hp_accel: do not call ACPI from invalid context

[linux-2.6-omap-h63xx.git] / drivers / hwmon / hp_accel.c

diff --git a/drivers/hwmon/hp_accel.c b/drivers/hwmon/hp_accel.c
index bf8d40580577d081e0ebafb95a22eab9b2d9c2ea..03705240000f7755e9773d6ec0492a3a2a27f63b 100644 (file)
--- a/drivers/hwmon/hp_accel.c
+++ b/drivers/hwmon/hp_accel.c
@@ -3,7 +3,7 @@
  *
  *  Copyright (C) 2007-2008 Yan Burman
  *  Copyright (C) 2008 Eric Piel
- *  Copyright (C) 2008 Pavel Machek
+ *  Copyright (C) 2008-2009 Pavel Machek
  *
  *  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
@@ -36,6 +36,7 @@
 #include <linux/freezer.h>
 #include <linux/version.h>
 #include <linux/uaccess.h>
+#include <linux/leds.h>
 #include <acpi/acpi_drivers.h>
 #include <asm/atomic.h>
 #include "lis3lv02d.h"
@@ -43,6 +44,36 @@
 #define DRIVER_NAME     "lis3lv02d"
 #define ACPI_MDPS_CLASS "accelerometer"
 
+/* Delayed LEDs infrastructure ------------------------------------ */
+
+/* Special LED class that can defer work */
+struct delayed_led_classdev {
+       struct led_classdev led_classdev;
+       struct work_struct work;
+       enum led_brightness new_brightness;
+
+       unsigned int led;               /* For driver */
+       void (*set_brightness)(struct delayed_led_classdev *data, enum led_brightness value);
+};
+
+static inline void delayed_set_status_worker(struct work_struct *work)
+{
+       struct delayed_led_classdev *data =
+                       container_of(work, struct delayed_led_classdev, work);
+
+       data->set_brightness(data, data->new_brightness);
+}
+
+static inline void delayed_sysfs_set(struct led_classdev *led_cdev,
+                             enum led_brightness brightness)
+{
+       struct delayed_led_classdev *data = container_of(led_cdev,
+                            struct delayed_led_classdev, led_classdev);
+       data->new_brightness = brightness;
+       schedule_work(&data->work);
+}
+
+/* HP-specific accelerometer driver ------------------------------------ */
 
 /* For automatic insertion of the module */
 static struct acpi_device_id lis3lv02d_device_ids[] = {
@@ -154,10 +185,33 @@ static struct dmi_system_id lis3lv02d_dmi_ids[] = {
  */
 };
 
+static void hpled_set(struct delayed_led_classdev *led_cdev, enum led_brightness value)
+{
+       acpi_handle handle = adev.device->handle;
+       unsigned long long ret; /* Not used when writing */
+       union acpi_object in_obj[1];
+       struct acpi_object_list args = { 1, in_obj };
+
+       in_obj[0].type          = ACPI_TYPE_INTEGER;
+       in_obj[0].integer.value = !!value;
+
+       acpi_evaluate_integer(handle, "ALED", &args, &ret);
+}
+
+static struct delayed_led_classdev hpled_led = {
+       .led_classdev = {
+               .name                   = "hp::hddprotect",
+               .default_trigger        = "none",
+               .brightness_set         = delayed_sysfs_set,
+               .flags                  = LED_CORE_SUSPENDRESUME,
+       },
+       .set_brightness = hpled_set,
+};
 
 static int lis3lv02d_add(struct acpi_device *device)
 {
        u8 val;
+       int ret;
 
        if (!device)
                return -EINVAL;
@@ -183,7 +237,19 @@ static int lis3lv02d_add(struct acpi_device *device)
                adev.ac = lis3lv02d_axis_normal;
        }
 
-       return lis3lv02d_init_device(&adev);
+       INIT_WORK(&hpled_led.work, delayed_set_status_worker);
+       ret = led_classdev_register(NULL, &hpled_led.led_classdev);
+       if (ret)
+               return ret;
+
+       ret = lis3lv02d_init_device(&adev);
+       if (ret) {
+               flush_work(&hpled_led.work);
+               led_classdev_unregister(&hpled_led.led_classdev);
+               return ret;
+       }
+
+       return ret;
 }
 
 static int lis3lv02d_remove(struct acpi_device *device, int type)
@@ -194,6 +260,9 @@ static int lis3lv02d_remove(struct acpi_device *device, int type)
        lis3lv02d_joystick_disable();
        lis3lv02d_poweroff(device->handle);
 
+       flush_work(&hpled_led.work);
+       led_classdev_unregister(&hpled_led.led_classdev);
+
        return lis3lv02d_remove_fs();
 }
 
@@ -256,7 +325,7 @@ static void __exit lis3lv02d_exit_module(void)
        acpi_bus_unregister_driver(&lis3lv02d_driver);
 }
 
-MODULE_DESCRIPTION("Glue between LIS3LV02Dx and HP ACPI BIOS");
+MODULE_DESCRIPTION("Glue between LIS3LV02Dx and HP ACPI BIOS and support for disk protection LED.");
 MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
 MODULE_LICENSE("GPL");