linux/arch/arm/mach-nomadik/gpio.c

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/*
* Generic GPIO driver for logic cells found in the Nomadik SoC
*
* Copyright (C) 2008,2009 STMicroelectronics
* Copyright (C) 2009 Alessandro Rubini <rubini@unipv.it>
* Rewritten based on work by Prafulla WADASKAR <prafulla.wadaskar@st.com>
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/amba/bus.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <mach/hardware.h>
#include <mach/gpio.h>
/*
* The GPIO module in the Nomadik family of Systems-on-Chip is an
* AMBA device, managing 32 pins and alternate functions. The logic block
* is currently only used in the Nomadik.
*
* Symbols in this file are called "nmk_gpio" for "nomadik gpio"
*/
#define NMK_GPIO_PER_CHIP 32
struct nmk_gpio_chip {
struct gpio_chip chip;
void __iomem *addr;
unsigned int parent_irq;
spinlock_t *lock;
/* Keep track of configured edges */
u32 edge_rising;
u32 edge_falling;
};
/* Mode functions */
int nmk_gpio_set_mode(int gpio, int gpio_mode)
{
struct nmk_gpio_chip *nmk_chip;
unsigned long flags;
u32 afunc, bfunc, bit;
nmk_chip = get_irq_chip_data(NOMADIK_GPIO_TO_IRQ(gpio));
if (!nmk_chip)
return -EINVAL;
bit = 1 << (gpio - nmk_chip->chip.base);
spin_lock_irqsave(&nmk_chip->lock, flags);
afunc = readl(nmk_chip->addr + NMK_GPIO_AFSLA) & ~bit;
bfunc = readl(nmk_chip->addr + NMK_GPIO_AFSLB) & ~bit;
if (gpio_mode & NMK_GPIO_ALT_A)
afunc |= bit;
if (gpio_mode & NMK_GPIO_ALT_B)
bfunc |= bit;
writel(afunc, nmk_chip->addr + NMK_GPIO_AFSLA);
writel(bfunc, nmk_chip->addr + NMK_GPIO_AFSLB);
spin_unlock_irqrestore(&nmk_chip->lock, flags);
return 0;
}
EXPORT_SYMBOL(nmk_gpio_set_mode);
int nmk_gpio_get_mode(int gpio)
{
struct nmk_gpio_chip *nmk_chip;
u32 afunc, bfunc, bit;
nmk_chip = get_irq_chip_data(NOMADIK_GPIO_TO_IRQ(gpio));
if (!nmk_chip)
return -EINVAL;
bit = 1 << (gpio - nmk_chip->chip.base);
afunc = readl(nmk_chip->addr + NMK_GPIO_AFSLA) & bit;
bfunc = readl(nmk_chip->addr + NMK_GPIO_AFSLB) & bit;
return (afunc ? NMK_GPIO_ALT_A : 0) | (bfunc ? NMK_GPIO_ALT_B : 0);
}
EXPORT_SYMBOL(nmk_gpio_get_mode);
/* IRQ functions */
static inline int nmk_gpio_get_bitmask(int gpio)
{
return 1 << (gpio % 32);
}
static void nmk_gpio_irq_ack(unsigned int irq)
{
int gpio;
struct nmk_gpio_chip *nmk_chip;
gpio = NOMADIK_IRQ_TO_GPIO(irq);
nmk_chip = get_irq_chip_data(irq);
if (!nmk_chip)
return;
writel(nmk_gpio_get_bitmask(gpio), nmk_chip->addr + NMK_GPIO_IC);
}
static void nmk_gpio_irq_mask(unsigned int irq)
{
int gpio;
struct nmk_gpio_chip *nmk_chip;
unsigned long flags;
u32 bitmask, reg;
gpio = NOMADIK_IRQ_TO_GPIO(irq);
nmk_chip = get_irq_chip_data(irq);
bitmask = nmk_gpio_get_bitmask(gpio);
if (!nmk_chip)
return;
/* we must individually clear the two edges */
spin_lock_irqsave(&nmk_chip->lock, flags);
if (nmk_chip->edge_rising & bitmask) {
reg = readl(nmk_chip->addr + NMK_GPIO_RWIMSC);
reg &= ~bitmask;
writel(reg, nmk_chip->addr + NMK_GPIO_RWIMSC);
}
if (nmk_chip->edge_falling & bitmask) {
reg = readl(nmk_chip->addr + NMK_GPIO_FWIMSC);
reg &= ~bitmask;
writel(reg, nmk_chip->addr + NMK_GPIO_FWIMSC);
}
spin_unlock_irqrestore(&nmk_chip->lock, flags);
};
static void nmk_gpio_irq_unmask(unsigned int irq)
{
int gpio;
struct nmk_gpio_chip *nmk_chip;
unsigned long flags;
u32 bitmask, reg;
gpio = NOMADIK_IRQ_TO_GPIO(irq);
nmk_chip = get_irq_chip_data(irq);
bitmask = nmk_gpio_get_bitmask(gpio);
if (!nmk_chip)
return;
/* we must individually set the two edges */
spin_lock_irqsave(&nmk_chip->lock, flags);
if (nmk_chip->edge_rising & bitmask) {
reg = readl(nmk_chip->addr + NMK_GPIO_RWIMSC);
reg |= bitmask;
writel(reg, nmk_chip->addr + NMK_GPIO_RWIMSC);
}
if (nmk_chip->edge_falling & bitmask) {
reg = readl(nmk_chip->addr + NMK_GPIO_FWIMSC);
reg |= bitmask;
writel(reg, nmk_chip->addr + NMK_GPIO_FWIMSC);
}
spin_unlock_irqrestore(&nmk_chip->lock, flags);
}
static int nmk_gpio_irq_set_type(unsigned int irq, unsigned int type)
{
int gpio;
struct nmk_gpio_chip *nmk_chip;
unsigned long flags;
u32 bitmask;
gpio = NOMADIK_IRQ_TO_GPIO(irq);
nmk_chip = get_irq_chip_data(irq);
bitmask = nmk_gpio_get_bitmask(gpio);
if (!nmk_chip)
return -EINVAL;
if (type & IRQ_TYPE_LEVEL_HIGH)
return -EINVAL;
if (type & IRQ_TYPE_LEVEL_LOW)
return -EINVAL;
spin_lock_irqsave(&nmk_chip->lock, flags);
nmk_chip->edge_rising &= ~bitmask;
if (type & IRQ_TYPE_EDGE_RISING)
nmk_chip->edge_rising |= bitmask;
writel(nmk_chip->edge_rising, nmk_chip->addr + NMK_GPIO_RIMSC);
nmk_chip->edge_falling &= ~bitmask;
if (type & IRQ_TYPE_EDGE_FALLING)
nmk_chip->edge_falling |= bitmask;
writel(nmk_chip->edge_falling, nmk_chip->addr + NMK_GPIO_FIMSC);
spin_unlock_irqrestore(&nmk_chip->lock, flags);
nmk_gpio_irq_unmask(irq);
return 0;
}
static struct irq_chip nmk_gpio_irq_chip = {
.name = "Nomadik-GPIO",
.ack = nmk_gpio_irq_ack,
.mask = nmk_gpio_irq_mask,
.unmask = nmk_gpio_irq_unmask,
.set_type = nmk_gpio_irq_set_type,
};
static void nmk_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
{
struct nmk_gpio_chip *nmk_chip;
struct irq_chip *host_chip;
unsigned int gpio_irq;
u32 pending;
unsigned int first_irq;
nmk_chip = get_irq_data(irq);
first_irq = NOMADIK_GPIO_TO_IRQ(nmk_chip->chip.base);
while ( (pending = readl(nmk_chip->addr + NMK_GPIO_IS)) ) {
gpio_irq = first_irq + __ffs(pending);
generic_handle_irq(gpio_irq);
}
if (0) {/* don't ack parent irq, as ack == disable */
host_chip = get_irq_chip(irq);
host_chip->ack(irq);
}
}
static int nmk_gpio_init_irq(struct nmk_gpio_chip *nmk_chip)
{
unsigned int first_irq;
int i;
first_irq = NOMADIK_GPIO_TO_IRQ(nmk_chip->chip.base);
for (i = first_irq; i < first_irq + NMK_GPIO_PER_CHIP; i++) {
set_irq_chip(i, &nmk_gpio_irq_chip);
set_irq_handler(i, handle_edge_irq);
set_irq_flags(i, IRQF_VALID);
set_irq_chip_data(i, nmk_chip);
}
set_irq_chained_handler(nmk_chip->parent_irq, nmk_gpio_irq_handler);
set_irq_data(nmk_chip->parent_irq, nmk_chip);
return 0;
}
/* I/O Functions */
static int nmk_gpio_make_input(struct gpio_chip *chip, unsigned offset)
{
struct nmk_gpio_chip *nmk_chip =
container_of(chip, struct nmk_gpio_chip, chip);
writel(1 << offset, nmk_chip->addr + NMK_GPIO_DIRC);
return 0;
}
static int nmk_gpio_make_output(struct gpio_chip *chip, unsigned offset,
int val)
{
struct nmk_gpio_chip *nmk_chip =
container_of(chip, struct nmk_gpio_chip, chip);
writel(1 << offset, nmk_chip->addr + NMK_GPIO_DIRS);
return 0;
}
static int nmk_gpio_get_input(struct gpio_chip *chip, unsigned offset)
{
struct nmk_gpio_chip *nmk_chip =
container_of(chip, struct nmk_gpio_chip, chip);
u32 bit = 1 << offset;
return (readl(nmk_chip->addr + NMK_GPIO_DAT) & bit) != 0;
}
static void nmk_gpio_set_output(struct gpio_chip *chip, unsigned offset,
int val)
{
struct nmk_gpio_chip *nmk_chip =
container_of(chip, struct nmk_gpio_chip, chip);
u32 bit = 1 << offset;
if (val)
writel(bit, nmk_chip->addr + NMK_GPIO_DATS);
else
writel(bit, nmk_chip->addr + NMK_GPIO_DATC);
}
/* This structure is replicated for each GPIO block allocated at probe time */
static struct gpio_chip nmk_gpio_template = {
.direction_input = nmk_gpio_make_input,
.get = nmk_gpio_get_input,
.direction_output = nmk_gpio_make_output,
.set = nmk_gpio_set_output,
.ngpio = NMK_GPIO_PER_CHIP,
.can_sleep = 0,
};
static int __init nmk_gpio_probe(struct amba_device *dev, struct amba_id *id)
{
struct nmk_gpio_platform_data *pdata;
struct nmk_gpio_chip *nmk_chip;
struct gpio_chip *chip;
int ret;
pdata = dev->dev.platform_data;
ret = amba_request_regions(dev, pdata->name);
if (ret)
return ret;
nmk_chip = kzalloc(sizeof(*nmk_chip), GFP_KERNEL);
if (!nmk_chip) {
ret = -ENOMEM;
goto out_amba;
}
/*
* The virt address in nmk_chip->addr is in the nomadik register space,
* so we can simply convert the resource address, without remapping
*/
nmk_chip->addr = io_p2v(dev->res.start);
nmk_chip->chip = nmk_gpio_template;
nmk_chip->parent_irq = pdata->parent_irq;
chip = &nmk_chip->chip;
chip->base = pdata->first_gpio;
chip->label = pdata->name;
chip->dev = &dev->dev;
chip->owner = THIS_MODULE;
ret = gpiochip_add(&nmk_chip->chip);
if (ret)
goto out_free;
amba_set_drvdata(dev, nmk_chip);
nmk_gpio_init_irq(nmk_chip);
dev_info(&dev->dev, "Bits %i-%i at address %p\n",
nmk_chip->chip.base, nmk_chip->chip.base+31, nmk_chip->addr);
return 0;
out_free:
kfree(nmk_chip);
out_amba:
amba_release_regions(dev);
dev_err(&dev->dev, "Failure %i for GPIO %i-%i\n", ret,
pdata->first_gpio, pdata->first_gpio+31);
return ret;
}
static int nmk_gpio_remove(struct amba_device *dev)
{
struct nmk_gpio_chip *nmk_chip;
nmk_chip = amba_get_drvdata(dev);
gpiochip_remove(&nmk_chip->chip);
kfree(nmk_chip);
amba_release_regions(dev);
return 0;
}
/* We have 0x1f080060 and 0x1f180060, accept both using the mask */
static struct amba_id nmk_gpio_ids[] = {
{
.id = 0x1f080060,
.mask = 0xffefffff,
},
{0, 0},
};
static struct amba_driver nmk_gpio_driver = {
.drv = {
.owner = THIS_MODULE,
.name = "gpio",
},
.probe = nmk_gpio_probe,
.remove = nmk_gpio_remove,
.suspend = NULL, /* to be done */
.resume = NULL,
.id_table = nmk_gpio_ids,
};
static int __init nmk_gpio_init(void)
{
return amba_driver_register(&nmk_gpio_driver);
}
arch_initcall(nmk_gpio_init);
MODULE_AUTHOR("Prafulla WADASKAR and Alessandro Rubini");
MODULE_DESCRIPTION("Nomadik GPIO Driver");
MODULE_LICENSE("GPL");