gpio: add Intel SCH GPIO controller driver

Signed-off-by: Denis Turischev <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/gpio/Kconfig

···
 	help
 	  Say yes here to support the NEC VR4100 series General-purpose I/O Uint
 
+config GPIO_SCH
+	tristate "Intel SCH GPIO"
+	depends on GPIOLIB
+	select LPC_SCH
+	help
+	  Say yes here to support GPIO interface on Intel Poulsbo SCH.
+	  The Intel SCH contains a total of 14 GPIO pins. Ten GPIOs are
+	  powered by the core power rail and are turned off during sleep
+	  modes (S3 and higher). The remaining four GPIOs are powered by
+	  the Intel SCH suspend power supply. These GPIOs remain
+	  active during S3. The suspend powered GPIOs can be used to wake the
+	  system from the Suspend-to-RAM state.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called sch-gpio.
+
 comment "I2C GPIO expanders:"
 
 config GPIO_MAX7300

drivers/gpio/Makefile

···
 obj-$(CONFIG_GPIO_WM831X)	+= wm831x-gpio.o
 obj-$(CONFIG_GPIO_WM8350)	+= wm8350-gpiolib.o
 obj-$(CONFIG_GPIO_WM8994)	+= wm8994-gpio.o
+obj-$(CONFIG_GPIO_SCH)		+= sch_gpio.o

drivers/gpio/sch_gpio.c

···
+/*
+ *  sch_gpio.c - GPIO interface for Intel Poulsbo SCH
+ *
+ *  Copyright (c) 2010 CompuLab Ltd
+ *  Author: Denis Turischev <[e-mail]>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; see the file COPYING.  If not, write to
+ *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <linux/acpi.h>
+#include <linux/platform_device.h>
+
+#include <linux/gpio.h>
+
+static DEFINE_SPINLOCK(gpio_lock);
+
+#define CGEN	(0x00)
+#define CGIO	(0x04)
+#define CGLV	(0x08)
+
+#define RGEN	(0x20)
+#define RGIO	(0x24)
+#define RGLV	(0x28)
+
+static unsigned short gpio_ba;
+
+static int sch_gpio_core_direction_in(struct gpio_chip *gc, unsigned  gpio_num)
+{
+	u8 curr_dirs;
+	unsigned short offset, bit;
+
+	spin_lock(&gpio_lock);
+
+	offset = CGIO + gpio_num / 8;
+	bit = gpio_num % 8;
+
+	curr_dirs = inb(gpio_ba + offset);
+
+	if (!(curr_dirs & (1 << bit)))
+		outb(curr_dirs | (1 << bit), gpio_ba + offset);
+
+	spin_unlock(&gpio_lock);
+	return 0;
+}
+
+static int sch_gpio_core_get(struct gpio_chip *gc, unsigned gpio_num)
+{
+	int res;
+	unsigned short offset, bit;
+
+	offset = CGLV + gpio_num / 8;
+	bit = gpio_num % 8;
+
+	res = !!(inb(gpio_ba + offset) & (1 << bit));
+	return res;
+}
+
+static void sch_gpio_core_set(struct gpio_chip *gc, unsigned gpio_num, int val)
+{
+	u8 curr_vals;
+	unsigned short offset, bit;
+
+	spin_lock(&gpio_lock);
+
+	offset = CGLV + gpio_num / 8;
+	bit = gpio_num % 8;
+
+	curr_vals = inb(gpio_ba + offset);
+
+	if (val)
+		outb(curr_vals | (1 << bit), gpio_ba + offset);
+	else
+		outb((curr_vals & ~(1 << bit)), gpio_ba + offset);
+	spin_unlock(&gpio_lock);
+}
+
+static int sch_gpio_core_direction_out(struct gpio_chip *gc,
+					unsigned gpio_num, int val)
+{
+	u8 curr_dirs;
+	unsigned short offset, bit;
+
+	sch_gpio_core_set(gc, gpio_num, val);
+
+	spin_lock(&gpio_lock);
+
+	offset = CGIO + gpio_num / 8;
+	bit = gpio_num % 8;
+
+	curr_dirs = inb(gpio_ba + offset);
+	if (curr_dirs & (1 << bit))
+		outb(curr_dirs & ~(1 << bit), gpio_ba + offset);
+
+	spin_unlock(&gpio_lock);
+	return 0;
+}
+
+static struct gpio_chip sch_gpio_core = {
+	.label			= "sch_gpio_core",
+	.owner			= THIS_MODULE,
+	.direction_input	= sch_gpio_core_direction_in,
+	.get			= sch_gpio_core_get,
+	.direction_output	= sch_gpio_core_direction_out,
+	.set			= sch_gpio_core_set,
+};
+
+static int sch_gpio_resume_direction_in(struct gpio_chip *gc,
+					unsigned gpio_num)
+{
+	u8 curr_dirs;
+
+	spin_lock(&gpio_lock);
+
+	curr_dirs = inb(gpio_ba + RGIO);
+
+	if (!(curr_dirs & (1 << gpio_num)))
+		outb(curr_dirs | (1 << gpio_num) , gpio_ba + RGIO);
+
+	spin_unlock(&gpio_lock);
+	return 0;
+}
+
+static int sch_gpio_resume_get(struct gpio_chip *gc, unsigned gpio_num)
+{
+	return !!(inb(gpio_ba + RGLV) & (1 << gpio_num));
+}
+
+static void sch_gpio_resume_set(struct gpio_chip *gc,
+				unsigned gpio_num, int val)
+{
+	u8 curr_vals;
+
+	spin_lock(&gpio_lock);
+
+	curr_vals = inb(gpio_ba + RGLV);
+
+	if (val)
+		outb(curr_vals | (1 << gpio_num), gpio_ba + RGLV);
+	else
+		outb((curr_vals & ~(1 << gpio_num)), gpio_ba + RGLV);
+
+	spin_unlock(&gpio_lock);
+}
+
+static int sch_gpio_resume_direction_out(struct gpio_chip *gc,
+					unsigned gpio_num, int val)
+{
+	u8 curr_dirs;
+
+	sch_gpio_resume_set(gc, gpio_num, val);
+
+	spin_lock(&gpio_lock);
+
+	curr_dirs = inb(gpio_ba + RGIO);
+	if (curr_dirs & (1 << gpio_num))
+		outb(curr_dirs & ~(1 << gpio_num), gpio_ba + RGIO);
+
+	spin_unlock(&gpio_lock);
+	return 0;
+}
+
+static struct gpio_chip sch_gpio_resume = {
+	.label			= "sch_gpio_resume",
+	.owner			= THIS_MODULE,
+	.direction_input	= sch_gpio_resume_direction_in,
+	.get			= sch_gpio_resume_get,
+	.direction_output	= sch_gpio_resume_direction_out,
+	.set			= sch_gpio_resume_set,
+};
+
+static int __devinit sch_gpio_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	int err;
+
+	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (!res)
+		return -EBUSY;
+
+	if (!request_region(res->start, resource_size(res), pdev->name))
+		return -EBUSY;
+
+	gpio_ba = res->start;
+
+	sch_gpio_core.base = 0;
+	sch_gpio_core.ngpio = 10;
+	sch_gpio_core.dev = &pdev->dev;
+
+	sch_gpio_resume.base = 10;
+	sch_gpio_resume.ngpio = 4;
+	sch_gpio_resume.dev = &pdev->dev;
+
+	err = gpiochip_add(&sch_gpio_core);
+	if (err < 0)
+		goto err_sch_gpio_core;
+
+	err = gpiochip_add(&sch_gpio_resume);
+	if (err < 0)
+		goto err_sch_gpio_resume;
+
+	/*
+	 * GPIO[6:0] enabled by default
+	 * GPIO7 is configured by the CMC as SLPIOVR
+	 * Enable GPIO[9:8] core powered gpios explicitly
+	 */
+	outb(0x3, gpio_ba + CGEN + 1);
+	/*
+	 * SUS_GPIO[2:0] enabled by default
+	 * Enable SUS_GPIO3 resume powered gpio explicitly
+	 */
+	outb(0x8, gpio_ba + RGEN);
+
+	return 0;
+
+err_sch_gpio_resume:
+	gpiochip_remove(&sch_gpio_core);
+
+err_sch_gpio_core:
+	release_region(res->start, resource_size(res));
+	gpio_ba = 0;
+
+	return err;
+}
+
+static int __devexit sch_gpio_remove(struct platform_device *pdev)
+{
+	struct resource *res;
+	if (gpio_ba) {
+		gpiochip_remove(&sch_gpio_core);
+		gpiochip_remove(&sch_gpio_resume);
+
+		res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+
+		release_region(res->start, resource_size(res));
+		gpio_ba = 0;
+	}
+
+	return 0;
+}
+
+static struct platform_driver sch_gpio_driver = {
+	.driver = {
+		.name = "sch_gpio",
+		.owner = THIS_MODULE,
+	},
+	.probe		= sch_gpio_probe,
+	.remove		= __devexit_p(sch_gpio_remove),
+};
+
+static int __init sch_gpio_init(void)
+{
+	return platform_driver_register(&sch_gpio_driver);
+}
+
+static void __exit sch_gpio_exit(void)
+{
+	platform_driver_unregister(&sch_gpio_driver);
+}
+
+module_init(sch_gpio_init);
+module_exit(sch_gpio_exit);
+
+MODULE_AUTHOR("Denis Turischev <[e-mail]>");
+MODULE_DESCRIPTION("GPIO interface for Intel Poulsbo SCH");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:sch_gpio");