in which more that one PL061s are connected to the same IRQ. The ISR
* interates through this list to find the source of the interrupt.
*/
struct list_head list;
/* Each of the two spinlocks protects a different set of hardware
* regiters and data structurs. This decouples the code of the IRQ from
* the GPIO code. This also makes the case of a GPIO routine call from
* the IRQ code simpler.
*/
spinlock_t lock; /* GPIO registers */
spinlock_t irq_lock; /* IRQ registers */
void __iomem *base;
unsigned irq_base;
struct gpio_chip gc;
};
static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
{
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
unsigned long flags;
unsigned char gpiodir;
if (offset >= gc->ngpio)
return -EINVAL;
spin_lock_irqsave(&chip->lock, flags);
gpiodir = readb(chip->base + GPIODIR);
gpiodir &= ~(1 << offset);
writeb(gpiodir, chip->base + GPIODIR);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
int value)
{
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
unsigned long flags;
unsigned char gpiodir;
if (offset >= gc->ngpio)
return -EINVAL;
spin_lock_irqsave(&chip->lock, flags);
writeb(!!value << offset, chip->base + (1 << (offset + 2)));
gpiodir = readb(chip->base + GPIODIR);
gpiodir |= 1 << offset;
writeb(gpiodir, chip->base + GPIODIR);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
{
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
return !!readb(chip->base + (1 << (offset + 2)));
}
static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
{
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
writeb(!!value << offset, chip->base + (1 << (offset + 2)));
}
static int pl061_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
if (chip->irq_base == (unsigned) -1)
return -EINVAL;
return chip->irq_base + offset;
}
/*
* PL061 GPIO IRQ
*/
static void pl061_irq_disable(unsigned irq)
{
struct pl061_gpio *chip = get_irq_chip_data(irq);
int offset = irq - chip->irq_base;
unsigned long flags;
u8 gpioie;
spin_lock_irqsave(&chip->irq_lock, flags);
gpioie = readb(chip->base + GPIOIE);
gpioie &= ~(1 << offset);
writeb(gpioie, chip->base + GPIOIE);
spin_unlock_irqrestore(&chip->irq_lock, flags);
}
static void pl061_irq_enable(unsigned irq)
{
struct pl061_gpio *chip = get_irq_chip_data(irq);
int offset = irq - chip->irq_base;
unsigned long flags;
u8 gpioie;
spin_lock_irqsave(&chip->irq_lock, flags);
gpioie = readb(chip->base + GPIOIE);
gpioie |= 1 << offset;
writeb(gpioie, chip->base + GPIOIE);
spin_unlock_irqrestore(&chip->irq_lock, flags);
}
static int pl061_irq_type(unsigned irq, unsigned trigger)
{
struct pl061_gpio *chip = get_irq_chip_data(irq);
int offset = irq - chip->irq_base;
unsigned long flags;
u8 gpiois, gpioibe, gpioiev;
if (offset < 0 || offset > PL061_GPIO_NR)
return -EINVAL;
spin_lock_irqsave(&chip->irq_lock, flags);
gpioiev = readb(chip->base + GPIOIEV);
gpiois = readb(chip->base + GPIOIS);
if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
gpiois |= 1 << offset;
if (trigger & IRQ_TYPE_LEVEL_HIGH)
gpioiev |= 1 << offset;
else
gpioiev &= ~(1 << offset);
} else
gpiois &= ~(1 << offset);
writeb(gpiois, chip->base + GPIOIS);
gpioibe = readb(chip->base + GPIOIBE);
if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
gpioibe |= 1 << offset;
else {
gpioibe &= ~(1 << offset);
if (trigger & IRQ_TYPE_EDGE_RISING)
gpioiev |= 1 << offset;
else
gpioiev &= ~(1 << offset);
}
writeb(gpioibe, chip->base + GPIOIBE);
writeb(gpioiev, chip->base + GPIOIEV);
spin_unlock_irqrestore(&chip->irq_lock, flags);
return 0;
}
static struct irq_chip pl061_irqchip = {
.name = "GPIO",
.enable = pl061_irq_enable,
.disable = pl061_irq_disable,
.set_type = pl061_irq_type,
};
static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
{
struct list_head *chip_list = get_irq_chip_data(irq);
struct list_head *ptr;
struct pl061_gpio *chip;
desc->chip->ack(irq);
list_for_each(ptr, chip_list) {
unsigned long pending;
int offset;
chip = list_entry(ptr, struct pl061_gpio, list);
pending = readb(chip->base + GPIOMIS);
writeb(pending, chip->base + GPIOIC);
if (pending == 0)
continue;
for_each_set_bit(offset, &pending, PL061_GPIO_NR)
generic_handle_irq(pl061_to_irq(&chip->gc, offset));
}
desc->chip->unmask(irq);
}
static int __init pl061_probe(struct amba_device *dev, struct amba_id *id)
{
struct pl061_platform_data *pdata;
struct pl061_gpio *chip;
struct list_head *chip_list;
int ret, irq, i;
static DECLARE_BITMAP(init_irq, NR_IRQS);
pdata = dev->dev.platform_data;
if (pdata == NULL)
return -ENODEV;
chip = kzalloc(sizeof(*chip), GFP_KERNEL);
if (chip == NULL)
return -ENOMEM;
if (!request_mem_region(dev->res.start,
resource_size(&dev->res), "pl061")) {
ret = -EBUSY;
goto free_mem;
}
chip->base = ioremap(dev
|