Message-Id: <1249290664.2670.252.camel@rzhang-dt>
Date:	Mon, 03 Aug 2009 17:11:04 +0800
From:	Zhang Rui <rui.zhang@...el.com>
To:	linux-acpi <linux-acpi@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Cc:	Len Brown <lenb@...nel.org>, Richard Purdie <rpurdie@...ys.net>,
	Matthew Garrett <mjg59@...f.ucam.org>,
	Pavel Machek <pavel@....cz>, "Zhang, Rui" <rui.zhang@...el.com>
Subject: [PATCH 1/3] ACPI: introduce ACPI ALS driver

introduce ACPI ALS device driver.

ACPI spec defines ACPI Ambient Light Sensor device (hid ACPI0008),
which provides a standard interface by which the OS may query properties
of the ambient light environment the system is currently operating in,
as well as the ability to detect meaningful changes in these values when the
environment changes.

Signed-off-by: Zhang Rui <rui.zhang@...el.com>
---
 Documentation/acpi/debug.txt |    1 
 drivers/acpi/Kconfig         |    9 
 drivers/acpi/Makefile        |    1 
 drivers/acpi/als.c           |  407 +++++++++++++++++++++++++++++++++++++++++++
 drivers/acpi/debug.c         |    1 
 include/acpi/acpi_drivers.h  |    1 
 6 files changed, 420 insertions(+)

Index: linux-2.6/drivers/acpi/als.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/acpi/als.c
@@ -0,0 +1,407 @@
+/*
+ *  als.c - ACPI Ambient Light Sensor Driver
+ *
+ *  Copyright (C) 2009 Zhang Rui <rui.zhang@...el.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+#define ACPI_ALS_CLASS			"als"
+#define ACPI_ALS_DEVICE_NAME		"Ambient Light Sensor"
+#define ACPI_ALS_NOTIFY_ILLUMINANCE	0x80
+#define ACPI_ALS_NOTIFY_COLOR_TEMP	0x81
+#define ACPI_ALS_NOTIFY_RESPONSE	0x82
+
+#define _COMPONENT		ACPI_ALS_COMPONENT
+ACPI_MODULE_NAME("als");
+
+MODULE_AUTHOR("Zhang Rui");
+MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver");
+MODULE_LICENSE("GPL");
+
+static int acpi_als_add(struct acpi_device *device);
+static int acpi_als_remove(struct acpi_device *device, int type);
+static int acpi_als_resume(struct acpi_device *device);
+static void acpi_als_notify(struct acpi_device *device, u32 event);
+
+static const struct acpi_device_id als_device_ids[] = {
+	{"ACPI0008", 0},
+	{"", 0},
+};
+
+MODULE_DEVICE_TABLE(acpi, als_device_ids);
+
+static struct acpi_driver acpi_als_driver = {
+	.name = "als",
+	.class = ACPI_ALS_CLASS,
+	.ids = als_device_ids,
+	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
+	.ops = {
+		.add = acpi_als_add,
+		.resume = acpi_als_resume,
+		.remove = acpi_als_remove,
+		.notify = acpi_als_notify,
+		},
+};
+
+struct als_cap {
+	u8 _ALI:1;
+	u8 _ALC:1;
+	u8 _ALT:1;
+	u8 _ALR:1;
+	u8 _ALP:1;
+};
+
+struct als_mapping {
+	int adjustment;
+	int illuminance;
+};
+
+struct acpi_als {
+	struct acpi_device *device;
+	struct als_cap cap;
+	int illuminance;
+	int chromaticity;
+	int temperature;
+	int polling;
+	int count;
+	struct als_mapping *mappings;
+};
+
+#define ALS_INVALID_VALUE_LOW		0
+#define ALS_INVALID_VALUE_HIGH		-1
+
+/* --------------------------------------------------------------------------
+		Ambient Light Sensor device Management
+   -------------------------------------------------------------------------- */
+
+/*
+ * acpi_als_get_illuminance - get the current ambient light illuminance
+ */
+static int acpi_als_get_illuminance(struct acpi_als *als)
+{
+	acpi_status status;
+	unsigned long long illuminance;
+
+	status =
+	    acpi_evaluate_integer(als->device->handle, "_ALI", NULL,
+				  &illuminance);
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status,
+				"Error reading ALS illuminance"));
+		als->illuminance = ALS_INVALID_VALUE_LOW;
+		return -ENODEV;
+	}
+	als->illuminance = illuminance;
+	return 0;
+}
+
+/*
+ * acpi_als_get_color_chromaticity - get the ambient light color chromaticity
+ */
+static int acpi_als_get_color_chromaticity(struct acpi_als *als)
+{
+	acpi_status status;
+	unsigned long long chromaticity;
+
+	if (!als->cap._ALC)
+		return -ENODEV;
+	status =
+	    acpi_evaluate_integer(als->device->handle, "_ALC", NULL,
+				  &chromaticity);
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "_ALC not available\n"));
+		als->cap._ALC = 0;
+		return -ENODEV;
+	}
+	als->chromaticity = chromaticity;
+	return 0;
+}
+
+/*
+ * acpi_als_get_color_temperature - get the ambient light color temperature
+ */
+static int acpi_als_get_color_temperature(struct acpi_als *als)
+{
+	acpi_status status;
+	unsigned long long temperature;
+
+	if (!als->cap._ALT)
+		return -ENODEV;
+	status =
+	    acpi_evaluate_integer(als->device->handle, "_ALT", NULL,
+				  &temperature);
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "_ALT not available\n"));
+		als->cap._ALT = 0;
+		return -ENODEV;
+	}
+	als->temperature = temperature;
+	return 0;
+}
+
+/*
+ * acpi_als_get_mappings - get the ALS illuminance mappings
+ *
+ * Return a package of ALS illuminance to display adjustment mappings
+ * that can be used by OS to calibrate its ambient light policy
+ * for a given sensor configuration.
+ */
+static int acpi_als_get_mappings(struct acpi_als *als)
+{
+	int result = 0;
+	acpi_status status = AE_OK;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *alr = NULL;
+	int i, j;
+
+	status =
+	    acpi_evaluate_object(als->device->handle, "_ALR", NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status, "Error reading ALS mappings"));
+		return -ENODEV;
+	}
+
+	alr = buffer.pointer;
+	if (!alr || (alr->type != ACPI_TYPE_PACKAGE)) {
+		printk(KERN_ERR PREFIX "Invalid _ALR data\n");
+		result = -EFAULT;
+		goto end;
+	}
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d illuminance mappings\n",
+			  alr->package.count));
+
+	als->count = alr->package.count;
+	als->mappings =
+	    kmalloc(sizeof(struct als_mapping) * als->count, GFP_KERNEL);
+	if (!als->mappings) {
+		result = -ENOMEM;
+		goto end;
+	}
+
+	for (i = 0, j = 0; i < als->count; i++) {
+		struct als_mapping *mapping = &(als->mappings[j]);
+		union acpi_object *element = &(alr->package.elements[i]);
+
+		if (element->type != ACPI_TYPE_PACKAGE)
+			continue;
+
+		if (element->package.count != 2)
+			continue;
+
+		if (element->package.elements[0].type != ACPI_TYPE_INTEGER ||
+		    element->package.elements[1].type != ACPI_TYPE_INTEGER)
+			continue;
+
+		mapping->adjustment =
+		    element->package.elements[0].integer.value;
+		mapping->illuminance =
+		    element->package.elements[1].integer.value;
+		j++;
+
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Mapping [%d]: "
+				  "adjuestment [%d] illuminance[%d]\n",
+				  i, mapping->adjustment,
+				  mapping->illuminance));
+	}
+
+end:
+	kfree(buffer.pointer);
+	return result;
+}
+
+/*
+ * acpi_als_get_polling - get the current ambient light illuminance
+ */
+static int acpi_als_get_polling(struct acpi_als *als)
+{
+	acpi_status status;
+	unsigned long long polling;
+
+	if (!als->cap._ALP)
+		return -ENODEV;
+	status =
+	    acpi_evaluate_integer(als->device->handle, "_ALP", NULL, &polling);
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "_ALP not available\n"));
+		als->cap._ALP = 0;
+		return -ENODEV;
+	}
+	als->polling = polling;
+	return 0;
+}
+
+static int acpi_als_find_cap(struct acpi_als *als)
+{
+	acpi_handle dummy;
+
+	memset(&als->cap, 0, sizeof(als->cap));
+
+	if (ACPI_SUCCESS(acpi_get_handle(als->device->handle, "_ALI", &dummy)))
+		als->cap._ALI = 1;
+	if (ACPI_SUCCESS(acpi_get_handle(als->device->handle, "_ALC", &dummy)))
+		als->cap._ALC = 1;
+	if (ACPI_SUCCESS(acpi_get_handle(als->device->handle, "_ALT", &dummy)))
+		als->cap._ALT = 1;
+	if (ACPI_SUCCESS(acpi_get_handle(als->device->handle, "_ALR", &dummy)))
+		als->cap._ALR = 1;
+	if (ACPI_SUCCESS(acpi_get_handle(als->device->handle, "_ALP", &dummy)))
+		als->cap._ALP = 1;
+
+	if (!als->cap._ALI || !als->cap._ALR) {
+		ACPI_EXCEPTION((AE_INFO, AE_NOT_FOUND,
+				"Mandatory methods _ALI/_ALR not available"));
+		return -ENODEV;
+	}
+	return 0;
+}
+
+/* --------------------------------------------------------------------------
+				 Driver Model
+   -------------------------------------------------------------------------- */
+
+static void acpi_als_notify(struct acpi_device *device, u32 event)
+{
+	struct acpi_als *als = acpi_driver_data(device);
+
+	if (!als)
+		return;
+
+	switch (event) {
+	case ACPI_ALS_NOTIFY_ILLUMINANCE:
+		acpi_als_get_illuminance(als);
+		break;
+	case ACPI_ALS_NOTIFY_COLOR_TEMP:
+		acpi_als_get_color_temperature(als);
+		acpi_als_get_color_chromaticity(als);
+		break;
+	case ACPI_ALS_NOTIFY_RESPONSE:
+		acpi_als_get_mappings(als);
+		break;
+	default:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Unsupported event [0x%x]\n", event));
+	}
+	acpi_bus_generate_proc_event(device, event, (u32) als->illuminance);
+	acpi_bus_generate_netlink_event(device->pnp.device_class,
+					dev_name(&device->dev), event,
+					(u32) als->illuminance);
+	return;
+}
+
+static int acpi_als_add(struct acpi_device *device)
+{
+	int result = 0;
+	struct acpi_als *als = NULL;
+
+	if (!device)
+		return -EINVAL;
+
+	als = kzalloc(sizeof(struct acpi_als), GFP_KERNEL);
+	if (!als)
+		return -ENOMEM;
+
+	als->device = device;
+	strcpy(acpi_device_name(device), ACPI_ALS_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_ALS_CLASS);
+	device->driver_data = als;
+
+	result = acpi_als_find_cap(als);
+	if (result)
+		goto end;
+
+	result = acpi_als_get_illuminance(als);
+	if (result)
+		goto end;
+
+	result = acpi_als_get_mappings(als);
+	if (result)
+		goto end;
+
+	acpi_als_get_color_temperature(als);
+	acpi_als_get_color_chromaticity(als);
+	acpi_als_get_polling(als);
+
+end:
+	if (result)
+		kfree(als);
+	return result;
+}
+
+static int acpi_als_resume(struct acpi_device *device)
+{
+	struct acpi_als *als;
+
+	if (!device || !acpi_driver_data(device))
+		return -EINVAL;
+
+	als = acpi_driver_data(device);
+
+	if (acpi_als_get_illuminance(als))
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Failed to re-evaluate"
+				  " ALS illuminance during resume\n"));
+	return 0;
+}
+
+static int acpi_als_remove(struct acpi_device *device, int type)
+{
+	struct acpi_als *als;
+
+	if (!device || !acpi_driver_data(device))
+		return -EINVAL;
+
+	als = acpi_driver_data(device);
+	if (!als)
+		return -EINVAL;
+
+	if (als->mappings)
+		kfree(als->mappings);
+	kfree(als);
+	return 0;
+}
+
+static int __init acpi_als_init(void)
+{
+	int result;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	result = acpi_bus_register_driver(&acpi_als_driver);
+	if (result < 0)
+		return -ENODEV;
+	return 0;
+}
+
+static void __exit acpi_als_exit(void)
+{
+	acpi_bus_unregister_driver(&acpi_als_driver);
+	return;
+}
+
+module_init(acpi_als_init);
+module_exit(acpi_als_exit);
Index: linux-2.6/drivers/acpi/Kconfig
===================================================================
--- linux-2.6.orig/drivers/acpi/Kconfig
+++ linux-2.6/drivers/acpi/Kconfig
@@ -333,4 +333,13 @@ config ACPI_SBS
 	  To compile this driver as a module, choose M here:
 	  the modules will be called sbs and sbshc.
 
+config ACPI_ALS
+	tristate "Ambient Light Sensor driver"
+	depends on X86
+	help
+	  This driver supports the ACPI Ambient Light Sensor.
+
+	  To compile this driver as a module, choose M here:
+	  the modules will be called als.
+
 endif	# ACPI
Index: linux-2.6/drivers/acpi/Makefile
===================================================================
--- linux-2.6.orig/drivers/acpi/Makefile
+++ linux-2.6/drivers/acpi/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_ACPI_HOTPLUG_MEMORY) += acp
 obj-$(CONFIG_ACPI_BATTERY)	+= battery.o
 obj-$(CONFIG_ACPI_SBS)		+= sbshc.o
 obj-$(CONFIG_ACPI_SBS)		+= sbs.o
+obj-$(CONFIG_ACPI_ALS)		+= als.o
 
 # processor has its own "processor." module_param namespace
 processor-y			:= processor_core.o processor_throttling.o
Index: linux-2.6/Documentation/acpi/debug.txt
===================================================================
--- linux-2.6.orig/Documentation/acpi/debug.txt
+++ linux-2.6/Documentation/acpi/debug.txt
@@ -63,6 +63,7 @@ shows the supported mask values, current
     ACPI_MEMORY_DEVICE_COMPONENT    0x08000000
     ACPI_VIDEO_COMPONENT            0x10000000
     ACPI_PROCESSOR_COMPONENT        0x20000000
+    ACPI_ALS_COMPONENT              0x40000000
 
 debug_level
 -----------
Index: linux-2.6/drivers/acpi/debug.c
===================================================================
--- linux-2.6.orig/drivers/acpi/debug.c
+++ linux-2.6/drivers/acpi/debug.c
@@ -53,6 +53,7 @@ static const struct acpi_dlayer acpi_deb
 	ACPI_DEBUG_INIT(ACPI_MEMORY_DEVICE_COMPONENT),
 	ACPI_DEBUG_INIT(ACPI_VIDEO_COMPONENT),
 	ACPI_DEBUG_INIT(ACPI_PROCESSOR_COMPONENT),
+	ACPI_DEBUG_INIT(ACPI_ALS_COMPONENT),
 };
 
 static const struct acpi_dlevel acpi_debug_levels[] = {
Index: linux-2.6/include/acpi/acpi_drivers.h
===================================================================
--- linux-2.6.orig/include/acpi/acpi_drivers.h
+++ linux-2.6/include/acpi/acpi_drivers.h
@@ -49,6 +49,7 @@
 #define ACPI_MEMORY_DEVICE_COMPONENT	0x08000000
 #define ACPI_VIDEO_COMPONENT		0x10000000
 #define ACPI_PROCESSOR_COMPONENT	0x20000000
+#define ACPI_ALS_COMPONENT		0x40000000
 
 /*
  * _HID definitions


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