drivers/gpu/drm/drm_encoder_slave.c

   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);