1 files changed, 318 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
new file mode 100644
index 00000000..5c1ef2b3
--- /dev/null
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -0,0 +1,318 @@
+/*
+ * ACPI helpers for GPIO API
+ *
+ * Copyright (C) 2012, Intel Corporation
+ * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
+ *          Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/export.h>
+#include <linux/acpi_gpio.h>
+#include <linux/acpi.h>
+#include <linux/interrupt.h>
+
+struct acpi_gpio_evt_pin {
+	struct list_head node;
+	acpi_handle *evt_handle;
+	unsigned int pin;
+	unsigned int irq;
+};
+
+static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
+{
+	if (!gc->dev)
+		return false;
+
+	return ACPI_HANDLE(gc->dev) == data;
+}
+
+/**
+ * acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number usable with GPIO API
+ * @path:	ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
+ * @pin:	ACPI GPIO pin number (0-based, controller-relative)
+ *
+ * Returns GPIO number to use with Linux generic GPIO API, or errno error value
+ */
+
+int acpi_get_gpio(char *path, int pin)
+{
+	struct gpio_chip *chip;
+	acpi_handle handle;
+	acpi_status status;
+
+	status = acpi_get_handle(NULL, path, &handle);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	chip = gpiochip_find(handle, acpi_gpiochip_find);
+	if (!chip)
+		return -ENODEV;
+
+	if (!gpio_is_valid(chip->base + pin))
+		return -EINVAL;
+
+	return chip->base + pin;
+}
+EXPORT_SYMBOL_GPL(acpi_get_gpio);
+
+static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
+{
+	acpi_handle handle = data;
+
+	acpi_evaluate_object(handle, NULL, NULL, NULL);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
+{
+	struct acpi_gpio_evt_pin *evt_pin = data;
+	struct acpi_object_list args;
+	union acpi_object arg;
+
+	arg.type = ACPI_TYPE_INTEGER;
+	arg.integer.value = evt_pin->pin;
+	args.count = 1;
+	args.pointer = &arg;
+
+	acpi_evaluate_object(evt_pin->evt_handle, NULL, &args, NULL);
+
+	return IRQ_HANDLED;
+}
+
+static void acpi_gpio_evt_dh(acpi_handle handle, void *data)
+{
+	/* The address of this function is used as a key. */
+}
+
+/**
+ * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
+ * @chip:      gpio chip
+ *
+ * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
+ * handled by ACPI event methods which need to be called from the GPIO
+ * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
+ * gpio pins have acpi event methods and assigns interrupt handlers that calls
+ * the acpi event methods for those pins.
+ */
+void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
+{
+	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+	struct acpi_resource *res;
+	acpi_handle handle, evt_handle;
+	struct list_head *evt_pins = NULL;
+	acpi_status status;
+	unsigned int pin;
+	int irq, ret;
+	char ev_name[5];
+
+	if (!chip->dev || !chip->to_irq)
+		return;
+
+	handle = ACPI_HANDLE(chip->dev);
+	if (!handle)
+		return;
+
+	status = acpi_get_event_resources(handle, &buf);
+	if (ACPI_FAILURE(status))
+		return;
+
+	status = acpi_get_handle(handle, "_EVT", &evt_handle);
+	if (ACPI_SUCCESS(status)) {
+		evt_pins = kzalloc(sizeof(*evt_pins), GFP_KERNEL);
+		if (evt_pins) {
+			INIT_LIST_HEAD(evt_pins);
+			status = acpi_attach_data(handle, acpi_gpio_evt_dh,
+						  evt_pins);
+			if (ACPI_FAILURE(status)) {
+				kfree(evt_pins);
+				evt_pins = NULL;
+			}
+		}
+	}
+
+	/*
+	 * If a GPIO interrupt has an ACPI event handler method, or _EVT is
+	 * present, set up an interrupt handler that calls the ACPI event
+	 * handler.
+	 */
+	for (res = buf.pointer;
+	     res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
+	     res = ACPI_NEXT_RESOURCE(res)) {
+		irq_handler_t handler = NULL;
+		void *data;
+
+		if (res->type != ACPI_RESOURCE_TYPE_GPIO ||
+		    res->data.gpio.connection_type !=
+		    ACPI_RESOURCE_GPIO_TYPE_INT)
+			continue;
+
+		pin = res->data.gpio.pin_table[0];
+		if (pin > chip->ngpio)
+			continue;
+
+		irq = chip->to_irq(chip, pin);
+		if (irq < 0)
+			continue;
+
+		if (pin <= 255) {
+			acpi_handle ev_handle;
+
+			sprintf(ev_name, "_%c%02X",
+				res->data.gpio.triggering ? 'E' : 'L', pin);
+			status = acpi_get_handle(handle, ev_name, &ev_handle);
+			if (ACPI_SUCCESS(status)) {
+				handler = acpi_gpio_irq_handler;
+				data = ev_handle;
+			}
+		}
+		if (!handler && evt_pins) {
+			struct acpi_gpio_evt_pin *evt_pin;
+
+			evt_pin = kzalloc(sizeof(*evt_pin), GFP_KERNEL);
+			if (!evt_pin)
+				continue;
+
+			list_add_tail(&evt_pin->node, evt_pins);
+			evt_pin->evt_handle = evt_handle;
+			evt_pin->pin = pin;
+			evt_pin->irq = irq;
+			handler = acpi_gpio_irq_handler_evt;
+			data = evt_pin;
+		}
+		if (!handler)
+			continue;
+
+		/* Assume BIOS sets the triggering, so no flags */
+		ret = devm_request_threaded_irq(chip->dev, irq, NULL, handler,
+						0, "GPIO-signaled-ACPI-event",
+						data);
+		if (ret)
+			dev_err(chip->dev,
+				"Failed to request IRQ %d ACPI event handler\n",
+				irq);
+	}
+}
+EXPORT_SYMBOL(acpi_gpiochip_request_interrupts);
+
+struct acpi_gpio_lookup {
+	struct acpi_gpio_info info;
+	int index;
+	int gpio;
+	int n;
+};
+
+static int acpi_find_gpio(struct acpi_resource *ares, void *data)
+{
+	struct acpi_gpio_lookup *lookup = data;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
+		return 1;
+
+	if (lookup->n++ == lookup->index && lookup->gpio < 0) {
+		const struct acpi_resource_gpio *agpio = &ares->data.gpio;
+
+		lookup->gpio = acpi_get_gpio(agpio->resource_source.string_ptr,
+					     agpio->pin_table[0]);
+		lookup->info.gpioint =
+			agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
+	}
+
+	return 1;
+}
+
+/**
+ * acpi_get_gpio_by_index() - get a GPIO number from device resources
+ * @dev: pointer to a device to get GPIO from
+ * @index: index of GpioIo/GpioInt resource (starting from %0)
+ * @info: info pointer to fill in (optional)
+ *
+ * Function goes through ACPI resources for @dev and based on @index looks
+ * up a GpioIo/GpioInt resource, translates it to the Linux GPIO number,
+ * and returns it. @index matches GpioIo/GpioInt resources only so if there
+ * are total %3 GPIO resources, the index goes from %0 to %2.
+ *
+ * If the GPIO cannot be translated or there is an error, negative errno is
+ * returned.
+ *
+ * Note: if the GPIO resource has multiple entries in the pin list, this
+ * function only returns the first.
+ */
+int acpi_get_gpio_by_index(struct device *dev, int index,
+			   struct acpi_gpio_info *info)
+{
+	struct acpi_gpio_lookup lookup;
+	struct list_head resource_list;
+	struct acpi_device *adev;
+	acpi_handle handle;
+	int ret;
+
+	if (!dev)
+		return -EINVAL;
+
+	handle = ACPI_HANDLE(dev);
+	if (!handle || acpi_bus_get_device(handle, &adev))
+		return -ENODEV;
+
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.index = index;
+	lookup.gpio = -ENODEV;
+
+	INIT_LIST_HEAD(&resource_list);
+	ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
+				     &lookup);
+	if (ret < 0)
+		return ret;
+
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (lookup.gpio >= 0 && info)
+		*info = lookup.info;
+
+	return lookup.gpio;
+}
+EXPORT_SYMBOL_GPL(acpi_get_gpio_by_index);
+
+/**
+ * acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts.
+ * @chip:      gpio chip
+ *
+ * Free interrupts associated with the _EVT method for the given GPIO chip.
+ *
+ * The remaining ACPI event interrupts associated with the chip are freed
+ * automatically.
+ */
+void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
+{
+	acpi_handle handle;
+	acpi_status status;
+	struct list_head *evt_pins;
+	struct acpi_gpio_evt_pin *evt_pin, *ep;
+
+	if (!chip->dev || !chip->to_irq)
+		return;
+
+	handle = ACPI_HANDLE(chip->dev);
+	if (!handle)
+		return;
+
+	status = acpi_get_data(handle, acpi_gpio_evt_dh, (void **)&evt_pins);
+	if (ACPI_FAILURE(status))
+		return;
+
+	list_for_each_entry_safe_reverse(evt_pin, ep, evt_pins, node) {
+		devm_free_irq(chip->dev, evt_pin->irq, evt_pin);
+		list_del(&evt_pin->node);
+		kfree(evt_pin);
+	}
+
+	acpi_detach_data(handle, acpi_gpio_evt_dh);
+	kfree(evt_pins);
+}
+EXPORT_SYMBOL(acpi_gpiochip_free_interrupts);