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 } 99