linux-zen-server/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/pad.c

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2023-08-30 17:53:23 +02:00
/*
* Copyright 2015 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors: Ben Skeggs <bskeggs@redhat.com>
*/
#include "pad.h"
static void
nvkm_i2c_pad_mode_locked(struct nvkm_i2c_pad *pad, enum nvkm_i2c_pad_mode mode)
{
PAD_TRACE(pad, "-> %s", (mode == NVKM_I2C_PAD_AUX) ? "aux" :
(mode == NVKM_I2C_PAD_I2C) ? "i2c" : "off");
if (pad->func->mode)
pad->func->mode(pad, mode);
}
void
nvkm_i2c_pad_mode(struct nvkm_i2c_pad *pad, enum nvkm_i2c_pad_mode mode)
{
PAD_TRACE(pad, "mode %d", mode);
mutex_lock(&pad->mutex);
nvkm_i2c_pad_mode_locked(pad, mode);
pad->mode = mode;
mutex_unlock(&pad->mutex);
}
void
nvkm_i2c_pad_release(struct nvkm_i2c_pad *pad)
{
PAD_TRACE(pad, "release");
if (pad->mode == NVKM_I2C_PAD_OFF)
nvkm_i2c_pad_mode_locked(pad, pad->mode);
mutex_unlock(&pad->mutex);
}
int
nvkm_i2c_pad_acquire(struct nvkm_i2c_pad *pad, enum nvkm_i2c_pad_mode mode)
{
PAD_TRACE(pad, "acquire");
mutex_lock(&pad->mutex);
if (pad->mode != mode) {
if (pad->mode != NVKM_I2C_PAD_OFF) {
mutex_unlock(&pad->mutex);
return -EBUSY;
}
nvkm_i2c_pad_mode_locked(pad, mode);
}
return 0;
}
void
nvkm_i2c_pad_fini(struct nvkm_i2c_pad *pad)
{
PAD_TRACE(pad, "fini");
nvkm_i2c_pad_mode_locked(pad, NVKM_I2C_PAD_OFF);
}
void
nvkm_i2c_pad_init(struct nvkm_i2c_pad *pad)
{
PAD_TRACE(pad, "init");
nvkm_i2c_pad_mode_locked(pad, pad->mode);
}
void
nvkm_i2c_pad_del(struct nvkm_i2c_pad **ppad)
{
struct nvkm_i2c_pad *pad = *ppad;
if (pad) {
PAD_TRACE(pad, "dtor");
list_del(&pad->head);
kfree(pad);
pad = NULL;
}
}
void
nvkm_i2c_pad_ctor(const struct nvkm_i2c_pad_func *func, struct nvkm_i2c *i2c,
int id, struct nvkm_i2c_pad *pad)
{
pad->func = func;
pad->i2c = i2c;
pad->id = id;
pad->mode = NVKM_I2C_PAD_OFF;
mutex_init(&pad->mutex);
list_add_tail(&pad->head, &i2c->pad);
PAD_TRACE(pad, "ctor");
}
int
nvkm_i2c_pad_new_(const struct nvkm_i2c_pad_func *func, struct nvkm_i2c *i2c,
int id, struct nvkm_i2c_pad **ppad)
{
if (!(*ppad = kzalloc(sizeof(**ppad), GFP_KERNEL)))
return -ENOMEM;
nvkm_i2c_pad_ctor(func, i2c, id, *ppad);
return 0;
}