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 29 static const u8 tags[] = { 30 DCB_GPIO_VID0, DCB_GPIO_VID1, DCB_GPIO_VID2, DCB_GPIO_VID3, 31 DCB_GPIO_VID4, DCB_GPIO_VID5, DCB_GPIO_VID6, DCB_GPIO_VID7, 32 }; 33 34 int 35 nvkm_voltgpio_get(struct nvkm_volt *volt) 36 { 37 struct nvkm_gpio *gpio = volt->subdev.device->gpio; 38 u8 vid = 0; 39 int i; 40 41 for (i = 0; i < ARRAY_SIZE(tags); i++) { 42 if (volt->vid_mask & (1 << i)) { 43 int ret = nvkm_gpio_get(gpio, 0, tags[i], 0xff); 44 if (ret < 0) 45 return ret; 46 vid |= ret << i; 47 } 48 } 49 50 return vid; 51 } 52 53 int 54 nvkm_voltgpio_set(struct nvkm_volt *volt, u8 vid) 55 { 56 struct nvkm_gpio *gpio = volt->subdev.device->gpio; 57 int i; 58 59 for (i = 0; i < ARRAY_SIZE(tags); i++, vid >>= 1) { 60 if (volt->vid_mask & (1 << i)) { 61 int ret = nvkm_gpio_set(gpio, 0, tags[i], 0xff, vid & 1); 62 if (ret < 0) 63 return ret; 64 } 65 } 66 67 return 0; 68 } 69 70 int 71 nvkm_voltgpio_init(struct nvkm_volt *volt) 72 { 73 struct nvkm_subdev *subdev = &volt->subdev; 74 struct nvkm_gpio *gpio = subdev->device->gpio; 75 struct dcb_gpio_func func; 76 int i; 77 78 /* check we have gpio function info for each vid bit. on some 79 * boards (ie. nvs295) the vid mask has more bits than there 80 * are valid gpio functions... from traces, nvidia appear to 81 * just touch the existing ones, so let's mask off the invalid 82 * bits and continue with life 83 */ 84 for (i = 0; i < ARRAY_SIZE(tags); i++) { 85 if (volt->vid_mask & (1 << i)) { 86 int ret = nvkm_gpio_find(gpio, 0, tags[i], 0xff, &func); 87 if (ret) { 88 if (ret != -ENOENT) 89 return ret; 90 nvkm_debug(subdev, "VID bit %d has no GPIO\n", i); 91 volt->vid_mask &= ~(1 << i); 92 } 93 } 94 } 95 96 return 0; 97 } 98