GPIO: Add support for GPIO on CLPS711X-target platform

The CLPS711X CPUs provide some GPIOs for use in the system. This
driver provides support for these via gpiolib. Due to platform
limitations, driver does not support interrupts, only inputs and
outputs.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 163 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-clps711x.c b/drivers/gpio/gpio-clps711x.c
new file mode 100644
index 0000000..ea21822
--- /dev/null
+++ b/drivers/gpio/gpio-clps711x.c
@@ -0,0 +1,163 @@
+/*
+ *  CLPS711X GPIO driver
+ *
+ *  Copyright (C) 2012 Alexander Shiyan <shc_work@mail.ru>
+ *
+ * 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/io.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+
+#include <mach/hardware.h>
+
+#define CLPS711X_GPIO_PORTS	5
+#define CLPS711X_GPIO_NAME	"gpio-clps711x"
+
+struct clps711x_gpio {
+	struct gpio_chip	chip[CLPS711X_GPIO_PORTS];
+	spinlock_t		lock;
+};
+
+static void __iomem *clps711x_ports[] = {
+	CLPS711X_VIRT_BASE + PADR,
+	CLPS711X_VIRT_BASE + PBDR,
+	CLPS711X_VIRT_BASE + PCDR,
+	CLPS711X_VIRT_BASE + PDDR,
+	CLPS711X_VIRT_BASE + PEDR,
+};
+
+static void __iomem *clps711x_pdirs[] = {
+	CLPS711X_VIRT_BASE + PADDR,
+	CLPS711X_VIRT_BASE + PBDDR,
+	CLPS711X_VIRT_BASE + PCDDR,
+	CLPS711X_VIRT_BASE + PDDDR,
+	CLPS711X_VIRT_BASE + PEDDR,
+};
+
+#define clps711x_port(x)	clps711x_ports[x->base / 8]
+#define clps711x_pdir(x)	clps711x_pdirs[x->base / 8]
+
+static int gpio_clps711x_get(struct gpio_chip *chip, unsigned offset)
+{
+	return !!readb(clps711x_port(chip)) & (1 << offset);
+}
+
+static void gpio_clps711x_set(struct gpio_chip *chip, unsigned offset,
+			      int value)
+{
+	int tmp;
+	unsigned long flags;
+	struct clps711x_gpio *gpio = dev_get_drvdata(chip->dev);
+
+	spin_lock_irqsave(&gpio->lock, flags);
+	tmp = readb(clps711x_port(chip)) & ~(1 << offset);
+	if (value)
+		tmp |= 1 << offset;
+	writeb(tmp, clps711x_port(chip));
+	spin_unlock_irqrestore(&gpio->lock, flags);
+}
+
+static int gpio_clps711x_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+	int tmp;
+	unsigned long flags;
+	struct clps711x_gpio *gpio = dev_get_drvdata(chip->dev);
+
+	spin_lock_irqsave(&gpio->lock, flags);
+	tmp = readb(clps711x_pdir(chip)) & ~(1 << offset);
+	writeb(tmp, clps711x_pdir(chip));
+	spin_unlock_irqrestore(&gpio->lock, flags);
+
+	return 0;
+}
+
+static int gpio_clps711x_direction_out(struct gpio_chip *chip, unsigned offset,
+				       int value)
+{
+	int tmp;
+	unsigned long flags;
+	struct clps711x_gpio *gpio = dev_get_drvdata(chip->dev);
+
+	spin_lock_irqsave(&gpio->lock, flags);
+	tmp = readb(clps711x_pdir(chip)) | (1 << offset);
+	writeb(tmp, clps711x_pdir(chip));
+	tmp = readb(clps711x_port(chip)) & ~(1 << offset);
+	if (value)
+		tmp |= 1 << offset;
+	writeb(tmp, clps711x_port(chip));
+	spin_unlock_irqrestore(&gpio->lock, flags);
+
+	return 0;
+}
+
+struct clps711x_gpio_port {
+	char	*name;
+	int	nr;
+};
+
+static const struct clps711x_gpio_port clps711x_gpio_ports[] __initconst = {
+	{ "PORTA", 8, },
+	{ "PORTB", 8, },
+	{ "PORTC", 8, },
+	{ "PORTD", 8, },
+	{ "PORTE", 3, },
+};
+
+static int __init gpio_clps711x_init(void)
+{
+	int i;
+	struct platform_device *pdev;
+	struct clps711x_gpio *gpio;
+
+	pdev = platform_device_alloc(CLPS711X_GPIO_NAME, 0);
+	if (!pdev) {
+		pr_err("Cannot create platform device: %s\n",
+		       CLPS711X_GPIO_NAME);
+		return -ENOMEM;
+	}
+
+	platform_device_add(pdev);
+
+	gpio = devm_kzalloc(&pdev->dev, sizeof(struct clps711x_gpio),
+			    GFP_KERNEL);
+	if (!gpio) {
+		dev_err(&pdev->dev, "GPIO allocating memory error\n");
+		platform_device_del(pdev);
+		platform_device_put(pdev);
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, gpio);
+
+	spin_lock_init(&gpio->lock);
+
+	for (i = 0; i < CLPS711X_GPIO_PORTS; i++) {
+		gpio->chip[i].owner		= THIS_MODULE;
+		gpio->chip[i].dev		= &pdev->dev;
+		gpio->chip[i].label		= clps711x_gpio_ports[i].name;
+		gpio->chip[i].base		= i * 8;
+		gpio->chip[i].ngpio		= clps711x_gpio_ports[i].nr;
+		gpio->chip[i].direction_input	= gpio_clps711x_direction_in;
+		gpio->chip[i].get		= gpio_clps711x_get;
+		gpio->chip[i].direction_output	= gpio_clps711x_direction_out;
+		gpio->chip[i].set		= gpio_clps711x_set;
+		WARN_ON(gpiochip_add(&gpio->chip[i]));
+	}
+
+	dev_info(&pdev->dev, "GPIO driver initialized\n");
+
+	return 0;
+}
+arch_initcall(gpio_clps711x_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("CLPS711X GPIO driver");