drm_encoder_slave.c

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/*
 * Copyright (C) 2009 Francisco Jerez.
 * All Rights Reserved.
 *
 * 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 (including the
 * next paragraph) 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 OWNER(S) AND/OR ITS SUPPLIERS 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.
 *
 */

#include <linux/module.h>

#include <drm/drm_encoder_slave.h>

int drm_i2c_encoder_init(struct drm_device *dev,
             struct drm_encoder_slave *encoder,
             struct i2c_adapter *adap,
             const struct i2c_board_info *info)
{
    char modalias[sizeof(I2C_MODULE_PREFIX)
              + I2C_NAME_SIZE];
    struct module *module = NULL;
    struct i2c_client *client;
    struct drm_i2c_encoder_driver *encoder_drv;
    int err = 0;

    snprintf(modalias, sizeof(modalias),
         "%s%s", I2C_MODULE_PREFIX, info->type);
    request_module(modalias);

    client = i2c_new_device(adap, info);
    if (!client) {
        err = -ENOMEM;
        goto fail;
    }

    if (!client->driver) {
        err = -ENODEV;
        goto fail_unregister;
    }

    module = client->driver->driver.owner;
    if (!try_module_get(module)) {
        err = -ENODEV;
        goto fail_unregister;
    }

    encoder->bus_priv = client;

    encoder_drv = to_drm_i2c_encoder_driver(client->driver);

    err = encoder_drv->encoder_init(client, dev, encoder);
    if (err)
        goto fail_unregister;

    if (info->platform_data)
        encoder->slave_funcs->set_config(&encoder->base,
                         info->platform_data);

    return 0;

fail_unregister:
    i2c_unregister_device(client);
    module_put(module);
fail:
    return err;
}
EXPORT_SYMBOL(drm_i2c_encoder_init);

void drm_i2c_encoder_destroy(struct drm_encoder *drm_encoder)
{
    struct drm_encoder_slave *encoder = to_encoder_slave(drm_encoder);
    struct i2c_client *client = drm_i2c_encoder_get_client(drm_encoder);
    struct module *module = client->driver->driver.owner;

    i2c_unregister_device(client);
    encoder->bus_priv = NULL;

    module_put(module);
}
EXPORT_SYMBOL(drm_i2c_encoder_destroy);