linux/arch/arm/mach-at91/gpio.c
David Brownell 37aca70c62 [ARM] 4848/1: at91: remove false lockdep warnings
Remove false lockdep warnings about lock recursion when declaring
IRQs as being wake-capable, by marking putting GPIO irq_desc locks
into their own class.

(Thanks to Peter Zijlstra for helping track down such a small
fix to this problem.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-03-06 12:18:18 +00:00

564 lines
13 KiB
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/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 <asm/io.h>
#include <asm/hardware.h>
#include <asm/arch/at91_pio.h>
#include <asm/arch/gpio.h>
#include "generic.h"
static struct at91_gpio_bank *gpio;
static int gpio_banks;
static inline void __iomem *pin_to_controller(unsigned pin)
{
pin -= PIN_BASE;
pin /= 32;
if (likely(pin < gpio_banks))
return gpio[pin].regbase;
return NULL;
}
static inline unsigned pin_to_mask(unsigned pin)
{
pin -= PIN_BASE;
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);
/*--------------------------------------------------------------------------*/
/* new-style GPIO calls; these expect at91_set_GPIO_periph to have been
* called, and maybe at91_set_multi_drive() for putout pins.
*/
int gpio_direction_input(unsigned pin)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio || !(__raw_readl(pio + PIO_PSR) & mask))
return -EINVAL;
__raw_writel(mask, pio + PIO_ODR);
return 0;
}
EXPORT_SYMBOL(gpio_direction_input);
int gpio_direction_output(unsigned pin, int value)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
if (!pio || !(__raw_readl(pio + PIO_PSR) & mask))
return -EINVAL;
__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
__raw_writel(mask, pio + PIO_OER);
return 0;
}
EXPORT_SYMBOL(gpio_direction_output);
/*--------------------------------------------------------------------------*/
/*
* 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(unsigned pin, unsigned state)
{
unsigned mask = pin_to_mask(pin);
unsigned bank = (pin - PIN_BASE) / 32;
if (unlikely(bank >= MAX_GPIO_BANKS))
return -EINVAL;
if (state)
wakeups[bank] |= mask;
else
wakeups[bank] &= ~mask;
set_irq_wake(gpio[bank].id, state);
return 0;
}
void at91_gpio_suspend(void)
{
int i;
for (i = 0; i < gpio_banks; i++) {
void __iomem *pio = gpio[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[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[i].regbase;
if (!wakeups[i])
clk_enable(gpio[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(unsigned pin)
{
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(unsigned pin)
{
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(unsigned pin, 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",
.mask = gpio_irq_mask,
.unmask = gpio_irq_unmask,
.set_type = gpio_irq_type,
.set_wake = gpio_irq_set_wake,
};
static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
{
unsigned pin;
struct irq_desc *gpio;
struct at91_gpio_bank *bank;
void __iomem *pio;
u32 isr;
bank = get_irq_chip_data(irq);
pio = bank->regbase;
/* temporarily mask (level sensitive) parent IRQ */
desc->chip->ack(irq);
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 (!bank->next)
break;
bank = bank->next;
pio = bank->regbase;
continue;
}
pin = bank->chipbase;
gpio = &irq_desc[pin];
while (isr) {
if (isr & 1) {
if (unlikely(gpio->depth)) {
/*
* The core ARM interrupt handler lazily disables IRQs so
* another IRQ must be generated before it actually gets
* here to be disabled on the GPIO controller.
*/
gpio_irq_mask(pin);
}
else
desc_handle_irq(pin, gpio);
}
pin++;
gpio++;
isr >>= 1;
}
}
desc->chip->unmask(irq);
/* 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 = PIN_BASE + (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, pin;
struct at91_gpio_bank *this, *prev;
for (pioc = 0, pin = PIN_BASE, this = gpio, prev = NULL;
pioc++ < gpio_banks;
prev = this, this++) {
unsigned id = this->id;
unsigned i;
/* enable PIO controller's clock */
clk_enable(this->clock);
__raw_writel(~0, this->regbase + PIO_IDR);
for (i = 0, pin = this->chipbase; i < 32; i++, pin++) {
lockdep_set_class(&irq_desc[pin].lock, &gpio_lock_class);
/*
* Can use the "simple" and not "edge" handler since it's
* shorter, and the AIC handles interrupts sanely.
*/
set_irq_chip(pin, &gpio_irqchip);
set_irq_handler(pin, handle_simple_irq);
set_irq_flags(pin, 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;
set_irq_chip_data(id, this);
set_irq_chained_handler(id, gpio_irq_handler);
}
pr_info("AT91: %d gpio irqs in %d banks\n", pin - PIN_BASE, gpio_banks);
}
/*
* 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_bank *last;
BUG_ON(nr_banks > MAX_GPIO_BANKS);
gpio = data;
gpio_banks = nr_banks;
for (i = 0, last = NULL; i < nr_banks; i++, last = data, data++) {
data->chipbase = PIN_BASE + i * 32;
data->regbase = data->offset + (void __iomem *)AT91_VA_BASE_SYS;
/* AT91SAM9263_ID_PIOCDE groups PIOC, PIOD, PIOE */
if (last && last->id == data->id)
last->next = data;
}
}