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3192 | Serge | 1 | /* |
2 | * Copyright © 2009 Keith Packard |
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3 | * |
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4 | * Permission to use, copy, modify, distribute, and sell this software and its |
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5 | * documentation for any purpose is hereby granted without fee, provided that |
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6 | * the above copyright notice appear in all copies and that both that copyright |
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7 | * notice and this permission notice appear in supporting documentation, and |
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8 | * that the name of the copyright holders not be used in advertising or |
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9 | * publicity pertaining to distribution of the software without specific, |
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10 | * written prior permission. The copyright holders make no representations |
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11 | * about the suitability of this software for any purpose. It is provided "as |
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12 | * is" without express or implied warranty. |
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13 | * |
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14 | * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, |
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15 | * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO |
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16 | * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR |
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17 | * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, |
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18 | * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER |
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19 | * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE |
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20 | * OF THIS SOFTWARE. |
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21 | */ |
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22 | |||
23 | #include |
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24 | #include |
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25 | //#include |
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26 | //#include |
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27 | #include |
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28 | #include |
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29 | #include |
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5271 | serge | 30 | #include |
5060 | serge | 31 | #include |
3192 | Serge | 32 | |
33 | /** |
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34 | * DOC: dp helpers |
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35 | * |
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36 | * These functions contain some common logic and helpers at various abstraction |
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37 | * levels to deal with Display Port sink devices and related things like DP aux |
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38 | * channel transfers, EDID reading over DP aux channels, decoding certain DPCD |
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39 | * blocks, ... |
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40 | */ |
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41 | |||
42 | /* Helpers for DP link training */ |
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4560 | Serge | 43 | static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r) |
3192 | Serge | 44 | { |
45 | return link_status[r - DP_LANE0_1_STATUS]; |
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46 | } |
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47 | |||
4560 | Serge | 48 | static u8 dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE], |
3192 | Serge | 49 | int lane) |
50 | { |
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51 | int i = DP_LANE0_1_STATUS + (lane >> 1); |
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52 | int s = (lane & 1) * 4; |
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53 | u8 l = dp_link_status(link_status, i); |
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54 | return (l >> s) & 0xf; |
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55 | } |
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56 | |||
4560 | Serge | 57 | bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], |
3192 | Serge | 58 | int lane_count) |
59 | { |
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60 | u8 lane_align; |
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61 | u8 lane_status; |
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62 | int lane; |
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63 | |||
64 | lane_align = dp_link_status(link_status, |
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65 | DP_LANE_ALIGN_STATUS_UPDATED); |
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66 | if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0) |
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67 | return false; |
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68 | for (lane = 0; lane < lane_count; lane++) { |
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69 | lane_status = dp_get_lane_status(link_status, lane); |
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70 | if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS) |
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71 | return false; |
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72 | } |
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73 | return true; |
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74 | } |
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75 | EXPORT_SYMBOL(drm_dp_channel_eq_ok); |
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76 | |||
4560 | Serge | 77 | bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE], |
3192 | Serge | 78 | int lane_count) |
79 | { |
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80 | int lane; |
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81 | u8 lane_status; |
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82 | |||
83 | for (lane = 0; lane < lane_count; lane++) { |
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84 | lane_status = dp_get_lane_status(link_status, lane); |
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85 | if ((lane_status & DP_LANE_CR_DONE) == 0) |
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86 | return false; |
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87 | } |
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88 | return true; |
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89 | } |
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90 | EXPORT_SYMBOL(drm_dp_clock_recovery_ok); |
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91 | |||
4560 | Serge | 92 | u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE], |
3192 | Serge | 93 | int lane) |
94 | { |
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95 | int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); |
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96 | int s = ((lane & 1) ? |
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97 | DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT : |
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98 | DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT); |
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99 | u8 l = dp_link_status(link_status, i); |
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100 | |||
101 | return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT; |
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102 | } |
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103 | EXPORT_SYMBOL(drm_dp_get_adjust_request_voltage); |
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104 | |||
4560 | Serge | 105 | u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE], |
3192 | Serge | 106 | int lane) |
107 | { |
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108 | int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); |
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109 | int s = ((lane & 1) ? |
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110 | DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT : |
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111 | DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT); |
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112 | u8 l = dp_link_status(link_status, i); |
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113 | |||
114 | return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT; |
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115 | } |
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116 | EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis); |
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117 | |||
4560 | Serge | 118 | void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { |
3192 | Serge | 119 | if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0) |
120 | udelay(100); |
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121 | else |
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122 | mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4); |
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123 | } |
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124 | EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); |
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125 | |||
4560 | Serge | 126 | void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { |
3192 | Serge | 127 | if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0) |
128 | udelay(400); |
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129 | else |
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130 | mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4); |
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131 | } |
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132 | EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); |
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133 | |||
134 | u8 drm_dp_link_rate_to_bw_code(int link_rate) |
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135 | { |
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136 | switch (link_rate) { |
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137 | case 162000: |
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138 | default: |
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139 | return DP_LINK_BW_1_62; |
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140 | case 270000: |
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141 | return DP_LINK_BW_2_7; |
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142 | case 540000: |
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143 | return DP_LINK_BW_5_4; |
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144 | } |
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145 | } |
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146 | EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code); |
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147 | |||
148 | int drm_dp_bw_code_to_link_rate(u8 link_bw) |
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149 | { |
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150 | switch (link_bw) { |
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151 | case DP_LINK_BW_1_62: |
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152 | default: |
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153 | return 162000; |
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154 | case DP_LINK_BW_2_7: |
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155 | return 270000; |
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156 | case DP_LINK_BW_5_4: |
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157 | return 540000; |
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158 | } |
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159 | } |
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160 | EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate); |
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5060 | serge | 161 | |
162 | /** |
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163 | * DOC: dp helpers |
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164 | * |
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165 | * The DisplayPort AUX channel is an abstraction to allow generic, driver- |
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166 | * independent access to AUX functionality. Drivers can take advantage of |
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167 | * this by filling in the fields of the drm_dp_aux structure. |
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168 | * |
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169 | * Transactions are described using a hardware-independent drm_dp_aux_msg |
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170 | * structure, which is passed into a driver's .transfer() implementation. |
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171 | * Both native and I2C-over-AUX transactions are supported. |
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172 | */ |
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173 | |||
174 | static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, |
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175 | unsigned int offset, void *buffer, size_t size) |
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176 | { |
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177 | struct drm_dp_aux_msg msg; |
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178 | unsigned int retry; |
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179 | int err; |
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180 | |||
181 | memset(&msg, 0, sizeof(msg)); |
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182 | msg.address = offset; |
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183 | msg.request = request; |
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184 | msg.buffer = buffer; |
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185 | msg.size = size; |
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186 | |||
187 | /* |
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188 | * The specification doesn't give any recommendation on how often to |
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5271 | serge | 189 | * retry native transactions. We used to retry 7 times like for |
190 | * aux i2c transactions but real world devices this wasn't |
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191 | * sufficient, bump to 32 which makes Dell 4k monitors happier. |
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5060 | serge | 192 | */ |
5271 | serge | 193 | for (retry = 0; retry < 32; retry++) { |
5060 | serge | 194 | |
195 | mutex_lock(&aux->hw_mutex); |
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196 | err = aux->transfer(aux, &msg); |
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197 | mutex_unlock(&aux->hw_mutex); |
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198 | if (err < 0) { |
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199 | if (err == -EBUSY) |
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200 | continue; |
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201 | |||
202 | return err; |
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203 | } |
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204 | |||
205 | |||
206 | switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { |
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207 | case DP_AUX_NATIVE_REPLY_ACK: |
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208 | if (err < size) |
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209 | return -EPROTO; |
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210 | return err; |
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211 | |||
212 | case DP_AUX_NATIVE_REPLY_NACK: |
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213 | return -EIO; |
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214 | |||
215 | case DP_AUX_NATIVE_REPLY_DEFER: |
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216 | usleep(500); |
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217 | break; |
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218 | } |
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219 | } |
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220 | |||
221 | DRM_DEBUG_KMS("too many retries, giving up\n"); |
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222 | return -EIO; |
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223 | } |
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224 | |||
225 | /** |
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226 | * drm_dp_dpcd_read() - read a series of bytes from the DPCD |
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227 | * @aux: DisplayPort AUX channel |
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228 | * @offset: address of the (first) register to read |
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229 | * @buffer: buffer to store the register values |
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230 | * @size: number of bytes in @buffer |
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231 | * |
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232 | * Returns the number of bytes transferred on success, or a negative error |
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233 | * code on failure. -EIO is returned if the request was NAKed by the sink or |
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234 | * if the retry count was exceeded. If not all bytes were transferred, this |
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235 | * function returns -EPROTO. Errors from the underlying AUX channel transfer |
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236 | * function, with the exception of -EBUSY (which causes the transaction to |
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237 | * be retried), are propagated to the caller. |
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238 | */ |
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239 | ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, |
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240 | void *buffer, size_t size) |
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241 | { |
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242 | return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer, |
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243 | size); |
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244 | } |
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245 | EXPORT_SYMBOL(drm_dp_dpcd_read); |
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246 | |||
247 | /** |
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248 | * drm_dp_dpcd_write() - write a series of bytes to the DPCD |
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249 | * @aux: DisplayPort AUX channel |
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250 | * @offset: address of the (first) register to write |
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251 | * @buffer: buffer containing the values to write |
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252 | * @size: number of bytes in @buffer |
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253 | * |
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254 | * Returns the number of bytes transferred on success, or a negative error |
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255 | * code on failure. -EIO is returned if the request was NAKed by the sink or |
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256 | * if the retry count was exceeded. If not all bytes were transferred, this |
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257 | * function returns -EPROTO. Errors from the underlying AUX channel transfer |
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258 | * function, with the exception of -EBUSY (which causes the transaction to |
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259 | * be retried), are propagated to the caller. |
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260 | */ |
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261 | ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, |
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262 | void *buffer, size_t size) |
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263 | { |
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264 | return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, |
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265 | size); |
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266 | } |
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267 | EXPORT_SYMBOL(drm_dp_dpcd_write); |
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268 | |||
269 | /** |
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270 | * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207) |
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271 | * @aux: DisplayPort AUX channel |
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272 | * @status: buffer to store the link status in (must be at least 6 bytes) |
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273 | * |
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274 | * Returns the number of bytes transferred on success or a negative error |
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275 | * code on failure. |
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276 | */ |
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277 | int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, |
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278 | u8 status[DP_LINK_STATUS_SIZE]) |
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279 | { |
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280 | return drm_dp_dpcd_read(aux, DP_LANE0_1_STATUS, status, |
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281 | DP_LINK_STATUS_SIZE); |
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282 | } |
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283 | EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); |
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284 | |||
285 | /** |
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286 | * drm_dp_link_probe() - probe a DisplayPort link for capabilities |
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287 | * @aux: DisplayPort AUX channel |
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288 | * @link: pointer to structure in which to return link capabilities |
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289 | * |
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290 | * The structure filled in by this function can usually be passed directly |
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291 | * into drm_dp_link_power_up() and drm_dp_link_configure() to power up and |
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292 | * configure the link based on the link's capabilities. |
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293 | * |
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294 | * Returns 0 on success or a negative error code on failure. |
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295 | */ |
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296 | int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link) |
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297 | { |
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298 | u8 values[3]; |
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299 | int err; |
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300 | |||
301 | memset(link, 0, sizeof(*link)); |
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302 | |||
303 | err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values)); |
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304 | if (err < 0) |
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305 | return err; |
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306 | |||
307 | link->revision = values[0]; |
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308 | link->rate = drm_dp_bw_code_to_link_rate(values[1]); |
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309 | link->num_lanes = values[2] & DP_MAX_LANE_COUNT_MASK; |
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310 | |||
311 | if (values[2] & DP_ENHANCED_FRAME_CAP) |
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312 | link->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING; |
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313 | |||
314 | return 0; |
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315 | } |
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316 | EXPORT_SYMBOL(drm_dp_link_probe); |
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317 | |||
318 | /** |
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319 | * drm_dp_link_power_up() - power up a DisplayPort link |
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320 | * @aux: DisplayPort AUX channel |
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321 | * @link: pointer to a structure containing the link configuration |
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322 | * |
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323 | * Returns 0 on success or a negative error code on failure. |
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324 | */ |
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325 | int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link) |
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326 | { |
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327 | u8 value; |
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328 | int err; |
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329 | |||
330 | /* DP_SET_POWER register is only available on DPCD v1.1 and later */ |
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331 | if (link->revision < 0x11) |
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332 | return 0; |
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333 | |||
334 | err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); |
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335 | if (err < 0) |
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336 | return err; |
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337 | |||
338 | value &= ~DP_SET_POWER_MASK; |
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339 | value |= DP_SET_POWER_D0; |
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340 | |||
341 | err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); |
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342 | if (err < 0) |
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343 | return err; |
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344 | |||
345 | /* |
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346 | * According to the DP 1.1 specification, a "Sink Device must exit the |
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347 | * power saving state within 1 ms" (Section 2.5.3.1, Table 5-52, "Sink |
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348 | * Control Field" (register 0x600). |
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349 | */ |
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350 | usleep(2000); |
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351 | |||
352 | return 0; |
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353 | } |
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354 | EXPORT_SYMBOL(drm_dp_link_power_up); |
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355 | |||
356 | /** |
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357 | * drm_dp_link_configure() - configure a DisplayPort link |
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358 | * @aux: DisplayPort AUX channel |
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359 | * @link: pointer to a structure containing the link configuration |
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360 | * |
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361 | * Returns 0 on success or a negative error code on failure. |
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362 | */ |
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363 | int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link) |
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364 | { |
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365 | u8 values[2]; |
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366 | int err; |
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367 | |||
368 | values[0] = drm_dp_link_rate_to_bw_code(link->rate); |
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369 | values[1] = link->num_lanes; |
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370 | |||
371 | if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING) |
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372 | values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN; |
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373 | |||
374 | err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, values, sizeof(values)); |
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375 | if (err < 0) |
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376 | return err; |
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377 | |||
378 | return 0; |
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379 | } |
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380 | EXPORT_SYMBOL(drm_dp_link_configure); |
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381 | |||
382 | /* |
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383 | * I2C-over-AUX implementation |
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384 | */ |
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385 | |||
386 | static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter) |
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387 | { |
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388 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | |
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389 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | |
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390 | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | |
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391 | I2C_FUNC_10BIT_ADDR; |
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392 | } |
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393 | |||
394 | /* |
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395 | * Transfer a single I2C-over-AUX message and handle various error conditions, |
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396 | * retrying the transaction as appropriate. It is assumed that the |
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397 | * aux->transfer function does not modify anything in the msg other than the |
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398 | * reply field. |
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399 | */ |
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400 | static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) |
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401 | { |
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402 | unsigned int retry; |
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403 | int err; |
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404 | |||
405 | /* |
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406 | * DP1.2 sections 2.7.7.1.5.6.1 and 2.7.7.1.6.6.1: A DP Source device |
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407 | * is required to retry at least seven times upon receiving AUX_DEFER |
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408 | * before giving up the AUX transaction. |
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409 | */ |
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410 | for (retry = 0; retry < 7; retry++) { |
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411 | mutex_lock(&aux->hw_mutex); |
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412 | err = aux->transfer(aux, msg); |
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413 | mutex_unlock(&aux->hw_mutex); |
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414 | if (err < 0) { |
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415 | if (err == -EBUSY) |
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416 | continue; |
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417 | |||
418 | DRM_DEBUG_KMS("transaction failed: %d\n", err); |
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419 | return err; |
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420 | } |
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421 | |||
422 | |||
423 | switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) { |
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424 | case DP_AUX_NATIVE_REPLY_ACK: |
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425 | /* |
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426 | * For I2C-over-AUX transactions this isn't enough, we |
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427 | * need to check for the I2C ACK reply. |
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428 | */ |
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429 | break; |
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430 | |||
431 | case DP_AUX_NATIVE_REPLY_NACK: |
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432 | DRM_DEBUG_KMS("native nack\n"); |
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433 | return -EREMOTEIO; |
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434 | |||
435 | case DP_AUX_NATIVE_REPLY_DEFER: |
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436 | DRM_DEBUG_KMS("native defer"); |
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437 | /* |
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438 | * We could check for I2C bit rate capabilities and if |
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439 | * available adjust this interval. We could also be |
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440 | * more careful with DP-to-legacy adapters where a |
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441 | * long legacy cable may force very low I2C bit rates. |
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442 | * |
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443 | * For now just defer for long enough to hopefully be |
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444 | * safe for all use-cases. |
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445 | */ |
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446 | usleep_range(500, 600); |
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447 | continue; |
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448 | |||
449 | default: |
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450 | DRM_ERROR("invalid native reply %#04x\n", msg->reply); |
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451 | return -EREMOTEIO; |
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452 | } |
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453 | |||
454 | switch (msg->reply & DP_AUX_I2C_REPLY_MASK) { |
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455 | case DP_AUX_I2C_REPLY_ACK: |
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456 | /* |
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457 | * Both native ACK and I2C ACK replies received. We |
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458 | * can assume the transfer was successful. |
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459 | */ |
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460 | if (err < msg->size) |
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461 | return -EPROTO; |
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462 | return 0; |
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463 | |||
464 | case DP_AUX_I2C_REPLY_NACK: |
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465 | DRM_DEBUG_KMS("I2C nack\n"); |
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466 | return -EREMOTEIO; |
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467 | |||
468 | case DP_AUX_I2C_REPLY_DEFER: |
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469 | DRM_DEBUG_KMS("I2C defer\n"); |
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470 | usleep_range(400, 500); |
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471 | continue; |
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472 | |||
473 | default: |
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474 | DRM_ERROR("invalid I2C reply %#04x\n", msg->reply); |
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475 | return -EREMOTEIO; |
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476 | } |
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477 | } |
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478 | |||
479 | DRM_DEBUG_KMS("too many retries, giving up\n"); |
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480 | return -EREMOTEIO; |
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481 | } |
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482 | |||
483 | static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, |
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484 | int num) |
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485 | { |
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486 | struct drm_dp_aux *aux = adapter->algo_data; |
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487 | unsigned int i, j; |
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488 | struct drm_dp_aux_msg msg; |
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489 | int err = 0; |
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490 | |||
491 | memset(&msg, 0, sizeof(msg)); |
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492 | |||
493 | for (i = 0; i < num; i++) { |
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494 | msg.address = msgs[i].addr; |
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495 | msg.request = (msgs[i].flags & I2C_M_RD) ? |
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496 | DP_AUX_I2C_READ : |
||
497 | DP_AUX_I2C_WRITE; |
||
498 | msg.request |= DP_AUX_I2C_MOT; |
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499 | /* Send a bare address packet to start the transaction. |
||
500 | * Zero sized messages specify an address only (bare |
||
501 | * address) transaction. |
||
502 | */ |
||
503 | msg.buffer = NULL; |
||
504 | msg.size = 0; |
||
505 | err = drm_dp_i2c_do_msg(aux, &msg); |
||
506 | if (err < 0) |
||
507 | break; |
||
508 | /* |
||
509 | * Many hardware implementations support FIFOs larger than a |
||
510 | * single byte, but it has been empirically determined that |
||
511 | * transferring data in larger chunks can actually lead to |
||
512 | * decreased performance. Therefore each message is simply |
||
513 | * transferred byte-by-byte. |
||
514 | */ |
||
515 | for (j = 0; j < msgs[i].len; j++) { |
||
516 | msg.buffer = msgs[i].buf + j; |
||
517 | msg.size = 1; |
||
518 | |||
519 | err = drm_dp_i2c_do_msg(aux, &msg); |
||
520 | if (err < 0) |
||
521 | break; |
||
522 | } |
||
523 | if (err < 0) |
||
524 | break; |
||
525 | } |
||
526 | if (err >= 0) |
||
527 | err = num; |
||
528 | /* Send a bare address packet to close out the transaction. |
||
529 | * Zero sized messages specify an address only (bare |
||
530 | * address) transaction. |
||
531 | */ |
||
532 | msg.request &= ~DP_AUX_I2C_MOT; |
||
533 | msg.buffer = NULL; |
||
534 | msg.size = 0; |
||
535 | (void)drm_dp_i2c_do_msg(aux, &msg); |
||
536 | |||
537 | return err; |
||
538 | } |
||
539 | |||
540 | static const struct i2c_algorithm drm_dp_i2c_algo = { |
||
541 | .functionality = drm_dp_i2c_functionality, |
||
542 | .master_xfer = drm_dp_i2c_xfer, |
||
543 | }; |
||
544 | |||
545 | /** |
||
546 | * drm_dp_aux_register() - initialise and register aux channel |
||
547 | * @aux: DisplayPort AUX channel |
||
548 | * |
||
549 | * Returns 0 on success or a negative error code on failure. |
||
550 | */ |
||
551 | int drm_dp_aux_register(struct drm_dp_aux *aux) |
||
552 | { |
||
553 | mutex_init(&aux->hw_mutex); |
||
554 | |||
555 | aux->ddc.algo = &drm_dp_i2c_algo; |
||
556 | aux->ddc.algo_data = aux; |
||
557 | aux->ddc.retries = 3; |
||
558 | |||
559 | aux->ddc.class = I2C_CLASS_DDC; |
||
560 | aux->ddc.owner = THIS_MODULE; |
||
561 | aux->ddc.dev.parent = aux->dev; |
||
562 | // aux->ddc.dev.of_node = aux->dev->of_node; |
||
563 | |||
564 | strlcpy(aux->ddc.name, aux->name ? aux->name : "aux", |
||
565 | sizeof(aux->ddc.name)); |
||
566 | |||
567 | return i2c_add_adapter(&aux->ddc); |
||
568 | } |
||
569 | EXPORT_SYMBOL(drm_dp_aux_register); |
||
570 | |||
571 | /** |
||
572 | * drm_dp_aux_unregister() - unregister an AUX adapter |
||
573 | * @aux: DisplayPort AUX channel |
||
574 | */ |
||
575 | void drm_dp_aux_unregister(struct drm_dp_aux *aux) |
||
576 | { |
||
577 | i2c_del_adapter(&aux->ddc); |
||
578 | } |
||
579 | EXPORT_SYMBOL(drm_dp_aux_unregister);>>>>>>>>>>>>>>>>><>><>>> |