- 根目录:
- arch
- arm
- mach-at91
- gpio.c
/*
* linux/arch/arm/mach-at91/gpio.c
*
* Copyright (C) 2005 HP Labs
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <mach/at91_pio.h>
#include "generic.h"
struct at91_gpio_chip {
struct gpio_chip chip;
struct at91_gpio_chip *next; /* Bank sharing same clock */
int id; /* ID of register bank */
void __iomem *regbase; /* Base of register bank */
struct clk *clock; /* associated clock */
};
#define to_at91_gpio_chip(c) container_of(c, struct at91_gpio_chip, chip)
static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip);
static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val);
static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset);
static int at91_gpiolib_direction_output(struct gpio_chip *chip,
unsigned offset, int val);
static int at91_gpiolib_direction_input(struct gpio_chip *chip,
unsigned offset);
#define AT91_GPIO_CHIP(name, base_gpio, nr_gpio) \
{ \
.chip = { \
.label = name, \
.direction_input = at91_gpiolib_direction_input, \
.direction_output = at91_gpiolib_direction_output, \
.get = at91_gpiolib_get, \
.set = at91_gpiolib_set, \
.dbg_show = at91_gpiolib_dbg_show, \
.base = base_gpio, \
.ngpio = nr_gpio, \
}, \
}
static struct at91_gpio_chip gpio_chip[] = {
AT91_GPIO_CHIP("pioA", 0x00, 32),
AT91_GPIO_CHIP("pioB", 0x20, 32),
AT91_GPIO_CHIP("pioC", 0x40, 32),
AT91_GPIO_CHIP("pioD", 0x60, 32),
AT91_GPIO_CHIP("pioE", 0x80, 32),
};
static int gpio_banks;
static inline void __iomem *pin_to_controller(unsigned pin)
{
pin /= 32;
if (likely(pin < gpio_banks))
return gpio_chip[pin].regbase;
return NULL;
}
static inline unsigned pin_to_mask(unsigned pin)
{
return 1 << (pin % 32);
}
/*--------------------------------------------------------------------------*/
/* Not all hardware capabilities are exposed through these calls; they
* only encapsulate the most common features and modes. (So if you
* want to change signals in groups, do it directly.)
*
* Bootloaders will usually handle some of the pin multiplexing setup.
* The intent is certainly that by the time Linux is fully booted, all
* pins should have been fully initialized. These setup calls should
* only be used by board setup routines, or possibly in driver probe().
*
* For bootloaders doing all that setup, these calls could be inlined
* as NOPs so Linux won't duplicate any setup code
*/
/*
* mux the pin to the "GPIO" peripheral role.
*/
int __init_or_module at91_set_GPIO_periph(unsigned pin, int use_pullup)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio)
return -EINVAL;
__raw_writel(mask, pio + PIO_IDR);
__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
__raw_writel(mask, pio + PIO_PER);
return 0;
}
EXPORT_SYMBOL(at91_set_GPIO_periph);
/*
* mux the pin to the "A" internal peripheral role.
*/
int __init_or_module at91_set_A_periph(unsigned pin, int use_pullup)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio)
return -EINVAL;
__raw_writel(mask, pio + PIO_IDR);
__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
__raw_writel(mask, pio + PIO_ASR);
__raw_writel(mask, pio + PIO_PDR);
return 0;
}
EXPORT_SYMBOL(at91_set_A_periph);
/*
* mux the pin to the "B" internal peripheral role.
*/
int __init_or_module at91_set_B_periph(unsigned pin, int use_pullup)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio)
return -EINVAL;
__raw_writel(mask, pio + PIO_IDR);
__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
__raw_writel(mask, pio + PIO_BSR);
__raw_writel(mask, pio + PIO_PDR);
return 0;
}
EXPORT_SYMBOL(at91_set_B_periph);
/*
* mux the pin to the gpio controller (instead of "A" or "B" peripheral), and
* configure it for an input.
*/
int __init_or_module at91_set_gpio_input(unsigned pin, int use_pullup)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio)
return -EINVAL;
__raw_writel(mask, pio + PIO_IDR);
__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
__raw_writel(mask, pio + PIO_ODR);
__raw_writel(mask, pio + PIO_PER);
return 0;
}
EXPORT_SYMBOL(at91_set_gpio_input);
/*
* mux the pin to the gpio controller (instead of "A" or "B" peripheral),
* and configure it for an output.
*/
int __init_or_module at91_set_gpio_output(unsigned pin, int value)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio)
return -EINVAL;
__raw_writel(mask, pio + PIO_IDR);
__raw_writel(mask, pio + PIO_PUDR);
__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
__raw_writel(mask, pio + PIO_OER);
__raw_writel(mask, pio + PIO_PER);
return 0;
}
EXPORT_SYMBOL(at91_set_gpio_output);
/*
* enable/disable the glitch filter; mostly used with IRQ handling.
*/
int __init_or_module at91_set_deglitch(unsigned pin, int is_on)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio)
return -EINVAL;
__raw_writel(mask, pio + (is_on ? PIO_IFER : PIO_IFDR));
return 0;
}
EXPORT_SYMBOL(at91_set_deglitch);
/*
* enable/disable the multi-driver; This is only valid for output and
* allows the output pin to run as an open collector output.
*/
int __init_or_module at91_set_multi_drive(unsigned pin, int is_on)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio)
return -EINVAL;
__raw_writel(mask, pio + (is_on ? PIO_MDER : PIO_MDDR));
return 0;
}
EXPORT_SYMBOL(at91_set_multi_drive);
/*
* assuming the pin is muxed as a gpio output, set its value.
*/
int at91_set_gpio_value(unsigned pin, int value)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio)
return -EINVAL;
__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
return 0;
}
EXPORT_SYMBOL(at91_set_gpio_value);
/*
* read the pin's value (works even if it's not muxed as a gpio).
*/
int at91_get_gpio_value(unsigned pin)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
u32 pdsr;
if (!pio)
return -EINVAL;
pdsr = __raw_readl(pio + PIO_PDSR);
return (pdsr & mask) != 0;
}
EXPORT_SYMBOL(at91_get_gpio_value);
/*--------------------------------------------------------------------------*/
#ifdef CONFIG_PM
static u32 wakeups[MAX_GPIO_BANKS];
static u32 backups[MAX_GPIO_BANKS];
static int gpio_irq_set_wake(struct irq_data *d, unsigned state)
{
unsigned pin = irq_to_gpio(d->irq);
unsigned mask = pin_to_mask(pin);
unsigned bank = pin / 32;
if (unlikely(bank >= MAX_GPIO_BANKS))
return -EINVAL;
if (state)
wakeups[bank] |= mask;
else
wakeups[bank] &= ~mask;
irq_set_irq_wake(gpio_chip[bank].id, state);
return 0;
}
void at91_gpio_suspend(void)
{
int i;
for (i = 0; i < gpio_banks; i++) {
void __iomem *pio = gpio_chip[i].regbase;
backups[i] = __raw_readl(pio + PIO_IMR);
__raw_writel(backups[i], pio + PIO_IDR);
__raw_writel(wakeups[i], pio + PIO_IER);
if (!wakeups[i])
clk_disable(gpio_chip[i].clock);
else {
#ifdef CONFIG_PM_DEBUG
printk(KERN_DEBUG "GPIO-%c may wake for %08x\n", 'A'+i, wakeups[i]);
#endif
}
}
}
void at91_gpio_resume(void)
{
int i;
for (i = 0; i < gpio_banks; i++) {
void __iomem *pio = gpio_chip[i].regbase;
if (!wakeups[i])
clk_enable(gpio_chip[i].clock);
__raw_writel(wakeups[i], pio + PIO_IDR);
__raw_writel(backups[i], pio + PIO_IER);
}
}
#else
#define gpio_irq_set_wake NULL
#endif
/* Several AIC controller irqs are dispatched through this GPIO handler.
* To use any AT91_PIN_* as an externally triggered IRQ, first call
* at91_set_gpio_input() then maybe enable its glitch filter.
* Then just request_irq() with the pin ID; it works like any ARM IRQ
* handler, though it always triggers on rising and falling edges.
*
* Alternatively, certain pins may be used directly as IRQ0..IRQ6 after
* configuring them with at91_set_a_periph() or at91_set_b_periph().
* IRQ0..IRQ6 should be configurable, e.g. level vs edge triggering.
*/
static void gpio_irq_mask(struct irq_data *d)
{
unsigned pin = irq_to_gpio(d->irq);
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (pio)
__raw_writel(mask, pio + PIO_IDR);
}
static void gpio_irq_unmask(struct irq_data *d)
{
unsigned pin = irq_to_gpio(d->irq);
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (pio)
__raw_writel(mask, pio + PIO_IER);
}
static int gpio_irq_type(struct irq_data *d, unsigned type)
{
switch (type) {
case IRQ_TYPE_NONE:
case IRQ_TYPE_EDGE_BOTH:
return 0;
default:
return -EINVAL;
}
}
static struct irq_chip gpio_irqchip = {
.name = "GPIO",
.irq_disable = gpio_irq_mask,
.irq_mask = gpio_irq_mask,
.irq_unmask = gpio_irq_unmask,
.irq_set_type = gpio_irq_type,
.irq_set_wake = gpio_irq_set_wake,
};
static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
{
unsigned irq_pin;
struct irq_data *idata = irq_desc_get_irq_data(desc);
struct irq_chip *chip = irq_data_get_irq_chip(idata);
struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(idata);
void __iomem *pio = at91_gpio->regbase;
u32 isr;
/* temporarily mask (level sensitive) parent IRQ */
chip->irq_ack(idata);
for (;;) {
/* Reading ISR acks pending (edge triggered) GPIO interrupts.
* When there none are pending, we're finished unless we need
* to process multiple banks (like ID_PIOCDE on sam9263).
*/
isr = __raw_readl(pio + PIO_ISR) & __raw_readl(pio + PIO_IMR);
if (!isr) {
if (!at91_gpio->next)
break;
at91_gpio = at91_gpio->next;
pio = at91_gpio->regbase;
continue;
}
irq_pin = gpio_to_irq(at91_gpio->chip.base);
while (isr) {
if (isr & 1)
generic_handle_irq(irq_pin);
irq_pin++;
isr >>= 1;
}
}
chip->irq_unmask(idata);
/* now it may re-trigger */
}
/*--------------------------------------------------------------------------*/
#ifdef CONFIG_DEBUG_FS
static int at91_gpio_show(struct seq_file *s, void *unused)
{
int bank, j;
/* print heading */
seq_printf(s, "Pin\t");
for (bank = 0; bank < gpio_banks; bank++) {
seq_printf(s, "PIO%c\t", 'A' + bank);
};
seq_printf(s, "\n\n");
/* print pin status */
for (j = 0; j < 32; j++) {
seq_printf(s, "%i:\t", j);
for (bank = 0; bank < gpio_banks; bank++) {
unsigned pin = (32 * bank) + j;
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (__raw_readl(pio + PIO_PSR) & mask)
seq_printf(s, "GPIO:%s", __raw_readl(pio + PIO_PDSR) & mask ? "1" : "0");
else
seq_printf(s, "%s", __raw_readl(pio + PIO_ABSR) & mask ? "B" : "A");
seq_printf(s, "\t");
}
seq_printf(s, "\n");
}
return 0;
}
static int at91_gpio_open(struct inode *inode, struct file *file)
{
return single_open(file, at91_gpio_show, NULL);
}
static const struct file_operations at91_gpio_operations = {
.open = at91_gpio_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init at91_gpio_debugfs_init(void)
{
/* /sys/kernel/debug/at91_gpio */
(void) debugfs_create_file("at91_gpio", S_IFREG | S_IRUGO, NULL, NULL, &at91_gpio_operations);
return 0;
}
postcore_initcall(at91_gpio_debugfs_init);
#endif
/*--------------------------------------------------------------------------*/
/*
* This lock class tells lockdep that GPIO irqs are in a different
* category than their parents, so it won't report false recursion.
*/
static struct lock_class_key gpio_lock_class;
/*
* Called from the processor-specific init to enable GPIO interrupt support.
*/
void __init at91_gpio_irq_setup(void)
{
unsigned pioc, irq = gpio_to_irq(0);
struct at91_gpio_chip *this, *prev;
for (pioc = 0, this = gpio_chip, prev = NULL;
pioc++ < gpio_banks;
prev = this, this++) {
unsigned id = this->id;
unsigned i;
__raw_writel(~0, this->regbase + PIO_IDR);
for (i = 0, irq = gpio_to_irq(this->chip.base); i < 32;
i++, irq++) {
irq_set_lockdep_class(irq, &gpio_lock_class);
/*
* Can use the "simple" and not "edge" handler since it's
* shorter, and the AIC handles interrupts sanely.
*/
irq_set_chip_and_handler(irq, &gpio_irqchip,
handle_simple_irq);
set_irq_flags(irq, IRQF_VALID);
}
/* The toplevel handler handles one bank of GPIOs, except
* AT91SAM9263_ID_PIOCDE handles three... PIOC is first in
* the list, so we only set up that handler.
*/
if (prev && prev->next == this)
continue;
irq_set_chip_data(id, this);
irq_set_chained_handler(id, gpio_irq_handler);
}
pr_info("AT91: %d gpio irqs in %d banks\n", irq - gpio_to_irq(0), gpio_banks);
}
/* gpiolib support */
static int at91_gpiolib_direction_input(struct gpio_chip *chip,
unsigned offset)
{
struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
void __iomem *pio = at91_gpio->regbase;
unsigned mask = 1 << offset;
__raw_writel(mask, pio + PIO_ODR);
return 0;
}
static int at91_gpiolib_direction_output(struct gpio_chip *chip,
unsigned offset, int val)
{
struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
void __iomem *pio = at91_gpio->regbase;
unsigned mask = 1 << offset;
__raw_writel(mask, pio + (val ? PIO_SODR : PIO_CODR));
__raw_writel(mask, pio + PIO_OER);
return 0;
}
static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset)
{
struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
void __iomem *pio = at91_gpio->regbase;
unsigned mask = 1 << offset;
u32 pdsr;
pdsr = __raw_readl(pio + PIO_PDSR);
return (pdsr & mask) != 0;
}
static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val)
{
struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
void __iomem *pio = at91_gpio->regbase;
unsigned mask = 1 << offset;
__raw_writel(mask, pio + (val ? PIO_SODR : PIO_CODR));
}
static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
int i;
for (i = 0; i < chip->ngpio; i++) {
unsigned pin = chip->base + i;
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
const char *gpio_label;
gpio_label = gpiochip_is_requested(chip, i);
if (gpio_label) {
seq_printf(s, "[%s] GPIO%s%d: ",
gpio_label, chip->label, i);
if (__raw_readl(pio + PIO_PSR) & mask)
seq_printf(s, "[gpio] %s\n",
at91_get_gpio_value(pin) ?
"set" : "clear");
else
seq_printf(s, "[periph %s]\n",
__raw_readl(pio + PIO_ABSR) &
mask ? "B" : "A");
}
}
}
/*
* Called from the processor-specific init to enable GPIO pin support.
*/
void __init at91_gpio_init(struct at91_gpio_bank *data, int nr_banks)
{
unsigned i;
struct at91_gpio_chip *at91_gpio, *last = NULL;
BUG_ON(nr_banks > MAX_GPIO_BANKS);
gpio_banks = nr_banks;
for (i = 0; i < nr_banks; i++) {
at91_gpio = &gpio_chip[i];
at91_gpio->id = data[i].id;
at91_gpio->chip.base = i * 32;
at91_gpio->regbase = ioremap(data[i].regbase, 512);
if (!at91_gpio->regbase) {
pr_err("at91_gpio.%d, failed to map registers, ignoring.\n", i);
continue;
}
at91_gpio->clock = clk_get_sys(NULL, at91_gpio->chip.label);
if (!at91_gpio->clock) {
pr_err("at91_gpio.%d, failed to get clock, ignoring.\n", i);
continue;
}
/* enable PIO controller's clock */
clk_enable(at91_gpio->clock);
/* AT91SAM9263_ID_PIOCDE groups PIOC, PIOD, PIOE */
if (last && last->id == at91_gpio->id)
last->next = at91_gpio;
last = at91_gpio;
gpiochip_add(&at91_gpio->chip);
}
}