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-rw-r--r--kernel/drivers/gpio/gpio-sch.c244
1 files changed, 244 insertions, 0 deletions
diff --git a/kernel/drivers/gpio/gpio-sch.c b/kernel/drivers/gpio/gpio-sch.c
new file mode 100644
index 000000000..b72906f5b
--- /dev/null
+++ b/kernel/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");