drm/nouveau/nouveau_led.c

0001 /*
0002  * Copyright (C) 2016 Martin Peres
0003  *
0004  * Permission is hereby granted, free of charge, to any person obtaining
0005  * a copy of this software and associated documentation files (the
0006  * "Software"), to deal in the Software without restriction, including
0007  * without limitation the rights to use, copy, modify, merge, publish,
0008  * distribute, sublicense, and/or sell copies of the Software, and to
0009  * permit persons to whom the Software is furnished to do so, subject to
0010  * the following conditions:
0011  *
0012  * The above copyright notice and this permission notice (including the
0013  * next paragraph) shall be included in all copies or substantial
0014  * portions of the Software.
0015  *
0016  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
0017  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
0018  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
0019  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
0020  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
0021  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
0022  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
0023  *
0024  */
0025
0026 /*
0027  * Authors:
0028  *  Martin Peres <martin.peres@free.fr>
0029  */
0030
0031 #include <linux/leds.h>
0032
0033 #include "nouveau_led.h"
0034 #include <nvkm/subdev/gpio.h>
0035
0036 static enum led_brightness
0037 nouveau_led_get_brightness(struct led_classdev *led)
0038 {
0039     struct drm_device *drm_dev = container_of(led, struct nouveau_led, led)->dev;
0040     struct nouveau_drm *drm = nouveau_drm(drm_dev);
0041     struct nvif_object *device = &drm->client.device.object;
0042     u32 div, duty;
0043
0044     div =  nvif_rd32(device, 0x61c880) & 0x00ffffff;
0045     duty = nvif_rd32(device, 0x61c884) & 0x00ffffff;
0046
0047     if (div > 0)
0048         return duty * LED_FULL / div;
0049     else
0050         return 0;
0051 }
0052
0053 static void
0054 nouveau_led_set_brightness(struct led_classdev *led, enum led_brightness value)
0055 {
0056     struct drm_device *drm_dev = container_of(led, struct nouveau_led, led)->dev;
0057     struct nouveau_drm *drm = nouveau_drm(drm_dev);
0058     struct nvif_object *device = &drm->client.device.object;
0059
0060     u32 input_clk = 27e6; /* PDISPLAY.SOR[1].PWM is connected to the crystal */
0061     u32 freq = 100; /* this is what nvidia uses and it should be good-enough */
0062     u32 div, duty;
0063
0064     div = input_clk / freq;
0065     duty = value * div / LED_FULL;
0066
0067     /* for now, this is safe to directly poke those registers because:
0068      *  - A: nvidia never puts the logo led to any other PWM controler
0069      *       than PDISPLAY.SOR[1].PWM.
0070      *  - B: nouveau does not touch these registers anywhere else
0071      */
0072     nvif_wr32(device, 0x61c880, div);
0073     nvif_wr32(device, 0x61c884, 0xc0000000 | duty);
0074 }
0075
0076
0077 int
0078 nouveau_led_init(struct drm_device *dev)
0079 {
0080     struct nouveau_drm *drm = nouveau_drm(dev);
0081     struct nvkm_gpio *gpio = nvxx_gpio(&drm->client.device);
0082     struct dcb_gpio_func logo_led;
0083     int ret;
0084
0085     if (!gpio)
0086         return 0;
0087
0088     /* check that there is a GPIO controlling the logo LED */
0089     if (nvkm_gpio_find(gpio, 0, DCB_GPIO_LOGO_LED_PWM, 0xff, &logo_led))
0090         return 0;
0091
0092     drm->led = kzalloc(sizeof(*drm->led), GFP_KERNEL);
0093     if (!drm->led)
0094         return -ENOMEM;
0095     drm->led->dev = dev;
0096
0097     drm->led->led.name = "nvidia-logo";
0098     drm->led->led.max_brightness = 255;
0099     drm->led->led.brightness_get = nouveau_led_get_brightness;
0100     drm->led->led.brightness_set = nouveau_led_set_brightness;
0101
0102     ret = led_classdev_register(dev->dev, &drm->led->led);
0103     if (ret) {
0104         kfree(drm->led);
0105         drm->led = NULL;
0106         return ret;
0107     }
0108
0109     return 0;
0110 }
0111
0112 void
0113 nouveau_led_suspend(struct drm_device *dev)
0114 {
0115     struct nouveau_drm *drm = nouveau_drm(dev);
0116
0117     if (drm->led)
0118         led_classdev_suspend(&drm->led->led);
0119 }
0120
0121 void
0122 nouveau_led_resume(struct drm_device *dev)
0123 {
0124     struct nouveau_drm *drm = nouveau_drm(dev);
0125
0126     if (drm->led)
0127         led_classdev_resume(&drm->led->led);
0128 }
0129
0130 void
0131 nouveau_led_fini(struct drm_device *dev)
0132 {
0133     struct nouveau_drm *drm = nouveau_drm(dev);
0134
0135     if (drm->led) {
0136         led_classdev_unregister(&drm->led->led);
0137         kfree(drm->led);
0138         drm->led = NULL;
0139     }
0140 }