1 | /** |
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2 | * \file : sdcard.c |
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3 | * \date : 30 August 2012 |
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4 | * \author : Cesar Fuguet |
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5 | * |
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6 | * This file defines the driver of a SD Card device using an SPI controller |
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7 | */ |
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8 | |
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9 | #include <sdcard.h> |
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10 | #include <reset_tty.h> |
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11 | |
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12 | /** |
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13 | * \param sdcard: Initialized pointer to the block device |
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14 | * |
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15 | * \return void |
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16 | * |
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17 | * \brief Enable SD Card select signal |
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18 | */ |
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19 | static void _sdcard_enable(struct sdcard_dev * sdcard) |
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20 | { |
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21 | spi_ss_assert(sdcard->spi, sdcard->slave_id); |
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22 | } |
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23 | |
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24 | /** |
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25 | * \param sdcard: Initialized pointer to the block device |
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26 | * |
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27 | * \return void |
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28 | * |
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29 | * \brief Disable SD Card select signal |
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30 | */ |
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31 | static void _sdcard_disable(struct sdcard_dev * sdcard) |
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32 | { |
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33 | spi_ss_deassert(sdcard->spi, sdcard->slave_id); |
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34 | } |
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35 | |
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36 | /** |
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37 | * \param tick_count: SD Card clock ticks number |
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38 | * |
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39 | * \return void |
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40 | * |
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41 | * \brief Enable SD Card clock |
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42 | * The tick count is byte measured (1 tick, 8 clock) |
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43 | */ |
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44 | static void _sdcard_gen_tick(struct sdcard_dev * sdcard, unsigned int tick_count) |
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45 | { |
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46 | register int i = 0; |
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47 | while(i++ < tick_count) spi_put_tx(sdcard->spi, 0xFF, 0); |
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48 | } |
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49 | |
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50 | /** |
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51 | * \param sdcard: Initialized pointer to the block device |
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52 | * |
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53 | * \return char from the SD card |
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54 | * |
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55 | * \brief Get a byte from the SD Card |
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56 | */ |
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57 | static unsigned char _sdcard_receive_char(struct sdcard_dev * sdcard) |
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58 | { |
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59 | _sdcard_gen_tick(sdcard, 1); |
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60 | |
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61 | return spi_get_rx(sdcard->spi, 0); |
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62 | } |
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63 | |
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64 | /** |
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65 | * \param sdcard: Initialized pointer to the block device |
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66 | * |
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67 | * \return sdcard response |
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68 | * |
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69 | * \brief Wait for a valid response after the send of a command |
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70 | * This function can return if one of the next two conditions are true: |
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71 | * 1. Bit valid received |
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72 | * 2. Timeout (not valid bit received after SDCARD_COMMAND_TIMEOUT |
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73 | * wait ticks) |
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74 | */ |
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75 | static unsigned char _sdcard_wait_response(struct sdcard_dev * sdcard) |
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76 | { |
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77 | unsigned char sdcard_rsp; |
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78 | register int iter; |
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79 | |
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80 | iter = 0; |
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81 | sdcard_rsp = _sdcard_receive_char(sdcard); |
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82 | while ( |
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83 | (iter < SDCARD_COMMAND_TIMEOUT) && |
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84 | !SDCARD_CHECK_R1_VALID(sdcard_rsp) |
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85 | ) |
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86 | { |
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87 | sdcard_rsp = _sdcard_receive_char(sdcard); |
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88 | iter++; |
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89 | } |
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90 | |
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91 | return sdcard_rsp; |
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92 | } |
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93 | |
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94 | /** |
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95 | * \params sdcard: Initialized pointer to the block device |
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96 | * |
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97 | * \return void |
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98 | * |
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99 | * \brief Wait data block start marker |
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100 | */ |
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101 | static void _sdcard_wait_data_block(struct sdcard_dev * sdcard) |
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102 | { |
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103 | while (_sdcard_receive_char(sdcard) != 0xFE); |
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104 | } |
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105 | |
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106 | /** |
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107 | * \param sdcard : Initialized pointer to block device |
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108 | * \param index : SD card CMD index |
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109 | * \param app : Type of command, 0 for normal command or 1 for application |
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110 | * specific |
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111 | * \param args : SD card CMD arguments |
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112 | * |
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113 | * \return response first byte |
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114 | * |
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115 | * \brief Send command to the SD card |
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116 | */ |
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117 | static int _sdcard_send_command ( |
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118 | struct sdcard_dev * sdcard , |
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119 | int index , |
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120 | int app , |
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121 | void * args , |
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122 | unsigned crc7 ) |
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123 | { |
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124 | unsigned char sdcard_rsp; |
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125 | unsigned char * _args; |
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126 | |
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127 | _sdcard_gen_tick(sdcard, 5); |
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128 | |
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129 | if (app == SDCARD_ACMD) |
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130 | { |
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131 | spi_put_tx(sdcard->spi, 0x40 | 55 , 0 );/* CMD and START bit */ |
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132 | spi_put_tx(sdcard->spi, 0x00 , 0 );/* Argument[0] */ |
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133 | spi_put_tx(sdcard->spi, 0x00 , 0 );/* Argument[1] */ |
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134 | spi_put_tx(sdcard->spi, 0x00 , 0 );/* Argument[2] */ |
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135 | spi_put_tx(sdcard->spi, 0x00 , 0 );/* Argument[3] */ |
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136 | spi_put_tx(sdcard->spi, 0x01 | (crc7 << 1), 0 );/* END bit */ |
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137 | |
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138 | sdcard_rsp = _sdcard_wait_response(sdcard); |
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139 | if (SDCARD_CHECK_R1_ERROR(sdcard_rsp)) |
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140 | { |
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141 | return sdcard_rsp; |
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142 | } |
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143 | } |
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144 | |
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145 | _args = (unsigned char *) args; |
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146 | |
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147 | _sdcard_gen_tick(sdcard, 1); |
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148 | |
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149 | spi_put_tx(sdcard->spi, 0x40 | index , 0 ); |
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150 | spi_put_tx(sdcard->spi, _args[0] , 0 ); |
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151 | spi_put_tx(sdcard->spi, _args[1] , 0 ); |
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152 | spi_put_tx(sdcard->spi, _args[2] , 0 ); |
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153 | spi_put_tx(sdcard->spi, _args[3] , 0 ); |
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154 | spi_put_tx(sdcard->spi, 0x01 | (crc7 << 1), 0 ); |
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155 | |
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156 | return _sdcard_wait_response(sdcard); |
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157 | } |
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158 | |
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159 | int sdcard_dev_open(struct sdcard_dev * sdcard, struct spi_dev * spi, int ss) |
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160 | { |
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161 | unsigned char args[4]; |
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162 | unsigned char sdcard_rsp; |
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163 | unsigned int iter, ersp; |
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164 | |
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165 | sdcard->spi = spi; |
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166 | sdcard->slave_id = ss; |
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167 | |
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168 | /* |
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169 | * Supply SD card ramp up time (min 74 cycles) |
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170 | */ |
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171 | _sdcard_gen_tick(sdcard, 10); |
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172 | |
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173 | /* |
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174 | * Assert slave select signal |
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175 | * Send CMD0 (Reset Command) |
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176 | * Deassert slave select signal |
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177 | */ |
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178 | _sdcard_enable(sdcard); |
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179 | |
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180 | args[0] = 0; |
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181 | args[1] = 0; |
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182 | args[2] = 0; |
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183 | args[3] = 0; |
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184 | sdcard_rsp = _sdcard_send_command(sdcard, 0, SDCARD_CMD, args, 0x4A); |
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185 | if ( sdcard_rsp != 0x01 ) |
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186 | { |
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187 | reset_puts("card CMD0 failed "); |
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188 | return sdcard_rsp; |
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189 | } |
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190 | |
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191 | _sdcard_disable(sdcard); |
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192 | /* |
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193 | * send CMD8. If card is pre-v2, It will reply with illegal command. |
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194 | * Otherwise we announce sdhc support. |
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195 | */ |
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196 | _sdcard_enable(sdcard); |
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197 | args[0] = 0; |
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198 | args[1] = 0; |
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199 | args[2] = 0x01; |
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200 | args[3] = 0x01; |
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201 | sdcard_rsp = _sdcard_send_command(sdcard, 8, SDCARD_CMD, args, 0x63); |
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202 | if (!SDCARD_CHECK_R1_VALID(sdcard_rsp)) { |
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203 | reset_puts("card CMD8 failed "); |
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204 | return sdcard_rsp; |
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205 | } |
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206 | if (!SDCARD_CHECK_R1_ERROR(sdcard_rsp)) { |
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207 | /* no error, command accepted. get whole reply */ |
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208 | ersp = _sdcard_receive_char(sdcard); |
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209 | ersp = (ersp << 8) | _sdcard_receive_char(sdcard); |
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210 | ersp = (ersp << 8) | _sdcard_receive_char(sdcard); |
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211 | ersp = (ersp << 8) | _sdcard_receive_char(sdcard); |
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212 | if ((ersp & 0xffff) != 0x0101) { |
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213 | /* voltage mismatch */ |
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214 | reset_puts("card CMD8 mismatch: "); |
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215 | reset_putx(ersp); |
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216 | return sdcard_rsp; |
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217 | } |
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218 | reset_puts("v2 or later "); |
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219 | sdcard->sdhc = 1; |
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220 | } else if ((sdcard_rsp & SDCARD_R1_ILLEGAL_CMD) == 0) { |
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221 | /* other error */ |
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222 | reset_puts("card CMD8 error "); |
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223 | return sdcard_rsp; |
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224 | } else { |
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225 | sdcard->sdhc = 0; |
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226 | } |
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227 | _sdcard_disable(sdcard); |
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228 | /* send CMD41, enabling the card */ |
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229 | _sdcard_enable(sdcard); |
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230 | args[0] = sdcard->sdhc ? 0x40: 0; |
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231 | args[1] = 0; |
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232 | args[2] = 0; |
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233 | args[3] = 0; |
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234 | |
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235 | iter = 0; |
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236 | while( iter++ < SDCARD_COMMAND_TIMEOUT ) |
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237 | { |
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238 | sdcard_rsp = _sdcard_send_command(sdcard, 41, SDCARD_ACMD, args, 0x00); |
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239 | if( sdcard_rsp == 0x01 ) |
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240 | { |
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241 | continue; |
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242 | } |
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243 | |
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244 | break; |
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245 | } |
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246 | |
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247 | _sdcard_disable(sdcard); |
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248 | if (sdcard_rsp) { |
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249 | reset_puts("SD ACMD41 failed "); |
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250 | return sdcard_rsp; |
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251 | } |
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252 | if (sdcard->sdhc != 0) { |
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253 | /* get the card capacity to see if it's really HC */ |
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254 | _sdcard_enable(sdcard); |
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255 | args[0] = sdcard->sdhc ? 0x40: 0; |
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256 | args[1] = 0; |
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257 | args[2] = 0; |
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258 | args[3] = 0; |
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259 | sdcard_rsp = _sdcard_send_command(sdcard, 58, SDCARD_CMD, |
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260 | args, 0x00); |
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261 | if (sdcard_rsp) { |
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262 | reset_puts("SD CMD58 failed "); |
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263 | return sdcard_rsp; |
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264 | } |
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265 | ersp = _sdcard_receive_char(sdcard); |
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266 | ersp = (ersp << 8) | _sdcard_receive_char(sdcard); |
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267 | ersp = (ersp << 8) | _sdcard_receive_char(sdcard); |
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268 | ersp = (ersp << 8) | _sdcard_receive_char(sdcard); |
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269 | if (ersp & 0x40000000) { |
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270 | reset_puts("SDHC "); |
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271 | } else { |
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272 | sdcard->sdhc = 0; |
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273 | } |
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274 | _sdcard_disable(sdcard); |
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275 | } |
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276 | reset_puts("card detected "); |
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277 | return 0; |
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278 | } |
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279 | |
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280 | int sdcard_dev_read(struct sdcard_dev * sdcard, void * buf, unsigned int count) |
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281 | { |
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282 | unsigned char args[4]; |
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283 | unsigned char sdcard_rsp; |
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284 | register int i; |
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285 | |
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286 | for (i = 0; i < 4; i++) |
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287 | { |
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288 | args[i] = (sdcard->access_pointer >> (32 - (i+1)*8)) & 0xFF; |
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289 | } |
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290 | |
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291 | _sdcard_enable(sdcard); |
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292 | |
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293 | sdcard_rsp = _sdcard_send_command(sdcard, 17, SDCARD_CMD, args, 0x00); |
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294 | if ( SDCARD_CHECK_R1_ERROR(sdcard_rsp) ) |
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295 | { |
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296 | _sdcard_disable(sdcard); |
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297 | return sdcard_rsp; |
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298 | } |
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299 | |
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300 | _sdcard_wait_data_block(sdcard); |
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301 | |
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302 | spi_get_data(sdcard->spi, buf, count); |
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303 | |
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304 | /* |
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305 | * Get the remainder of the block bytes and the CRC16 (comes |
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306 | * at the end of the data block) |
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307 | */ |
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308 | i = count; |
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309 | while( i++ < (512 + 2) ) _sdcard_receive_char(sdcard); |
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310 | |
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311 | _sdcard_disable(sdcard); |
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312 | |
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313 | /* |
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314 | * Move the access pointer to the next block |
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315 | */ |
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316 | sdcard->access_pointer += sdcard->block_length; |
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317 | |
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318 | return 0; |
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319 | } |
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320 | |
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321 | unsigned int sdcard_dev_write(struct sdcard_dev *sdcard, void * buf, unsigned int count) |
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322 | { |
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323 | return 0; |
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324 | } |
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325 | |
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326 | void sdcard_dev_lseek(struct sdcard_dev * sdcard, unsigned int blk_pos) |
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327 | { |
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328 | sdcard->access_pointer = sdcard->block_length * blk_pos; |
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329 | } |
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330 | |
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331 | int sdcard_dev_set_blocklen(struct sdcard_dev * sdcard, unsigned int len) |
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332 | { |
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333 | unsigned char args[4]; |
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334 | unsigned char sdcard_rsp; |
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335 | register int i; |
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336 | |
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337 | if (len != 512) |
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338 | return 1; |
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339 | |
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340 | if (sdcard->sdhc) { |
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341 | sdcard->block_length = 1; |
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342 | return 0; |
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343 | } |
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344 | |
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345 | for (i = 0; i < 4; i++) |
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346 | args[i] = (len >> (32 - (i+1)*8)) & 0xFF; |
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347 | |
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348 | _sdcard_enable(sdcard); |
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349 | |
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350 | sdcard_rsp = _sdcard_send_command(sdcard, 16, SDCARD_CMD, args, 0x00); |
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351 | if ( SDCARD_CHECK_R1_ERROR(sdcard_rsp) ) |
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352 | { |
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353 | _sdcard_disable(sdcard); |
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354 | return sdcard_rsp; |
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355 | } |
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356 | |
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357 | _sdcard_disable(sdcard); |
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358 | |
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359 | sdcard->block_length = len; |
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360 | |
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361 | return 0; |
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362 | } |
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363 | |
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364 | /* |
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365 | * vim: tabstop=4 : shiftwidth=4 : expandtab : softtabstop=4 |
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366 | */ |
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