/*
 * 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_obj(**ppad)))
                return -ENOMEM;
        nvkm_i2c_pad_ctor(func, i2c, id, *ppad);
        return 0;
}