[PATCH 3/4] gpio: add ARM Primcell pl061 support

[Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>]

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
---
 arch/arm/Kconfig           |    1 +
 drivers/gpio/Kconfig       |    6 ++
 drivers/gpio/Makefile      |    2 +
 drivers/gpio/gpio-pl061.c  |  168 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/amba/pl061.h |   16 +++++
 5 files changed, 193 insertions(+)
 create mode 100644 drivers/gpio/gpio-pl061.c
 create mode 100644 include/linux/amba/pl061.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8278c82..f599d5b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -10,6 +10,7 @@ config ARM
 
 config ARM_AMBA
 	bool
+	select GPIOLIB
 
 config ARM_LINUX
 	bool
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index f03fbf6..a0e9b58 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -6,6 +6,12 @@ if GPIOLIB
 
 menu "GPIO                          "
 
+config GPIO_PL061
+	bool "PrimeCell PL061 GPIO support"
+	depends on ARM_AMBA
+	help
+	  Say yes here to support the PrimeCell PL061 GPIO device
+
 config GPIO_STMPE
 	depends on I2C_STMPE
 	bool "STMPE GPIO Expander"
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 945122b..e2e97d3 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -1,2 +1,4 @@
 obj-$(CONFIG_GPIOLIB) += gpio.o
+
+obj-$(CONFIG_GPIO_PL061)	+= gpio-pl061.o
 obj-$(CONFIG_GPIO_STMPE) += gpio-stmpe.o
diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c
new file mode 100644
index 0000000..ff4c883
--- /dev/null
+++ b/drivers/gpio/gpio-pl061.c
@@ -0,0 +1,168 @@
+/*
+ * 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 <common.h>
+#include <malloc.h>
+#include <errno.h>
+#include <io.h>
+#include <gpio.h>
+#include <init.h>
+
+#include <linux/amba/bus.h>
+#include <linux/amba/pl061.h>
+
+#define GPIODIR 0x400
+#define GPIOIS  0x404
+#define GPIOIBE 0x408
+#define GPIOIEV 0x40C
+#define GPIOIE  0x410
+#define GPIORIS 0x414
+#define GPIOMIS 0x418
+#define GPIOIC  0x41C
+
+#define PL061_GPIO_NR	8
+
+struct pl061_gpio {
+	void __iomem		*base;
+	struct gpio_chip	gc;
+};
+
+static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+	unsigned char gpiodir;
+
+	if (offset >= gc->ngpio)
+		return -EINVAL;
+
+	gpiodir = readb(chip->base + GPIODIR);
+	gpiodir &= ~(1 << offset);
+	writeb(gpiodir, chip->base + GPIODIR);
+
+	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 char gpiodir;
+
+	if (offset >= gc->ngpio)
+		return -EINVAL;
+
+	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
+	gpiodir = readb(chip->base + GPIODIR);
+	gpiodir |= 1 << offset;
+	writeb(gpiodir, chip->base + GPIODIR);
+
+	/*
+	 * gpio value is set again, because pl061 doesn't allow to set value of
+	 * a gpio pin before configuring it in OUT mode.
+	 */
+	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
+
+	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)));
+}
+
+static struct gpio_ops pl061_gpio_ops = {
+	.direction_input = pl061_direction_input,
+	.direction_output = pl061_direction_output,
+	.get = pl061_get_value,
+	.set = pl061_set_value,
+};
+
+static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
+{
+	struct pl061_platform_data *pdata;
+	struct pl061_gpio *chip;
+	int ret, i;
+
+	chip = xzalloc(sizeof(*chip));
+
+	pdata = dev->dev.platform_data;
+	if (pdata) {
+		chip->gc.base = pdata->gpio_base;
+	} else {
+		chip->gc.base = -1;
+	}
+
+	chip->base = amba_get_mem_region(dev);
+
+	chip->gc.ops = &pl061_gpio_ops;
+	chip->gc.ngpio = PL061_GPIO_NR;
+	chip->gc.dev = &dev->dev;
+
+	ret = gpiochip_add(&chip->gc);
+	if (ret) {
+		dev_err(&dev->dev, "couldn't add gpiochip\n");
+		goto free_mem;
+	}
+
+	writeb(0, chip->base + GPIOIE); /* disable irqs */
+
+	for (i = 0; i < PL061_GPIO_NR; i++) {
+		if (pdata) {
+			if (pdata->directions & (1 << i))
+				pl061_direction_output(&chip->gc, i,
+						pdata->values & (1 << i));
+			else
+				pl061_direction_input(&chip->gc, i);
+		}
+	}
+
+	return 0;
+
+free_mem:
+	kfree(chip);
+
+	return ret;
+}
+
+static struct amba_id pl061_ids[] = {
+	{
+		.id	= 0x00041061,
+		.mask	= 0x000fffff,
+	},
+	{ 0, 0 },
+};
+
+static struct amba_driver pl061_gpio_driver = {
+	.drv = {
+		.name	= "pl061_gpio",
+	},
+	.id_table	= pl061_ids,
+	.probe		= pl061_probe,
+};
+
+static int __init pl061_gpio_init(void)
+{
+	return amba_driver_register(&pl061_gpio_driver);
+}
+coredevice_initcall(pl061_gpio_init);
+
+MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
+MODULE_DESCRIPTION("PL061 GPIO driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/amba/pl061.h b/include/linux/amba/pl061.h
new file mode 100644
index 0000000..fb83c04
--- /dev/null
+++ b/include/linux/amba/pl061.h
@@ -0,0 +1,16 @@
+#include <linux/types.h>
+
+/* platform data for the PL061 GPIO driver */
+
+struct pl061_platform_data {
+	/* number of the first GPIO */
+	unsigned	gpio_base;
+
+	/* number of the first IRQ.
+	 * If the IRQ functionality in not desired this must be set to 0.
+	 */
+	unsigned	irq_base;
+
+	u8		directions;	/* startup directions, 1: out, 0: in */
+	u8		values;		/* startup values */
+};
-- 
1.7.10.4


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