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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2012-11-30 12:38:51 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2012-11-30 12:38:51 +0100
commitd9ba1025a46d368bc00a2981cb2b2a918e9209b7 (patch)
treec0451a56f972b01e16c776b572a23b4371ce5c5d /drivers/gpio
parentad063fbbdda6247c4653b708bf011986e8ab7ec8 (diff)
parent64bee4d28c9e2296f4f12a6c4cc40d085c2c9534 (diff)
downloadlinux-d9ba1025a46d368bc00a2981cb2b2a918e9209b7.tar.bz2
Merge branch 'acpi-enumeration'
* acpi-enumeration: spi / ACPI: add ACPI enumeration support gpio / ACPI: add ACPI support
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/Kconfig4
-rw-r--r--drivers/gpio/Makefile1
-rw-r--r--drivers/gpio/gpiolib-acpi.c54
3 files changed, 59 insertions, 0 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 47150f5ded04..f16557690cfd 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -49,6 +49,10 @@ config OF_GPIO
def_bool y
depends on OF
+config GPIO_ACPI
+ def_bool y
+ depends on ACPI
+
config DEBUG_GPIO
bool "Debug GPIO calls"
depends on DEBUG_KERNEL
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 9aeed6707326..420dbaca05f1 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -4,6 +4,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG
obj-$(CONFIG_GPIOLIB) += gpiolib.o devres.o
obj-$(CONFIG_OF_GPIO) += gpiolib-of.o
+obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o
# Device drivers. Generally keep list sorted alphabetically
obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
new file mode 100644
index 000000000000..cbad6e908d30
--- /dev/null
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -0,0 +1,54 @@
+/*
+ * 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>
+
+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);