releases/upstream/2.6.26-rc1/0009-ACPI-thinkpad-acpi-add-sysfs-led-class-support-for.patch

   1 From e306501d1c4ff610feaba74ac35dd13e470480e6 Mon Sep 17 00:00:00 2001
   2 From: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
   3 Date: Sat, 26 Apr 2008 01:02:24 -0300
   4 Subject: ACPI: thinkpad-acpi: add sysfs led class support for thinklight (v3.1)
   5
   6 Add a sysfs led class interface to the thinklight (light subdriver).
   7
   8 Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
   9 Cc: Richard Purdie <rpurdie@rpsys.net>
  10 Signed-off-by: Len Brown <len.brown@intel.com>
  11 ---
  12  Documentation/laptops/thinkpad-acpi.txt |   25 +++++++++++---
  13  drivers/misc/thinkpad_acpi.c            |   57 ++++++++++++++++++++++++++++++-
  14  2 files changed, 76 insertions(+), 6 deletions(-)
  15
  16 diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
  17 index a41bc89..af1f2bc 100644
  18 --- a/Documentation/laptops/thinkpad-acpi.txt
  19 +++ b/Documentation/laptops/thinkpad-acpi.txt
  20 @@ -693,16 +693,31 @@ while others are still having problems. For more information:
  21
  22  https://bugs.freedesktop.org/show_bug.cgi?id=2000
  23
  24 -ThinkLight control -- /proc/acpi/ibm/light
  25 -------------------------------------------
  26 +ThinkLight control
  27 +------------------
  28 +
  29 +procfs: /proc/acpi/ibm/light
  30 +sysfs attributes: as per led class, for the "tpacpi::thinklight" led
  31 +
  32 +procfs notes:
  33
  34 -The current status of the ThinkLight can be found in this file. A few
  35 -models which do not make the status available will show it as
  36 -"unknown". The available commands are:
  37 +The ThinkLight status can be read and set through the procfs interface.  A
  38 +few models which do not make the status available will show the ThinkLight
  39 +status as "unknown". The available commands are:
  40
  41         echo on  > /proc/acpi/ibm/light
  42         echo off > /proc/acpi/ibm/light
  43
  44 +sysfs notes:
  45 +
  46 +The ThinkLight sysfs interface is documented by the led class
  47 +documentation, in Documentation/leds-class.txt.  The ThinkLight led name
  48 +is "tpacpi::thinklight".
  49 +
  50 +Due to limitations in the sysfs led class, if the status of the thinklight
  51 +cannot be read or if it is unknown, thinkpad-acpi will report it as "off".
  52 +It is impossible to know if the status returned through sysfs is valid.
  53 +
  54  Docking / undocking -- /proc/acpi/ibm/dock
  55  ------------------------------------------
  56
  57 diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
  58 index 5a3fb09..38a119b 100644
  59 --- a/drivers/misc/thinkpad_acpi.c
  60 +++ b/drivers/misc/thinkpad_acpi.c
  61 @@ -3280,13 +3280,49 @@ static int light_set_status(int status)
  62         return -ENXIO;
  63  }
  64
  65 +static void light_set_status_worker(struct work_struct *work)
  66 +{
  67 +       struct tpacpi_led_classdev *data =
  68 +                       container_of(work, struct tpacpi_led_classdev, work);
  69 +
  70 +       if (likely(tpacpi_lifecycle == TPACPI_LIFE_RUNNING))
  71 +               light_set_status((data->new_brightness != LED_OFF));
  72 +}
  73 +
  74 +static void light_sysfs_set(struct led_classdev *led_cdev,
  75 +                       enum led_brightness brightness)
  76 +{
  77 +       struct tpacpi_led_classdev *data =
  78 +               container_of(led_cdev,
  79 +                            struct tpacpi_led_classdev,
  80 +                            led_classdev);
  81 +       data->new_brightness = brightness;
  82 +       schedule_work(&data->work);
  83 +}
  84 +
  85 +static enum led_brightness light_sysfs_get(struct led_classdev *led_cdev)
  86 +{
  87 +       return (light_get_status() == 1)? LED_FULL : LED_OFF;
  88 +}
  89 +
  90 +static struct tpacpi_led_classdev tpacpi_led_thinklight = {
  91 +       .led_classdev = {
  92 +               .name           = "tpacpi::thinklight",
  93 +               .brightness_set = &light_sysfs_set,
  94 +               .brightness_get = &light_sysfs_get,
  95 +       }
  96 +};
  97 +
  98  static int __init light_init(struct ibm_init_struct *iibm)
  99  {
 100 +       int rc = 0;
 101 +
 102         vdbg_printk(TPACPI_DBG_INIT, "initializing light subdriver\n");
 103
 104         TPACPI_ACPIHANDLE_INIT(ledb);
 105         TPACPI_ACPIHANDLE_INIT(lght);
 106         TPACPI_ACPIHANDLE_INIT(cmos);
 107 +       INIT_WORK(&tpacpi_led_thinklight.work, light_set_status_worker);
 108
 109         /* light not supported on 570, 600e/x, 770e, 770x, G4x, R30, R31 */
 110         tp_features.light = (cmos_handle || lght_handle) && !ledb_handle;
 111 @@ -3300,7 +3336,25 @@ static int __init light_init(struct ibm_init_struct *iibm)
 112         vdbg_printk(TPACPI_DBG_INIT, "light is %s\n",
 113                 str_supported(tp_features.light));
 114
 115 -       return (tp_features.light)? 0 : 1;
 116 +       if (tp_features.light) {
 117 +               rc = led_classdev_register(&tpacpi_pdev->dev,
 118 +                                          &tpacpi_led_thinklight.led_classdev);
 119 +       }
 120 +
 121 +       if (rc < 0) {
 122 +               tp_features.light = 0;
 123 +               tp_features.light_status = 0;
 124 +       } else {
 125 +               rc = (tp_features.light)? 0 : 1;
 126 +       }
 127 +       return rc;
 128 +}
 129 +
 130 +static void light_exit(void)
 131 +{
 132 +       led_classdev_unregister(&tpacpi_led_thinklight.led_classdev);
 133 +       if (work_pending(&tpacpi_led_thinklight.work))
 134 +               flush_scheduled_work();
 135  }
 136
 137  static int light_read(char *p)
 138 @@ -3348,6 +3402,7 @@ static struct ibm_struct light_driver_data = {
 139         .name = "light",
 140         .read = light_read,
 141         .write = light_write,
 142 +       .exit = light_exit,
 143  };
 144
 145  /*************************************************************************
 146 --
 147 1.5.4.4
 148