MSI S270 Laptop support: backlight, wlan, bluetooth states

Create a driver to support the platform-specific features
of MSI S270 laptops (and maybe other MSI laptops).
This driver implements a backlight device for controlling LCD brightness
(/sys/class/backlight/msi-laptop-bl/).
In addition it allows access to the WLAN and Bluetooth states
through a platform driver (/sys/devices/platform/msi-laptop-pf/).
Signed-off-by: Lennart Poettering <mzxreary@0pointer.de>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>

MAINTAINERS

@@ -1998,6 +1998,13 @@ M:	rubini@ipvvis.unipv.it
 L:	linux-kernel@vger.kernel.org
 S:	Maintained
 
+MSI LAPTOP SUPPORT
+P:	Lennart Poettering
+M:	mzxreary@0pointer.de
+L:	https://tango.0pointer.de/mailman/listinfo/s270-linux
+W:	http://0pointer.de/lennart/tchibo.html
+S:	Maintained
+
 MTRR AND SIMILAR SUPPORT [i386]
 P:	Richard Gooch
 M:	rgooch@atnf.csiro.au

drivers/misc/Kconfig

@@ -57,4 +57,23 @@ config TIFM_7XX1
           To compile this driver as a module, choose M here: the module will
 	  be called tifm_7xx1.
 
+config MSI_LAPTOP
+        tristate "MSI Laptop Extras"
+        depends on X86
+        depends on ACPI_EC
+        depends on BACKLIGHT_CLASS_DEVICE
+        ---help---
+	  This is a driver for laptops built by MSI (MICRO-STAR
+	  INTERNATIONAL):
+
+	  MSI MegaBook S270 (MS-1013)
+	  Cytron/TCM/Medion/Tchibo MD96100/SAM2000
+
+	  It adds support for Bluetooth, WLAN and LCD brightness control.
+
+	  More information about this driver is available at
+	  <http://0pointer.de/lennart/tchibo.html>.
+
+	  If you have an MSI S270 laptop, say Y or M here.
+
 endmenu

drivers/misc/Makefile

@@ -5,6 +5,7 @@ obj- := misc.o	# Dummy rule to force built-in.o to be made
 
 obj-$(CONFIG_IBM_ASM)		+= ibmasm/
 obj-$(CONFIG_HDPU_FEATURES)	+= hdpuftrs/
+obj-$(CONFIG_MSI_LAPTOP)     += msi-laptop.o
 obj-$(CONFIG_LKDTM)		+= lkdtm.o
 obj-$(CONFIG_TIFM_CORE)       	+= tifm_core.o
 obj-$(CONFIG_TIFM_7XX1)       	+= tifm_7xx1.o

drivers/misc/msi-laptop.c

+/*-*-linux-c-*-*/
+
+/*
+  Copyright (C) 2006 Lennart Poettering <mzxreary (at) 0pointer (dot) de>
+
+  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., 51 Franklin Street, Fifth Floor, Boston, MA
+  02110-1301, USA.
+ */
+
+/*
+ * msi-laptop.c - MSI S270 laptop support. This laptop is sold under
+ * various brands, including "Cytron/TCM/Medion/Tchibo MD96100".
+ *
+ * This driver exports a few files in /sys/devices/platform/msi-laptop-pf/:
+ *
+ *   lcd_level - Screen brightness: contains a single integer in the
+ *   range 0..8. (rw)
+ *
+ *   auto_brightness - Enable automatic brightness control: contains
+ *   either 0 or 1. If set to 1 the hardware adjusts the screen
+ *   brightness automatically when the power cord is
+ *   plugged/unplugged. (rw)
+ *
+ *   wlan - WLAN subsystem enabled: contains either 0 or 1. (ro)
+ *
+ *   bluetooth - Bluetooth subsystem enabled: contains either 0 or 1
+ *   Please note that this file is constantly 0 if no Bluetooth
+ *   hardware is available. (ro)
+ *
+ * In addition to these platform device attributes the driver
+ * registers itself in the Linux backlight control subsystem and is
+ * available to userspace under /sys/class/backlight/msi-laptop-bl/.
+ *
+ * This driver might work on other laptops produced by MSI. If you
+ * want to try it you can pass force=1 as argument to the module which
+ * will force it to load even when the DMI data doesn't identify the
+ * laptop as MSI S270. YMMV.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/backlight.h>
+#include <linux/platform_device.h>
+#include <linux/autoconf.h>
+
+#define MSI_DRIVER_VERSION "0.5"
+
+#define MSI_LCD_LEVEL_MAX 9
+
+#define MSI_EC_COMMAND_WIRELESS 0x10
+#define MSI_EC_COMMAND_LCD_LEVEL 0x11
+
+static int force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
+
+static int auto_brightness;
+module_param(auto_brightness, int, 0);
+MODULE_PARM_DESC(auto_brightness, "Enable automatic brightness control (0: disabled; 1: enabled; 2: don't touch)");
+
+/* Hardware access */
+
+static int set_lcd_level(int level)
+{
+	u8 buf[2];
+
+	if (level < 0 || level >= MSI_LCD_LEVEL_MAX)
+		return -EINVAL;
+
+	buf[0] = 0x80;
+	buf[1] = (u8) (level*31);
+
+	return ec_transaction(MSI_EC_COMMAND_LCD_LEVEL, buf, sizeof(buf), NULL, 0);
+}
+
+static int get_lcd_level(void)
+{
+	u8 wdata = 0, rdata;
+	int result;
+
+	result = ec_transaction(MSI_EC_COMMAND_LCD_LEVEL, &wdata, 1, &rdata, 1);
+	if (result < 0)
+		return result;
+
+	return (int) rdata / 31;
+}
+
+static int get_auto_brightness(void)
+{
+	u8 wdata = 4, rdata;
+	int result;
+
+	result = ec_transaction(MSI_EC_COMMAND_LCD_LEVEL, &wdata, 1, &rdata, 1);
+	if (result < 0)
+		return result;
+
+	return !!(rdata & 8);
+}
+
+static int set_auto_brightness(int enable)
+{
+	u8 wdata[2], rdata;
+	int result;
+
+	wdata[0] = 4;
+
+	result = ec_transaction(MSI_EC_COMMAND_LCD_LEVEL, wdata, 1, &rdata, 1);
+	if (result < 0)
+		return result;
+
+	wdata[0] = 0x84;
+	wdata[1] = (rdata & 0xF7) | (enable ? 8 : 0);
+
+	return ec_transaction(MSI_EC_COMMAND_LCD_LEVEL, wdata, 2, NULL, 0);
+}
+
+static int get_wireless_state(int *wlan, int *bluetooth)
+{
+	u8 wdata = 0, rdata;
+	int result;
+
+	result = ec_transaction(MSI_EC_COMMAND_WIRELESS, &wdata, 1, &rdata, 1);
+	if (result < 0)
+		return -1;
+
+	if (wlan)
+		*wlan = !!(rdata & 8);
+
+	if (bluetooth)
+		*bluetooth = !!(rdata & 128);
+
+	return 0;
+}
+
+/* Backlight device stuff */
+
+static int bl_get_brightness(struct backlight_device *b)
+{
+	return get_lcd_level();
+}
+
+
+static int bl_update_status(struct backlight_device *b)
+{
+	return set_lcd_level(b->props->brightness);
+}
+
+static struct backlight_properties msibl_props = {
+	.owner		= THIS_MODULE,
+	.get_brightness = bl_get_brightness,
+	.update_status  = bl_update_status,
+	.max_brightness = MSI_LCD_LEVEL_MAX-1,
+};
+
+static struct backlight_device *msibl_device;
+
+/* Platform device */
+
+static ssize_t show_wlan(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+
+	int ret, enabled;
+
+	ret = get_wireless_state(&enabled, NULL);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%i\n", enabled);
+}
+
+static ssize_t show_bluetooth(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+
+	int ret, enabled;
+
+	ret = get_wireless_state(NULL, &enabled);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%i\n", enabled);
+}
+
+static ssize_t show_lcd_level(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+
+	int ret;
+
+	ret = get_lcd_level();
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%i\n", ret);
+}
+
+static ssize_t store_lcd_level(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+
+	int level, ret;
+
+	if (sscanf(buf, "%i", &level) != 1 || (level < 0 || level >= MSI_LCD_LEVEL_MAX))
+		return -EINVAL;
+
+	ret = set_lcd_level(level);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static ssize_t show_auto_brightness(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+
+	int ret;
+
+	ret = get_auto_brightness();
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%i\n", ret);
+}
+
+static ssize_t store_auto_brightness(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+
+	int enable, ret;
+
+	if (sscanf(buf, "%i", &enable) != 1 || (enable != (enable & 1)))
+		return -EINVAL;
+
+	ret = set_auto_brightness(enable);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(lcd_level, 0644, show_lcd_level, store_lcd_level);
+static DEVICE_ATTR(auto_brightness, 0644, show_auto_brightness, store_auto_brightness);
+static DEVICE_ATTR(bluetooth, 0444, show_bluetooth, NULL);
+static DEVICE_ATTR(wlan, 0444, show_wlan, NULL);
+
+static struct attribute *msipf_attributes[] = {
+	&dev_attr_lcd_level.attr,
+	&dev_attr_auto_brightness.attr,
+	&dev_attr_bluetooth.attr,
+	&dev_attr_wlan.attr,
+	NULL
+};
+
+static struct attribute_group msipf_attribute_group = {
+	.attrs = msipf_attributes
+};
+
+static struct platform_driver msipf_driver = {
+	.driver = {
+		.name = "msi-laptop-pf",
+		.owner = THIS_MODULE,
+	}
+};
+
+static struct platform_device *msipf_device;
+
+/* Initialization */
+
+static struct dmi_system_id __initdata msi_dmi_table[] = {
+	{
+		.ident = "MSI S270",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "MICRO-STAR INT'L CO.,LTD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MS-1013"),
+		}
+	},
+	{
+		.ident = "Medion MD96100",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "NOTEBOOK"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "SAM2000"),
+		}
+	},
+	{ }
+};
+
+
+static int __init msi_init(void)
+{
+	int ret;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	if (!force && !dmi_check_system(msi_dmi_table))
+		return -ENODEV;
+
+	if (auto_brightness < 0 || auto_brightness > 2)
+		return -EINVAL;
+
+	/* Register backlight stuff */
+
+	msibl_device = backlight_device_register("msi-laptop-bl", NULL, &msibl_props);
+	if (IS_ERR(msibl_device))
+		return PTR_ERR(msibl_device);
+
+	ret = platform_driver_register(&msipf_driver);
+	if (ret)
+		goto fail_backlight;
+
+	/* Register platform stuff */
+
+	msipf_device = platform_device_alloc("msi-laptop-pf", -1);
+	if (!msipf_device) {
+		ret = -ENOMEM;
+		goto fail_platform_driver;
+	}
+
+	ret = platform_device_add(msipf_device);
+	if (ret)
+		goto fail_platform_device1;
+
+	ret = sysfs_create_group(&msipf_device->dev.kobj, &msipf_attribute_group);
+	if (ret)
+		goto fail_platform_device2;
+
+	/* Disable automatic brightness control by default because
+	 * this module was probably loaded to do brightness control in
+	 * software. */
+
+	if (auto_brightness != 2)
+		set_auto_brightness(auto_brightness);
+
+	printk(KERN_INFO "msi-laptop: driver "MSI_DRIVER_VERSION" successfully loaded.\n");
+
+	return 0;
+
+fail_platform_device2:
+
+	platform_device_del(msipf_device);
+
+fail_platform_device1:
+
+	platform_device_put(msipf_device);
+
+fail_platform_driver:
+
+	platform_driver_unregister(&msipf_driver);
+
+fail_backlight:
+
+	backlight_device_unregister(msibl_device);
+
+	return ret;
+}
+
+static void __exit msi_cleanup(void)
+{
+
+	sysfs_remove_group(&msipf_device->dev.kobj, &msipf_attribute_group);
+	platform_device_unregister(msipf_device);
+	platform_driver_unregister(&msipf_driver);
+	backlight_device_unregister(msibl_device);
+
+	/* Enable automatic brightness control again */
+	if (auto_brightness != 2)
+		set_auto_brightness(1);
+
+	printk(KERN_INFO "msi-laptop: driver unloaded.\n");
+}
+
+module_init(msi_init);
+module_exit(msi_cleanup);
+
+MODULE_AUTHOR("Lennart Poettering");
+MODULE_DESCRIPTION("MSI Laptop Support");
+MODULE_VERSION(MSI_DRIVER_VERSION);
+MODULE_LICENSE("GPL");