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      1 /*	$NetBSD: nouveau_nvkm_subdev_i2c_pad.c,v 1.5 2021/12/18 23:45:40 riastradh Exp $	*/
      2 
      3 /*
      4  * Copyright 2015 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 <bskeggs (at) redhat.com>
     25  */
     26 #include <sys/cdefs.h>
     27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_i2c_pad.c,v 1.5 2021/12/18 23:45:40 riastradh Exp $");
     28 
     29 #include "pad.h"
     30 
     31 #include <linux/nbsd-namespace.h>
     32 
     33 static void
     34 nvkm_i2c_pad_mode_locked(struct nvkm_i2c_pad *pad, enum nvkm_i2c_pad_mode mode)
     35 {
     36 	PAD_TRACE(pad, "-> %s", (mode == NVKM_I2C_PAD_AUX) ? "aux" :
     37 			      (mode == NVKM_I2C_PAD_I2C) ? "i2c" : "off");
     38 	if (pad->func->mode)
     39 		pad->func->mode(pad, mode);
     40 }
     41 
     42 void
     43 nvkm_i2c_pad_mode(struct nvkm_i2c_pad *pad, enum nvkm_i2c_pad_mode mode)
     44 {
     45 	PAD_TRACE(pad, "mode %d", mode);
     46 	mutex_lock(&pad->mutex);
     47 	nvkm_i2c_pad_mode_locked(pad, mode);
     48 	pad->mode = mode;
     49 	mutex_unlock(&pad->mutex);
     50 }
     51 
     52 void
     53 nvkm_i2c_pad_release(struct nvkm_i2c_pad *pad)
     54 {
     55 	PAD_TRACE(pad, "release");
     56 	if (pad->mode == NVKM_I2C_PAD_OFF)
     57 		nvkm_i2c_pad_mode_locked(pad, pad->mode);
     58 	mutex_unlock(&pad->mutex);
     59 }
     60 
     61 int
     62 nvkm_i2c_pad_acquire(struct nvkm_i2c_pad *pad, enum nvkm_i2c_pad_mode mode)
     63 {
     64 	PAD_TRACE(pad, "acquire");
     65 	mutex_lock(&pad->mutex);
     66 	if (pad->mode != mode) {
     67 		if (pad->mode != NVKM_I2C_PAD_OFF) {
     68 			mutex_unlock(&pad->mutex);
     69 			return -EBUSY;
     70 		}
     71 		nvkm_i2c_pad_mode_locked(pad, mode);
     72 	}
     73 	return 0;
     74 }
     75 
     76 void
     77 nvkm_i2c_pad_fini(struct nvkm_i2c_pad *pad)
     78 {
     79 	PAD_TRACE(pad, "fini");
     80 	nvkm_i2c_pad_mode_locked(pad, NVKM_I2C_PAD_OFF);
     81 }
     82 
     83 void
     84 nvkm_i2c_pad_init(struct nvkm_i2c_pad *pad)
     85 {
     86 	PAD_TRACE(pad, "init");
     87 	nvkm_i2c_pad_mode_locked(pad, pad->mode);
     88 }
     89 
     90 void
     91 nvkm_i2c_pad_del(struct nvkm_i2c_pad **ppad)
     92 {
     93 	struct nvkm_i2c_pad *pad = *ppad;
     94 	if (pad) {
     95 		PAD_TRACE(pad, "dtor");
     96 		list_del(&pad->head);
     97 		mutex_destroy(&pad->mutex);
     98 		kfree(pad);
     99 		pad = NULL;
    100 	}
    101 }
    102 
    103 void
    104 nvkm_i2c_pad_ctor(const struct nvkm_i2c_pad_func *func, struct nvkm_i2c *i2c,
    105 		  int id, struct nvkm_i2c_pad *pad)
    106 {
    107 	pad->func = func;
    108 	pad->i2c = i2c;
    109 	pad->id = id;
    110 	pad->mode = NVKM_I2C_PAD_OFF;
    111 	mutex_init(&pad->mutex);
    112 	list_add_tail(&pad->head, &i2c->pad);
    113 	PAD_TRACE(pad, "ctor");
    114 }
    115 
    116 int
    117 nvkm_i2c_pad_new_(const struct nvkm_i2c_pad_func *func, struct nvkm_i2c *i2c,
    118 		  int id, struct nvkm_i2c_pad **ppad)
    119 {
    120 	if (!(*ppad = kzalloc(sizeof(**ppad), GFP_KERNEL)))
    121 		return -ENOMEM;
    122 	nvkm_i2c_pad_ctor(func, i2c, id, *ppad);
    123 	return 0;
    124 }
    125