LXR linux/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
  30static 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
  35int
  36nvkm_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
  54int
  55nvkm_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
  71int
  72nvkm_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}
  99