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linux/drivers/gpio/gpio-pl061.c
Viresh Kumar 6e33aceda2 gpio/gpio-pl061: No need of thaw and poweroff routines for hibernate 
pl061 uses same routines for suspend/freeze/poweroff and resume/thaw/restore.
We are only saving and restoring register values on these routines.

During hibernation, in freeze() we take a snapshot of gpio registers. In thaw()
we don't actually need to restore these registers, as power was never shut down
till now. Similarly, in poweroff() we don't need to take snapshot of these
registers again, as it was done during freeze() and by now the image is already
saved on disk.

This patch passes poweroff() and thaw() routines as NULL to avoid this extra
work done.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-02-16 06:37:51 -07:00

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/*
* 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/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 <linux/pm.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
#ifdef CONFIG_PM
struct pl061_context_save_regs {
u8 gpio_data;
u8 gpio_dir;
u8 gpio_is;
u8 gpio_ibe;
u8 gpio_iev;
u8 gpio_ie;
};
#endif
struct pl061_gpio {
/* 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;
#ifdef CONFIG_PM
struct pl061_context_save_regs csave_regs;
#endif
};
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)
{
unsigned long pending;
int offset;
struct pl061_gpio *chip = irq_desc_get_handler_data(desc);
struct irq_chip *irqchip = irq_desc_get_chip(desc);
chained_irq_enter(irqchip, desc);
pending = readb(chip->base + GPIOMIS);
writeb(pending, chip->base + GPIOIC);
if (pending) {
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;
int ret, irq, i;
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);
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);
irq_set_handler_data(irq, chip);
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);
}
}
amba_set_drvdata(dev, chip);
return 0;
iounmap:
iounmap(chip->base);
release_region:
release_mem_region(dev->res.start, resource_size(&dev->res));
free_mem:
kfree(chip);
return ret;
}
#ifdef CONFIG_PM
static int pl061_suspend(struct device *dev)
{
struct pl061_gpio *chip = dev_get_drvdata(dev);
int offset;
chip->csave_regs.gpio_data = 0;
chip->csave_regs.gpio_dir = readb(chip->base + GPIODIR);
chip->csave_regs.gpio_is = readb(chip->base + GPIOIS);
chip->csave_regs.gpio_ibe = readb(chip->base + GPIOIBE);
chip->csave_regs.gpio_iev = readb(chip->base + GPIOIEV);
chip->csave_regs.gpio_ie = readb(chip->base + GPIOIE);
for (offset = 0; offset < PL061_GPIO_NR; offset++) {
if (chip->csave_regs.gpio_dir & (1 << offset))
chip->csave_regs.gpio_data |=
pl061_get_value(&chip->gc, offset) << offset;
}
return 0;
}
static int pl061_resume(struct device *dev)
{
struct pl061_gpio *chip = dev_get_drvdata(dev);
int offset;
for (offset = 0; offset < PL061_GPIO_NR; offset++) {
if (chip->csave_regs.gpio_dir & (1 << offset))
pl061_direction_output(&chip->gc, offset,
chip->csave_regs.gpio_data &
(1 << offset));
else
pl061_direction_input(&chip->gc, offset);
}
writeb(chip->csave_regs.gpio_is, chip->base + GPIOIS);
writeb(chip->csave_regs.gpio_ibe, chip->base + GPIOIBE);
writeb(chip->csave_regs.gpio_iev, chip->base + GPIOIEV);
writeb(chip->csave_regs.gpio_ie, chip->base + GPIOIE);
return 0;
}
static const struct dev_pm_ops pl061_dev_pm_ops = {
.suspend = pl061_suspend,
.resume = pl061_resume,
.freeze = pl061_suspend,
.restore = pl061_resume,
};
#endif
static struct amba_id pl061_ids[] = {
{
.id = 0x00041061,
.mask = 0x000fffff,
},
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, pl061_ids);
static struct amba_driver pl061_gpio_driver = {
.drv = {
.name = "pl061_gpio",
#ifdef CONFIG_PM
.pm = &pl061_dev_pm_ops,
#endif
},
.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");
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