drivers/gpu/drm/nouveau/nouveau_led.c

   1 /*
   2  * Copyright (C) 2016 Martin Peres
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the
  13  * next paragraph) shall be included in all copies or substantial
  14  * portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  19  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
  20  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  21  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  *
  24  */
  25
  26 /*
  27  * Authors:
  28  *  Martin Peres <martin.peres@free.fr>
  29  */
  30
  31 #include <linux/leds.h>
  32
  33 #include "nouveau_led.h"
  34 #include <nvkm/subdev/gpio.h>
  35
  36 static enum led_brightness
  37 nouveau_led_get_brightness(struct led_classdev *led)
  38 {
  39         struct drm_device *drm_dev = container_of(led, struct nouveau_led, led)->dev;
  40         struct nouveau_drm *drm = nouveau_drm(drm_dev);
  41         struct nvif_object *device = &drm->client.device.object;
  42         u32 div, duty;
  43
  44         div =  nvif_rd32(device, 0x61c880) & 0x00ffffff;
  45         duty = nvif_rd32(device, 0x61c884) & 0x00ffffff;
  46
  47         if (div > 0)
  48                 return duty * LED_FULL / div;
  49         else
  50                 return 0;
  51 }
  52
  53 static void
  54 nouveau_led_set_brightness(struct led_classdev *led, enum led_brightness value)
  55 {
  56         struct drm_device *drm_dev = container_of(led, struct nouveau_led, led)->dev;
  57         struct nouveau_drm *drm = nouveau_drm(drm_dev);
  58         struct nvif_object *device = &drm->client.device.object;
  59
  60         u32 input_clk = 27e6; /* PDISPLAY.SOR[1].PWM is connected to the crystal */
  61         u32 freq = 100; /* this is what nvidia uses and it should be good-enough */
  62         u32 div, duty;
  63
  64         div = input_clk / freq;
  65         duty = value * div / LED_FULL;
  66
  67         /* for now, this is safe to directly poke those registers because:
  68          *  - A: nvidia never puts the logo led to any other PWM controler
  69          *       than PDISPLAY.SOR[1].PWM.
  70          *  - B: nouveau does not touch these registers anywhere else
  71          */
  72         nvif_wr32(device, 0x61c880, div);
  73         nvif_wr32(device, 0x61c884, 0xc0000000 | duty);
  74 }
  75
  76
  77 int
  78 nouveau_led_init(struct drm_device *dev)
  79 {
  80         struct nouveau_drm *drm = nouveau_drm(dev);
  81         struct nvkm_gpio *gpio = nvxx_gpio(&drm->client.device);
  82         struct dcb_gpio_func logo_led;
  83         int ret;
  84
  85         if (!gpio)
  86                 return 0;
  87
  88         /* check that there is a GPIO controlling the logo LED */
  89         if (nvkm_gpio_find(gpio, 0, DCB_GPIO_LOGO_LED_PWM, 0xff, &logo_led))
  90                 return 0;
  91
  92         drm->led = kzalloc(sizeof(*drm->led), GFP_KERNEL);
  93         if (!drm->led)
  94                 return -ENOMEM;
  95         drm->led->dev = dev;
  96
  97         drm->led->led.name = "nvidia-logo";
  98         drm->led->led.max_brightness = 255;
  99         drm->led->led.brightness_get = nouveau_led_get_brightness;
 100         drm->led->led.brightness_set = nouveau_led_set_brightness;
 101
 102         ret = led_classdev_register(dev->dev, &drm->led->led);
 103         if (ret) {
 104                 kfree(drm->led);
 105                 drm->led = NULL;
 106                 return ret;
 107         }
 108
 109         return 0;
 110 }
 111
 112 void
 113 nouveau_led_suspend(struct drm_device *dev)
 114 {
 115         struct nouveau_drm *drm = nouveau_drm(dev);
 116
 117         if (drm->led)
 118                 led_classdev_suspend(&drm->led->led);
 119 }
 120
 121 void
 122 nouveau_led_resume(struct drm_device *dev)
 123 {
 124         struct nouveau_drm *drm = nouveau_drm(dev);
 125
 126         if (drm->led)
 127                 led_classdev_resume(&drm->led->led);
 128 }
 129
 130 void
 131 nouveau_led_fini(struct drm_device *dev)
 132 {
 133         struct nouveau_drm *drm = nouveau_drm(dev);
 134
 135         if (drm->led) {
 136                 led_classdev_unregister(&drm->led->led);
 137                 kfree(drm->led);
 138                 drm->led = NULL;
 139         }
 140 }