1/*
2 * Copyright (C) 2009 Francisco Jerez.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the
14 * next paragraph) shall be included in all copies or substantial
15 * portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
21 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 *
25 */
26
27#include <linux/module.h>
28
29#include <drm/drm_encoder_slave.h>
30
31/**
32 * drm_i2c_encoder_init - Initialize an I2C slave encoder
33 * @dev:	DRM device.
34 * @encoder:    Encoder to be attached to the I2C device. You aren't
35 *		required to have called drm_encoder_init() before.
36 * @adap:	I2C adapter that will be used to communicate with
37 *		the device.
38 * @info:	Information that will be used to create the I2C device.
39 *		Required fields are @addr and @type.
40 *
41 * Create an I2C device on the specified bus (the module containing its
42 * driver is transparently loaded) and attach it to the specified
43 * &drm_encoder_slave. The @slave_funcs field will be initialized with
44 * the hooks provided by the slave driver.
45 *
46 * If @info.platform_data is non-NULL it will be used as the initial
47 * slave config.
48 *
49 * Returns 0 on success or a negative errno on failure, in particular,
50 * -ENODEV is returned when no matching driver is found.
51 */
52int drm_i2c_encoder_init(struct drm_device *dev,
53			 struct drm_encoder_slave *encoder,
54			 struct i2c_adapter *adap,
55			 const struct i2c_board_info *info)
56{
57	struct module *module = NULL;
58	struct i2c_client *client;
59	struct drm_i2c_encoder_driver *encoder_drv;
60	int err = 0;
61
62	request_module("%s%s", I2C_MODULE_PREFIX, info->type);
63
64	client = i2c_new_client_device(adap, info);
65	if (!i2c_client_has_driver(client)) {
66		err = -ENODEV;
67		goto fail_unregister;
68	}
69
70	module = client->dev.driver->owner;
71	if (!try_module_get(module)) {
72		err = -ENODEV;
73		goto fail_unregister;
74	}
75
76	encoder->bus_priv = client;
77
78	encoder_drv = to_drm_i2c_encoder_driver(to_i2c_driver(client->dev.driver));
79
80	err = encoder_drv->encoder_init(client, dev, encoder);
81	if (err)
82		goto fail_module_put;
83
84	if (info->platform_data)
85		encoder->slave_funcs->set_config(&encoder->base,
86						 info->platform_data);
87
88	return 0;
89
90fail_module_put:
91	module_put(module);
92fail_unregister:
93	i2c_unregister_device(client);
94	return err;
95}
96EXPORT_SYMBOL(drm_i2c_encoder_init);
97
98/**
99 * drm_i2c_encoder_destroy - Unregister the I2C device backing an encoder
100 * @drm_encoder:	Encoder to be unregistered.
101 *
102 * This should be called from the @destroy method of an I2C slave
103 * encoder driver once I2C access is no longer needed.
104 */
105void drm_i2c_encoder_destroy(struct drm_encoder *drm_encoder)
106{
107	struct drm_encoder_slave *encoder = to_encoder_slave(drm_encoder);
108	struct i2c_client *client = drm_i2c_encoder_get_client(drm_encoder);
109	struct module *module = client->dev.driver->owner;
110
111	i2c_unregister_device(client);
112	encoder->bus_priv = NULL;
113
114	module_put(module);
115}
116EXPORT_SYMBOL(drm_i2c_encoder_destroy);
117
118/*
119 * Wrapper fxns which can be plugged in to drm_encoder_helper_funcs:
120 */
121
122static inline const struct drm_encoder_slave_funcs *
123get_slave_funcs(struct drm_encoder *enc)
124{
125	return to_encoder_slave(enc)->slave_funcs;
126}
127
128void drm_i2c_encoder_dpms(struct drm_encoder *encoder, int mode)
129{
130	get_slave_funcs(encoder)->dpms(encoder, mode);
131}
132EXPORT_SYMBOL(drm_i2c_encoder_dpms);
133
134bool drm_i2c_encoder_mode_fixup(struct drm_encoder *encoder,
135		const struct drm_display_mode *mode,
136		struct drm_display_mode *adjusted_mode)
137{
138	if (!get_slave_funcs(encoder)->mode_fixup)
139		return true;
140
141	return get_slave_funcs(encoder)->mode_fixup(encoder, mode, adjusted_mode);
142}
143EXPORT_SYMBOL(drm_i2c_encoder_mode_fixup);
144
145void drm_i2c_encoder_prepare(struct drm_encoder *encoder)
146{
147	drm_i2c_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
148}
149EXPORT_SYMBOL(drm_i2c_encoder_prepare);
150
151void drm_i2c_encoder_commit(struct drm_encoder *encoder)
152{
153	drm_i2c_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
154}
155EXPORT_SYMBOL(drm_i2c_encoder_commit);
156
157void drm_i2c_encoder_mode_set(struct drm_encoder *encoder,
158		struct drm_display_mode *mode,
159		struct drm_display_mode *adjusted_mode)
160{
161	get_slave_funcs(encoder)->mode_set(encoder, mode, adjusted_mode);
162}
163EXPORT_SYMBOL(drm_i2c_encoder_mode_set);
164
165enum drm_connector_status drm_i2c_encoder_detect(struct drm_encoder *encoder,
166	    struct drm_connector *connector)
167{
168	return get_slave_funcs(encoder)->detect(encoder, connector);
169}
170EXPORT_SYMBOL(drm_i2c_encoder_detect);
171
172void drm_i2c_encoder_save(struct drm_encoder *encoder)
173{
174	get_slave_funcs(encoder)->save(encoder);
175}
176EXPORT_SYMBOL(drm_i2c_encoder_save);
177
178void drm_i2c_encoder_restore(struct drm_encoder *encoder)
179{
180	get_slave_funcs(encoder)->restore(encoder);
181}
182EXPORT_SYMBOL(drm_i2c_encoder_restore);
183