cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

gpio.c (2844B)

      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}