1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief Inter-Integrated Circuit (I2C) Bus Implementation |
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5 | * |
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6 | * @ingroup I2CDevice |
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7 | */ |
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8 | |
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9 | /* |
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10 | * Copyright (c) 2014 embedded brains GmbH. All rights reserved. |
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11 | * |
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12 | * embedded brains GmbH |
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13 | * Dornierstr. 4 |
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14 | * 82178 Puchheim |
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15 | * Germany |
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16 | * <rtems@embedded-brains.de> |
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17 | * |
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18 | * The license and distribution terms for this file may be |
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19 | * found in the file LICENSE in this distribution or at |
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20 | * http://www.rtems.org/license/LICENSE. |
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21 | */ |
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22 | |
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23 | #if HAVE_CONFIG_H |
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24 | #include "config.h" |
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25 | #endif |
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26 | |
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27 | #include <dev/i2c/i2c.h> |
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28 | |
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29 | #include <rtems/imfs.h> |
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30 | #include <rtems/score/assert.h> |
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31 | |
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32 | #include <fcntl.h> |
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33 | #include <stdlib.h> |
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34 | #include <unistd.h> |
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35 | |
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36 | static ssize_t i2c_dev_read( |
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37 | rtems_libio_t *iop, |
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38 | void *buffer, |
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39 | size_t count |
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40 | ) |
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41 | { |
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42 | i2c_dev *dev = IMFS_generic_get_context_by_iop(iop); |
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43 | ssize_t n; |
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44 | |
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45 | n = (*dev->read)(dev, buffer, count, iop->offset); |
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46 | if (n > 0) { |
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47 | iop->offset += n; |
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48 | } |
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49 | |
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50 | return n; |
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51 | } |
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52 | |
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53 | static ssize_t i2c_dev_write( |
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54 | rtems_libio_t *iop, |
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55 | const void *buffer, |
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56 | size_t count |
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57 | ) |
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58 | { |
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59 | i2c_dev *dev = IMFS_generic_get_context_by_iop(iop); |
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60 | ssize_t n; |
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61 | |
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62 | n = (*dev->write)(dev, buffer, count, iop->offset); |
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63 | if (n > 0) { |
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64 | iop->offset += n; |
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65 | } |
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66 | |
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67 | return n; |
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68 | } |
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69 | |
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70 | static int i2c_dev_ioctl( |
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71 | rtems_libio_t *iop, |
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72 | ioctl_command_t command, |
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73 | void *arg |
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74 | ) |
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75 | { |
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76 | i2c_dev *dev = IMFS_generic_get_context_by_iop(iop); |
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77 | int err; |
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78 | |
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79 | err = (*dev->ioctl)(dev, command, arg); |
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80 | |
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81 | if (err == 0) { |
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82 | return 0; |
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83 | } else { |
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84 | rtems_set_errno_and_return_minus_one(-err); |
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85 | } |
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86 | } |
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87 | |
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88 | static int i2c_dev_fstat( |
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89 | const rtems_filesystem_location_info_t *loc, |
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90 | struct stat *buf |
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91 | ) |
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92 | { |
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93 | i2c_dev *dev = IMFS_generic_get_context_by_location(loc); |
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94 | |
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95 | buf->st_size = (*dev->get_size)(dev); |
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96 | buf->st_blksize = (*dev->get_block_size)(dev); |
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97 | |
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98 | return IMFS_stat(loc, buf); |
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99 | } |
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100 | |
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101 | static const rtems_filesystem_file_handlers_r i2c_dev_handler = { |
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102 | .open_h = rtems_filesystem_default_open, |
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103 | .close_h = rtems_filesystem_default_close, |
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104 | .read_h = i2c_dev_read, |
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105 | .write_h = i2c_dev_write, |
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106 | .ioctl_h = i2c_dev_ioctl, |
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107 | .lseek_h = rtems_filesystem_default_lseek_file, |
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108 | .fstat_h = i2c_dev_fstat, |
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109 | .ftruncate_h = rtems_filesystem_default_ftruncate, |
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110 | .fsync_h = rtems_filesystem_default_fsync_or_fdatasync, |
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111 | .fdatasync_h = rtems_filesystem_default_fsync_or_fdatasync, |
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112 | .fcntl_h = rtems_filesystem_default_fcntl, |
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113 | .kqfilter_h = rtems_filesystem_default_kqfilter, |
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114 | .poll_h = rtems_filesystem_default_poll, |
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115 | .readv_h = rtems_filesystem_default_readv, |
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116 | .writev_h = rtems_filesystem_default_writev |
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117 | }; |
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118 | |
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119 | static IMFS_jnode_t *i2c_dev_node_destroy(IMFS_jnode_t *node) |
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120 | { |
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121 | i2c_dev *dev; |
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122 | |
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123 | dev = IMFS_generic_get_context_by_node(node); |
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124 | (*dev->destroy)(dev); |
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125 | |
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126 | return node; |
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127 | } |
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128 | |
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129 | static const IMFS_node_control i2c_dev_node_control = { |
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130 | .imfs_type = IMFS_GENERIC, |
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131 | .handlers = &i2c_dev_handler, |
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132 | .node_initialize = IMFS_node_initialize_generic, |
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133 | .node_remove = IMFS_node_remove_default, |
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134 | .node_destroy = i2c_dev_node_destroy |
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135 | }; |
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136 | |
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137 | int i2c_dev_register( |
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138 | i2c_dev *dev, |
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139 | const char *dev_path |
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140 | ) |
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141 | { |
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142 | int rv; |
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143 | |
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144 | rv = IMFS_make_generic_node( |
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145 | dev_path, |
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146 | S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO, |
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147 | &i2c_dev_node_control, |
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148 | dev |
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149 | ); |
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150 | if (rv != 0) { |
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151 | (*dev->destroy)(dev); |
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152 | } |
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153 | |
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154 | return rv; |
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155 | } |
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156 | |
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157 | static ssize_t i2c_dev_read_default( |
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158 | i2c_dev *dev, |
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159 | void *buf, |
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160 | size_t n, |
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161 | off_t offset |
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162 | ) |
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163 | { |
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164 | (void) dev; |
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165 | (void) buf; |
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166 | (void) n; |
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167 | (void) offset; |
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168 | |
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169 | return -EIO; |
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170 | } |
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171 | |
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172 | static ssize_t i2c_dev_write_default( |
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173 | i2c_dev *dev, |
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174 | const void *buf, |
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175 | size_t n, |
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176 | off_t offset |
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177 | ) |
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178 | { |
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179 | (void) dev; |
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180 | (void) buf; |
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181 | (void) n; |
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182 | (void) offset; |
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183 | |
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184 | return -EIO; |
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185 | } |
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186 | |
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187 | static int i2c_dev_ioctl_default( |
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188 | i2c_dev *dev, |
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189 | ioctl_command_t command, |
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190 | void *arg |
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191 | ) |
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192 | { |
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193 | (void) dev; |
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194 | (void) command; |
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195 | (void) arg; |
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196 | |
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197 | return -ENOTTY; |
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198 | } |
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199 | |
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200 | static off_t i2c_dev_get_size_default(i2c_dev *dev) |
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201 | { |
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202 | (void) dev; |
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203 | |
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204 | return 0; |
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205 | } |
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206 | |
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207 | static blksize_t i2c_dev_get_block_size_default(i2c_dev *dev) |
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208 | { |
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209 | (void) dev; |
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210 | |
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211 | return 1; |
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212 | } |
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213 | |
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214 | static int i2c_dev_do_init( |
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215 | i2c_dev *dev, |
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216 | const char *bus_path, |
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217 | uint16_t address, |
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218 | void (*destroy)(i2c_dev *dev) |
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219 | ) |
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220 | { |
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221 | int fd; |
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222 | int rv; |
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223 | |
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224 | fd = open(bus_path, O_RDWR); |
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225 | if (fd < 0) { |
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226 | (*destroy)(dev); |
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227 | return -1; |
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228 | } |
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229 | |
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230 | rv = ioctl(fd, I2C_BUS_GET_CONTROL, &dev->bus); |
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231 | if (rv != 0) { |
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232 | (void) close(fd); |
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233 | (*destroy)(dev); |
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234 | return -1; |
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235 | } |
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236 | |
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237 | dev->read = i2c_dev_read_default; |
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238 | dev->write = i2c_dev_write_default; |
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239 | dev->ioctl = i2c_dev_ioctl_default; |
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240 | dev->get_size = i2c_dev_get_size_default; |
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241 | dev->get_block_size = i2c_dev_get_block_size_default; |
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242 | dev->destroy = destroy; |
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243 | dev->bus_fd = fd; |
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244 | dev->address = address; |
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245 | |
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246 | return 0; |
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247 | } |
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248 | |
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249 | void i2c_dev_destroy(i2c_dev *dev) |
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250 | { |
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251 | int rv; |
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252 | |
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253 | rv = close(dev->bus_fd); |
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254 | _Assert(rv == 0); |
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255 | (void) rv; |
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256 | } |
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257 | |
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258 | void i2c_dev_destroy_and_free(i2c_dev *dev) |
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259 | { |
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260 | i2c_dev_destroy(dev); |
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261 | free(dev); |
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262 | } |
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263 | |
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264 | int i2c_dev_init(i2c_dev *dev, const char *bus_path, uint16_t address) |
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265 | { |
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266 | return i2c_dev_do_init(dev, bus_path, address, i2c_dev_destroy); |
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267 | } |
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268 | |
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269 | i2c_dev *i2c_dev_alloc_and_init( |
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270 | size_t size, |
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271 | const char *bus_path, |
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272 | uint16_t address |
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273 | ) |
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274 | { |
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275 | i2c_dev *dev = NULL; |
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276 | |
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277 | if (size >= sizeof(*dev)) { |
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278 | dev = calloc(1, size); |
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279 | if (dev != NULL) { |
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280 | int rv; |
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281 | |
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282 | rv = i2c_dev_do_init(dev, bus_path, address, i2c_dev_destroy_and_free); |
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283 | if (rv != 0) { |
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284 | return NULL; |
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285 | } |
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286 | } |
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287 | } |
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288 | |
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289 | return dev; |
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290 | } |
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