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linux-pinenote/drivers/gpio/gpio-pl061.c
Javier Martinez Canillas bea415041c gpio: pl061: use BIT() macro instead of shifting bits 
Using the BIT() macro instead of shifting bits
makes the code less error prone and also more readable.

Signed-off-by: Javier Martinez Canillas <javier@dowhile0.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-05-03 12:16:24 -07:00

400 lines
9.6 KiB
C
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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/irqchip/chained_irq.h>
#include <linux/bitops.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/pinctrl/consumer.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 {
spinlock_t lock;
void __iomem *base;
struct gpio_chip gc;
#ifdef CONFIG_PM
struct pl061_context_save_regs csave_regs;
#endif
};
static int pl061_gpio_request(struct gpio_chip *chip, unsigned offset)
{
/*
* Map back to global GPIO space and request muxing, the direction
* parameter does not matter for this controller.
*/
int gpio = chip->base + offset;
return pinctrl_request_gpio(gpio);
}
static void pl061_gpio_free(struct gpio_chip *chip, unsigned offset)
{
int gpio = chip->base + offset;
pinctrl_free_gpio(gpio);
}
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 &= ~(BIT(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 + (BIT(offset + 2)));
gpiodir = readb(chip->base + GPIODIR);
gpiodir |= BIT(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 + (BIT(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 + (BIT(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 + (BIT(offset + 2)));
}
static int pl061_irq_type(struct irq_data *d, unsigned trigger)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
int offset = irqd_to_hwirq(d);
unsigned long flags;
u8 gpiois, gpioibe, gpioiev;
u8 bit = BIT(offset);
if (offset < 0 || offset >= PL061_GPIO_NR)
return -EINVAL;
spin_lock_irqsave(&chip->lock, flags);
gpioiev = readb(chip->base + GPIOIEV);
gpiois = readb(chip->base + GPIOIS);
gpioibe = readb(chip->base + GPIOIBE);
if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
gpiois |= bit;
if (trigger & IRQ_TYPE_LEVEL_HIGH)
gpioiev |= bit;
else
gpioiev &= ~bit;
} else
gpiois &= ~bit;
if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
/* Setting this makes GPIOEV be ignored */
gpioibe |= bit;
else {
gpioibe &= ~bit;
if (trigger & IRQ_TYPE_EDGE_RISING)
gpioiev |= bit;
else if (trigger & IRQ_TYPE_EDGE_FALLING)
gpioiev &= ~bit;
}
writeb(gpiois, chip->base + GPIOIS);
writeb(gpioibe, chip->base + GPIOIBE);
writeb(gpioiev, chip->base + GPIOIEV);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
{
unsigned long pending;
int offset;
struct gpio_chip *gc = irq_desc_get_handler_data(desc);
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
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(irq_find_mapping(gc->irqdomain,
offset));
}
chained_irq_exit(irqchip, desc);
}
static void pl061_irq_mask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
u8 gpioie;
spin_lock(&chip->lock);
gpioie = readb(chip->base + GPIOIE) & ~mask;
writeb(gpioie, chip->base + GPIOIE);
spin_unlock(&chip->lock);
}
static void pl061_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
u8 gpioie;
spin_lock(&chip->lock);
gpioie = readb(chip->base + GPIOIE) | mask;
writeb(gpioie, chip->base + GPIOIE);
spin_unlock(&chip->lock);
}
static struct irq_chip pl061_irqchip = {
.name = "pl061",
.irq_mask = pl061_irq_mask,
.irq_unmask = pl061_irq_unmask,
.irq_set_type = pl061_irq_type,
};
static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
{
struct device *dev = &adev->dev;
struct pl061_platform_data *pdata = dev_get_platdata(dev);
struct pl061_gpio *chip;
int ret, irq, i, irq_base;
chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
if (chip == NULL)
return -ENOMEM;
if (pdata) {
chip->gc.base = pdata->gpio_base;
irq_base = pdata->irq_base;
if (irq_base <= 0) {
dev_err(&adev->dev, "invalid IRQ base in pdata\n");
return -ENODEV;
}
} else {
chip->gc.base = -1;
irq_base = 0;
}
chip->base = devm_ioremap_resource(dev, &adev->res);
if (IS_ERR(chip->base))
return PTR_ERR(chip->base);
spin_lock_init(&chip->lock);
chip->gc.request = pl061_gpio_request;
chip->gc.free = pl061_gpio_free;
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.ngpio = PL061_GPIO_NR;
chip->gc.label = dev_name(dev);
chip->gc.dev = dev;
chip->gc.owner = THIS_MODULE;
ret = gpiochip_add(&chip->gc);
if (ret)
return ret;
/*
* irq_chip support
*/
writeb(0, chip->base + GPIOIE); /* disable irqs */
irq = adev->irq[0];
if (irq < 0) {
dev_err(&adev->dev, "invalid IRQ\n");
return -ENODEV;
}
ret = gpiochip_irqchip_add(&chip->gc, &pl061_irqchip,
irq_base, handle_simple_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_info(&adev->dev, "could not add irqchip\n");
return ret;
}
gpiochip_set_chained_irqchip(&chip->gc, &pl061_irqchip,
irq, pl061_irq_handler);
for (i = 0; i < PL061_GPIO_NR; i++) {
if (pdata) {
if (pdata->directions & (BIT(i)))
pl061_direction_output(&chip->gc, i,
pdata->values & (BIT(i)));
else
pl061_direction_input(&chip->gc, i);
}
}
amba_set_drvdata(adev, chip);
dev_info(&adev->dev, "PL061 GPIO chip @%pa registered\n",
&adev->res.start);
return 0;
}
#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 & (BIT(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 & (BIT(offset)))
pl061_direction_output(&chip->gc, offset,
chip->csave_regs.gpio_data &
(BIT(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);
}
module_init(pl061_gpio_init);
MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
MODULE_DESCRIPTION("PL061 GPIO driver");
MODULE_LICENSE("GPL");
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