gpio: Add support for Intel ICHx/3100/Series[56] GPIO

This driver works on many Intel chipsets, including the ICH6, ICH7,
ICH8, ICH9, ICH10, 3100, Series 5/3400 (Ibex Peak), Series 6/C200
(Cougar Point), and NM10 (Tiger Point).

Additional Intel chipsets should be easily supported if needed, eg the
ICH1-5, EP80579, etc.

Tested on QM67 (Cougar Point), QM57 (Ibex Peak), 3100 (Whitmore Lake),
and NM10 (Tiger Point).

Includes work from Jean Delvare:
        - Resource leak removal during module load/unload
        - GPIO API bit value enforcement

Also includes code cleanup from Guenter Roeck and Grant Likely.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 419 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-ich.c b/drivers/gpio/gpio-ich.c
new file mode 100644
index 00000000000..b7c06517403
--- /dev/null
+++ b/drivers/gpio/gpio-ich.c
@@ -0,0 +1,419 @@
+/*
+ * Intel ICH6-10, Series 5 and 6 GPIO driver
+ *
+ * Copyright (C) 2010 Extreme Engineering Solutions.
+ *
+ * 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.
+ *
+ * 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; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/lpc_ich.h>
+
+#define DRV_NAME "gpio_ich"
+
+/*
+ * GPIO register offsets in GPIO I/O space.
+ * Each chunk of 32 GPIOs is manipulated via its own USE_SELx, IO_SELx, and
+ * LVLx registers.  Logic in the read/write functions takes a register and
+ * an absolute bit number and determines the proper register offset and bit
+ * number in that register.  For example, to read the value of GPIO bit 50
+ * the code would access offset ichx_regs[2(=GPIO_LVL)][1(=50/32)],
+ * bit 18 (50%32).
+ */
+enum GPIO_REG {
+	GPIO_USE_SEL = 0,
+	GPIO_IO_SEL,
+	GPIO_LVL,
+};
+
+static const u8 ichx_regs[3][3] = {
+	{0x00, 0x30, 0x40},	/* USE_SEL[1-3] offsets */
+	{0x04, 0x34, 0x44},	/* IO_SEL[1-3] offsets */
+	{0x0c, 0x38, 0x48},	/* LVL[1-3] offsets */
+};
+
+#define ICHX_WRITE(val, reg, base_res)	outl(val, (reg) + (base_res)->start)
+#define ICHX_READ(reg, base_res)	inl((reg) + (base_res)->start)
+
+struct ichx_desc {
+	/* Max GPIO pins the chipset can have */
+	uint ngpio;
+
+	/* Whether the chipset has GPIO in GPE0_STS in the PM IO region */
+	bool uses_gpe0;
+
+	/* USE_SEL is bogus on some chipsets, eg 3100 */
+	u32 use_sel_ignore[3];
+
+	/* Some chipsets have quirks, let these use their own request/get */
+	int (*request)(struct gpio_chip *chip, unsigned offset);
+	int (*get)(struct gpio_chip *chip, unsigned offset);
+};
+
+static struct {
+	spinlock_t lock;
+	struct platform_device *dev;
+	struct gpio_chip chip;
+	struct resource *gpio_base;	/* GPIO IO base */
+	struct resource *pm_base;	/* Power Mangagment IO base */
+	struct ichx_desc *desc;	/* Pointer to chipset-specific description */
+	u32 orig_gpio_ctrl;	/* Orig CTRL value, used to restore on exit */
+} ichx_priv;
+
+static int modparam_gpiobase = -1;	/* dynamic */
+module_param_named(gpiobase, modparam_gpiobase, int, 0444);
+MODULE_PARM_DESC(gpiobase, "The GPIO number base. -1 means dynamic, "
+			   "which is the default.");
+
+static int ichx_write_bit(int reg, unsigned nr, int val, int verify)
+{
+	unsigned long flags;
+	u32 data, tmp;
+	int reg_nr = nr / 32;
+	int bit = nr & 0x1f;
+	int ret = 0;
+
+	spin_lock_irqsave(&ichx_priv.lock, flags);
+
+	data = ICHX_READ(ichx_regs[reg][reg_nr], ichx_priv.gpio_base);
+	if (val)
+		data |= 1 << bit;
+	else
+		data &= ~(1 << bit);
+	ICHX_WRITE(data, ichx_regs[reg][reg_nr], ichx_priv.gpio_base);
+	tmp = ICHX_READ(ichx_regs[reg][reg_nr], ichx_priv.gpio_base);
+	if (verify && data != tmp)
+		ret = -EPERM;
+
+	spin_unlock_irqrestore(&ichx_priv.lock, flags);
+
+	return ret;
+}
+
+static int ichx_read_bit(int reg, unsigned nr)
+{
+	unsigned long flags;
+	u32 data;
+	int reg_nr = nr / 32;
+	int bit = nr & 0x1f;
+
+	spin_lock_irqsave(&ichx_priv.lock, flags);
+
+	data = ICHX_READ(ichx_regs[reg][reg_nr], ichx_priv.gpio_base);
+
+	spin_unlock_irqrestore(&ichx_priv.lock, flags);
+
+	return data & (1 << bit) ? 1 : 0;
+}
+
+static int ichx_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
+{
+	/*
+	 * Try setting pin as an input and verify it worked since many pins
+	 * are output-only.
+	 */
+	if (ichx_write_bit(GPIO_IO_SEL, nr, 1, 1))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ichx_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
+					int val)
+{
+	/* Set GPIO output value. */
+	ichx_write_bit(GPIO_LVL, nr, val, 0);
+
+	/*
+	 * Try setting pin as an output and verify it worked since many pins
+	 * are input-only.
+	 */
+	if (ichx_write_bit(GPIO_IO_SEL, nr, 0, 1))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ichx_gpio_get(struct gpio_chip *chip, unsigned nr)
+{
+	return ichx_read_bit(GPIO_LVL, nr);
+}
+
+static int ich6_gpio_get(struct gpio_chip *chip, unsigned nr)
+{
+	unsigned long flags;
+	u32 data;
+
+	/*
+	 * GPI 0 - 15 need to be read from the power management registers on
+	 * a ICH6/3100 bridge.
+	 */
+	if (nr < 16) {
+		if (!ichx_priv.pm_base)
+			return -ENXIO;
+
+		spin_lock_irqsave(&ichx_priv.lock, flags);
+
+		/* GPI 0 - 15 are latched, write 1 to clear*/
+		ICHX_WRITE(1 << (16 + nr), 0, ichx_priv.pm_base);
+		data = ICHX_READ(0, ichx_priv.pm_base);
+
+		spin_unlock_irqrestore(&ichx_priv.lock, flags);
+
+		return (data >> 16) & (1 << nr) ? 1 : 0;
+	} else {
+		return ichx_gpio_get(chip, nr);
+	}
+}
+
+static int ichx_gpio_request(struct gpio_chip *chip, unsigned nr)
+{
+	/*
+	 * Note we assume the BIOS properly set a bridge's USE value.  Some
+	 * chips (eg Intel 3100) have bogus USE values though, so first see if
+	 * the chipset's USE value can be trusted for this specific bit.
+	 * If it can't be trusted, assume that the pin can be used as a GPIO.
+	 */
+	if (ichx_priv.desc->use_sel_ignore[nr / 32] & (1 << (nr & 0x1f)))
+		return 1;
+
+	return ichx_read_bit(GPIO_USE_SEL, nr) ? 0 : -ENODEV;
+}
+
+static int ich6_gpio_request(struct gpio_chip *chip, unsigned nr)
+{
+	/*
+	 * Fixups for bits 16 and 17 are necessary on the Intel ICH6/3100
+	 * bridge as they are controlled by USE register bits 0 and 1.  See
+	 * "Table 704 GPIO_USE_SEL1 register" in the i3100 datasheet for
+	 * additional info.
+	 */
+	if (nr == 16 || nr == 17)
+		nr -= 16;
+
+	return ichx_gpio_request(chip, nr);
+}
+
+static void ichx_gpio_set(struct gpio_chip *chip, unsigned nr, int val)
+{
+	ichx_write_bit(GPIO_LVL, nr, val, 0);
+}
+
+static void __devinit ichx_gpiolib_setup(struct gpio_chip *chip)
+{
+	chip->owner = THIS_MODULE;
+	chip->label = DRV_NAME;
+	chip->dev = &ichx_priv.dev->dev;
+
+	/* Allow chip-specific overrides of request()/get() */
+	chip->request = ichx_priv.desc->request ?
+		ichx_priv.desc->request : ichx_gpio_request;
+	chip->get = ichx_priv.desc->get ?
+		ichx_priv.desc->get : ichx_gpio_get;
+
+	chip->set = ichx_gpio_set;
+	chip->direction_input = ichx_gpio_direction_input;
+	chip->direction_output = ichx_gpio_direction_output;
+	chip->base = modparam_gpiobase;
+	chip->ngpio = ichx_priv.desc->ngpio;
+	chip->can_sleep = 0;
+	chip->dbg_show = NULL;
+}
+
+/* ICH6-based, 631xesb-based */
+static struct ichx_desc ich6_desc = {
+	/* Bridges using the ICH6 controller need fixups for GPIO 0 - 17 */
+	.request = ich6_gpio_request,
+	.get = ich6_gpio_get,
+
+	/* GPIO 0-15 are read in the GPE0_STS PM register */
+	.uses_gpe0 = true,
+
+	.ngpio = 50,
+};
+
+/* Intel 3100 */
+static struct ichx_desc i3100_desc = {
+	/*
+	 * Bits 16,17, 20 of USE_SEL and bit 16 of USE_SEL2 always read 0 on
+	 * the Intel 3100.  See "Table 712. GPIO Summary Table" of 3100
+	 * Datasheet for more info.
+	 */
+	.use_sel_ignore = {0x00130000, 0x00010000, 0x0},
+
+	/* The 3100 needs fixups for GPIO 0 - 17 */
+	.request = ich6_gpio_request,
+	.get = ich6_gpio_get,
+
+	/* GPIO 0-15 are read in the GPE0_STS PM register */
+	.uses_gpe0 = true,
+
+	.ngpio = 50,
+};
+
+/* ICH7 and ICH8-based */
+static struct ichx_desc ich7_desc = {
+	.ngpio = 50,
+};
+
+/* ICH9-based */
+static struct ichx_desc ich9_desc = {
+	.ngpio = 61,
+};
+
+/* ICH10-based - Consumer/corporate versions have different amount of GPIO */
+static struct ichx_desc ich10_cons_desc = {
+	.ngpio = 61,
+};
+static struct ichx_desc ich10_corp_desc = {
+	.ngpio = 72,
+};
+
+/* Intel 5 series, 6 series, 3400 series, and C200 series */
+static struct ichx_desc intel5_desc = {
+	.ngpio = 76,
+};
+
+static int __devinit ichx_gpio_probe(struct platform_device *pdev)
+{
+	struct resource *res_base, *res_pm;
+	int err;
+	struct lpc_ich_info *ich_info = pdev->dev.platform_data;
+
+	if (!ich_info)
+		return -ENODEV;
+
+	ichx_priv.dev = pdev;
+
+	switch (ich_info->gpio_version) {
+	case ICH_I3100_GPIO:
+		ichx_priv.desc = &i3100_desc;
+		break;
+	case ICH_V5_GPIO:
+		ichx_priv.desc = &intel5_desc;
+		break;
+	case ICH_V6_GPIO:
+		ichx_priv.desc = &ich6_desc;
+		break;
+	case ICH_V7_GPIO:
+		ichx_priv.desc = &ich7_desc;
+		break;
+	case ICH_V9_GPIO:
+		ichx_priv.desc = &ich9_desc;
+		break;
+	case ICH_V10CORP_GPIO:
+		ichx_priv.desc = &ich10_corp_desc;
+		break;
+	case ICH_V10CONS_GPIO:
+		ichx_priv.desc = &ich10_cons_desc;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	res_base = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPIO);
+	if (!res_base || !res_base->start || !res_base->end)
+		return -ENODEV;
+
+	if (!request_region(res_base->start, resource_size(res_base),
+				pdev->name))
+		return -EBUSY;
+
+	ichx_priv.gpio_base = res_base;
+
+	/*
+	 * If necessary, determine the I/O address of ACPI/power management
+	 * registers which are needed to read the the GPE0 register for GPI pins
+	 * 0 - 15 on some chipsets.
+	 */
+	if (!ichx_priv.desc->uses_gpe0)
+		goto init;
+
+	res_pm = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPE0);
+	if (!res_pm) {
+		pr_warn("ACPI BAR is unavailable, GPI 0 - 15 unavailable\n");
+		goto init;
+	}
+
+	if (!request_region(res_pm->start, resource_size(res_pm),
+			pdev->name)) {
+		pr_warn("ACPI BAR is busy, GPI 0 - 15 unavailable\n");
+		goto init;
+	}
+
+	ichx_priv.pm_base = res_pm;
+
+init:
+	ichx_gpiolib_setup(&ichx_priv.chip);
+	err = gpiochip_add(&ichx_priv.chip);
+	if (err) {
+		pr_err("Failed to register GPIOs\n");
+		goto add_err;
+	}
+
+	pr_info("GPIO from %d to %d on %s\n", ichx_priv.chip.base,
+	       ichx_priv.chip.base + ichx_priv.chip.ngpio - 1, DRV_NAME);
+
+	return 0;
+
+add_err:
+	release_region(ichx_priv.gpio_base->start,
+			resource_size(ichx_priv.gpio_base));
+	if (ichx_priv.pm_base)
+		release_region(ichx_priv.pm_base->start,
+				resource_size(ichx_priv.pm_base));
+	return err;
+}
+
+static int __devexit ichx_gpio_remove(struct platform_device *pdev)
+{
+	int err;
+
+	err = gpiochip_remove(&ichx_priv.chip);
+	if (err) {
+		dev_err(&pdev->dev, "%s failed, %d\n",
+				"gpiochip_remove()", err);
+		return err;
+	}
+
+	release_region(ichx_priv.gpio_base->start,
+				resource_size(ichx_priv.gpio_base));
+	if (ichx_priv.pm_base)
+		release_region(ichx_priv.pm_base->start,
+				resource_size(ichx_priv.pm_base));
+
+	return 0;
+}
+
+static struct platform_driver ichx_gpio_driver = {
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= DRV_NAME,
+	},
+	.probe		= ichx_gpio_probe,
+	.remove		= __devexit_p(ichx_gpio_remove),
+};
+
+module_platform_driver(ichx_gpio_driver);
+
+MODULE_AUTHOR("Peter Tyser <ptyser@xes-inc.com>");
+MODULE_DESCRIPTION("GPIO interface for Intel ICH series");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:"DRV_NAME);