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kernel-hacking-2024-linux-s.../drivers/gpio/gpio-pl061.c
Deepak Sikri e198a8de14 GPIO/pl061: Add suspend resume capability 
This patch adds the suspend and resume operations in the driver. The patch
ensures the data save and restore for the device registers during the
suspend and resume operations respectively.

Signed-off-by: Deepak Sikri <deepak.sikri@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-01-04 00:37:37 -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/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 <linux/pm.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 {
/* 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;
#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 == NO_IRQ)
return -EINVAL;
return chip->irq_base + offset;
}
/*
* PL061 GPIO IRQ
*/
static void pl061_irq_disable(struct irq_data *d)
{
struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
int offset = d->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(struct irq_data *d)
{
struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
int offset = d->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(struct irq_data *d, unsigned trigger)
{
struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
int offset = d->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 if (trigger & IRQ_TYPE_EDGE_FALLING)
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",
.irq_enable = pl061_irq_enable,
.irq_disable = pl061_irq_disable,
.irq_set_type = pl061_irq_type,
};
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;
desc->irq_data.chip->irq_ack(&desc->irq_data);
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->irq_data.chip->irq_unmask(&desc->irq_data);
}
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);
pdata = dev->dev.platform_data;
if (pdata == NULL)
return -ENODEV;
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 = NO_IRQ;
} 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);
spin_lock_init(&chip->irq_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 == NO_IRQ)
return 0;
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);
}
irq_set_chip_and_handler(i + chip->irq_base, &pl061_irqchip,
handle_simple_irq);
set_irq_flags(i+chip->irq_base, IRQF_VALID);
irq_set_chip_data(i + chip->irq_base, chip);
}
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 SIMPLE_DEV_PM_OPS(pl061_dev_pm_ops, pl061_suspend, pl061_resume);
#endif
static struct amba_id pl061_ids[] = {
{
.id = 0x00041061,
.mask = 0x000fffff,
},
{ 0, 0 },
};
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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