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 <dispnv04/i2c/encoder_i2c.h>
30 
31 /**
32  * nouveau_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  * &nouveau_i2c_encoder. The @encoder_i2c_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  */
nouveau_i2c_encoder_init(struct drm_device * dev,struct nouveau_i2c_encoder * encoder,struct i2c_adapter * adap,const struct i2c_board_info * info)52 int nouveau_i2c_encoder_init(struct drm_device *dev,
53 			     struct nouveau_i2c_encoder *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 nouveau_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->i2c_client = client;
77 
78 	encoder_drv = to_nouveau_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->encoder_i2c_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 
97 /**
98  * nouveau_i2c_encoder_destroy - Unregister the I2C device backing an encoder
99  * @drm_encoder:	Encoder to be unregistered.
100  *
101  * This should be called from the @destroy method of an I2C slave
102  * encoder driver once I2C access is no longer needed.
103  */
nouveau_i2c_encoder_destroy(struct drm_encoder * drm_encoder)104 void nouveau_i2c_encoder_destroy(struct drm_encoder *drm_encoder)
105 {
106 	struct nouveau_i2c_encoder *encoder = to_encoder_i2c(drm_encoder);
107 	struct i2c_client *client = nouveau_i2c_encoder_get_client(drm_encoder);
108 	struct module *module = client->dev.driver->owner;
109 
110 	i2c_unregister_device(client);
111 	encoder->i2c_client = NULL;
112 
113 	module_put(module);
114 }
115 EXPORT_SYMBOL(nouveau_i2c_encoder_destroy);
116 
117 /*
118  * Wrapper fxns which can be plugged in to drm_encoder_helper_funcs:
119  */
120 
nouveau_i2c_encoder_mode_fixup(struct drm_encoder * encoder,const struct drm_display_mode * mode,struct drm_display_mode * adjusted_mode)121 bool nouveau_i2c_encoder_mode_fixup(struct drm_encoder *encoder,
122 				    const struct drm_display_mode *mode,
123 				    struct drm_display_mode *adjusted_mode)
124 {
125 	if (!get_encoder_i2c_funcs(encoder)->mode_fixup)
126 		return true;
127 
128 	return get_encoder_i2c_funcs(encoder)->mode_fixup(encoder, mode, adjusted_mode);
129 }
130 
nouveau_i2c_encoder_detect(struct drm_encoder * encoder,struct drm_connector * connector)131 enum drm_connector_status nouveau_i2c_encoder_detect(struct drm_encoder *encoder,
132 						     struct drm_connector *connector)
133 {
134 	return get_encoder_i2c_funcs(encoder)->detect(encoder, connector);
135 }
136 
nouveau_i2c_encoder_save(struct drm_encoder * encoder)137 void nouveau_i2c_encoder_save(struct drm_encoder *encoder)
138 {
139 	get_encoder_i2c_funcs(encoder)->save(encoder);
140 }
141 
nouveau_i2c_encoder_restore(struct drm_encoder * encoder)142 void nouveau_i2c_encoder_restore(struct drm_encoder *encoder)
143 {
144 	get_encoder_i2c_funcs(encoder)->restore(encoder);
145 }
146