3 files changed, 208 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index d86e1a3ee0b7..505eb64c329c 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -278,6 +278,13 @@ config LEDS_ADP5520
           To compile this driver as a module, choose M here: the module will
           be called leds-adp5520.
 
+config LEDS_DELL_NETBOOKS
+        tristate "External LED on Dell Business Netbooks"
+        depends on X86 && ACPI_WMI
+        help
+          This adds support for the Latitude 2100 and similar
+          notebooks that have an external LED.
+
 config LEDS_TRIGGERS
         bool "LED Trigger support"
         help
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d76fb32b77c0..0cd8b9957380 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_LEDS_REGULATOR)		+= leds-regulator.o
 obj-$(CONFIG_LEDS_INTEL_SS4200)         += leds-ss4200.o
 obj-$(CONFIG_LEDS_LT3593)               += leds-lt3593.o
 obj-$(CONFIG_LEDS_ADP5520)              += leds-adp5520.o
+obj-$(CONFIG_LEDS_DELL_NETBOOKS)        += dell-led.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)           += leds-dac124s085.o
diff --git a/drivers/leds/dell-led.c b/drivers/leds/dell-led.c
new file mode 100644
index 000000000000..ee310891fff8
--- /dev/null
+++ b/drivers/leds/dell-led.c
@@ -0,0 +1,200 @@
+/*
+ * dell_led.c - Dell LED Driver
+ *
+ * Copyright (C) 2010 Dell Inc.
+ * Louis Davis <louis_davis@dell.com>
+ * Jim Dailey <jim_dailey@dell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/acpi.h>
+#include <linux/leds.h>
+
+MODULE_AUTHOR("Louis Davis/Jim Dailey");
+MODULE_DESCRIPTION("Dell LED Control Driver");
+MODULE_LICENSE("GPL");
+
+#define DELL_LED_BIOS_GUID "F6E4FE6E-909D-47cb-8BAB-C9F6F2F8D396"
+MODULE_ALIAS("wmi:" DELL_LED_BIOS_GUID);
+
+/* Error Result Codes: */
+#define INVALID_DEVICE_ID       250
+#define INVALID_PARAMETER       251
+#define INVALID_BUFFER          252
+#define INTERFACE_ERROR         253
+#define UNSUPPORTED_COMMAND     254
+#define UNSPECIFIED_ERROR       255
+
+/* Device ID */
+#define DEVICE_ID_PANEL_BACK    1
+
+/* LED Commands */
+#define CMD_LED_ON      16
+#define CMD_LED_OFF     17
+#define CMD_LED_BLINK   18
+
+struct bios_args {
+        unsigned char length;
+        unsigned char result_code;
+        unsigned char device_id;
+        unsigned char command;
+        unsigned char on_time;
+        unsigned char off_time;
+};
+
+static int dell_led_perform_fn(u8 length,
+                u8 result_code,
+                u8 device_id,
+                u8 command,
+                u8 on_time,
+                u8 off_time)
+{
+        struct bios_args *bios_return;
+        u8 return_code;
+        union acpi_object *obj;
+        struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+        struct acpi_buffer input;
+        acpi_status status;
+
+        struct bios_args args;
+        args.length = length;
+        args.result_code = result_code;
+        args.device_id = device_id;
+        args.command = command;
+        args.on_time = on_time;
+        args.off_time = off_time;
+
+        input.length = sizeof(struct bios_args);
+        input.pointer = &args;
+
+        status = wmi_evaluate_method(DELL_LED_BIOS_GUID,
+                1,
+                1,
+                &input,
+                &output);
+
+        if (ACPI_FAILURE(status))
+                return status;
+
+        obj = output.pointer;
+
+        if (!obj)
+                return -EINVAL;
+        else if (obj->type != ACPI_TYPE_BUFFER) {
+                kfree(obj);
+                return -EINVAL;
+        }
+
+        bios_return = ((struct bios_args *)obj->buffer.pointer);
+        return_code = bios_return->result_code;
+
+        kfree(obj);
+
+        return return_code;
+}
+
+static int led_on(void)
+{
+        return dell_led_perform_fn(3,   /* Length of command */
+                INTERFACE_ERROR,        /* Init to  INTERFACE_ERROR */
+                DEVICE_ID_PANEL_BACK,   /* Device ID */
+                CMD_LED_ON,             /* Command */
+                0,                      /* not used */
+                0);                     /* not used */
+}
+
+static int led_off(void)
+{
+        return dell_led_perform_fn(3,   /* Length of command */
+                INTERFACE_ERROR,        /* Init to  INTERFACE_ERROR */
+                DEVICE_ID_PANEL_BACK,   /* Device ID */
+                CMD_LED_OFF,            /* Command */
+                0,                      /* not used */
+                0);                     /* not used */
+}
+
+static int led_blink(unsigned char on_eighths,
+                unsigned char off_eighths)
+{
+        return dell_led_perform_fn(5,   /* Length of command */
+                INTERFACE_ERROR,        /* Init to  INTERFACE_ERROR */
+                DEVICE_ID_PANEL_BACK,   /* Device ID */
+                CMD_LED_BLINK,          /* Command */
+                on_eighths,             /* blink on in eigths of a second */
+                off_eighths);           /* blink off in eights of a second */
+}
+
+static void dell_led_set(struct led_classdev *led_cdev,
+                enum led_brightness value)
+{
+        if (value == LED_OFF)
+                led_off();
+        else
+                led_on();
+}
+
+static int dell_led_blink(struct led_classdev *led_cdev,
+                unsigned long *delay_on,
+                unsigned long *delay_off)
+{
+        unsigned long on_eighths;
+        unsigned long off_eighths;
+
+        /* The Dell LED delay is based on 125ms intervals.
+           Need to round up to next interval. */
+
+        on_eighths = (*delay_on + 124) / 125;
+        if (0 == on_eighths)
+                on_eighths = 1;
+        if (on_eighths > 255)
+                on_eighths = 255;
+        *delay_on = on_eighths * 125;
+
+        off_eighths = (*delay_off + 124) / 125;
+        if (0 == off_eighths)
+                off_eighths = 1;
+        if (off_eighths > 255)
+                off_eighths = 255;
+        *delay_off = off_eighths * 125;
+
+        led_blink(on_eighths, off_eighths);
+
+        return 0;
+}
+
+static struct led_classdev dell_led = {
+        .name           = "dell::lid",
+        .brightness     = LED_OFF,
+        .max_brightness = 1,
+        .brightness_set = dell_led_set,
+        .blink_set      = dell_led_blink,
+        .flags          = LED_CORE_SUSPENDRESUME,
+};
+
+static int __init dell_led_init(void)
+{
+        int error = 0;
+
+        if (!wmi_has_guid(DELL_LED_BIOS_GUID))
+                return -ENODEV;
+
+        error = led_off();
+        if (error != 0)
+                return -ENODEV;
+
+        return led_classdev_register(NULL, &dell_led);
+}
+
+static void __exit dell_led_exit(void)
+{
+        led_classdev_unregister(&dell_led);
+
+        led_off();
+}
+
+module_init(dell_led_init);
+module_exit(dell_led_exit);