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_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 
90 fail_module_put:
91 	module_put(module);
92 fail_unregister:
93 	i2c_unregister_device(client);
94 	return err;
95 }
96 EXPORT_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  */
105 void 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 }
116 EXPORT_SYMBOL(drm_i2c_encoder_destroy);
117 
118 /*
119  * Wrapper fxns which can be plugged in to drm_encoder_helper_funcs:
120  */
121 
122 static inline const struct drm_encoder_slave_funcs *
123 get_slave_funcs(struct drm_encoder *enc)
124 {
125 	return to_encoder_slave(enc)->slave_funcs;
126 }
127 
128 void drm_i2c_encoder_dpms(struct drm_encoder *encoder, int mode)
129 {
130 	get_slave_funcs(encoder)->dpms(encoder, mode);
131 }
132 EXPORT_SYMBOL(drm_i2c_encoder_dpms);
133 
134 bool 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 }
143 EXPORT_SYMBOL(drm_i2c_encoder_mode_fixup);
144 
145 void drm_i2c_encoder_prepare(struct drm_encoder *encoder)
146 {
147 	drm_i2c_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
148 }
149 EXPORT_SYMBOL(drm_i2c_encoder_prepare);
150 
151 void drm_i2c_encoder_commit(struct drm_encoder *encoder)
152 {
153 	drm_i2c_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
154 }
155 EXPORT_SYMBOL(drm_i2c_encoder_commit);
156 
157 void 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 }
163 EXPORT_SYMBOL(drm_i2c_encoder_mode_set);
164 
165 enum 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 }
170 EXPORT_SYMBOL(drm_i2c_encoder_detect);
171 
172 void drm_i2c_encoder_save(struct drm_encoder *encoder)
173 {
174 	get_slave_funcs(encoder)->save(encoder);
175 }
176 EXPORT_SYMBOL(drm_i2c_encoder_save);
177 
178 void drm_i2c_encoder_restore(struct drm_encoder *encoder)
179 {
180 	get_slave_funcs(encoder)->restore(encoder);
181 }
182 EXPORT_SYMBOL(drm_i2c_encoder_restore);
183