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path: root/drivers/platform/x86/dell-wmi-led.c
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Diffstat (limited to 'drivers/platform/x86/dell-wmi-led.c')
-rw-r--r--drivers/platform/x86/dell-wmi-led.c186
1 files changed, 186 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell-wmi-led.c b/drivers/platform/x86/dell-wmi-led.c
new file mode 100644
index 000000000000..a0c7e99530ef
--- /dev/null
+++ b/drivers/platform/x86/dell-wmi-led.c
@@ -0,0 +1,186 @@
+/*
+ * 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>
+#include <linux/slab.h>
+#include <linux/module.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 acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct bios_args *bios_return;
+ struct acpi_buffer input;
+ union acpi_object *obj;
+ acpi_status status;
+ u8 return_code;
+
+ struct bios_args args = {
+ .length = length,
+ .result_code = result_code,
+ .device_id = device_id,
+ .command = command,
+ .on_time = on_time,
+ .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;
+ 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 = DIV_ROUND_UP(*delay_on, 125);
+ on_eighths = clamp_t(unsigned long, on_eighths, 1, 255);
+ *delay_on = on_eighths * 125;
+
+ off_eighths = DIV_ROUND_UP(*delay_off, 125);
+ off_eighths = clamp_t(unsigned long, off_eighths, 1, 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);