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Rev | Author | Line No. | Line |
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1125 | serge | 1 | /* ------------------------------------------------------------------------- |
2 | * i2c-algo-bit.c i2c driver algorithms for bit-shift adapters |
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3 | * ------------------------------------------------------------------------- |
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4 | * Copyright (C) 1995-2000 Simon G. Vogl |
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5 | |||
6 | This program is free software; you can redistribute it and/or modify |
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7 | it under the terms of the GNU General Public License as published by |
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8 | the Free Software Foundation; either version 2 of the License, or |
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9 | (at your option) any later version. |
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10 | |||
11 | This program is distributed in the hope that it will be useful, |
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12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | GNU General Public License for more details. |
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15 | |||
16 | You should have received a copy of the GNU General Public License |
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17 | along with this program; if not, write to the Free Software |
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18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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19 | * ------------------------------------------------------------------------- */ |
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20 | |||
21 | /* With some changes from Frodo Looijaard |
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22 |
|
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23 | |||
24 | #include |
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25 | #include |
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1403 | serge | 26 | #include |
1125 | serge | 27 | #include |
28 | #include |
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29 | #include |
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30 | #include |
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31 | |||
32 | |||
33 | /* ----- global defines ----------------------------------------------- */ |
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34 | |||
35 | #ifdef DEBUG |
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36 | #define bit_dbg(level, dev, format, args...) \ |
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37 | do { \ |
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38 | if (i2c_debug >= level) \ |
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39 | dev_dbg(dev, format, ##args); \ |
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40 | } while (0) |
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41 | #else |
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42 | #define bit_dbg(level, dev, format, args...) \ |
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43 | do {} while (0) |
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44 | #endif /* DEBUG */ |
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45 | |||
46 | /* ----- global variables --------------------------------------------- */ |
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47 | |||
48 | static int bit_test; /* see if the line-setting functions work */ |
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49 | |||
50 | |||
51 | /* --- setting states on the bus with the right timing: --------------- */ |
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52 | |||
53 | #define setsda(adap, val) adap->setsda(adap->data, val) |
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54 | #define setscl(adap, val) adap->setscl(adap->data, val) |
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55 | #define getsda(adap) adap->getsda(adap->data) |
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56 | #define getscl(adap) adap->getscl(adap->data) |
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57 | |||
58 | static inline void sdalo(struct i2c_algo_bit_data *adap) |
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59 | { |
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60 | setsda(adap, 0); |
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61 | udelay((adap->udelay + 1) / 2); |
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62 | } |
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63 | |||
64 | static inline void sdahi(struct i2c_algo_bit_data *adap) |
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65 | { |
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66 | setsda(adap, 1); |
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67 | udelay((adap->udelay + 1) / 2); |
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68 | } |
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69 | |||
70 | static inline void scllo(struct i2c_algo_bit_data *adap) |
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71 | { |
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72 | setscl(adap, 0); |
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73 | udelay(adap->udelay / 2); |
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74 | } |
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75 | |||
76 | /* |
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77 | * Raise scl line, and do checking for delays. This is necessary for slower |
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78 | * devices. |
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79 | */ |
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80 | static int sclhi(struct i2c_algo_bit_data *adap) |
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81 | { |
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82 | unsigned long start; |
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83 | |||
84 | setscl(adap, 1); |
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85 | |||
86 | /* Not all adapters have scl sense line... */ |
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87 | if (!adap->getscl) |
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88 | goto done; |
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89 | |||
90 | // start = jiffies; |
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91 | while (!getscl(adap)) { |
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92 | /* This hw knows how to read the clock line, so we wait |
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93 | * until it actually gets high. This is safer as some |
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94 | * chips may hold it low ("clock stretching") while they |
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95 | * are processing data internally. |
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96 | */ |
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97 | // if (time_after(jiffies, start + adap->timeout)) |
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98 | // return -ETIMEDOUT; |
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99 | |||
100 | udelay(adap->udelay); |
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101 | |||
102 | // cond_resched(); |
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103 | } |
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104 | #ifdef DEBUG |
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105 | if (jiffies != start && i2c_debug >= 3) |
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106 | pr_debug("i2c-algo-bit: needed %ld jiffies for SCL to go " |
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107 | "high\n", jiffies - start); |
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108 | #endif |
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109 | |||
110 | done: |
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111 | udelay(adap->udelay); |
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112 | return 0; |
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113 | } |
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114 | |||
115 | |||
116 | /* --- other auxiliary functions -------------------------------------- */ |
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117 | static void i2c_start(struct i2c_algo_bit_data *adap) |
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118 | { |
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119 | /* assert: scl, sda are high */ |
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120 | setsda(adap, 0); |
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121 | udelay(adap->udelay); |
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122 | scllo(adap); |
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123 | } |
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124 | |||
125 | static void i2c_repstart(struct i2c_algo_bit_data *adap) |
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126 | { |
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127 | /* assert: scl is low */ |
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128 | sdahi(adap); |
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129 | sclhi(adap); |
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130 | setsda(adap, 0); |
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131 | udelay(adap->udelay); |
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132 | scllo(adap); |
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133 | } |
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134 | |||
135 | |||
136 | static void i2c_stop(struct i2c_algo_bit_data *adap) |
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137 | { |
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138 | /* assert: scl is low */ |
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139 | sdalo(adap); |
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140 | sclhi(adap); |
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141 | setsda(adap, 1); |
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142 | udelay(adap->udelay); |
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143 | } |
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144 | |||
145 | |||
146 | |||
147 | /* send a byte without start cond., look for arbitration, |
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148 | check ackn. from slave */ |
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149 | /* returns: |
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150 | * 1 if the device acknowledged |
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151 | * 0 if the device did not ack |
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152 | * -ETIMEDOUT if an error occurred (while raising the scl line) |
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153 | */ |
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154 | static int i2c_outb(struct i2c_adapter *i2c_adap, unsigned char c) |
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155 | { |
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156 | int i; |
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157 | int sb; |
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158 | int ack; |
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159 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
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160 | |||
161 | /* assert: scl is low */ |
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162 | for (i = 7; i >= 0; i--) { |
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163 | sb = (c >> i) & 1; |
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164 | setsda(adap, sb); |
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165 | udelay((adap->udelay + 1) / 2); |
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166 | if (sclhi(adap) < 0) { /* timed out */ |
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1963 | serge | 167 | bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " |
168 | "timeout at bit #%d\n", (int)c, i); |
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1125 | serge | 169 | return -ETIMEDOUT; |
170 | } |
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171 | /* FIXME do arbitration here: |
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172 | * if (sb && !getsda(adap)) -> ouch! Get out of here. |
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173 | * |
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174 | * Report a unique code, so higher level code can retry |
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175 | * the whole (combined) message and *NOT* issue STOP. |
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176 | */ |
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177 | scllo(adap); |
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178 | } |
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179 | sdahi(adap); |
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180 | if (sclhi(adap) < 0) { /* timeout */ |
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1963 | serge | 181 | bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " |
182 | "timeout at ack\n", (int)c); |
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1125 | serge | 183 | return -ETIMEDOUT; |
184 | } |
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185 | |||
186 | /* read ack: SDA should be pulled down by slave, or it may |
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187 | * NAK (usually to report problems with the data we wrote). |
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188 | */ |
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189 | ack = !getsda(adap); /* ack: sda is pulled low -> success */ |
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1963 | serge | 190 | bit_dbg(2, &i2c_adap->dev, "i2c_outb: 0x%02x %s\n", (int)c, |
191 | ack ? "A" : "NA"); |
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1125 | serge | 192 | |
193 | scllo(adap); |
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194 | return ack; |
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195 | /* assert: scl is low (sda undef) */ |
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196 | } |
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197 | |||
198 | |||
199 | static int i2c_inb(struct i2c_adapter *i2c_adap) |
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200 | { |
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201 | /* read byte via i2c port, without start/stop sequence */ |
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202 | /* acknowledge is sent in i2c_read. */ |
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203 | int i; |
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204 | unsigned char indata = 0; |
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205 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
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206 | |||
207 | /* assert: scl is low */ |
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208 | sdahi(adap); |
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209 | for (i = 0; i < 8; i++) { |
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210 | if (sclhi(adap) < 0) { /* timeout */ |
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211 | bit_dbg(1, &i2c_adap->dev, "i2c_inb: timeout at bit " |
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212 | "#%d\n", 7 - i); |
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213 | return -ETIMEDOUT; |
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214 | } |
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215 | indata *= 2; |
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216 | if (getsda(adap)) |
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217 | indata |= 0x01; |
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218 | setscl(adap, 0); |
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219 | udelay(i == 7 ? adap->udelay / 2 : adap->udelay); |
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220 | } |
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221 | /* assert: scl is low */ |
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222 | return indata; |
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223 | } |
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224 | |||
225 | /* |
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226 | * Sanity check for the adapter hardware - check the reaction of |
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227 | * the bus lines only if it seems to be idle. |
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228 | */ |
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1963 | serge | 229 | static int test_bus(struct i2c_adapter *i2c_adap) |
1125 | serge | 230 | { |
1963 | serge | 231 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
232 | const char *name = i2c_adap->name; |
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233 | int scl, sda, ret; |
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1125 | serge | 234 | |
1963 | serge | 235 | if (adap->pre_xfer) { |
236 | ret = adap->pre_xfer(i2c_adap); |
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237 | if (ret < 0) |
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238 | return -ENODEV; |
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239 | } |
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240 | |||
1125 | serge | 241 | if (adap->getscl == NULL) |
242 | pr_info("%s: Testing SDA only, SCL is not readable\n", name); |
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243 | |||
244 | sda = getsda(adap); |
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245 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
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246 | if (!scl || !sda) { |
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247 | printk(KERN_WARNING "%s: bus seems to be busy\n", name); |
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248 | goto bailout; |
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249 | } |
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250 | |||
251 | sdalo(adap); |
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252 | sda = getsda(adap); |
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253 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
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254 | if (sda) { |
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255 | printk(KERN_WARNING "%s: SDA stuck high!\n", name); |
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256 | goto bailout; |
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257 | } |
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258 | if (!scl) { |
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259 | printk(KERN_WARNING "%s: SCL unexpected low " |
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260 | "while pulling SDA low!\n", name); |
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261 | goto bailout; |
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262 | } |
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263 | |||
264 | sdahi(adap); |
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265 | sda = getsda(adap); |
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266 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
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267 | if (!sda) { |
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268 | printk(KERN_WARNING "%s: SDA stuck low!\n", name); |
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269 | goto bailout; |
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270 | } |
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271 | if (!scl) { |
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272 | printk(KERN_WARNING "%s: SCL unexpected low " |
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273 | "while pulling SDA high!\n", name); |
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274 | goto bailout; |
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275 | } |
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276 | |||
277 | scllo(adap); |
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278 | sda = getsda(adap); |
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279 | scl = (adap->getscl == NULL) ? 0 : getscl(adap); |
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280 | if (scl) { |
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281 | printk(KERN_WARNING "%s: SCL stuck high!\n", name); |
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282 | goto bailout; |
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283 | } |
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284 | if (!sda) { |
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285 | printk(KERN_WARNING "%s: SDA unexpected low " |
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286 | "while pulling SCL low!\n", name); |
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287 | goto bailout; |
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288 | } |
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289 | |||
290 | sclhi(adap); |
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291 | sda = getsda(adap); |
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292 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
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293 | if (!scl) { |
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294 | printk(KERN_WARNING "%s: SCL stuck low!\n", name); |
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295 | goto bailout; |
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296 | } |
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297 | if (!sda) { |
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298 | printk(KERN_WARNING "%s: SDA unexpected low " |
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299 | "while pulling SCL high!\n", name); |
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300 | goto bailout; |
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301 | } |
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1963 | serge | 302 | |
303 | if (adap->post_xfer) |
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304 | adap->post_xfer(i2c_adap); |
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305 | |||
1125 | serge | 306 | pr_info("%s: Test OK\n", name); |
307 | return 0; |
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308 | bailout: |
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309 | sdahi(adap); |
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310 | sclhi(adap); |
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1963 | serge | 311 | |
312 | if (adap->post_xfer) |
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313 | adap->post_xfer(i2c_adap); |
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314 | |||
1125 | serge | 315 | return -ENODEV; |
316 | } |
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317 | |||
318 | /* ----- Utility functions |
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319 | */ |
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320 | |||
321 | /* try_address tries to contact a chip for a number of |
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322 | * times before it gives up. |
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323 | * return values: |
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324 | * 1 chip answered |
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325 | * 0 chip did not answer |
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326 | * -x transmission error |
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327 | */ |
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328 | static int try_address(struct i2c_adapter *i2c_adap, |
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329 | unsigned char addr, int retries) |
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330 | { |
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331 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
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332 | int i, ret = 0; |
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333 | |||
334 | for (i = 0; i <= retries; i++) { |
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335 | ret = i2c_outb(i2c_adap, addr); |
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336 | if (ret == 1 || i == retries) |
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337 | break; |
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338 | bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); |
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339 | i2c_stop(adap); |
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340 | udelay(adap->udelay); |
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341 | // yield(); |
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342 | bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); |
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343 | i2c_start(adap); |
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344 | } |
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345 | if (i && ret) |
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346 | bit_dbg(1, &i2c_adap->dev, "Used %d tries to %s client at " |
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347 | "0x%02x: %s\n", i + 1, |
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348 | addr & 1 ? "read from" : "write to", addr >> 1, |
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349 | ret == 1 ? "success" : "failed, timeout?"); |
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350 | return ret; |
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351 | } |
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352 | |||
353 | static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
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354 | { |
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355 | const unsigned char *temp = msg->buf; |
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356 | int count = msg->len; |
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357 | unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; |
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358 | int retval; |
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359 | int wrcount = 0; |
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360 | |||
361 | while (count > 0) { |
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362 | retval = i2c_outb(i2c_adap, *temp); |
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363 | |||
364 | /* OK/ACK; or ignored NAK */ |
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365 | if ((retval > 0) || (nak_ok && (retval == 0))) { |
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366 | count--; |
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367 | temp++; |
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368 | wrcount++; |
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369 | |||
370 | /* A slave NAKing the master means the slave didn't like |
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371 | * something about the data it saw. For example, maybe |
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372 | * the SMBus PEC was wrong. |
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373 | */ |
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374 | } else if (retval == 0) { |
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375 | // dev_err(&i2c_adap->dev, "sendbytes: NAK bailout.\n"); |
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376 | return -EIO; |
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377 | |||
378 | /* Timeout; or (someday) lost arbitration |
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379 | * |
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380 | * FIXME Lost ARB implies retrying the transaction from |
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381 | * the first message, after the "winning" master issues |
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382 | * its STOP. As a rule, upper layer code has no reason |
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383 | * to know or care about this ... it is *NOT* an error. |
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384 | */ |
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385 | } else { |
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386 | // dev_err(&i2c_adap->dev, "sendbytes: error %d\n", |
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387 | // retval); |
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388 | return retval; |
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389 | } |
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390 | } |
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391 | return wrcount; |
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392 | } |
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393 | |||
394 | static int acknak(struct i2c_adapter *i2c_adap, int is_ack) |
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395 | { |
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396 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
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397 | |||
398 | /* assert: sda is high */ |
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399 | if (is_ack) /* send ack */ |
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400 | setsda(adap, 0); |
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401 | udelay((adap->udelay + 1) / 2); |
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402 | if (sclhi(adap) < 0) { /* timeout */ |
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403 | // dev_err(&i2c_adap->dev, "readbytes: ack/nak timeout\n"); |
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404 | // return -ETIMEDOUT; |
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405 | } |
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406 | scllo(adap); |
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407 | return 0; |
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408 | } |
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409 | |||
410 | static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
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411 | { |
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412 | int inval; |
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413 | int rdcount = 0; /* counts bytes read */ |
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414 | unsigned char *temp = msg->buf; |
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415 | int count = msg->len; |
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416 | const unsigned flags = msg->flags; |
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417 | |||
418 | while (count > 0) { |
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419 | inval = i2c_inb(i2c_adap); |
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420 | if (inval >= 0) { |
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421 | *temp = inval; |
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422 | rdcount++; |
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423 | } else { /* read timed out */ |
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424 | break; |
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425 | } |
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426 | |||
427 | temp++; |
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428 | count--; |
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429 | |||
430 | /* Some SMBus transactions require that we receive the |
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431 | transaction length as the first read byte. */ |
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432 | if (rdcount == 1 && (flags & I2C_M_RECV_LEN)) { |
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433 | if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) { |
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434 | if (!(flags & I2C_M_NO_RD_ACK)) |
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435 | acknak(i2c_adap, 0); |
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436 | // dev_err(&i2c_adap->dev, "readbytes: invalid " |
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437 | // "block length (%d)\n", inval); |
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438 | return -EREMOTEIO; |
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439 | } |
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440 | /* The original count value accounts for the extra |
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441 | bytes, that is, either 1 for a regular transaction, |
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442 | or 2 for a PEC transaction. */ |
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443 | count += inval; |
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444 | msg->len += inval; |
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445 | } |
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446 | |||
1963 | serge | 447 | bit_dbg(2, &i2c_adap->dev, "readbytes: 0x%02x %s\n", |
448 | inval, |
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449 | (flags & I2C_M_NO_RD_ACK) |
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450 | ? "(no ack/nak)" |
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451 | : (count ? "A" : "NA")); |
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1125 | serge | 452 | |
453 | if (!(flags & I2C_M_NO_RD_ACK)) { |
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454 | inval = acknak(i2c_adap, count); |
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455 | if (inval < 0) |
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456 | return inval; |
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457 | } |
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458 | } |
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459 | return rdcount; |
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460 | } |
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461 | |||
462 | /* doAddress initiates the transfer by generating the start condition (in |
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463 | * try_address) and transmits the address in the necessary format to handle |
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464 | * reads, writes as well as 10bit-addresses. |
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465 | * returns: |
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466 | * 0 everything went okay, the chip ack'ed, or IGNORE_NAK flag was set |
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467 | * -x an error occurred (like: -EREMOTEIO if the device did not answer, or |
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468 | * -ETIMEDOUT, for example if the lines are stuck...) |
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469 | */ |
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470 | static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
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471 | { |
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472 | unsigned short flags = msg->flags; |
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473 | unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; |
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474 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
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475 | |||
476 | unsigned char addr; |
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477 | int ret, retries; |
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478 | |||
479 | retries = nak_ok ? 0 : i2c_adap->retries; |
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480 | |||
481 | if (flags & I2C_M_TEN) { |
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482 | /* a ten bit address */ |
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483 | addr = 0xf0 | ((msg->addr >> 7) & 0x03); |
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484 | bit_dbg(2, &i2c_adap->dev, "addr0: %d\n", addr); |
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485 | /* try extended address code...*/ |
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486 | ret = try_address(i2c_adap, addr, retries); |
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487 | if ((ret != 1) && !nak_ok) { |
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488 | // dev_err(&i2c_adap->dev, |
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489 | // "died at extended address code\n"); |
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490 | return -EREMOTEIO; |
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491 | } |
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492 | /* the remaining 8 bit address */ |
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493 | ret = i2c_outb(i2c_adap, msg->addr & 0x7f); |
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494 | if ((ret != 1) && !nak_ok) { |
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495 | /* the chip did not ack / xmission error occurred */ |
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496 | // dev_err(&i2c_adap->dev, "died at 2nd address code\n"); |
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497 | return -EREMOTEIO; |
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498 | } |
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499 | if (flags & I2C_M_RD) { |
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500 | bit_dbg(3, &i2c_adap->dev, "emitting repeated " |
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501 | "start condition\n"); |
||
502 | i2c_repstart(adap); |
||
503 | /* okay, now switch into reading mode */ |
||
504 | addr |= 0x01; |
||
505 | ret = try_address(i2c_adap, addr, retries); |
||
506 | if ((ret != 1) && !nak_ok) { |
||
507 | // dev_err(&i2c_adap->dev, |
||
508 | // "died at repeated address code\n"); |
||
509 | return -EREMOTEIO; |
||
510 | } |
||
511 | } |
||
512 | } else { /* normal 7bit address */ |
||
513 | addr = msg->addr << 1; |
||
514 | if (flags & I2C_M_RD) |
||
515 | addr |= 1; |
||
516 | if (flags & I2C_M_REV_DIR_ADDR) |
||
517 | addr ^= 1; |
||
518 | ret = try_address(i2c_adap, addr, retries); |
||
519 | if ((ret != 1) && !nak_ok) |
||
520 | return -ENXIO; |
||
521 | } |
||
522 | |||
523 | return 0; |
||
524 | } |
||
525 | |||
526 | static int bit_xfer(struct i2c_adapter *i2c_adap, |
||
527 | struct i2c_msg msgs[], int num) |
||
528 | { |
||
529 | struct i2c_msg *pmsg; |
||
530 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
||
531 | int i, ret; |
||
532 | unsigned short nak_ok; |
||
533 | |||
1963 | serge | 534 | //ENTER(); |
535 | if (adap->pre_xfer) { |
||
536 | ret = adap->pre_xfer(i2c_adap); |
||
537 | if (ret < 0) |
||
538 | return ret; |
||
539 | } |
||
540 | |||
1125 | serge | 541 | bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); |
542 | i2c_start(adap); |
||
543 | for (i = 0; i < num; i++) { |
||
544 | pmsg = &msgs[i]; |
||
545 | nak_ok = pmsg->flags & I2C_M_IGNORE_NAK; |
||
546 | if (!(pmsg->flags & I2C_M_NOSTART)) { |
||
547 | if (i) { |
||
548 | bit_dbg(3, &i2c_adap->dev, "emitting " |
||
549 | "repeated start condition\n"); |
||
550 | i2c_repstart(adap); |
||
551 | } |
||
552 | ret = bit_doAddress(i2c_adap, pmsg); |
||
553 | if ((ret != 0) && !nak_ok) { |
||
554 | bit_dbg(1, &i2c_adap->dev, "NAK from " |
||
555 | "device addr 0x%02x msg #%d\n", |
||
556 | msgs[i].addr, i); |
||
557 | goto bailout; |
||
558 | } |
||
559 | } |
||
560 | if (pmsg->flags & I2C_M_RD) { |
||
561 | /* read bytes into buffer*/ |
||
562 | ret = readbytes(i2c_adap, pmsg); |
||
563 | if (ret >= 1) |
||
564 | bit_dbg(2, &i2c_adap->dev, "read %d byte%s\n", |
||
565 | ret, ret == 1 ? "" : "s"); |
||
566 | if (ret < pmsg->len) { |
||
567 | if (ret >= 0) |
||
568 | ret = -EREMOTEIO; |
||
569 | goto bailout; |
||
570 | } |
||
571 | } else { |
||
572 | /* write bytes from buffer */ |
||
573 | ret = sendbytes(i2c_adap, pmsg); |
||
574 | if (ret >= 1) |
||
575 | bit_dbg(2, &i2c_adap->dev, "wrote %d byte%s\n", |
||
576 | ret, ret == 1 ? "" : "s"); |
||
577 | if (ret < pmsg->len) { |
||
578 | if (ret >= 0) |
||
579 | ret = -EREMOTEIO; |
||
580 | goto bailout; |
||
581 | } |
||
582 | } |
||
583 | } |
||
584 | ret = i; |
||
585 | |||
586 | bailout: |
||
587 | bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); |
||
588 | i2c_stop(adap); |
||
1963 | serge | 589 | // LEAVE(); |
590 | |||
591 | if (adap->post_xfer) |
||
592 | adap->post_xfer(i2c_adap); |
||
1125 | serge | 593 | return ret; |
594 | } |
||
595 | |||
596 | static u32 bit_func(struct i2c_adapter *adap) |
||
597 | { |
||
598 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | |
||
599 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | |
||
600 | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | |
||
601 | I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; |
||
602 | } |
||
603 | |||
604 | |||
605 | /* -----exported algorithm data: ------------------------------------- */ |
||
606 | |||
607 | static const struct i2c_algorithm i2c_bit_algo = { |
||
608 | .master_xfer = bit_xfer, |
||
609 | .functionality = bit_func, |
||
610 | }; |
||
611 | |||
612 | /* |
||
613 | * registering functions to load algorithms at runtime |
||
614 | */ |
||
1963 | serge | 615 | static int __i2c_bit_add_bus(struct i2c_adapter *adap, |
616 | int (*add_adapter)(struct i2c_adapter *)) |
||
1125 | serge | 617 | { |
618 | struct i2c_algo_bit_data *bit_adap = adap->algo_data; |
||
1963 | serge | 619 | int ret; |
1125 | serge | 620 | |
1963 | serge | 621 | if (bit_test) { |
622 | ret = test_bus(adap); |
||
623 | if (ret < 0) |
||
624 | return -ENODEV; |
||
625 | } |
||
1125 | serge | 626 | |
627 | /* register new adapter to i2c module... */ |
||
628 | adap->algo = &i2c_bit_algo; |
||
629 | adap->retries = 3; |
||
630 | |||
631 | return 0; |
||
632 | } |
||
633 | |||
634 | int i2c_bit_add_bus(struct i2c_adapter *adap) |
||
635 | { |
||
1963 | serge | 636 | return __i2c_bit_add_bus(adap, NULL); |
637 | }>>>>>><>>=>>=>>>>>> |
||
1125 | serge | 638 |