[PATCH] gpio: driver for PrimeCell PL061 GPIO controller

[Baruch Siach]

Signed-off-by: Baruch Siach <baruch@xxxxxxxxxx>
---
 drivers/gpio/Kconfig       |    5 +
 drivers/gpio/Makefile      |    1 +
 drivers/gpio/pl061.c       |  336 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/gpio/pl061.h |   18 +++
 4 files changed, 360 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpio/pl061.c
 create mode 100644 include/linux/gpio/pl061.h

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index edb0253..30d7948 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -67,6 +67,11 @@ config GPIO_SYSFS
 
 comment "Memory mapped GPIO expanders:"
 
+config GPIO_PL061
+	bool "PrimeCell PL061 GPIO support"
+	help
+	  Say yes here to support the PrimeCell PL061 GPIO device
+
 config GPIO_XILINX
 	bool "Xilinx GPIO support"
 	depends on PPC_OF
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 49ac64e..ef90203 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_GPIO_MAX732X)	+= max732x.o
 obj-$(CONFIG_GPIO_MCP23S08)	+= mcp23s08.o
 obj-$(CONFIG_GPIO_PCA953X)	+= pca953x.o
 obj-$(CONFIG_GPIO_PCF857X)	+= pcf857x.o
+obj-$(CONFIG_GPIO_PL061)	+= pl061.o
 obj-$(CONFIG_GPIO_TWL4030)	+= twl4030-gpio.o
 obj-$(CONFIG_GPIO_XILINX)	+= xilinx_gpio.o
 obj-$(CONFIG_GPIO_BT8XX)	+= bt8xxgpio.o
diff --git a/drivers/gpio/pl061.c b/drivers/gpio/pl061.c
new file mode 100644
index 0000000..87bfd7a
--- /dev/null
+++ b/drivers/gpio/pl061.c
@@ -0,0 +1,336 @@
+/*
+ *  linux/drivers/gpio/pl061.c
+ *
+ *  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/platform_device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/bitops.h>
+#include <linux/workqueue.h>
+#include <linux/gpio.h>
+#include <linux/gpio/pl061.h>
+
+#define PL061_GPIO_NR	8
+
+struct pl061_gpio {
+	spinlock_t		lock;
+	spinlock_t		irq_lock;
+	void __iomem		*base;
+	struct gpio_chip	gc;
+	struct work_struct	gpio_free_work;
+	DECLARE_BITMAP(gpios_to_free, PL061_GPIO_NR);
+};
+
+static u32 (*pl061_pending_irq)(int irq);
+
+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 &= ~(1 << 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 + (1 << (offset + 2)));
+	gpiodir = readb(chip->base + GPIODIR);
+	gpiodir |= 1 << offset;
+	writeb(gpiodir, chip->base + GPIODIR);
+	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 + (1 << (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 + (1 << (offset + 2)));
+}
+
+/*
+ * PL061 GPIO IRQ
+ */
+static void pl061_irq_disable(unsigned irq)
+{
+	struct pl061_gpio *chip = get_irq_chip_data(irq);
+	int offset = irq_to_gpio(irq) - chip->gc.base;
+	unsigned long flags;
+	u8 gpioie;
+
+	spin_lock_irqsave(&chip->irq_lock, flags);
+	gpioie = readb(chip->base + GPIOIE);
+	gpioie &= ~(1 << offset);
+	writeb(gpioie, chip->base + GPIOIE);
+	spin_unlock_irqrestore(&chip->irq_lock, flags);
+}
+
+static void pl061_irq_shutdown(unsigned irq)
+{
+	struct pl061_gpio *chip = get_irq_chip_data(irq);
+	int offset = irq_to_gpio(irq) - chip->gc.base;
+
+	pl061_irq_disable(irq);
+	set_bit(offset, chip->gpios_to_free);
+	schedule_work(&chip->gpio_free_work);
+}
+
+static void pl061_irq_enable(unsigned irq)
+{
+	struct pl061_gpio *chip = get_irq_chip_data(irq);
+	int offset = irq_to_gpio(irq) - chip->gc.base;
+	unsigned long flags;
+	u8 gpioie;
+
+	spin_lock_irqsave(&chip->irq_lock, flags);
+	gpioie = readb (chip->base + GPIOIE);
+	gpioie |= 1 << offset;
+	writeb(gpioie, chip->base + GPIOIE);
+	spin_unlock_irqrestore(&chip->irq_lock, flags);
+}
+
+static unsigned int pl061_irq_startup(unsigned irq)
+{
+	int ret;
+
+	ret = gpio_request(irq_to_gpio(irq), "IRQ");
+	if (ret < 0) {
+		pr_warning("%s: warning: gpio_request(%d) returned %d\n",
+				__func__, irq_to_gpio(irq), ret);
+		return 0;
+	}
+
+	gpio_direction_input(irq_to_gpio(irq));
+	pl061_irq_enable(irq);
+
+	return 0;
+}
+
+static int pl061_irq_type(unsigned irq, unsigned trigger)
+{
+	struct pl061_gpio *chip = get_irq_chip_data(irq);
+	int offset = irq_to_gpio(irq) - chip->gc.base;
+	unsigned long flags;
+	u8 gpiois, gpioibe, gpioiev;
+
+	if (irq_to_gpio(irq) < 0)
+		return -EINVAL;
+
+	spin_lock_irqsave(&chip->irq_lock, flags);
+
+	gpioiev = readb(chip->base + GPIOIEV);
+
+	gpiois = readb(chip->base + GPIOIS);
+	if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
+		gpiois |= 1 << offset;
+		if (trigger & IRQ_TYPE_LEVEL_HIGH)
+			gpioiev |= 1 << offset;
+		else
+			gpioiev &= ~(1 << offset);
+	}
+	else
+		gpiois &= ~(1 << offset);
+	writeb(gpiois, chip->base + GPIOIS);
+
+	gpioibe = readb(chip->base + GPIOIBE);
+	if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
+		gpioibe |= 1 << offset;
+	else {
+		gpioibe &= ~(1 << offset);
+		if (trigger & IRQ_TYPE_EDGE_RISING)
+			gpioiev |= 1 << offset;
+		else
+			gpioiev &= ~(1 << offset);
+	}
+	writeb(gpioibe, chip->base + GPIOIBE);
+
+	writeb(gpioiev, chip->base + GPIOIEV);
+
+	spin_unlock_irqrestore (&chip->irq_lock, flags);
+
+	return 0;
+}
+
+static struct irq_chip pl061_irqchip = {
+	.name		="GPIO",
+	.startup	= pl061_irq_startup,
+	.enable		= pl061_irq_enable,
+	.disable	= pl061_irq_disable,
+	.shutdown	= pl061_irq_shutdown,
+	.set_type	= pl061_irq_type,
+};
+
+static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
+{
+	desc->chip->ack(irq);
+	while (1) {
+		unsigned long pending;
+		int gpio;
+
+		pending = pl061_pending_irq(irq);
+		if (pending == 0)
+			break;
+
+		for_each_bit(gpio, &pending, BITS_PER_LONG) {
+			generic_handle_irq(gpio_to_irq(gpio));
+		}
+	}
+	desc->chip->unmask(irq);
+}
+
+static void pl061_gpio_free(struct work_struct *work)
+{
+	struct pl061_gpio *chip = container_of(work, struct pl061_gpio,
+			gpio_free_work);
+	int offset;
+
+	while (!bitmap_empty(chip->gpios_to_free, PL061_GPIO_NR)) {
+		for_each_bit(offset, chip->gpios_to_free, PL061_GPIO_NR) {
+			int gpio = offset + chip->gc.base;
+
+			if (test_and_clear_bit(offset, chip->gpios_to_free))
+				gpio_free(gpio);
+		}
+	}
+}
+
+static int __init pl061_probe(struct platform_device *dev)
+{
+	struct pl061_platform_data *pdata;
+	struct pl061_gpio *chip;
+	struct resource *r;
+	int ret, irq, i;
+
+	pdata = dev->dev.platform_data;
+	if (pdata == NULL)
+		return -ENODEV;
+
+	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+	if (chip == NULL)
+		return -ENOMEM;
+
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		ret = -ENODEV;
+		goto free_mem;
+	}
+
+	chip->base = ioremap(r->start, r->end - r->start + 1);
+	if (chip->base == NULL) {
+		ret = -ENOMEM;
+		goto free_mem;
+	}
+
+	spin_lock_init(&chip->lock);
+	spin_lock_init(&chip->irq_lock);
+
+	bitmap_zero(chip->gpios_to_free, PL061_GPIO_NR);
+	INIT_WORK(&chip->gpio_free_work, 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.base = pdata->gpio_base;
+	chip->gc.ngpio = PL061_GPIO_NR;
+	chip->gc.label = dev->name;
+	chip->gc.dev = &dev->dev;
+	chip->gc.owner = THIS_MODULE;
+
+	ret = gpiochip_add(&chip->gc);
+	if (ret)
+		goto iounmap;
+
+	/*
+	 * irq_chip support
+	 */
+	writeb(0, chip->base + GPIOIE); /* disable irqs */
+	irq = platform_get_irq(dev, 0);
+	if (irq < 0) {
+		ret = -ENODEV;
+		goto iounmap;
+	}
+	set_irq_chained_handler(irq, pl061_irq_handler);
+	pl061_pending_irq = pdata->pending_irqs;
+
+	for (i = 0; i < PL061_GPIO_NR; i++) {
+		if (pdata->directions & (1 << i))
+			pl061_direction_output(&chip->gc, i,
+					pdata->values & (1 << i));
+		else
+			pl061_direction_input(&chip->gc, i);
+
+		set_irq_chip(gpio_to_irq(i+pdata->gpio_base), &pl061_irqchip);
+		set_irq_handler(gpio_to_irq(i+pdata->gpio_base),
+				handle_simple_irq);
+		set_irq_flags(gpio_to_irq(i+pdata->gpio_base), IRQF_VALID);
+		set_irq_chip_data(gpio_to_irq(i+pdata->gpio_base), chip);
+	}
+
+	return 0;
+
+iounmap:
+	iounmap(chip->base);
+free_mem:
+	kfree(chip);
+
+	return ret;
+}
+
+static struct platform_driver pl061_gpio_driver = {
+	.probe = pl061_probe,
+	.driver = {
+		.name = "pl061_gpio",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init pl061_gpio_init(void)
+{
+	return platform_driver_register(&pl061_gpio_driver);
+}
+subsys_initcall(pl061_gpio_init);
+
+MODULE_AUTHOR("Baruch Siach <baruch@xxxxxxxxxx>");
+MODULE_DESCRIPTION("PL061 GPIO driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/gpio/pl061.h b/include/linux/gpio/pl061.h
new file mode 100644
index 0000000..9e18fa3
--- /dev/null
+++ b/include/linux/gpio/pl061.h
@@ -0,0 +1,18 @@
+/* platform data for the PL061 GPIO driver */
+
+#define GPIODIR 0x400
+#define GPIOIS  0x404
+#define GPIOIBE 0x408
+#define GPIOIEV 0x40C
+#define GPIOIE  0x410
+#define GPIORIS 0x414
+#define GPIOMIS 0x418
+#define GPIOIC  0x41C
+
+struct pl061_platform_data {
+	/* number of the first GPIO */
+	unsigned	gpio_base;
+	u32		(*pending_irqs)(int irq);
+	u8		directions;	/* startup directions, 1: out, 0: in */
+	u8		values;		/* startup values */
+};
-- 
1.6.2.4

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