drivers/gpu/drm/nouveau/nvkm/subdev/volt/gpio.c

   1 /*
   2  * Copyright 2013 Red Hat Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * Authors: Ben Skeggs
  23  */
  24 #include <subdev/volt.h>
  25 #include <subdev/bios.h>
  26 #include <subdev/bios/gpio.h>
  27 #include <subdev/gpio.h>
  28 #include "priv.h"
  29
  30 static const u8 tags[] = {
  31         DCB_GPIO_VID0, DCB_GPIO_VID1, DCB_GPIO_VID2, DCB_GPIO_VID3,
  32         DCB_GPIO_VID4, DCB_GPIO_VID5, DCB_GPIO_VID6, DCB_GPIO_VID7,
  33 };
  34
  35 int
  36 nvkm_voltgpio_get(struct nvkm_volt *volt)
  37 {
  38         struct nvkm_gpio *gpio = volt->subdev.device->gpio;
  39         u8 vid = 0;
  40         int i;
  41
  42         for (i = 0; i < ARRAY_SIZE(tags); i++) {
  43                 if (volt->vid_mask & (1 << i)) {
  44                         int ret = nvkm_gpio_get(gpio, 0, tags[i], 0xff);
  45                         if (ret < 0)
  46                                 return ret;
  47                         vid |= ret << i;
  48                 }
  49         }
  50
  51         return vid;
  52 }
  53
  54 int
  55 nvkm_voltgpio_set(struct nvkm_volt *volt, u8 vid)
  56 {
  57         struct nvkm_gpio *gpio = volt->subdev.device->gpio;
  58         int i;
  59
  60         for (i = 0; i < ARRAY_SIZE(tags); i++, vid >>= 1) {
  61                 if (volt->vid_mask & (1 << i)) {
  62                         int ret = nvkm_gpio_set(gpio, 0, tags[i], 0xff, vid & 1);
  63                         if (ret < 0)
  64                                 return ret;
  65                 }
  66         }
  67
  68         return 0;
  69 }
  70
  71 int
  72 nvkm_voltgpio_init(struct nvkm_volt *volt)
  73 {
  74         struct nvkm_subdev *subdev = &volt->subdev;
  75         struct nvkm_gpio *gpio = subdev->device->gpio;
  76         struct dcb_gpio_func func;
  77         int i;
  78
  79         /* check we have gpio function info for each vid bit.  on some
  80          * boards (ie. nvs295) the vid mask has more bits than there
  81          * are valid gpio functions... from traces, nvidia appear to
  82          * just touch the existing ones, so let's mask off the invalid
  83          * bits and continue with life
  84          */
  85         for (i = 0; i < ARRAY_SIZE(tags); i++) {
  86                 if (volt->vid_mask & (1 << i)) {
  87                         int ret = nvkm_gpio_find(gpio, 0, tags[i], 0xff, &func);
  88                         if (ret) {
  89                                 if (ret != -ENOENT)
  90                                         return ret;
  91                                 nvkm_debug(subdev, "VID bit %d has no GPIO\n", i);
  92                                 volt->vid_mask &= ~(1 << i);
  93                         }
  94                 }
  95         }
  96
  97         return 0;
  98 }