/*
* 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>
#include <asm/mach/irq.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 */
void __iomem *base;
int irq_base;
struct irq_chip_generic *irq_gc;
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);
/*
* gpio value is set again, because pl061 doesn't allow to set value of
* a gpio pin before configuring it in OUT mode.
*/
writeb(!!value << offset, chip->base + (1 << (offset + 2)));
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 <= 0)
return -EINVAL;
return chip->irq_base + offset;
}
static int pl061_irq_type(struct irq_data *d, unsigned trigger)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct pl061_gpio *chip = gc->private;
int offset = d->irq - chip->irq_base;
unsigned long flags;
u8 gpiois, gpioibe, gpioiev;
if (offset < 0 || offset >= PL061_GPIO_NR)
return -EINVAL;
raw_spin_lock_irqsave(&gc->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 if (trigger & IRQ_TYPE_EDGE_FALLING)
gpioiev &= ~(1 << offset);
}
writeb(gpioibe, chip->base + GPIOIBE);
writeb(gpioiev, chip->base + GPIOIEV);
raw_spin_unlock_irqrestore(&gc->lock, flags);
return 0;
}
static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
{
struct list_head *chip_list = irq_get_handler_data(irq);
struct list_head *ptr;
struct pl061_gpio *chip;
struct irq_chip *irqchip = irq_desc_get_chip(desc);
chained_irq_enter(irqchip, desc);
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));
}
chained_irq_exit(irqchip, desc);
}
static void __init pl061_init_gc(struct pl061_gpio *chip, int irq_base)
{
struct irq_chip_type *ct;
chip->irq_gc = irq_alloc_generic_chip("gpio-pl061", 1, irq_base,
chip->base, handle_simple_irq);
chip->irq_gc->private = chip;
ct = chip->irq_gc->chip_types;
ct->chip.irq_mask = irq_gc_mask_clr_bit;
ct->chip.irq_unmask = irq_gc_mask_set_bit;
ct->chip.irq_set_type = pl061_irq_type;
ct->chip.irq_set_wake = irq_gc_set_wake;
ct->regs.mask = GPIOIE;
irq_setup_generic_chip(chip->irq_gc, IRQ_MSK(PL061_GPIO_NR),
IRQ_GC_INIT_NESTED_LOCK, IRQ_NOREQUEST, 0);
}
static int pl061_probe(struct amba_device *dev, const 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);
chip = kzalloc(sizeof(*chip), GFP_KERNEL);
if (chip == NULL)
return -ENOMEM;
pdata = dev->dev.platform_data;
if (pdata) {
chip->gc.base = pdata->gpio_base;
chip->irq_base = pdata->irq_base;
} else if (dev->dev.of_node) {
chip->gc.base = -1;
chip->irq_base = 0;
} else {
ret = -ENODEV;
goto free_mem;
}
if (!request_mem_region(dev->res.start,
resource_size(&dev->res), "pl061")) {
ret = -EBUSY;
goto free_mem;
}
chip->base = ioremap(dev->res.start, resource_size(&dev->res));
if (chip->base == NULL) {
ret = -ENOMEM;
goto release_region;
}
spin_lock_init(&chip->lock);
INIT_LIST_HEAD(&chip->list);
chip->gc.direction_input = pl061_direction_input;
chip->gc.direction_output = pl061_direction_output;
chip->gc.get = pl061_get_value;
chip->gc.set = pl061_set_value;
chip->gc.to_irq = pl061_to_irq;
chip->gc.ngpio = PL061_GPIO_NR;
chip->gc.label = dev_name(&dev->dev);
chip->gc.dev = &dev->dev;
chip->gc.owner = THIS_MODULE;
ret = gpiochip_add(&chip->gc);
if (ret)
goto iounmap;
/*
* irq_chip support
*/
if (chip->irq_base <= 0)
return 0;
pl061_init_gc(chip, chip->irq_base);
writeb(0, chip->base + GPIOIE); /* disable irqs */
irq = dev->irq[0];
if (irq < 0) {
ret = -ENODEV;
goto iounmap;
}
irq_set_chained_handler(irq, pl061_irq_handler);
if (!test_and_set_bit(irq, init_irq)) { /* list initialized? */
chip_list = kmalloc(sizeof(*chip_list), GFP_KERNEL);
if (chip_list == NULL) {
clear_bit(irq, init_irq);
ret = -ENOMEM;
goto iounmap;
}
INIT_LIST_HEAD(chip_list);
irq_set_handler_data(irq, chip_list);
} else
chip_list = irq_get_handler_data(irq);
list_add(&chip->list, chip_list);
for (i = 0; i < PL061_GPIO_NR; i++) {
if (pdata) {
if (pdata->directions & (1 << i))
pl061_direction_output(&chip->gc, i,
pdata->values & (1 << i));
else
pl061_direction_input(&chip->gc, i);
}
}
return 0;
iounmap:
iounmap(chip->base);
release_region:
release_mem_region(dev->res.start, resource_size(&dev->res));
free_mem:
kfree(chip);
return ret;
}
static struct amba_id pl061_ids[] = {
{
.id = 0x00041061,
.mask = 0x000fffff,
},
{ 0, 0 },
};
static struct amba_driver pl061_gpio_driver = {
.drv = {
.name = "pl061_gpio",
},
.id_table = pl061_ids,
.probe = pl061_probe,
};
static int __init pl061_gpio_init(void)
{
return amba_driver_register(&pl061_gpio_driver);
}
subsys_initcall(pl061_gpio_init);
MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
MODULE_DESCRIPTION("PL061 GPIO driver");
MODULE_LICENSE("GPL");
