117 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			117 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (C) 2009 Francisco Jerez.
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 * All Rights Reserved.
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 *
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 * Permission is hereby granted, free of charge, to any person obtaining
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 * a copy of this software and associated documentation files (the
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 * "Software"), to deal in the Software without restriction, including
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 * without limitation the rights to use, copy, modify, merge, publish,
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 * distribute, sublicense, and/or sell copies of the Software, and to
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 * permit persons to whom the Software is furnished to do so, subject to
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 * the following conditions:
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 *
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 * The above copyright notice and this permission notice (including the
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 * next paragraph) shall be included in all copies or substantial
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 * portions of the Software.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
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 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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 *
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 */
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#include "drm_encoder_slave.h"
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/**
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 * drm_i2c_encoder_init - Initialize an I2C slave encoder
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 * @dev:	DRM device.
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 * @encoder:    Encoder to be attached to the I2C device. You aren't
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 *		required to have called drm_encoder_init() before.
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 * @adap:	I2C adapter that will be used to communicate with
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 *		the device.
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 * @info:	Information that will be used to create the I2C device.
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 *		Required fields are @addr and @type.
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 *
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 * Create an I2C device on the specified bus (the module containing its
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 * driver is transparently loaded) and attach it to the specified
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 * &drm_encoder_slave. The @slave_funcs field will be initialized with
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 * the hooks provided by the slave driver.
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 *
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 * Returns 0 on success or a negative errno on failure, in particular,
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 * -ENODEV is returned when no matching driver is found.
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 */
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int drm_i2c_encoder_init(struct drm_device *dev,
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			 struct drm_encoder_slave *encoder,
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			 struct i2c_adapter *adap,
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			 const struct i2c_board_info *info)
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{
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	char modalias[sizeof(I2C_MODULE_PREFIX)
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		      + I2C_NAME_SIZE];
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	struct module *module = NULL;
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	struct i2c_client *client;
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	struct drm_i2c_encoder_driver *encoder_drv;
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	int err = 0;
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	snprintf(modalias, sizeof(modalias),
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		 "%s%s", I2C_MODULE_PREFIX, info->type);
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	request_module(modalias);
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	client = i2c_new_device(adap, info);
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	if (!client) {
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		err = -ENOMEM;
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		goto fail;
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	}
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	if (!client->driver) {
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		err = -ENODEV;
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		goto fail_unregister;
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	}
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	module = client->driver->driver.owner;
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	if (!try_module_get(module)) {
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		err = -ENODEV;
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		goto fail_unregister;
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	}
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	encoder->bus_priv = client;
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	encoder_drv = to_drm_i2c_encoder_driver(client->driver);
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	err = encoder_drv->encoder_init(client, dev, encoder);
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	if (err)
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		goto fail_unregister;
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	return 0;
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fail_unregister:
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	i2c_unregister_device(client);
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	module_put(module);
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fail:
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	return err;
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}
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EXPORT_SYMBOL(drm_i2c_encoder_init);
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/**
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 * drm_i2c_encoder_destroy - Unregister the I2C device backing an encoder
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 * @drm_encoder:	Encoder to be unregistered.
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 *
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 * This should be called from the @destroy method of an I2C slave
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 * encoder driver once I2C access is no longer needed.
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 */
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void drm_i2c_encoder_destroy(struct drm_encoder *drm_encoder)
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{
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	struct drm_encoder_slave *encoder = to_encoder_slave(drm_encoder);
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	struct i2c_client *client = drm_i2c_encoder_get_client(drm_encoder);
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	struct module *module = client->driver->driver.owner;
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	i2c_unregister_device(client);
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	encoder->bus_priv = NULL;
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	module_put(module);
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}
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EXPORT_SYMBOL(drm_i2c_encoder_destroy);
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