Pull platform-drivers into test branch

5 files changed, 1131 insertions, 221 deletions

diff --git a/Documentation/ibm-acpi.txt b/Documentation/ibm-acpi.txt
index e50595bfd8e..0132d363feb 100644
--- a/Documentation/ibm-acpi.txt
+++ b/Documentation/ibm-acpi.txt
@@ -398,25 +398,67 @@ Temperature sensors -- /proc/acpi/ibm/thermal
 
 Most ThinkPads include six or more separate temperature sensors but
 only expose the CPU temperature through the standard ACPI methods.
-This feature shows readings from up to eight different sensors. Some
-readings may not be valid, e.g. may show large negative values. For
-example, on the X40, a typical output may be:
+This feature shows readings from up to eight different sensors on older
+ThinkPads, and it has experimental support for up to sixteen different
+sensors on newer ThinkPads.  Readings from sensors that are not available
+return -128.
 
+No commands can be written to this file.
+
+EXPERIMENTAL: The 16-sensors feature is marked EXPERIMENTAL because the
+implementation directly accesses hardware registers and may not work as
+expected. USE WITH CAUTION! To use this feature, you need to supply the
+experimental=1 parameter when loading the module.  When EXPERIMENTAL
+mode is enabled, reading the first 8 sensors on newer ThinkPads will
+also use an new experimental thermal sensor access mode.
+
+For example, on the X40, a typical output may be:
 temperatures:   42 42 45 41 36 -128 33 -128
 
-Thomas Gruber took his R51 apart and traced all six active sensors in
-his laptop (the location of sensors may vary on other models):
+EXPERIMENTAL: On the T43/p, a typical output may be:
+temperatures:   48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
+
+The mapping of thermal sensors to physical locations varies depending on
+system-board model (and thus, on ThinkPad model).
+
+http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
+tries to track down these locations for various models.
+
+Most (newer?) models seem to follow this pattern:
 
 1:  CPU
-2:  Mini PCI Module
-3:  HDD
+2:  (depends on model)
+3:  (depends on model)
 4:  GPU
-5:  Battery
-6:  N/A
-7:  Battery
-8:  N/A
+5:  Main battery: main sensor
+6:  Bay battery: main sensor
+7:  Main battery: secondary sensor
+8:  Bay battery: secondary sensor
+9-15: (depends on model)
+
+For the R51 (source: Thomas Gruber):
+2:  Mini-PCI
+3:  Internal HDD
+
+For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
+http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
+2:  System board, left side (near PCMCIA slot), reported as HDAPS temp
+3:  PCMCIA slot
+9:  MCH (northbridge) to DRAM Bus
+10: ICH (southbridge), under Mini-PCI card, under touchpad
+11: Power regulator, underside of system board, below F2 key
+
+The A31 has a very atypical layout for the thermal sensors
+(source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
+1:  CPU
+2:  Main Battery: main sensor
+3:  Power Converter
+4:  Bay Battery: main sensor
+5:  MCH (northbridge)
+6:  PCMCIA/ambient
+7:  Main Battery: secondary sensor
+8:  Bay Battery: secondary sensor
 
-No commands can be written to this file.
 
 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
 ------------------------------------------------------------------------
@@ -529,27 +571,57 @@ directly accesses hardware registers and may not work as expected. USE
 WITH CAUTION! To use this feature, you need to supply the
 experimental=1 parameter when loading the module.
 
-This feature attempts to show the current fan speed. The speed is read
-directly from the hardware registers of the embedded controller. This
-is known to work on later R, T and X series ThinkPads but may show a
-bogus value on other models.
+This feature attempts to show the current fan speed, control mode and
+other fan data that might be available.  The speed is read directly
+from the hardware registers of the embedded controller.  This is known
+to work on later R, T and X series ThinkPads but may show a bogus
+value on other models.
+
+Most ThinkPad fans work in "levels".  Level 0 stops the fan.  The higher
+the level, the higher the fan speed, although adjacent levels often map
+to the same fan speed.  7 is the highest level, where the fan reaches
+the maximum recommended speed.  Level "auto" means the EC changes the
+fan level according to some internal algorithm, usually based on
+readings from the thermal sensors.  Level "disengaged" means the EC
+disables the speed-locked closed-loop fan control, and drives the fan as
+fast as it can go, which might exceed hardware limits, so use this level
+with caution.
+
+The fan usually ramps up or down slowly from one speed to another,
+and it is normal for the EC to take several seconds to react to fan
+commands.
 
 The fan may be enabled or disabled with the following commands:
 
         echo enable  >/proc/acpi/ibm/fan
         echo disable >/proc/acpi/ibm/fan
 
+Placing a fan on level 0 is the same as disabling it.  Enabling a fan
+will try to place it in a safe level if it is too slow or disabled.
+
 WARNING WARNING WARNING: do not leave the fan disabled unless you are
-monitoring the temperature sensor readings and you are ready to enable
-it if necessary to avoid overheating.
+monitoring all of the temperature sensor readings and you are ready to
+enable it if necessary to avoid overheating.
 
-The fan only runs if it's enabled *and* the various temperature
-sensors which control it read high enough. On the X40, this seems to
-depend on the CPU and HDD temperatures. Specifically, the fan is
-turned on when either the CPU temperature climbs to 56 degrees or the
-HDD temperature climbs to 46 degrees. The fan is turned off when the
-CPU temperature drops to 49 degrees and the HDD temperature drops to
-41 degrees. These thresholds cannot currently be controlled.
+An enabled fan in level "auto" may stop spinning if the EC decides the
+ThinkPad is cool enough and doesn't need the extra airflow.  This is
+normal, and the EC will spin the fan up if the varios thermal readings
+rise too much.
+
+On the X40, this seems to depend on the CPU and HDD temperatures.
+Specifically, the fan is turned on when either the CPU temperature
+climbs to 56 degrees or the HDD temperature climbs to 46 degrees.  The
+fan is turned off when the CPU temperature drops to 49 degrees and the
+HDD temperature drops to 41 degrees.  These thresholds cannot
+currently be controlled.
+
+The fan level can be controlled with the command:
+
+        echo 'level <level>' > /proc/acpi/ibm/thermal
+
+Where <level> is an integer from 0 to 7, or one of the words "auto"
+or "disengaged" (without the quotes).  Not all ThinkPads support the
+"auto" and "disengaged" levels.
 
 On the X31 and X40 (and ONLY on those models), the fan speed can be
 controlled to a certain degree. Once the fan is running, it can be
@@ -562,12 +634,9 @@ about 3700 to about 7350. Values outside this range either do not have
 any effect or the fan speed eventually settles somewhere in that
 range. The fan cannot be stopped or started with this command.
 
-On the 570, temperature readings are not available through this
-feature and the fan control works a little differently. The fan speed
-is reported in levels from 0 (off) to 7 (max) and can be controlled
-with the following command:
-
-        echo 'level <level>' > /proc/acpi/ibm/thermal
+The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
+certain conditions are met.  It will override any fan programming done
+through ibm-acpi.
 
 EXPERIMENTAL: WAN -- /proc/acpi/ibm/wan
 ---------------------------------------
@@ -601,6 +670,26 @@ example:
 
         modprobe ibm_acpi hotkey=enable,0xffff video=auto_disable
 
+The ibm-acpi kernel driver can be programmed to revert the fan level
+to a safe setting if userspace does not issue one of the fan commands:
+"enable", "disable", "level" or "watchdog" within a configurable
+ammount of time.  To do this, use the "watchdog" command.
+
+        echo 'watchdog <interval>' > /proc/acpi/ibm/fan
+
+Interval is the ammount of time in seconds to wait for one of the
+above mentioned fan commands before reseting the fan level to a safe
+one.  If set to zero, the watchdog is disabled (default).  When the
+watchdog timer runs out, it does the exact equivalent of the "enable"
+fan command.
+
+Note that the watchdog timer stops after it enables the fan.  It will
+be rearmed again automatically (using the same interval) when one of
+the above mentioned fan commands is received.  The fan watchdog is,
+therefore, not suitable to protect against fan mode changes made
+through means other than the "enable", "disable", and "level" fan
+commands.
+
 
 Example Configuration
 ---------------------
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 0ed80122967..b0897a0b206 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -173,6 +173,7 @@ config ACPI_NUMA
 config ACPI_ASUS
         tristate "ASUS/Medion Laptop Extras"
         depends on X86
+        select BACKLIGHT_CLASS_DEVICE
         ---help---
           This driver provides support for extra features of ACPI-compatible
           ASUS laptops. As some of Medion laptops are made by ASUS, it may also
@@ -201,6 +202,7 @@ config ACPI_ASUS
 config ACPI_IBM
         tristate "IBM ThinkPad Laptop Extras"
         depends on X86
+        select BACKLIGHT_CLASS_DEVICE
         ---help---
           This is a Linux ACPI driver for the IBM ThinkPad laptops. It adds
           support for Fn-Fx key combinations, Bluetooth control, video
@@ -223,9 +225,21 @@ config ACPI_IBM_DOCK
 
           If you are not sure, say N here.
 
+config ACPI_IBM_BAY
+        bool "Legacy Removable Bay Support"
+        depends on ACPI_IBM
+        depends on ACPI_BAY=n
+        default n
+        ---help---
+          Allows the ibm_acpi driver to handle removable bays.
+          This support is obsoleted by CONFIG_ACPI_BAY.
+
+          If you are not sure, say N here.
+
 config ACPI_TOSHIBA
         tristate "Toshiba Laptop Extras"
         depends on X86
+        select BACKLIGHT_CLASS_DEVICE
         ---help---
           This driver adds support for access to certain system settings
           on "legacy free" Toshiba laptops.  These laptops can be recognized by
diff --git a/drivers/acpi/asus_acpi.c b/drivers/acpi/asus_acpi.c
index c7ac9297a20..bf7bc25e680 100644
--- a/drivers/acpi/asus_acpi.c
+++ b/drivers/acpi/asus_acpi.c
@@ -35,6 +35,7 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
+#include <linux/backlight.h>
 #include <acpi/acpi_drivers.h>
 #include <acpi/acpi_bus.h>
 #include <asm/uaccess.h>
@@ -402,6 +403,8 @@ static struct model_data model_conf[END_MODEL] = {
 /* procdir we use */
 static struct proc_dir_entry *asus_proc_dir;
 
+static struct backlight_device *asus_backlight_device;
+
 /*
  * This header is made available to allow proper configuration given model,
  * revision number , ... this info cannot go in struct asus_hotk because it is
@@ -779,7 +782,7 @@ proc_write_lcd(struct file *file, const char __user * buffer,
         return rv;
 }
 
-static int read_brightness(void)
+static int read_brightness(struct backlight_device *bd)
 {
         int value;
 
@@ -801,9 +804,10 @@ static int read_brightness(void)
 /*
  * Change the brightness level
  */
-static void set_brightness(int value)
+static int set_brightness(int value)
 {
         acpi_status status = 0;
+        int ret = 0;
 
         /* SPLV laptop */
         if (hotk->methods->brightness_set) {
@@ -811,11 +815,12 @@ static void set_brightness(int value)
                                     value, NULL))
                         printk(KERN_WARNING
                                "Asus ACPI: Error changing brightness\n");
-                return;
+                        ret = -EIO;
+                goto out;
         }
 
         /* No SPLV method if we are here, act as appropriate */
-        value -= read_brightness();
+        value -= read_brightness(NULL);
         while (value != 0) {
                 status = acpi_evaluate_object(NULL, (value > 0) ?
                                               hotk->methods->brightness_up :
@@ -825,15 +830,22 @@ static void set_brightness(int value)
                 if (ACPI_FAILURE(status))
                         printk(KERN_WARNING
                                "Asus ACPI: Error changing brightness\n");
+                        ret = -EIO;
         }
-        return;
+out:
+        return ret;
+}
+
+static int set_brightness_status(struct backlight_device *bd)
+{
+        return set_brightness(bd->props->brightness);
 }
 
 static int
 proc_read_brn(char *page, char **start, off_t off, int count, int *eof,
               void *data)
 {
-        return sprintf(page, "%d\n", read_brightness());
+        return sprintf(page, "%d\n", read_brightness(NULL));
 }
 
 static int
@@ -1333,6 +1345,26 @@ static int asus_hotk_remove(struct acpi_device *device, int type)
         return 0;
 }
 
+static struct backlight_properties asus_backlight_data = {
+        .owner          = THIS_MODULE,
+        .get_brightness = read_brightness,
+        .update_status  = set_brightness_status,
+        .max_brightness = 15,
+};
+
+static void __exit asus_acpi_exit(void)
+{
+        if (asus_backlight_device)
+                backlight_device_unregister(asus_backlight_device);
+
+        acpi_bus_unregister_driver(&asus_hotk_driver);
+        remove_proc_entry(PROC_ASUS, acpi_root_dir);
+
+        kfree(asus_info);
+
+        return;
+}
+
 static int __init asus_acpi_init(void)
 {
         int result;
@@ -1370,17 +1402,15 @@ static int __init asus_acpi_init(void)
                 return result;
         }
 
-        return 0;
-}
-
-static void __exit asus_acpi_exit(void)
-{
-        acpi_bus_unregister_driver(&asus_hotk_driver);
-        remove_proc_entry(PROC_ASUS, acpi_root_dir);
-
-        kfree(asus_info);
+        asus_backlight_device = backlight_device_register("asus", NULL,
+                                                          &asus_backlight_data);
+        if (IS_ERR(asus_backlight_device)) {
+                printk(KERN_ERR "Could not register asus backlight device\n");
+                asus_backlight_device = NULL;
+                asus_acpi_exit();
+        }
 
-        return;
+        return 0;
 }
 
 module_init(asus_acpi_init);
diff --git a/drivers/acpi/ibm_acpi.c b/drivers/acpi/ibm_acpi.c
index 003a9876c96..92e7b6eb8f1 100644
--- a/drivers/acpi/ibm_acpi.c
+++ b/drivers/acpi/ibm_acpi.c
@@ -3,6 +3,7 @@
  *
  *
  *  Copyright (C) 2004-2005 Borislav Deianov <borislav@users.sf.net>
+ *  Copyright (C) 2006 Henrique de Moraes Holschuh <hmh@hmh.eng.br>
  *
  *  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
@@ -19,10 +20,14 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
-#define IBM_VERSION "0.12a"
+#define IBM_VERSION "0.13"
 
 /*
  *  Changelog:
+ *
+ *  2006-11-22  0.13    new maintainer
+ *                      changelog now lives in git commit history, and will
+ *                      not be updated further in-file.
  *  
  *  2005-08-17  0.12    fix compilation on 2.6.13-rc kernels
  *  2005-03-17  0.11    support for 600e, 770x
@@ -77,9 +82,16 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
+#include <linux/string.h>
+
 #include <linux/proc_fs.h>
+#include <linux/backlight.h>
 #include <asm/uaccess.h>
 
+#include <linux/dmi.h>
+#include <linux/jiffies.h>
+#include <linux/workqueue.h>
+
 #include <acpi/acpi_drivers.h>
 #include <acpi/acnamesp.h>
 
@@ -88,7 +100,7 @@
 #define IBM_FILE "ibm_acpi"
 #define IBM_URL "http://ibm-acpi.sf.net/"
 
-MODULE_AUTHOR("Borislav Deianov");
+MODULE_AUTHOR("Borislav Deianov, Henrique de Moraes Holschuh");
 MODULE_DESCRIPTION(IBM_DESC);
 MODULE_VERSION(IBM_VERSION);
 MODULE_LICENSE("GPL");
@@ -116,28 +128,6 @@ static acpi_handle root_handle = NULL;
         static char        *object##_path;                      \
         static char        *object##_paths[] = { paths }
 
-/*
- * The following models are supported to various degrees:
- *
- * 570, 600e, 600x, 770e, 770x
- * A20m, A21e, A21m, A21p, A22p, A30, A30p, A31, A31p
- * G40, G41
- * R30, R31, R32, R40, R40e, R50, R50e, R50p, R51
- * T20, T21, T22, T23, T30, T40, T40p, T41, T41p, T42, T42p, T43
- * X20, X21, X22, X23, X24, X30, X31, X40
- *
- * The following models have no supported features:
- *
- * 240, 240x, i1400
- *
- * Still missing DSDTs for the following models:
- *
- * A20p, A22e, A22m
- * R52
- * S31
- * T43p
- */
-
 IBM_HANDLE(ec, root, "\\_SB.PCI0.ISA.EC0",      /* 240, 240x */
            "\\_SB.PCI.ISA.EC",  /* 570 */
            "\\_SB.PCI0.ISA0.EC0",       /* 600e/x, 770e, 770x */
@@ -167,8 +157,10 @@ IBM_HANDLE(dock, root, "\\_SB.GDCK",	/* X30, X31, X40 */
            "\\_SB.PCI.ISA.SLCE",        /* 570 */
     );                          /* A21e,G4x,R30,R31,R32,R40,R40e,R50e */
 #endif
+#ifdef CONFIG_ACPI_IBM_BAY
 IBM_HANDLE(bay, root, "\\_SB.PCI.IDE.SECN.MAST",        /* 570 */
            "\\_SB.PCI0.IDE0.IDES.IDSM", /* 600e/x, 770e, 770x */
+           "\\_SB.PCI0.SATA.SCND.MSTR", /* T60, X60, Z60 */ 
            "\\_SB.PCI0.IDE0.SCND.MSTR", /* all others */
     );                          /* A21e, R30, R31 */
 
@@ -183,6 +175,7 @@ IBM_HANDLE(bay2, root, "\\_SB.PCI0.IDE0.PRIM.SLAV",	/* A3x, R32 */
 IBM_HANDLE(bay2_ej, bay2, "_EJ3",       /* 600e/x, 770e, A3x */
            "_EJ0",              /* 770x */
     );                          /* all others */
+#endif
 
 /* don't list other alternatives as we install a notify handler on the 570 */
 IBM_HANDLE(pci, root, "\\_SB.PCI");     /* 570 */
@@ -203,7 +196,7 @@ IBM_HANDLE(led, ec, "SLED",	/* 570 */
 IBM_HANDLE(beep, ec, "BEEP");   /* all except R30, R31 */
 IBM_HANDLE(ecrd, ec, "ECRD");   /* 570 */
 IBM_HANDLE(ecwr, ec, "ECWR");   /* 570 */
-IBM_HANDLE(fans, ec, "FANS");   /* X31, X40 */
+IBM_HANDLE(fans, ec, "FANS");   /* X31, X40, X41 */
 
 IBM_HANDLE(gfan, ec, "GFAN",    /* 570 */
            "\\FSPD",            /* 600e/x, 770e, 770x */
@@ -216,6 +209,152 @@ IBM_HANDLE(sfan, ec, "SFAN",	/* 570 */
 #define IBM_HKEY_HID    "IBM0068"
 #define IBM_PCI_HID     "PNP0A03"
 
+enum thermal_access_mode {
+        IBMACPI_THERMAL_NONE = 0,       /* No thermal support */
+        IBMACPI_THERMAL_ACPI_TMP07,     /* Use ACPI TMP0-7 */
+        IBMACPI_THERMAL_ACPI_UPDT,      /* Use ACPI TMP0-7 with UPDT */
+        IBMACPI_THERMAL_TPEC_8,         /* Use ACPI EC regs, 8 sensors */
+        IBMACPI_THERMAL_TPEC_16,        /* Use ACPI EC regs, 16 sensors */
+};
+
+#define IBMACPI_MAX_THERMAL_SENSORS 16  /* Max thermal sensors supported */
+struct ibm_thermal_sensors_struct {
+        s32 temp[IBMACPI_MAX_THERMAL_SENSORS];
+};
+
+/*
+ * FAN ACCESS MODES
+ *
+ * IBMACPI_FAN_RD_ACPI_GFAN:
+ *      ACPI GFAN method: returns fan level
+ *
+ *      see IBMACPI_FAN_WR_ACPI_SFAN
+ *      EC 0x2f not available if GFAN exists
+ *
+ * IBMACPI_FAN_WR_ACPI_SFAN:
+ *      ACPI SFAN method: sets fan level, 0 (stop) to 7 (max)
+ *
+ *      EC 0x2f might be available *for reading*, but never for writing.
+ *
+ * IBMACPI_FAN_WR_TPEC:
+ *      ThinkPad EC register 0x2f (HFSP): fan control loop mode Supported
+ *      on almost all ThinkPads
+ *
+ *      Fan speed changes of any sort (including those caused by the
+ *      disengaged mode) are usually done slowly by the firmware as the
+ *      maximum ammount of fan duty cycle change per second seems to be
+ *      limited.
+ *
+ *      Reading is not available if GFAN exists.
+ *      Writing is not available if SFAN exists.
+ *
+ *      Bits
+ *       7      automatic mode engaged;
+ *              (default operation mode of the ThinkPad)
+ *              fan level is ignored in this mode.
+ *       6      disengage mode (takes precedence over bit 7);
+ *              not available on all thinkpads.  May disable
+ *              the tachometer, and speeds up fan to 100% duty-cycle,
+ *              which speeds it up far above the standard RPM
+ *              levels.  It is not impossible that it could cause
+ *              hardware damage.
+ *      5-3     unused in some models.  Extra bits for fan level
+ *              in others, but still useless as all values above
+ *              7 map to the same speed as level 7 in these models.
+ *      2-0     fan level (0..7 usually)
+ *                      0x00 = stop
+ *                      0x07 = max (set when temperatures critical)
+ *              Some ThinkPads may have other levels, see
+ *              IBMACPI_FAN_WR_ACPI_FANS (X31/X40/X41)
+ *
+ *      FIRMWARE BUG: on some models, EC 0x2f might not be initialized at
+ *      boot. Apparently the EC does not intialize it, so unless ACPI DSDT
+ *      does so, its initial value is meaningless (0x07).
+ *
+ *      For firmware bugs, refer to:
+ *      http://thinkwiki.org/wiki/Embedded_Controller_Firmware#Firmware_Issues
+ *
+ *      ----
+ *
+ *      ThinkPad EC register 0x84 (LSB), 0x85 (MSB):
+ *      Main fan tachometer reading (in RPM)
+ *
+ *      This register is present on all ThinkPads with a new-style EC, and
+ *      it is known not to be present on the A21m/e, and T22, as there is
+ *      something else in offset 0x84 according to the ACPI DSDT.  Other
+ *      ThinkPads from this same time period (and earlier) probably lack the
+ *      tachometer as well.
+ *
+ *      Unfortunately a lot of ThinkPads with new-style ECs but whose firwmare
+ *      was never fixed by IBM to report the EC firmware version string
+ *      probably support the tachometer (like the early X models), so
+ *      detecting it is quite hard.  We need more data to know for sure.
+ *
+ *      FIRMWARE BUG: always read 0x84 first, otherwise incorrect readings
+ *      might result.
+ *
+ *      FIRMWARE BUG: when EC 0x2f bit 6 is set (disengaged mode), this
+ *      register is not invalidated in ThinkPads that disable tachometer
+ *      readings.  Thus, the tachometer readings go stale.
+ *
+ *      For firmware bugs, refer to:
+ *      http://thinkwiki.org/wiki/Embedded_Controller_Firmware#Firmware_Issues
+ *
+ * IBMACPI_FAN_WR_ACPI_FANS:
+ *      ThinkPad X31, X40, X41.  Not available in the X60.
+ *
+ *      FANS ACPI handle: takes three arguments: low speed, medium speed,
+ *      high speed.  ACPI DSDT seems to map these three speeds to levels
+ *      as follows: STOP LOW LOW MED MED HIGH HIGH HIGH HIGH
+ *      (this map is stored on FAN0..FAN8 as "0,1,1,2,2,3,3,3,3")
+ *
+ *      The speeds are stored on handles
+ *      (FANA:FAN9), (FANC:FANB), (FANE:FAND).
+ *
+ *      There are three default speed sets, acessible as handles:
+ *      FS1L,FS1M,FS1H; FS2L,FS2M,FS2H; FS3L,FS3M,FS3H
+ *
+ *      ACPI DSDT switches which set is in use depending on various
+ *      factors.
+ *
+ *      IBMACPI_FAN_WR_TPEC is also available and should be used to
+ *      command the fan.  The X31/X40/X41 seems to have 8 fan levels,
+ *      but the ACPI tables just mention level 7.
+ */
+
+enum fan_status_access_mode {
+        IBMACPI_FAN_NONE = 0,           /* No fan status or control */
+        IBMACPI_FAN_RD_ACPI_GFAN,       /* Use ACPI GFAN */
+        IBMACPI_FAN_RD_TPEC,            /* Use ACPI EC regs 0x2f, 0x84-0x85 */
+};
+
+enum fan_control_access_mode {
+        IBMACPI_FAN_WR_NONE = 0,        /* No fan control */
+        IBMACPI_FAN_WR_ACPI_SFAN,       /* Use ACPI SFAN */
+        IBMACPI_FAN_WR_TPEC,            /* Use ACPI EC reg 0x2f */
+        IBMACPI_FAN_WR_ACPI_FANS,       /* Use ACPI FANS and EC reg 0x2f */
+};
+
+enum fan_control_commands {
+        IBMACPI_FAN_CMD_SPEED   = 0x0001,       /* speed command */
+        IBMACPI_FAN_CMD_LEVEL   = 0x0002,       /* level command  */
+        IBMACPI_FAN_CMD_ENABLE  = 0x0004,       /* enable/disable cmd,
+                                                 * and also watchdog cmd */
+};
+
+enum {                                  /* Fan control constants */
+        fan_status_offset = 0x2f,       /* EC register 0x2f */
+        fan_rpm_offset = 0x84,          /* EC register 0x84: LSB, 0x85 MSB (RPM)
+                                         * 0x84 must be read before 0x85 */
+
+        IBMACPI_FAN_EC_DISENGAGED       = 0x40, /* EC mode: tachometer
+                                                 * disengaged */
+        IBMACPI_FAN_EC_AUTO             = 0x80, /* EC mode: auto fan
+                                                 * control */
+};
+
+static char *ibm_thinkpad_ec_found = NULL;
+
 struct ibm_struct {
         char *name;
         char param[32];
@@ -243,6 +382,8 @@ struct ibm_struct {
 
 static struct proc_dir_entry *proc_dir = NULL;
 
+static struct backlight_device *ibm_backlight_device = NULL;
+
 #define onoff(status,bit) ((status) & (1 << (bit)) ? "on" : "off")
 #define enabled(status,bit) ((status) & (1 << (bit)) ? "enabled" : "disabled")
 #define strlencmp(a,b) (strncmp((a), (b), strlen(b)))
@@ -581,8 +722,7 @@ static int wan_status(void)
 {
         int status;
 
-        if (!wan_supported ||
-            !acpi_evalf(hkey_handle, &status, "GWAN", "d"))
+        if (!wan_supported || !acpi_evalf(hkey_handle, &status, "GWAN", "d"))
                 status = 0;
 
         return status;
@@ -630,12 +770,15 @@ static int wan_write(char *buf)
         return 0;
 }
 
-static int video_supported;
-static int video_orig_autosw;
+enum video_access_mode {
+        IBMACPI_VIDEO_NONE = 0,
+        IBMACPI_VIDEO_570,      /* 570 */
+        IBMACPI_VIDEO_770,      /* 600e/x, 770e, 770x */
+        IBMACPI_VIDEO_NEW,      /* all others */
+};
 
-#define VIDEO_570 1
-#define VIDEO_770 2
-#define VIDEO_NEW 3
+static enum video_access_mode video_supported;
+static int video_orig_autosw;
 
 static int video_init(void)
 {
@@ -647,16 +790,16 @@ static int video_init(void)
 
         if (!vid_handle)
                 /* video switching not supported on R30, R31 */
-                video_supported = 0;
+                video_supported = IBMACPI_VIDEO_NONE;
         else if (acpi_evalf(vid_handle, &video_orig_autosw, "SWIT", "qd"))
                 /* 570 */
-                video_supported = VIDEO_570;
+                video_supported = IBMACPI_VIDEO_570;
         else if (acpi_evalf(vid_handle, &video_orig_autosw, "^VADL", "qd"))
                 /* 600e/x, 770e, 770x */
-                video_supported = VIDEO_770;
+                video_supported = IBMACPI_VIDEO_770;
         else
                 /* all others */
-                video_supported = VIDEO_NEW;
+                video_supported = IBMACPI_VIDEO_NEW;
 
         return 0;
 }
@@ -666,15 +809,15 @@ static int video_status(void)
         int status = 0;
         int i;
 
-        if (video_supported == VIDEO_570) {
+        if (video_supported == IBMACPI_VIDEO_570) {
                 if (acpi_evalf(NULL, &i, "\\_SB.PHS", "dd", 0x87))
                         status = i & 3;
-        } else if (video_supported == VIDEO_770) {
+        } else if (video_supported == IBMACPI_VIDEO_770) {
                 if (acpi_evalf(NULL, &i, "\\VCDL", "d"))
                         status |= 0x01 * i;
                 if (acpi_evalf(NULL, &i, "\\VCDC", "d"))
                         status |= 0x02 * i;
-        } else if (video_supported == VIDEO_NEW) {
+        } else if (video_supported == IBMACPI_VIDEO_NEW) {
                 acpi_evalf(NULL, NULL, "\\VUPS", "vd", 1);
                 if (acpi_evalf(NULL, &i, "\\VCDC", "d"))
                         status |= 0x02 * i;
@@ -693,9 +836,10 @@ static int video_autosw(void)
 {
         int autosw = 0;
 
-        if (video_supported == VIDEO_570)
+        if (video_supported == IBMACPI_VIDEO_570)
                 acpi_evalf(vid_handle, &autosw, "SWIT", "d");
-        else if (video_supported == VIDEO_770 || video_supported == VIDEO_NEW)
+        else if (video_supported == IBMACPI_VIDEO_770 ||
+                 video_supported == IBMACPI_VIDEO_NEW)
                 acpi_evalf(vid_handle, &autosw, "^VDEE", "d");
 
         return autosw & 1;
@@ -715,12 +859,12 @@ static int video_read(char *p)
         len += sprintf(p + len, "status:\t\tsupported\n");
         len += sprintf(p + len, "lcd:\t\t%s\n", enabled(status, 0));
         len += sprintf(p + len, "crt:\t\t%s\n", enabled(status, 1));
-        if (video_supported == VIDEO_NEW)
+        if (video_supported == IBMACPI_VIDEO_NEW)
                 len += sprintf(p + len, "dvi:\t\t%s\n", enabled(status, 3));
         len += sprintf(p + len, "auto:\t\t%s\n", enabled(autosw, 0));
         len += sprintf(p + len, "commands:\tlcd_enable, lcd_disable\n");
         len += sprintf(p + len, "commands:\tcrt_enable, crt_disable\n");
-        if (video_supported == VIDEO_NEW)
+        if (video_supported == IBMACPI_VIDEO_NEW)
                 len += sprintf(p + len, "commands:\tdvi_enable, dvi_disable\n");
         len += sprintf(p + len, "commands:\tauto_enable, auto_disable\n");
         len += sprintf(p + len, "commands:\tvideo_switch, expand_toggle\n");
@@ -735,7 +879,7 @@ static int video_switch(void)
 
         if (!acpi_evalf(vid_handle, NULL, "_DOS", "vd", 1))
                 return -EIO;
-        ret = video_supported == VIDEO_570 ?
+        ret = video_supported == IBMACPI_VIDEO_570 ?
             acpi_evalf(ec_handle, NULL, "_Q16", "v") :
             acpi_evalf(vid_handle, NULL, "VSWT", "v");
         acpi_evalf(vid_handle, NULL, "_DOS", "vd", autosw);
@@ -745,9 +889,9 @@ static int video_switch(void)
 
 static int video_expand(void)
 {
-        if (video_supported == VIDEO_570)
+        if (video_supported == IBMACPI_VIDEO_570)
                 return acpi_evalf(ec_handle, NULL, "_Q17", "v");
-        else if (video_supported == VIDEO_770)
+        else if (video_supported == IBMACPI_VIDEO_770)
                 return acpi_evalf(vid_handle, NULL, "VEXP", "v");
         else
                 return acpi_evalf(NULL, NULL, "\\VEXP", "v");
@@ -757,10 +901,10 @@ static int video_switch2(int status)
 {
         int ret;
 
-        if (video_supported == VIDEO_570) {
+        if (video_supported == IBMACPI_VIDEO_570) {
                 ret = acpi_evalf(NULL, NULL,
                                  "\\_SB.PHS2", "vdd", 0x8b, status | 0x80);
-        } else if (video_supported == VIDEO_770) {
+        } else if (video_supported == IBMACPI_VIDEO_770) {
                 int autosw = video_autosw();
                 if (!acpi_evalf(vid_handle, NULL, "_DOS", "vd", 1))
                         return -EIO;
@@ -796,10 +940,10 @@ static int video_write(char *buf)
                         enable |= 0x02;
                 } else if (strlencmp(cmd, "crt_disable") == 0) {
                         disable |= 0x02;
-                } else if (video_supported == VIDEO_NEW &&
+                } else if (video_supported == IBMACPI_VIDEO_NEW &&
                            strlencmp(cmd, "dvi_enable") == 0) {
                         enable |= 0x08;
-                } else if (video_supported == VIDEO_NEW &&
+                } else if (video_supported == IBMACPI_VIDEO_NEW &&
                            strlencmp(cmd, "dvi_disable") == 0) {
                         disable |= 0x08;
                 } else if (strlencmp(cmd, "auto_enable") == 0) {
@@ -898,6 +1042,7 @@ static int light_write(char *buf)
         return 0;
 }
 
+#if defined(CONFIG_ACPI_IBM_DOCK) || defined(CONFIG_ACPI_IBM_BAY)
 static int _sta(acpi_handle handle)
 {
         int status;
@@ -907,6 +1052,7 @@ static int _sta(acpi_handle handle)
 
         return status;
 }
+#endif
 #ifdef CONFIG_ACPI_IBM_DOCK
 #define dock_docked() (_sta(dock_handle) & 1)
 
@@ -972,6 +1118,7 @@ static void dock_notify(struct ibm_struct *ibm, u32 event)
 }
 #endif
 
+#ifdef CONFIG_ACPI_IBM_BAY
 static int bay_status_supported;
 static int bay_status2_supported;
 static int bay_eject_supported;
@@ -1047,6 +1194,7 @@ static void bay_notify(struct ibm_struct *ibm, u32 event)
 {
         acpi_bus_generate_event(ibm->device, event, 0);
 }
+#endif
 
 static int cmos_read(char *p)
 {
@@ -1094,26 +1242,28 @@ static int cmos_write(char *buf)
         return 0;
 }
 
-static int led_supported;
-
-#define LED_570 1
-#define LED_OLD 2
-#define LED_NEW 3
+enum led_access_mode {
+        IBMACPI_LED_NONE = 0,
+        IBMACPI_LED_570,        /* 570 */
+        IBMACPI_LED_OLD,        /* 600e/x, 770e, 770x, A21e, A2xm/p, T20-22, X20-21 */
+        IBMACPI_LED_NEW,        /* all others */
+};
+static enum led_access_mode led_supported;
 
 static int led_init(void)
 {
         if (!led_handle)
                 /* led not supported on R30, R31 */
-                led_supported = 0;
+                led_supported = IBMACPI_LED_NONE;
         else if (strlencmp(led_path, "SLED") == 0)
                 /* 570 */
-                led_supported = LED_570;
+                led_supported = IBMACPI_LED_570;
         else if (strlencmp(led_path, "SYSL") == 0)
                 /* 600e/x, 770e, 770x, A21e, A2xm/p, T20-22, X20-21 */
-                led_supported = LED_OLD;
+                led_supported = IBMACPI_LED_OLD;
         else
                 /* all others */
-                led_supported = LED_NEW;
+                led_supported = IBMACPI_LED_NEW;
 
         return 0;
 }
@@ -1130,7 +1280,7 @@ static int led_read(char *p)
         }
         len += sprintf(p + len, "status:\t\tsupported\n");
 
-        if (led_supported == LED_570) {
+        if (led_supported == IBMACPI_LED_570) {
                 /* 570 */
                 int i, status;
                 for (i = 0; i < 8; i++) {
@@ -1179,13 +1329,13 @@ static int led_write(char *buf)
                 } else
                         return -EINVAL;
 
-                if (led_supported == LED_570) {
+                if (led_supported == IBMACPI_LED_570) {
                         /* 570 */
                         led = 1 << led;
                         if (!acpi_evalf(led_handle, NULL, NULL, "vdd",
                                         led, led_sled_arg1[ind]))
                                 return -EIO;
-                } else if (led_supported == LED_OLD) {
+                } else if (led_supported == IBMACPI_LED_OLD) {
                         /* 600e/x, 770e, 770x, A21e, A2xm/p, T20-22, X20 */
                         led = 1 << led;
                         ret = ec_write(EC_HLMS, led);
@@ -1272,50 +1422,142 @@ static int acpi_ec_write(int i, u8 v)
         return 1;
 }
 
-static int thermal_tmp_supported;
-static int thermal_updt_supported;
+static enum thermal_access_mode thermal_read_mode;
 
 static int thermal_init(void)
 {
-        /* temperatures not supported on 570, G4x, R30, R31, R32 */
-        thermal_tmp_supported = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
+        u8 t, ta1, ta2;
+        int i;
+        int acpi_tmp7 = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
+
+        if (ibm_thinkpad_ec_found && experimental) {
+                /*
+                 * Direct EC access mode: sensors at registers
+                 * 0x78-0x7F, 0xC0-0xC7.  Registers return 0x00 for
+                 * non-implemented, thermal sensors return 0x80 when
+                 * not available
+                 */
 
-        /* 600e/x, 770e, 770x */
-        thermal_updt_supported = acpi_evalf(ec_handle, NULL, "UPDT", "qv");
+                ta1 = ta2 = 0;
+                for (i = 0; i < 8; i++) {
+                        if (likely(acpi_ec_read(0x78 + i, &t))) {
+                                ta1 |= t;
+                        } else {
+                                ta1 = 0;
+                                break;
+                        }
+                        if (likely(acpi_ec_read(0xC0 + i, &t))) {
+                                ta2 |= t;
+                        } else {
+                                ta1 = 0;
+                                break;
+                        }
+                }
+                if (ta1 == 0) {
+                        /* This is sheer paranoia, but we handle it anyway */
+                        if (acpi_tmp7) {
+                                printk(IBM_ERR
+                                       "ThinkPad ACPI EC access misbehaving, "
+                                       "falling back to ACPI TMPx access mode\n");
+                                thermal_read_mode = IBMACPI_THERMAL_ACPI_TMP07;
+                        } else {
+                                printk(IBM_ERR
+                                       "ThinkPad ACPI EC access misbehaving, "
+                                       "disabling thermal sensors access\n");
+                                thermal_read_mode = IBMACPI_THERMAL_NONE;
+                        }
+                } else {
+                        thermal_read_mode =
+                            (ta2 != 0) ?
+                            IBMACPI_THERMAL_TPEC_16 : IBMACPI_THERMAL_TPEC_8;
+                }
+        } else if (acpi_tmp7) {
+                if (acpi_evalf(ec_handle, NULL, "UPDT", "qv")) {
+                        /* 600e/x, 770e, 770x */
+                        thermal_read_mode = IBMACPI_THERMAL_ACPI_UPDT;
+                } else {
+                        /* Standard ACPI TMPx access, max 8 sensors */
+                        thermal_read_mode = IBMACPI_THERMAL_ACPI_TMP07;
+                }
+        } else {
+                /* temperatures not supported on 570, G4x, R30, R31, R32 */
+                thermal_read_mode = IBMACPI_THERMAL_NONE;
+        }
 
         return 0;
 }
 
-static int thermal_read(char *p)
+static int thermal_get_sensors(struct ibm_thermal_sensors_struct *s)
 {
-        int len = 0;
+        int i, t;
+        s8 tmp;
+        char tmpi[] = "TMPi";
 
-        if (!thermal_tmp_supported)
-                len += sprintf(p + len, "temperatures:\tnot supported\n");
-        else {
-                int i, t;
-                char tmpi[] = "TMPi";
-                s8 tmp[8];
+        if (!s)
+                return -EINVAL;
 
-                if (thermal_updt_supported)
-                        if (!acpi_evalf(ec_handle, NULL, "UPDT", "v"))
+        switch (thermal_read_mode) {
+#if IBMACPI_MAX_THERMAL_SENSORS >= 16
+        case IBMACPI_THERMAL_TPEC_16:
+                for (i = 0; i < 8; i++) {
+                        if (!acpi_ec_read(0xC0 + i, &tmp))
+                                return -EIO;
+                        s->temp[i + 8] = tmp * 1000;
+                }
+                /* fallthrough */
+#endif
+        case IBMACPI_THERMAL_TPEC_8:
+                for (i = 0; i < 8; i++) {
+                        if (!acpi_ec_read(0x78 + i, &tmp))
                                 return -EIO;
+                        s->temp[i] = tmp * 1000;
+                }
+                return (thermal_read_mode == IBMACPI_THERMAL_TPEC_16) ? 16 : 8;
 
+        case IBMACPI_THERMAL_ACPI_UPDT:
+                if (!acpi_evalf(ec_handle, NULL, "UPDT", "v"))
+                        return -EIO;
                 for (i = 0; i < 8; i++) {
                         tmpi[3] = '0' + i;
                         if (!acpi_evalf(ec_handle, &t, tmpi, "d"))
                                 return -EIO;
-                        if (thermal_updt_supported)
-                                tmp[i] = (t - 2732 + 5) / 10;
-                        else
-                                tmp[i] = t;
+                        s->temp[i] = (t - 2732) * 100;
                 }
+                return 8;
 
-                len += sprintf(p + len,
-                               "temperatures:\t%d %d %d %d %d %d %d %d\n",
-                               tmp[0], tmp[1], tmp[2], tmp[3],
-                               tmp[4], tmp[5], tmp[6], tmp[7]);
+        case IBMACPI_THERMAL_ACPI_TMP07:
+                for (i = 0; i < 8; i++) {
+                        tmpi[3] = '0' + i;
+                        if (!acpi_evalf(ec_handle, &t, tmpi, "d"))
+                                return -EIO;
+                        s->temp[i] = t * 1000;
+                }
+                return 8;
+
+        case IBMACPI_THERMAL_NONE:
+        default:
+                return 0;
         }
+}
+
+static int thermal_read(char *p)
+{
+        int len = 0;
+        int n, i;
+        struct ibm_thermal_sensors_struct t;
+
+        n = thermal_get_sensors(&t);
+        if (unlikely(n < 0))
+                return n;
+
+        len += sprintf(p + len, "temperatures:\t");
+
+        if (n > 0) {
+                for (i = 0; i < (n - 1); i++)
+                        len += sprintf(p + len, "%d ", t.temp[i] / 1000);
+                len += sprintf(p + len, "%d\n", t.temp[i] / 1000);
+        } else
+                len += sprintf(p + len, "not supported\n");
 
         return len;
 }
@@ -1381,12 +1623,23 @@ static int ecdump_write(char *buf)
 
 static int brightness_offset = 0x31;
 
+static int brightness_get(struct backlight_device *bd)
+{
+        u8 level;
+        if (!acpi_ec_read(brightness_offset, &level))
+                return -EIO;
+
+        level &= 0x7;
+
+        return level;
+}
+
 static int brightness_read(char *p)
 {
         int len = 0;
-        u8 level;
+        int level;
 
-        if (!acpi_ec_read(brightness_offset, &level)) {
+        if ((level = brightness_get(NULL)) < 0) {
                 len += sprintf(p + len, "level:\t\tunreadable\n");
         } else {
                 len += sprintf(p + len, "level:\t\t%d\n", level & 0x7);
@@ -1401,16 +1654,34 @@ static int brightness_read(char *p)
 #define BRIGHTNESS_UP   4
 #define BRIGHTNESS_DOWN 5
 
-static int brightness_write(char *buf)
+static int brightness_set(int value)
 {
         int cmos_cmd, inc, i;
-        u8 level;
+        int current_value = brightness_get(NULL);
+
+        value &= 7;
+
+        cmos_cmd = value > current_value ? BRIGHTNESS_UP : BRIGHTNESS_DOWN;
+        inc = value > current_value ? 1 : -1;
+        for (i = current_value; i != value; i += inc) {
+                if (!cmos_eval(cmos_cmd))
+                        return -EIO;
+                if (!acpi_ec_write(brightness_offset, i + inc))
+                        return -EIO;
+        }
+
+        return 0;
+}
+
+static int brightness_write(char *buf)
+{
+        int level;
         int new_level;
         char *cmd;
 
         while ((cmd = next_cmd(&buf))) {
-                if (!acpi_ec_read(brightness_offset, &level))
-                        return -EIO;
+                if ((level = brightness_get(NULL)) < 0)
+                        return level;
                 level &= 7;
 
                 if (strlencmp(cmd, "up") == 0) {
@@ -1423,19 +1694,44 @@ static int brightness_write(char *buf)
                 } else
                         return -EINVAL;
 
-                cmos_cmd = new_level > level ? BRIGHTNESS_UP : BRIGHTNESS_DOWN;
-                inc = new_level > level ? 1 : -1;
-                for (i = level; i != new_level; i += inc) {
-                        if (!cmos_eval(cmos_cmd))
-                                return -EIO;
-                        if (!acpi_ec_write(brightness_offset, i + inc))
-                                return -EIO;
-                }
+                brightness_set(new_level);
         }
 
         return 0;
 }
 
+static int brightness_update_status(struct backlight_device *bd)
+{
+        return brightness_set(bd->props->brightness);
+}
+
+static struct backlight_properties ibm_backlight_data = {
+        .owner          = THIS_MODULE,
+        .get_brightness = brightness_get,
+        .update_status  = brightness_update_status,
+        .max_brightness = 7,
+};
+
+static int brightness_init(void)
+{
+        ibm_backlight_device = backlight_device_register("ibm", NULL,
+                                                         &ibm_backlight_data);
+        if (IS_ERR(ibm_backlight_device)) {
+                printk(IBM_ERR "Could not register backlight device\n");
+                return PTR_ERR(ibm_backlight_device);
+        }
+
+        return 0;
+}
+
+static void brightness_exit(void)
+{
+        if (ibm_backlight_device) {
+                backlight_device_unregister(ibm_backlight_device);
+                ibm_backlight_device = NULL;
+        }
+}
+
 static int volume_offset = 0x30;
 
 static int volume_read(char *p)
@@ -1522,86 +1818,482 @@ static int volume_write(char *buf)
         return 0;
 }
 
-static int fan_status_offset = 0x2f;
-static int fan_rpm_offset = 0x84;
+static enum fan_status_access_mode fan_status_access_mode;
+static enum fan_control_access_mode fan_control_access_mode;
+static enum fan_control_commands fan_control_commands;
 
-static int fan_read(char *p)
+static int fan_control_status_known;
+static u8 fan_control_initial_status;
+
+static void fan_watchdog_fire(void *ignored);
+static int fan_watchdog_maxinterval;
+static DECLARE_WORK(fan_watchdog_task, fan_watchdog_fire, NULL);
+
+static int fan_init(void)
 {
-        int len = 0;
-        int s;
-        u8 lo, hi, status;
+        fan_status_access_mode = IBMACPI_FAN_NONE;
+        fan_control_access_mode = IBMACPI_FAN_WR_NONE;
+        fan_control_commands = 0;
+        fan_control_status_known = 1;
+        fan_watchdog_maxinterval = 0;
 
         if (gfan_handle) {
                 /* 570, 600e/x, 770e, 770x */
-                if (!acpi_evalf(gfan_handle, &s, NULL, "d"))
-                        return -EIO;
+                fan_status_access_mode = IBMACPI_FAN_RD_ACPI_GFAN;
+        } else {
+                /* all other ThinkPads: note that even old-style
+                 * ThinkPad ECs supports the fan control register */
+                if (likely(acpi_ec_read(fan_status_offset,
+                                        &fan_control_initial_status))) {
+                        fan_status_access_mode = IBMACPI_FAN_RD_TPEC;
+
+                        /* In some ThinkPads, neither the EC nor the ACPI
+                         * DSDT initialize the fan status, and it ends up
+                         * being set to 0x07 when it *could* be either
+                         * 0x07 or 0x80.
+                         *
+                         * Enable for TP-1Y (T43), TP-78 (R51e),
+                         * TP-76 (R52), TP-70 (T43, R52), which are known
+                         * to be buggy. */
+                        if (fan_control_initial_status == 0x07 &&
+                            ibm_thinkpad_ec_found &&
+                            ((ibm_thinkpad_ec_found[0] == '1' &&
+                              ibm_thinkpad_ec_found[1] == 'Y') ||
+                             (ibm_thinkpad_ec_found[0] == '7' &&
+                              (ibm_thinkpad_ec_found[1] == '6' ||
+                               ibm_thinkpad_ec_found[1] == '8' ||
+                               ibm_thinkpad_ec_found[1] == '0'))
+                            )) {
+                                printk(IBM_NOTICE
+                                       "fan_init: initial fan status is "
+                                       "unknown, assuming it is in auto "
+                                       "mode\n");
+                                fan_control_status_known = 0;
+                        }
+                } else {
+                        printk(IBM_ERR
+                               "ThinkPad ACPI EC access misbehaving, "
+                               "fan status and control unavailable\n");
+                        return 0;
+                }
+        }
 
-                len += sprintf(p + len, "level:\t\t%d\n", s);
+        if (sfan_handle) {
+                /* 570, 770x-JL */
+                fan_control_access_mode = IBMACPI_FAN_WR_ACPI_SFAN;
+                fan_control_commands |=
+                    IBMACPI_FAN_CMD_LEVEL | IBMACPI_FAN_CMD_ENABLE;
         } else {
+                if (!gfan_handle) {
+                        /* gfan without sfan means no fan control */
+                        /* all other models implement TP EC 0x2f control */
+
+                        if (fans_handle) {
+                                /* X31, X40, X41 */
+                                fan_control_access_mode =
+                                    IBMACPI_FAN_WR_ACPI_FANS;
+                                fan_control_commands |=
+                                    IBMACPI_FAN_CMD_SPEED |
+                                    IBMACPI_FAN_CMD_LEVEL |
+                                    IBMACPI_FAN_CMD_ENABLE;
+                        } else {
+                                fan_control_access_mode = IBMACPI_FAN_WR_TPEC;
+                                fan_control_commands |=
+                                    IBMACPI_FAN_CMD_LEVEL |
+                                    IBMACPI_FAN_CMD_ENABLE;
+                        }
+                }
+        }
+
+        return 0;
+}
+
+static int fan_get_status(u8 *status)
+{
+        u8 s;
+
+        /* TODO:
+         * Add IBMACPI_FAN_RD_ACPI_FANS ? */
+
+        switch (fan_status_access_mode) {
+        case IBMACPI_FAN_RD_ACPI_GFAN:
+                /* 570, 600e/x, 770e, 770x */
+
+                if (unlikely(!acpi_evalf(gfan_handle, &s, NULL, "d")))
+                        return -EIO;
+
+                if (likely(status))
+                        *status = s & 0x07;
+
+                break;
+
+        case IBMACPI_FAN_RD_TPEC:
                 /* all except 570, 600e/x, 770e, 770x */
-                if (!acpi_ec_read(fan_status_offset, &status))
-                        len += sprintf(p + len, "status:\t\tunreadable\n");
-                else
-                        len += sprintf(p + len, "status:\t\t%s\n",
-                                       enabled(status, 7));
+                if (unlikely(!acpi_ec_read(fan_status_offset, &s)))
+                        return -EIO;
 
-                if (!acpi_ec_read(fan_rpm_offset, &lo) ||
-                    !acpi_ec_read(fan_rpm_offset + 1, &hi))
-                        len += sprintf(p + len, "speed:\t\tunreadable\n");
-                else
-                        len += sprintf(p + len, "speed:\t\t%d\n",
-                                       (hi << 8) + lo);
+                if (likely(status))
+                        *status = s;
+
+                break;
+
+        default:
+                return -ENXIO;
         }
 
-        if (sfan_handle)
-                /* 570, 770x-JL */
-                len += sprintf(p + len, "commands:\tlevel <level>"
-                               " (<level> is 0-7)\n");
-        if (!gfan_handle)
+        return 0;
+}
+
+static int fan_get_speed(unsigned int *speed)
+{
+        u8 hi, lo;
+
+        switch (fan_status_access_mode) {
+        case IBMACPI_FAN_RD_TPEC:
                 /* all except 570, 600e/x, 770e, 770x */
-                len += sprintf(p + len, "commands:\tenable, disable\n");
-        if (fans_handle)
-                /* X31, X40 */
+                if (unlikely(!acpi_ec_read(fan_rpm_offset, &lo) ||
+                             !acpi_ec_read(fan_rpm_offset + 1, &hi)))
+                        return -EIO;
+
+                if (likely(speed))
+                        *speed = (hi << 8) | lo;
+
+                break;
+
+        default:
+                return -ENXIO;
+        }
+
+        return 0;
+}
+
+static void fan_exit(void)
+{
+        cancel_delayed_work(&fan_watchdog_task);
+        flush_scheduled_work();
+}
+
+static void fan_watchdog_reset(void)
+{
+        static int fan_watchdog_active = 0;
+
+        if (fan_watchdog_active)
+                cancel_delayed_work(&fan_watchdog_task);
+
+        if (fan_watchdog_maxinterval > 0) {
+                fan_watchdog_active = 1;
+                if (!schedule_delayed_work(&fan_watchdog_task,
+                                msecs_to_jiffies(fan_watchdog_maxinterval
+                                                 * 1000))) {
+                        printk(IBM_ERR "failed to schedule the fan watchdog, "
+                               "watchdog will not trigger\n");
+                }
+        } else
+                fan_watchdog_active = 0;
+}
+
+static int fan_read(char *p)
+{
+        int len = 0;
+        int rc;
+        u8 status;
+        unsigned int speed = 0;
+
+        switch (fan_status_access_mode) {
+        case IBMACPI_FAN_RD_ACPI_GFAN:
+                /* 570, 600e/x, 770e, 770x */
+                if ((rc = fan_get_status(&status)) < 0)
+                        return rc;
+
+                len += sprintf(p + len, "status:\t\t%s\n"
+                               "level:\t\t%d\n",
+                               (status != 0) ? "enabled" : "disabled", status);
+                break;
+
+        case IBMACPI_FAN_RD_TPEC:
+                /* all except 570, 600e/x, 770e, 770x */
+                if ((rc = fan_get_status(&status)) < 0)
+                        return rc;
+
+                if (unlikely(!fan_control_status_known)) {
+                        if (status != fan_control_initial_status)
+                                fan_control_status_known = 1;
+                        else
+                                /* Return most likely status. In fact, it
+                                 * might be the only possible status */
+                                status = IBMACPI_FAN_EC_AUTO;
+                }
+
+                len += sprintf(p + len, "status:\t\t%s\n",
+                               (status != 0) ? "enabled" : "disabled");
+
+                /* No ThinkPad boots on disengaged mode, we can safely
+                 * assume the tachometer is online if fan control status
+                 * was unknown */
+                if ((rc = fan_get_speed(&speed)) < 0)
+                        return rc;
+
+                len += sprintf(p + len, "speed:\t\t%d\n", speed);
+
+                if (status & IBMACPI_FAN_EC_DISENGAGED)
+                        /* Disengaged mode takes precedence */
+                        len += sprintf(p + len, "level:\t\tdisengaged\n");
+                else if (status & IBMACPI_FAN_EC_AUTO)
+                        len += sprintf(p + len, "level:\t\tauto\n");
+                else
+                        len += sprintf(p + len, "level:\t\t%d\n", status);
+                break;
+
+        case IBMACPI_FAN_NONE:
+        default:
+                len += sprintf(p + len, "status:\t\tnot supported\n");
+        }
+
+        if (fan_control_commands & IBMACPI_FAN_CMD_LEVEL) {
+                len += sprintf(p + len, "commands:\tlevel <level>");
+
+                switch (fan_control_access_mode) {
+                case IBMACPI_FAN_WR_ACPI_SFAN:
+                        len += sprintf(p + len, " (<level> is 0-7)\n");
+                        break;
+
+                default:
+                        len += sprintf(p + len, " (<level> is 0-7, "
+                                       "auto, disengaged)\n");
+                        break;
+                }
+        }
+
+        if (fan_control_commands & IBMACPI_FAN_CMD_ENABLE)
+                len += sprintf(p + len, "commands:\tenable, disable\n"
+                               "commands:\twatchdog <timeout> (<timeout> is 0 (off), "
+                               "1-120 (seconds))\n");
+
+        if (fan_control_commands & IBMACPI_FAN_CMD_SPEED)
                 len += sprintf(p + len, "commands:\tspeed <speed>"
                                " (<speed> is 0-65535)\n");
 
         return len;
 }
 
-static int fan_write(char *buf)
+static int fan_set_level(int level)
 {
-        char *cmd;
-        int level, speed;
-
-        while ((cmd = next_cmd(&buf))) {
-                if (sfan_handle &&
-                    sscanf(cmd, "level %d", &level) == 1 &&
-                    level >= 0 && level <= 7) {
-                        /* 570, 770x-JL */
+        switch (fan_control_access_mode) {
+        case IBMACPI_FAN_WR_ACPI_SFAN:
+                if (level >= 0 && level <= 7) {
                         if (!acpi_evalf(sfan_handle, NULL, NULL, "vd", level))
                                 return -EIO;
-                } else if (!gfan_handle && strlencmp(cmd, "enable") == 0) {
-                        /* all except 570, 600e/x, 770e, 770x */
-                        if (!acpi_ec_write(fan_status_offset, 0x80))
-                                return -EIO;
-                } else if (!gfan_handle && strlencmp(cmd, "disable") == 0) {
-                        /* all except 570, 600e/x, 770e, 770x */
-                        if (!acpi_ec_write(fan_status_offset, 0x00))
-                                return -EIO;
-                } else if (fans_handle &&
-                           sscanf(cmd, "speed %d", &speed) == 1 &&
-                           speed >= 0 && speed <= 65535) {
-                        /* X31, X40 */
+                } else
+                        return -EINVAL;
+                break;
+
+        case IBMACPI_FAN_WR_ACPI_FANS:
+        case IBMACPI_FAN_WR_TPEC:
+                if ((level != IBMACPI_FAN_EC_AUTO) &&
+                    (level != IBMACPI_FAN_EC_DISENGAGED) &&
+                    ((level < 0) || (level > 7)))
+                        return -EINVAL;
+
+                if (!acpi_ec_write(fan_status_offset, level))
+                        return -EIO;
+                else
+                        fan_control_status_known = 1;
+                break;
+
+        default:
+                return -ENXIO;
+        }
+        return 0;
+}
+
+static int fan_set_enable(void)
+{
+        u8 s;
+        int rc;
+
+        switch (fan_control_access_mode) {
+        case IBMACPI_FAN_WR_ACPI_FANS:
+        case IBMACPI_FAN_WR_TPEC:
+                if ((rc = fan_get_status(&s)) < 0)
+                        return rc;
+
+                /* Don't go out of emergency fan mode */
+                if (s != 7)
+                        s = IBMACPI_FAN_EC_AUTO;
+
+                if (!acpi_ec_write(fan_status_offset, s))
+                        return -EIO;
+                else
+                        fan_control_status_known = 1;
+                break;
+
+        case IBMACPI_FAN_WR_ACPI_SFAN:
+                if ((rc = fan_get_status(&s)) < 0)
+                        return rc;
+
+                s &= 0x07;
+
+                /* Set fan to at least level 4 */
+                if (s < 4)
+                        s = 4;
+
+                if (!acpi_evalf(sfan_handle, NULL, NULL, "vd", s))
+                        return -EIO;
+                break;
+
+        default:
+                return -ENXIO;
+        }
+        return 0;
+}
+
+static int fan_set_disable(void)
+{
+        switch (fan_control_access_mode) {
+        case IBMACPI_FAN_WR_ACPI_FANS:
+        case IBMACPI_FAN_WR_TPEC:
+                if (!acpi_ec_write(fan_status_offset, 0x00))
+                        return -EIO;
+                else
+                        fan_control_status_known = 1;
+                break;
+
+        case IBMACPI_FAN_WR_ACPI_SFAN:
+                if (!acpi_evalf(sfan_handle, NULL, NULL, "vd", 0x00))
+                        return -EIO;
+                break;
+
+        default:
+                return -ENXIO;
+        }
+        return 0;
+}
+
+static int fan_set_speed(int speed)
+{
+        switch (fan_control_access_mode) {
+        case IBMACPI_FAN_WR_ACPI_FANS:
+                if (speed >= 0 && speed <= 65535) {
                         if (!acpi_evalf(fans_handle, NULL, NULL, "vddd",
                                         speed, speed, speed))
                                 return -EIO;
                 } else
                         return -EINVAL;
-        }
+                break;
 
+        default:
+                return -ENXIO;
+        }
         return 0;
 }
 
+static int fan_write_cmd_level(const char *cmd, int *rc)
+{
+        int level;
+
+        if (strlencmp(cmd, "level auto") == 0)
+                level = IBMACPI_FAN_EC_AUTO;
+        else if (strlencmp(cmd, "level disengaged") == 0)
+                level = IBMACPI_FAN_EC_DISENGAGED;
+        else if (sscanf(cmd, "level %d", &level) != 1)
+                return 0;
+
+        if ((*rc = fan_set_level(level)) == -ENXIO)
+                printk(IBM_ERR "level command accepted for unsupported "
+                       "access mode %d", fan_control_access_mode);
+
+        return 1;
+}
+
+static int fan_write_cmd_enable(const char *cmd, int *rc)
+{
+        if (strlencmp(cmd, "enable") != 0)
+                return 0;
+
+        if ((*rc = fan_set_enable()) == -ENXIO)
+                printk(IBM_ERR "enable command accepted for unsupported "
+                       "access mode %d", fan_control_access_mode);
+
+        return 1;
+}
+
+static int fan_write_cmd_disable(const char *cmd, int *rc)
+{
+        if (strlencmp(cmd, "disable") != 0)
+                return 0;
+
+        if ((*rc = fan_set_disable()) == -ENXIO)
+                printk(IBM_ERR "disable command accepted for unsupported "
+                       "access mode %d", fan_control_access_mode);
+
+        return 1;
+}
+
+static int fan_write_cmd_speed(const char *cmd, int *rc)
+{
+        int speed;
+
+        /* TODO:
+         * Support speed <low> <medium> <high> ? */
+
+        if (sscanf(cmd, "speed %d", &speed) != 1)
+                return 0;
+
+        if ((*rc = fan_set_speed(speed)) == -ENXIO)
+                printk(IBM_ERR "speed command accepted for unsupported "
+                       "access mode %d", fan_control_access_mode);
+
+        return 1;
+}
+
+static int fan_write_cmd_watchdog(const char *cmd, int *rc)
+{
+        int interval;
+
+        if (sscanf(cmd, "watchdog %d", &interval) != 1)
+                return 0;
+
+        if (interval < 0 || interval > 120)
+                *rc = -EINVAL;
+        else
+                fan_watchdog_maxinterval = interval;
+
+        return 1;
+}
+
+static int fan_write(char *buf)
+{
+        char *cmd;
+        int rc = 0;
+
+        while (!rc && (cmd = next_cmd(&buf))) {
+                if (!((fan_control_commands & IBMACPI_FAN_CMD_LEVEL) &&
+                      fan_write_cmd_level(cmd, &rc)) &&
+                    !((fan_control_commands & IBMACPI_FAN_CMD_ENABLE) &&
+                      (fan_write_cmd_enable(cmd, &rc) ||
+                       fan_write_cmd_disable(cmd, &rc) ||
+                       fan_write_cmd_watchdog(cmd, &rc))) &&
+                    !((fan_control_commands & IBMACPI_FAN_CMD_SPEED) &&
+                      fan_write_cmd_speed(cmd, &rc))
+                    )
+                        rc = -EINVAL;
+                else if (!rc)
+                        fan_watchdog_reset();
+        }
+
+        return rc;
+}
+
+static void fan_watchdog_fire(void *ignored)
+{
+        printk(IBM_NOTICE "fan watchdog: enabling fan\n");
+        if (fan_set_enable()) {
+                printk(IBM_ERR "fan watchdog: error while enabling fan\n");
+                /* reschedule for later */
+                fan_watchdog_reset();
+        }
+}
+
 static struct ibm_struct ibms[] = {
         {
          .name = "driver",
@@ -1662,6 +2354,7 @@ static struct ibm_struct ibms[] = {
          .type = ACPI_SYSTEM_NOTIFY,
          },
 #endif
+#ifdef CONFIG_ACPI_IBM_BAY
         {
          .name = "bay",
          .init = bay_init,
@@ -1671,6 +2364,7 @@ static struct ibm_struct ibms[] = {
          .handle = &bay_handle,
          .type = ACPI_SYSTEM_NOTIFY,
          },
+#endif
         {
          .name = "cmos",
          .read = cmos_read,
@@ -1702,6 +2396,8 @@ static struct ibm_struct ibms[] = {
          .name = "brightness",
          .read = brightness_read,
          .write = brightness_write,
+         .init = brightness_init,
+         .exit = brightness_exit,
          },
         {
          .name = "volume",
@@ -1712,6 +2408,8 @@ static struct ibm_struct ibms[] = {
          .name = "fan",
          .read = fan_read,
          .write = fan_write,
+         .init = fan_init,
+         .exit = fan_exit,
          .experimental = 1,
          },
 };
@@ -1825,7 +2523,7 @@ static int __init register_driver(struct ibm_struct *ibm)
         }
 
         memset(ibm->driver, 0, sizeof(struct acpi_driver));
-        sprintf(ibm->driver->name, "%s/%s", IBM_NAME, ibm->name);
+        sprintf(ibm->driver->name, "%s_%s", IBM_NAME, ibm->name);
         ibm->driver->ids = ibm->hid;
         ibm->driver->ops.add = &ibm_device_add;
 
@@ -1954,7 +2652,9 @@ IBM_PARAM(light);
 #ifdef CONFIG_ACPI_IBM_DOCK
 IBM_PARAM(dock);
 #endif
+#ifdef CONFIG_ACPI_IBM_BAY
 IBM_PARAM(bay);
+#endif
 IBM_PARAM(cmos);
 IBM_PARAM(led);
 IBM_PARAM(beep);
@@ -1971,6 +2671,33 @@ static void acpi_ibm_exit(void)
                 ibm_exit(&ibms[i]);
 
         remove_proc_entry(IBM_DIR, acpi_root_dir);
+
+        if (ibm_thinkpad_ec_found)
+                kfree(ibm_thinkpad_ec_found);
+}
+
+static char* __init check_dmi_for_ec(void)
+{
+        struct dmi_device *dev = NULL;
+        char ec_fw_string[18];
+
+        /*
+         * ThinkPad T23 or newer, A31 or newer, R50e or newer,
+         * X32 or newer, all Z series;  Some models must have an
+         * up-to-date BIOS or they will not be detected.
+         *
+         * See http://thinkwiki.org/wiki/List_of_DMI_IDs
+         */
+        while ((dev = dmi_find_device(DMI_DEV_TYPE_OEM_STRING, NULL, dev))) {
+                if (sscanf(dev->name,
+                           "IBM ThinkPad Embedded Controller -[%17c",
+                           ec_fw_string) == 1) {
+                        ec_fw_string[sizeof(ec_fw_string) - 1] = 0;
+                        ec_fw_string[strcspn(ec_fw_string, " ]")] = 0;
+                        return kstrdup(ec_fw_string, GFP_KERNEL);
+                }
+        }
+        return NULL;
 }
 
 static int __init acpi_ibm_init(void)
@@ -1992,6 +2719,12 @@ static int __init acpi_ibm_init(void)
                 return -ENODEV;
         }
 
+        /* Models with newer firmware report the EC in DMI */
+        ibm_thinkpad_ec_found = check_dmi_for_ec();
+        if (ibm_thinkpad_ec_found)
+                printk(IBM_INFO "ThinkPad EC firmware %s\n",
+                       ibm_thinkpad_ec_found);
+
         /* these handles are not required */
         IBM_HANDLE_INIT(vid);
         IBM_HANDLE_INIT(vid2);
@@ -2004,12 +2737,14 @@ static int __init acpi_ibm_init(void)
         IBM_HANDLE_INIT(dock);
 #endif
         IBM_HANDLE_INIT(pci);
+#ifdef CONFIG_ACPI_IBM_BAY
         IBM_HANDLE_INIT(bay);
         if (bay_handle)
                 IBM_HANDLE_INIT(bay_ej);
         IBM_HANDLE_INIT(bay2);
         if (bay2_handle)
                 IBM_HANDLE_INIT(bay2_ej);
+#endif
         IBM_HANDLE_INIT(beep);
         IBM_HANDLE_INIT(ecrd);
         IBM_HANDLE_INIT(ecwr);
diff --git a/drivers/acpi/toshiba_acpi.c b/drivers/acpi/toshiba_acpi.c
index 7fe0b7ae973..2f35f891593 100644
--- a/drivers/acpi/toshiba_acpi.c
+++ b/drivers/acpi/toshiba_acpi.c
@@ -41,6 +41,8 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
+#include <linux/backlight.h>
+
 #include <asm/uaccess.h>
 
 #include <acpi/acpi_drivers.h>
@@ -210,6 +212,7 @@ static acpi_status hci_read1(u32 reg, u32 * out1, u32 * result)
 }
 
 static struct proc_dir_entry *toshiba_proc_dir /*= 0*/ ;
+static struct backlight_device *toshiba_backlight_device;
 static int force_fan;
 static int last_key_event;
 static int key_event_valid;
@@ -271,14 +274,23 @@ dispatch_write(struct file *file, const char __user * buffer,
         return result;
 }
 
-static char *read_lcd(char *p)
+static int get_lcd(struct backlight_device *bd)
 {
         u32 hci_result;
         u32 value;
 
         hci_read1(HCI_LCD_BRIGHTNESS, &value, &hci_result);
         if (hci_result == HCI_SUCCESS) {
-                value = value >> HCI_LCD_BRIGHTNESS_SHIFT;
+                return (value >> HCI_LCD_BRIGHTNESS_SHIFT);
+        } else
+                return -EFAULT;
+}
+
+static char *read_lcd(char *p)
+{
+        int value = get_lcd(NULL);
+
+        if (value >= 0) {
                 p += sprintf(p, "brightness:              %d\n", value);
                 p += sprintf(p, "brightness_levels:       %d\n",
                              HCI_LCD_BRIGHTNESS_LEVELS);
@@ -289,22 +301,34 @@ static char *read_lcd(char *p)
         return p;
 }
 
+static int set_lcd(int value)
+{
+        u32 hci_result;
+
+        value = value << HCI_LCD_BRIGHTNESS_SHIFT;
+        hci_write1(HCI_LCD_BRIGHTNESS, value, &hci_result);
+        if (hci_result != HCI_SUCCESS)
+                return -EFAULT;
+
+        return 0;
+}
+
+static int set_lcd_status(struct backlight_device *bd)
+{
+        return set_lcd(bd->props->brightness);
+}
+
 static unsigned long write_lcd(const char *buffer, unsigned long count)
 {
         int value;
-        u32 hci_result;
+        int ret = count;
 
         if (sscanf(buffer, " brightness : %i", &value) == 1 &&
-            value >= 0 && value < HCI_LCD_BRIGHTNESS_LEVELS) {
-                value = value << HCI_LCD_BRIGHTNESS_SHIFT;
-                hci_write1(HCI_LCD_BRIGHTNESS, value, &hci_result);
-                if (hci_result != HCI_SUCCESS)
-                        return -EFAULT;
-        } else {
-                return -EINVAL;
-        }
-
-        return count;
+            value >= 0 && value < HCI_LCD_BRIGHTNESS_LEVELS)
+                ret = set_lcd(value);
+        else
+                ret = -EINVAL;
+        return ret;
 }
 
 static char *read_video(char *p)
@@ -506,6 +530,26 @@ static acpi_status __exit remove_device(void)
         return AE_OK;
 }
 
+static struct backlight_properties toshiba_backlight_data = {
+        .owner          = THIS_MODULE,
+        .get_brightness = get_lcd,
+        .update_status  = set_lcd_status,
+        .max_brightness = HCI_LCD_BRIGHTNESS_LEVELS - 1,
+};
+
+static void __exit toshiba_acpi_exit(void)
+{
+        if (toshiba_backlight_device)
+                backlight_device_unregister(toshiba_backlight_device);
+
+        remove_device();
+
+        if (toshiba_proc_dir)
+                remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
+
+        return;
+}
+
 static int __init toshiba_acpi_init(void)
 {
         acpi_status status = AE_OK;
@@ -546,17 +590,15 @@ static int __init toshiba_acpi_init(void)
                         remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
         }
 
-        return (ACPI_SUCCESS(status)) ? 0 : -ENODEV;
-}
-
-static void __exit toshiba_acpi_exit(void)
-{
-        remove_device();
-
-        if (toshiba_proc_dir)
-                remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
+        toshiba_backlight_device = backlight_device_register("toshiba", NULL,
+                                                &toshiba_backlight_data);
+        if (IS_ERR(toshiba_backlight_device)) {
+                printk(KERN_ERR "Could not register toshiba backlight device\n");
+                toshiba_backlight_device = NULL;
+                toshiba_acpi_exit();
+        }
 
-        return;
+        return (ACPI_SUCCESS(status)) ? 0 : -ENODEV;
 }
 
 module_init(toshiba_acpi_init);