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  */
52 int 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_device(adap, info);
65 	if (!client) {
66 		err = -ENOMEM;
67 		goto fail;
68 	}
69 
70 	if (!client->dev.driver) {
71 		err = -ENODEV;
72 		goto fail_unregister;
73 	}
74 
75 	module = client->dev.driver->owner;
76 	if (!try_module_get(module)) {
77 		err = -ENODEV;
78 		goto fail_unregister;
79 	}
80 
81 	encoder->bus_priv = client;
82 
83 	encoder_drv = to_drm_i2c_encoder_driver(to_i2c_driver(client->dev.driver));
84 
85 	err = encoder_drv->encoder_init(client, dev, encoder);
86 	if (err)
87 		goto fail_unregister;
88 
89 	if (info->platform_data)
90 		encoder->slave_funcs->set_config(&encoder->base,
91 						 info->platform_data);
92 
93 	return 0;
94 
95 fail_unregister:
96 	i2c_unregister_device(client);
97 	module_put(module);
98 fail:
99 	return err;
100 }
101 EXPORT_SYMBOL(drm_i2c_encoder_init);
102 
103 /**
104  * drm_i2c_encoder_destroy - Unregister the I2C device backing an encoder
105  * @drm_encoder:	Encoder to be unregistered.
106  *
107  * This should be called from the @destroy method of an I2C slave
108  * encoder driver once I2C access is no longer needed.
109  */
110 void drm_i2c_encoder_destroy(struct drm_encoder *drm_encoder)
111 {
112 	struct drm_encoder_slave *encoder = to_encoder_slave(drm_encoder);
113 	struct i2c_client *client = drm_i2c_encoder_get_client(drm_encoder);
114 	struct module *module = client->dev.driver->owner;
115 
116 	i2c_unregister_device(client);
117 	encoder->bus_priv = NULL;
118 
119 	module_put(module);
120 }
121 EXPORT_SYMBOL(drm_i2c_encoder_destroy);
122 
123 /*
124  * Wrapper fxns which can be plugged in to drm_encoder_helper_funcs:
125  */
126 
127 static inline struct drm_encoder_slave_funcs *
128 get_slave_funcs(struct drm_encoder *enc)
129 {
130 	return to_encoder_slave(enc)->slave_funcs;
131 }
132 
133 void drm_i2c_encoder_dpms(struct drm_encoder *encoder, int mode)
134 {
135 	get_slave_funcs(encoder)->dpms(encoder, mode);
136 }
137 EXPORT_SYMBOL(drm_i2c_encoder_dpms);
138 
139 bool drm_i2c_encoder_mode_fixup(struct drm_encoder *encoder,
140 		const struct drm_display_mode *mode,
141 		struct drm_display_mode *adjusted_mode)
142 {
143 	return get_slave_funcs(encoder)->mode_fixup(encoder, mode, adjusted_mode);
144 }
145 EXPORT_SYMBOL(drm_i2c_encoder_mode_fixup);
146 
147 void drm_i2c_encoder_prepare(struct drm_encoder *encoder)
148 {
149 	drm_i2c_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
150 }
151 EXPORT_SYMBOL(drm_i2c_encoder_prepare);
152 
153 void drm_i2c_encoder_commit(struct drm_encoder *encoder)
154 {
155 	drm_i2c_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
156 }
157 EXPORT_SYMBOL(drm_i2c_encoder_commit);
158 
159 void drm_i2c_encoder_mode_set(struct drm_encoder *encoder,
160 		struct drm_display_mode *mode,
161 		struct drm_display_mode *adjusted_mode)
162 {
163 	get_slave_funcs(encoder)->mode_set(encoder, mode, adjusted_mode);
164 }
165 EXPORT_SYMBOL(drm_i2c_encoder_mode_set);
166 
167 enum drm_connector_status drm_i2c_encoder_detect(struct drm_encoder *encoder,
168 	    struct drm_connector *connector)
169 {
170 	return get_slave_funcs(encoder)->detect(encoder, connector);
171 }
172 EXPORT_SYMBOL(drm_i2c_encoder_detect);
173 
174 void drm_i2c_encoder_save(struct drm_encoder *encoder)
175 {
176 	get_slave_funcs(encoder)->save(encoder);
177 }
178 EXPORT_SYMBOL(drm_i2c_encoder_save);
179 
180 void drm_i2c_encoder_restore(struct drm_encoder *encoder)
181 {
182 	get_slave_funcs(encoder)->restore(encoder);
183 }
184 EXPORT_SYMBOL(drm_i2c_encoder_restore);
185