1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-sch.c b/drivers/gpio/gpio-sch.c
new file mode 100644
index 000000000..b72906f5b
--- /dev/null
+++ b/drivers/gpio/gpio-sch.c
@@ -0,0 +1,244 @@
+/*
+ * GPIO interface for Intel Poulsbo SCH
+ *
+ *  Copyright (c) 2010 CompuLab Ltd
+ *  Author: Denis Turischev <denis@compulab.co.il>
+ *
+ *  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/pci_ids.h>
+
+#include <linux/gpio.h>
+
+#define GEN	0x00
+#define GIO	0x04
+#define GLV	0x08
+
+struct sch_gpio {
+	struct gpio_chip chip;
+	spinlock_t lock;
+	unsigned short iobase;
+	unsigned short core_base;
+	unsigned short resume_base;
+};
+
+#define to_sch_gpio(gc)	container_of(gc, struct sch_gpio, chip)
+
+static unsigned sch_gpio_offset(struct sch_gpio *sch, unsigned gpio,
+				unsigned reg)
+{
+	unsigned base = 0;
+
+	if (gpio >= sch->resume_base) {
+		gpio -= sch->resume_base;
+		base += 0x20;
+	}
+
+	return base + reg + gpio / 8;
+}
+
+static unsigned sch_gpio_bit(struct sch_gpio *sch, unsigned gpio)
+{
+	if (gpio >= sch->resume_base)
+		gpio -= sch->resume_base;
+	return gpio % 8;
+}
+
+static int sch_gpio_reg_get(struct gpio_chip *gc, unsigned gpio, unsigned reg)
+{
+	struct sch_gpio *sch = to_sch_gpio(gc);
+	unsigned short offset, bit;
+	u8 reg_val;
+
+	offset = sch_gpio_offset(sch, gpio, reg);
+	bit = sch_gpio_bit(sch, gpio);
+
+	reg_val = !!(inb(sch->iobase + offset) & BIT(bit));
+
+	return reg_val;
+}
+
+static void sch_gpio_reg_set(struct gpio_chip *gc, unsigned gpio, unsigned reg,
+			     int val)
+{
+	struct sch_gpio *sch = to_sch_gpio(gc);
+	unsigned short offset, bit;
+	u8 reg_val;
+
+	offset = sch_gpio_offset(sch, gpio, reg);
+	bit = sch_gpio_bit(sch, gpio);
+
+	reg_val = inb(sch->iobase + offset);
+
+	if (val)
+		outb(reg_val | BIT(bit), sch->iobase + offset);
+	else
+		outb((reg_val & ~BIT(bit)), sch->iobase + offset);
+}
+
+static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num)
+{
+	struct sch_gpio *sch = to_sch_gpio(gc);
+
+	spin_lock(&sch->lock);
+	sch_gpio_reg_set(gc, gpio_num, GIO, 1);
+	spin_unlock(&sch->lock);
+	return 0;
+}
+
+static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num)
+{
+	return sch_gpio_reg_get(gc, gpio_num, GLV);
+}
+
+static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val)
+{
+	struct sch_gpio *sch = to_sch_gpio(gc);
+
+	spin_lock(&sch->lock);
+	sch_gpio_reg_set(gc, gpio_num, GLV, val);
+	spin_unlock(&sch->lock);
+}
+
+static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num,
+				  int val)
+{
+	struct sch_gpio *sch = to_sch_gpio(gc);
+
+	spin_lock(&sch->lock);
+	sch_gpio_reg_set(gc, gpio_num, GIO, 0);
+	spin_unlock(&sch->lock);
+
+	/*
+	 * according to the datasheet, writing to the level register has no
+	 * effect when GPIO is programmed as input.
+	 * Actually the the level register is read-only when configured as input.
+	 * Thus presetting the output level before switching to output is _NOT_ possible.
+	 * Hence we set the level after configuring the GPIO as output.
+	 * But we cannot prevent a short low pulse if direction is set to high
+	 * and an external pull-up is connected.
+	 */
+	sch_gpio_set(gc, gpio_num, val);
+	return 0;
+}
+
+static struct gpio_chip sch_gpio_chip = {
+	.label			= "sch_gpio",
+	.owner			= THIS_MODULE,
+	.direction_input	= sch_gpio_direction_in,
+	.get			= sch_gpio_get,
+	.direction_output	= sch_gpio_direction_out,
+	.set			= sch_gpio_set,
+};
+
+static int sch_gpio_probe(struct platform_device *pdev)
+{
+	struct sch_gpio *sch;
+	struct resource *res;
+
+	sch = devm_kzalloc(&pdev->dev, sizeof(*sch), GFP_KERNEL);
+	if (!sch)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (!res)
+		return -EBUSY;
+
+	if (!devm_request_region(&pdev->dev, res->start, resource_size(res),
+				 pdev->name))
+		return -EBUSY;
+
+	spin_lock_init(&sch->lock);
+	sch->iobase = res->start;
+	sch->chip = sch_gpio_chip;
+	sch->chip.label = dev_name(&pdev->dev);
+	sch->chip.dev = &pdev->dev;
+
+	switch (pdev->id) {
+	case PCI_DEVICE_ID_INTEL_SCH_LPC:
+		sch->core_base = 0;
+		sch->resume_base = 10;
+		sch->chip.ngpio = 14;
+
+		/*
+		 * GPIO[6:0] enabled by default
+		 * GPIO7 is configured by the CMC as SLPIOVR
+		 * Enable GPIO[9:8] core powered gpios explicitly
+		 */
+		sch_gpio_reg_set(&sch->chip, 8, GEN, 1);
+		sch_gpio_reg_set(&sch->chip, 9, GEN, 1);
+		/*
+		 * SUS_GPIO[2:0] enabled by default
+		 * Enable SUS_GPIO3 resume powered gpio explicitly
+		 */
+		sch_gpio_reg_set(&sch->chip, 13, GEN, 1);
+		break;
+
+	case PCI_DEVICE_ID_INTEL_ITC_LPC:
+		sch->core_base = 0;
+		sch->resume_base = 5;
+		sch->chip.ngpio = 14;
+		break;
+
+	case PCI_DEVICE_ID_INTEL_CENTERTON_ILB:
+		sch->core_base = 0;
+		sch->resume_base = 21;
+		sch->chip.ngpio = 30;
+		break;
+
+	case PCI_DEVICE_ID_INTEL_QUARK_X1000_ILB:
+		sch->core_base = 0;
+		sch->resume_base = 2;
+		sch->chip.ngpio = 8;
+		break;
+
+	default:
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, sch);
+
+	return gpiochip_add(&sch->chip);
+}
+
+static int sch_gpio_remove(struct platform_device *pdev)
+{
+	struct sch_gpio *sch = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&sch->chip);
+	return 0;
+}
+
+static struct platform_driver sch_gpio_driver = {
+	.driver = {
+		.name = "sch_gpio",
+	},
+	.probe		= sch_gpio_probe,
+	.remove		= sch_gpio_remove,
+};
+
+module_platform_driver(sch_gpio_driver);
+
+MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
+MODULE_DESCRIPTION("GPIO interface for Intel Poulsbo SCH");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:sch_gpio");