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      1 /*	$NetBSD: nouveau_nvkm_subdev_volt_gpio.c,v 1.4 2021/12/18 23:45:42 riastradh Exp $	*/
      2 
      3 /*
      4  * Copyright 2013 Red Hat Inc.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the "Software"),
      8  * to deal in the Software without restriction, including without limitation
      9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     10  * and/or sell copies of the Software, and to permit persons to whom the
     11  * Software is furnished to do so, subject to the following conditions:
     12  *
     13  * The above copyright notice and this permission notice shall be included in
     14  * all copies or substantial portions of the Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
     20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     22  * OTHER DEALINGS IN THE SOFTWARE.
     23  *
     24  * Authors: Ben Skeggs
     25  */
     26 #include <sys/cdefs.h>
     27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_volt_gpio.c,v 1.4 2021/12/18 23:45:42 riastradh Exp $");
     28 
     29 #include <subdev/volt.h>
     30 #include <subdev/bios.h>
     31 #include <subdev/bios/gpio.h>
     32 #include <subdev/gpio.h>
     33 #include "priv.h"
     34 
     35 #include "priv.h"
     36 
     37 static const u8 tags[] = {
     38 	DCB_GPIO_VID0, DCB_GPIO_VID1, DCB_GPIO_VID2, DCB_GPIO_VID3,
     39 	DCB_GPIO_VID4, DCB_GPIO_VID5, DCB_GPIO_VID6, DCB_GPIO_VID7,
     40 };
     41 
     42 int
     43 nvkm_voltgpio_get(struct nvkm_volt *volt)
     44 {
     45 	struct nvkm_gpio *gpio = volt->subdev.device->gpio;
     46 	u8 vid = 0;
     47 	int i;
     48 
     49 	for (i = 0; i < ARRAY_SIZE(tags); i++) {
     50 		if (volt->vid_mask & (1 << i)) {
     51 			int ret = nvkm_gpio_get(gpio, 0, tags[i], 0xff);
     52 			if (ret < 0)
     53 				return ret;
     54 			vid |= ret << i;
     55 		}
     56 	}
     57 
     58 	return vid;
     59 }
     60 
     61 int
     62 nvkm_voltgpio_set(struct nvkm_volt *volt, u8 vid)
     63 {
     64 	struct nvkm_gpio *gpio = volt->subdev.device->gpio;
     65 	int i;
     66 
     67 	for (i = 0; i < ARRAY_SIZE(tags); i++, vid >>= 1) {
     68 		if (volt->vid_mask & (1 << i)) {
     69 			int ret = nvkm_gpio_set(gpio, 0, tags[i], 0xff, vid & 1);
     70 			if (ret < 0)
     71 				return ret;
     72 		}
     73 	}
     74 
     75 	return 0;
     76 }
     77 
     78 int
     79 nvkm_voltgpio_init(struct nvkm_volt *volt)
     80 {
     81 	struct nvkm_subdev *subdev = &volt->subdev;
     82 	struct nvkm_gpio *gpio = subdev->device->gpio;
     83 	struct dcb_gpio_func func;
     84 	int i;
     85 
     86 	/* check we have gpio function info for each vid bit.  on some
     87 	 * boards (ie. nvs295) the vid mask has more bits than there
     88 	 * are valid gpio functions... from traces, nvidia appear to
     89 	 * just touch the existing ones, so let's mask off the invalid
     90 	 * bits and continue with life
     91 	 */
     92 	for (i = 0; i < ARRAY_SIZE(tags); i++) {
     93 		if (volt->vid_mask & (1 << i)) {
     94 			int ret = nvkm_gpio_find(gpio, 0, tags[i], 0xff, &func);
     95 			if (ret) {
     96 				if (ret != -ENOENT)
     97 					return ret;
     98 				nvkm_debug(subdev, "VID bit %d has no GPIO\n", i);
     99 				volt->vid_mask &= ~(1 << i);
    100 			}
    101 		}
    102 	}
    103 
    104 	return 0;
    105 }
    106