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authorAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
committerAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
commitb4b6116a13633898cf868f2f103c96a90c4c20f8 (patch)
tree93d1b7e2cfcdf473d8d4ff3ad141fa864f8491f6 /arch/arm/mach-at91/gpio.c
parentedd4be777c953e5faafc80d091d3084b4343f5d3 (diff)
downloadkernel-uprobes-b4b6116a13633898cf868f2f103c96a90c4c20f8.tar.gz
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fedora kernel: d9aad82f3319f3cfd1aebc01234254ef0c37ad84v3.3.2-1
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/arm/mach-at91/gpio.c')
-rw-r--r--arch/arm/mach-at91/gpio.c643
1 files changed, 643 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/gpio.c b/arch/arm/mach-at91/gpio.c
new file mode 100644
index 00000000000..74d6783eeab
--- /dev/null
+++ b/arch/arm/mach-at91/gpio.c
@@ -0,0 +1,643 @@
+/*
+ * 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);
+ }
+}