File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/gpio/gpio-cs5535.c b/drivers/gpio/gpio-cs5535.c
new file mode 100644
index 0000000..7b0b198
--- /dev/null
+++ b/drivers/gpio/gpio-cs5535.c
@@ -0,0 +1,380 @@
+/*
+ * AMD CS5535/CS5536 GPIO driver
+ * Copyright (C) 2006  Advanced Micro Devices, Inc.
+ * Copyright (C) 2007-2009  Andres Salomon <dilinger@collabora.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/cs5535.h>
+#include <asm/msr.h>
+
+#define DRV_NAME "cs5535-gpio"
+
+/*
+ * Some GPIO pins
+ *  31-29,23 : reserved (always mask out)
+ *  28       : Power Button
+ *  26       : PME#
+ *  22-16    : LPC
+ *  14,15    : SMBus
+ *  9,8      : UART1
+ *  7        : PCI INTB
+ *  3,4      : UART2/DDC
+ *  2        : IDE_IRQ0
+ *  1        : AC_BEEP
+ *  0        : PCI INTA
+ *
+ * If a mask was not specified, allow all except
+ * reserved and Power Button
+ */
+#define GPIO_DEFAULT_MASK 0x0F7FFFFF
+
+static ulong mask = GPIO_DEFAULT_MASK;
+module_param_named(mask, mask, ulong, 0444);
+MODULE_PARM_DESC(mask, "GPIO channel mask.");
+
+static struct cs5535_gpio_chip {
+	struct gpio_chip chip;
+	resource_size_t base;
+
+	struct platform_device *pdev;
+	spinlock_t lock;
+} cs5535_gpio_chip;
+
+/*
+ * The CS5535/CS5536 GPIOs support a number of extra features not defined
+ * by the gpio_chip API, so these are exported.  For a full list of the
+ * registers, see include/linux/cs5535.h.
+ */
+
+static void errata_outl(struct cs5535_gpio_chip *chip, u32 val,
+		unsigned int reg)
+{
+	unsigned long addr = chip->base + 0x80 + reg;
+
+	/*
+	 * According to the CS5536 errata (#36), after suspend
+	 * a write to the high bank GPIO register will clear all
+	 * non-selected bits; the recommended workaround is a
+	 * read-modify-write operation.
+	 *
+	 * Don't apply this errata to the edge status GPIOs, as writing
+	 * to their lower bits will clear them.
+	 */
+	if (reg != GPIO_POSITIVE_EDGE_STS && reg != GPIO_NEGATIVE_EDGE_STS) {
+		if (val & 0xffff)
+			val |= (inl(addr) & 0xffff); /* ignore the high bits */
+		else
+			val |= (inl(addr) ^ (val >> 16));
+	}
+	outl(val, addr);
+}
+
+static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset,
+		unsigned int reg)
+{
+	if (offset < 16)
+		/* low bank register */
+		outl(1 << offset, chip->base + reg);
+	else
+		/* high bank register */
+		errata_outl(chip, 1 << (offset - 16), reg);
+}
+
+void cs5535_gpio_set(unsigned offset, unsigned int reg)
+{
+	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	__cs5535_gpio_set(chip, offset, reg);
+	spin_unlock_irqrestore(&chip->lock, flags);
+}
+EXPORT_SYMBOL_GPL(cs5535_gpio_set);
+
+static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset,
+		unsigned int reg)
+{
+	if (offset < 16)
+		/* low bank register */
+		outl(1 << (offset + 16), chip->base + reg);
+	else
+		/* high bank register */
+		errata_outl(chip, 1 << offset, reg);
+}
+
+void cs5535_gpio_clear(unsigned offset, unsigned int reg)
+{
+	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	__cs5535_gpio_clear(chip, offset, reg);
+	spin_unlock_irqrestore(&chip->lock, flags);
+}
+EXPORT_SYMBOL_GPL(cs5535_gpio_clear);
+
+int cs5535_gpio_isset(unsigned offset, unsigned int reg)
+{
+	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
+	unsigned long flags;
+	long val;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	if (offset < 16)
+		/* low bank register */
+		val = inl(chip->base + reg);
+	else {
+		/* high bank register */
+		val = inl(chip->base + 0x80 + reg);
+		offset -= 16;
+	}
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	return (val & (1 << offset)) ? 1 : 0;
+}
+EXPORT_SYMBOL_GPL(cs5535_gpio_isset);
+
+int cs5535_gpio_set_irq(unsigned group, unsigned irq)
+{
+	uint32_t lo, hi;
+
+	if (group > 7 || irq > 15)
+		return -EINVAL;
+
+	rdmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
+
+	lo &= ~(0xF << (group * 4));
+	lo |= (irq & 0xF) << (group * 4);
+
+	wrmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cs5535_gpio_set_irq);
+
+void cs5535_gpio_setup_event(unsigned offset, int pair, int pme)
+{
+	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
+	uint32_t shift = (offset % 8) * 4;
+	unsigned long flags;
+	uint32_t val;
+
+	if (offset >= 24)
+		offset = GPIO_MAP_W;
+	else if (offset >= 16)
+		offset = GPIO_MAP_Z;
+	else if (offset >= 8)
+		offset = GPIO_MAP_Y;
+	else
+		offset = GPIO_MAP_X;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	val = inl(chip->base + offset);
+
+	/* Clear whatever was there before */
+	val &= ~(0xF << shift);
+
+	/* Set the new value */
+	val |= ((pair & 7) << shift);
+
+	/* Set the PME bit if this is a PME event */
+	if (pme)
+		val |= (1 << (shift + 3));
+
+	outl(val, chip->base + offset);
+	spin_unlock_irqrestore(&chip->lock, flags);
+}
+EXPORT_SYMBOL_GPL(cs5535_gpio_setup_event);
+
+/*
+ * Generic gpio_chip API support.
+ */
+
+static int chip_gpio_request(struct gpio_chip *c, unsigned offset)
+{
+	struct cs5535_gpio_chip *chip =
+		container_of(c, struct cs5535_gpio_chip, chip);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+
+	/* check if this pin is available */
+	if ((mask & (1 << offset)) == 0) {
+		dev_info(&chip->pdev->dev,
+			"pin %u is not available (check mask)\n", offset);
+		spin_unlock_irqrestore(&chip->lock, flags);
+		return -EINVAL;
+	}
+
+	/* disable output aux 1 & 2 on this pin */
+	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX1);
+	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX2);
+
+	/* disable input aux 1 on this pin */
+	__cs5535_gpio_clear(chip, offset, GPIO_INPUT_AUX1);
+
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	return 0;
+}
+
+static int chip_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	return cs5535_gpio_isset(offset, GPIO_READ_BACK);
+}
+
+static void chip_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+	if (val)
+		cs5535_gpio_set(offset, GPIO_OUTPUT_VAL);
+	else
+		cs5535_gpio_clear(offset, GPIO_OUTPUT_VAL);
+}
+
+static int chip_direction_input(struct gpio_chip *c, unsigned offset)
+{
+	struct cs5535_gpio_chip *chip =
+		container_of(c, struct cs5535_gpio_chip, chip);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
+	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_ENABLE);
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	return 0;
+}
+
+static int chip_direction_output(struct gpio_chip *c, unsigned offset, int val)
+{
+	struct cs5535_gpio_chip *chip =
+		container_of(c, struct cs5535_gpio_chip, chip);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+
+	__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
+	__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_ENABLE);
+	if (val)
+		__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_VAL);
+	else
+		__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_VAL);
+
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	return 0;
+}
+
+static const char * const cs5535_gpio_names[] = {
+	"GPIO0", "GPIO1", "GPIO2", "GPIO3",
+	"GPIO4", "GPIO5", "GPIO6", "GPIO7",
+	"GPIO8", "GPIO9", "GPIO10", "GPIO11",
+	"GPIO12", "GPIO13", "GPIO14", "GPIO15",
+	"GPIO16", "GPIO17", "GPIO18", "GPIO19",
+	"GPIO20", "GPIO21", "GPIO22", NULL,
+	"GPIO24", "GPIO25", "GPIO26", "GPIO27",
+	"GPIO28", NULL, NULL, NULL,
+};
+
+static struct cs5535_gpio_chip cs5535_gpio_chip = {
+	.chip = {
+		.owner = THIS_MODULE,
+		.label = DRV_NAME,
+
+		.base = 0,
+		.ngpio = 32,
+		.names = cs5535_gpio_names,
+		.request = chip_gpio_request,
+
+		.get = chip_gpio_get,
+		.set = chip_gpio_set,
+
+		.direction_input = chip_direction_input,
+		.direction_output = chip_direction_output,
+	},
+};
+
+static int cs5535_gpio_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	int err = -EIO;
+	ulong mask_orig = mask;
+
+	/* There are two ways to get the GPIO base address; one is by
+	 * fetching it from MSR_LBAR_GPIO, the other is by reading the
+	 * PCI BAR info.  The latter method is easier (especially across
+	 * different architectures), so we'll stick with that for now.  If
+	 * it turns out to be unreliable in the face of crappy BIOSes, we
+	 * can always go back to using MSRs.. */
+
+	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "can't fetch device resource info\n");
+		goto done;
+	}
+
+	if (!devm_request_region(&pdev->dev, res->start, resource_size(res),
+				 pdev->name)) {
+		dev_err(&pdev->dev, "can't request region\n");
+		goto done;
+	}
+
+	/* set up the driver-specific struct */
+	cs5535_gpio_chip.base = res->start;
+	cs5535_gpio_chip.pdev = pdev;
+	spin_lock_init(&cs5535_gpio_chip.lock);
+
+	dev_info(&pdev->dev, "reserved resource region %pR\n", res);
+
+	/* mask out reserved pins */
+	mask &= 0x1F7FFFFF;
+
+	/* do not allow pin 28, Power Button, as there's special handling
+	 * in the PMC needed. (note 12, p. 48) */
+	mask &= ~(1 << 28);
+
+	if (mask_orig != mask)
+		dev_info(&pdev->dev, "mask changed from 0x%08lX to 0x%08lX\n",
+				mask_orig, mask);
+
+	/* finally, register with the generic GPIO API */
+	err = gpiochip_add(&cs5535_gpio_chip.chip);
+	if (err)
+		goto done;
+
+	return 0;
+
+done:
+	return err;
+}
+
+static int cs5535_gpio_remove(struct platform_device *pdev)
+{
+	gpiochip_remove(&cs5535_gpio_chip.chip);
+
+	return 0;
+}
+
+static struct platform_driver cs5535_gpio_driver = {
+	.driver = {
+		.name = DRV_NAME,
+	},
+	.probe = cs5535_gpio_probe,
+	.remove = cs5535_gpio_remove,
+};
+
+module_platform_driver(cs5535_gpio_driver);
+
+MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
+MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);