drivers/leds/leds-aaeon.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * AAEON LED driver
   4  *
   5  * Copyright (c) 2021, AAEON Ltd.
   6  *
   7  * Author: Kunyang Fan <kunyang_fan@aaeon.com.tw>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  */
  14 #include <linux/acpi.h>
  15 #include <linux/bitops.h>
  16 #include <linux/leds.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_data/x86/asus-wmi.h>
  19 #include <linux/platform_device.h>
  20
  21 #define DRVNAME "led_aaeon"
  22 #define ASUS_NB_WMI_EVENT_GUID   "0B3CBB35-E3C2-45ED-91C2-4C5A6D195D1C"
  23 #define AAEON_WMI_MGMT_GUID      "97845ED0-4E6D-11DE-8A39-0800200C9A66"
  24
  25 #define GET_LED_NUMBER_ID        0x00060000
  26 #define GET_LED_METHOD_ID        0x00060001
  27 #define SET_LED_METHOD_ID        0x00060002
  28 #define GET_LED_NUMBER_METHOD_ID 0x10
  29
  30
  31 struct aaeon_led_data {
  32         int id;
  33         struct led_classdev cdev;
  34 };
  35
  36 static int aaeon_led_get_number(void)
  37 {
  38         int err, retval;
  39
  40         err = asus_wmi_evaluate_method(GET_LED_NUMBER_ID,
  41                                        GET_LED_NUMBER_METHOD_ID,
  42                                        0, &retval);
  43         if (err)
  44                 return err;
  45
  46         return retval;
  47 }
  48
  49 static enum led_brightness aaeon_led_brightness_get(struct led_classdev
  50                                                       *cdev)
  51 {
  52         int err, brightness;
  53         struct aaeon_led_data *led =
  54                         container_of(cdev, struct aaeon_led_data, cdev);
  55         u32 arg0;
  56
  57         arg0 = (u32)(led->id & 0xF);
  58         err = asus_wmi_evaluate_method(GET_LED_METHOD_ID, arg0, 0, &brightness);
  59         if (err)
  60                 return err;
  61
  62         return brightness;
  63 };
  64
  65 static void aaeon_led_brightness_set(struct led_classdev *cdev,
  66                                        enum led_brightness brightness)
  67 {
  68         int err, retval;
  69         struct aaeon_led_data *led =
  70                         container_of(cdev, struct aaeon_led_data, cdev);
  71         u32 arg0;
  72
  73         arg0 = (u32)(led->id & 0xF);
  74         if (brightness != LED_OFF)
  75                 arg0 |= BIT(16);
  76
  77         err = asus_wmi_evaluate_method(SET_LED_METHOD_ID, arg0, 0, &retval);
  78 };
  79
  80 static int __init aaeon_add_led_device(struct platform_device *pdev,
  81                                            int id)
  82 {
  83         struct aaeon_led_data *led;
  84
  85         led = devm_kzalloc(&pdev->dev, sizeof(struct aaeon_led_data), GFP_KERNEL);
  86         if (!led)
  87                 return -ENOMEM;
  88
  89         led->id = id;
  90         led->cdev.brightness_get = aaeon_led_brightness_get;
  91         led->cdev.brightness_set = aaeon_led_brightness_set;
  92         led->cdev.name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "led:%d:", id);
  93
  94         if (!led->cdev.name)
  95                 return -ENOMEM;
  96
  97         return devm_led_classdev_register(&pdev->dev, &led->cdev);
  98 }
  99
 100 static int aaeon_led_probe(struct platform_device *pdev)
 101 {
 102         int err = -ENODEV, i;
 103         int led_number = 0;
 104
 105         pr_debug("aaeon led device probe!\n");
 106         /* Prevent other drivers adding this platfom device */
 107         if (!wmi_has_guid(AAEON_WMI_MGMT_GUID)) {
 108                 pr_debug("AAEON Management GUID not found\n");
 109                 return -ENODEV;
 110         }
 111
 112         /* Query the number of led devices board support */
 113         led_number = aaeon_led_get_number();
 114
 115         /*
 116          * If the number is 0 or can't get the number of leds,
 117          * no need to register any led device node.
 118          */
 119         if (led_number <= 0)
 120                 return -ENODEV;
 121
 122         for (i = 0; i < led_number; i++) {
 123                 err = aaeon_add_led_device(pdev, i);
 124                 if (err)
 125                         break;
 126         }
 127
 128         return err;
 129 }
 130
 131 static struct platform_driver aaeon_led_driver = {
 132         .driver = {
 133                 .name = "leds-aaeon",
 134         },
 135 };
 136
 137 module_platform_driver_probe(aaeon_led_driver, aaeon_led_probe);
 138
 139 MODULE_ALIAS("platform:leds-aaeon");
 140 MODULE_DESCRIPTION("AAEON LED Driver");
 141 MODULE_AUTHOR("Kunyang Fan <kunyang_fan@asus.com>");
 142 MODULE_LICENSE("GPL v2");