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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1404 | 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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| 30 | #include |
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| 31 | #include "drm_dp_helper.h" |
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| 32 | #include "drmP.h" |
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| 33 | |||
| 34 | /* Run a single AUX_CH I2C transaction, writing/reading data as necessary */ |
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| 35 | static int |
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| 36 | i2c_algo_dp_aux_transaction(struct i2c_adapter *adapter, int mode, |
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| 37 | uint8_t write_byte, uint8_t *read_byte) |
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| 38 | { |
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| 39 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; |
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| 40 | int ret; |
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| 41 | |||
| 42 | ret = (*algo_data->aux_ch)(adapter, mode, |
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| 43 | write_byte, read_byte); |
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| 44 | return ret; |
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| 45 | } |
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| 46 | |||
| 47 | /* |
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| 48 | * I2C over AUX CH |
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| 49 | */ |
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| 50 | |||
| 51 | /* |
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| 52 | * Send the address. If the I2C link is running, this 'restarts' |
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| 53 | * the connection with the new address, this is used for doing |
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| 54 | * a write followed by a read (as needed for DDC) |
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| 55 | */ |
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| 56 | static int |
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| 57 | i2c_algo_dp_aux_address(struct i2c_adapter *adapter, u16 address, bool reading) |
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| 58 | { |
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| 59 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; |
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| 60 | int mode = MODE_I2C_START; |
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| 61 | int ret; |
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| 62 | |||
| 63 | if (reading) |
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| 64 | mode |= MODE_I2C_READ; |
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| 65 | else |
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| 66 | mode |= MODE_I2C_WRITE; |
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| 67 | algo_data->address = address; |
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| 68 | algo_data->running = true; |
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| 69 | ret = i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL); |
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| 70 | return ret; |
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| 71 | } |
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| 72 | |||
| 73 | /* |
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| 74 | * Stop the I2C transaction. This closes out the link, sending |
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| 75 | * a bare address packet with the MOT bit turned off |
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| 76 | */ |
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| 77 | static void |
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| 78 | i2c_algo_dp_aux_stop(struct i2c_adapter *adapter, bool reading) |
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| 79 | { |
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| 80 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; |
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| 81 | int mode = MODE_I2C_STOP; |
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| 82 | |||
| 83 | if (reading) |
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| 84 | mode |= MODE_I2C_READ; |
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| 85 | else |
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| 86 | mode |= MODE_I2C_WRITE; |
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| 87 | if (algo_data->running) { |
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| 88 | (void) i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL); |
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| 89 | algo_data->running = false; |
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| 90 | } |
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| 91 | } |
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| 92 | |||
| 93 | /* |
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| 94 | * Write a single byte to the current I2C address, the |
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| 95 | * the I2C link must be running or this returns -EIO |
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| 96 | */ |
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| 97 | static int |
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| 98 | i2c_algo_dp_aux_put_byte(struct i2c_adapter *adapter, u8 byte) |
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| 99 | { |
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| 100 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; |
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| 101 | int ret; |
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| 102 | |||
| 103 | if (!algo_data->running) |
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| 104 | return -EIO; |
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| 105 | |||
| 106 | ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_WRITE, byte, NULL); |
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| 107 | return ret; |
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| 108 | } |
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| 109 | |||
| 110 | /* |
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| 111 | * Read a single byte from the current I2C address, the |
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| 112 | * I2C link must be running or this returns -EIO |
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| 113 | */ |
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| 114 | static int |
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| 115 | i2c_algo_dp_aux_get_byte(struct i2c_adapter *adapter, u8 *byte_ret) |
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| 116 | { |
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| 117 | struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data; |
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| 118 | int ret; |
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| 119 | |||
| 120 | if (!algo_data->running) |
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| 121 | return -EIO; |
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| 122 | |||
| 123 | ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_READ, 0, byte_ret); |
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| 124 | return ret; |
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| 125 | } |
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| 126 | |||
| 127 | static int |
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| 128 | i2c_algo_dp_aux_xfer(struct i2c_adapter *adapter, |
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| 129 | struct i2c_msg *msgs, |
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| 130 | int num) |
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| 131 | { |
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| 132 | int ret = 0; |
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| 133 | bool reading = false; |
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| 134 | int m; |
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| 135 | int b; |
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| 136 | |||
| 137 | for (m = 0; m < num; m++) { |
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| 138 | u16 len = msgs[m].len; |
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| 139 | u8 *buf = msgs[m].buf; |
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| 140 | reading = (msgs[m].flags & I2C_M_RD) != 0; |
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| 141 | ret = i2c_algo_dp_aux_address(adapter, msgs[m].addr, reading); |
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| 142 | if (ret < 0) |
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| 143 | break; |
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| 144 | if (reading) { |
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| 145 | for (b = 0; b < len; b++) { |
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| 146 | ret = i2c_algo_dp_aux_get_byte(adapter, &buf[b]); |
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| 147 | if (ret < 0) |
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| 148 | break; |
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| 149 | } |
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| 150 | } else { |
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| 151 | for (b = 0; b < len; b++) { |
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| 152 | ret = i2c_algo_dp_aux_put_byte(adapter, buf[b]); |
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| 153 | if (ret < 0) |
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| 154 | break; |
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| 155 | } |
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| 156 | } |
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| 157 | if (ret < 0) |
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| 158 | break; |
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| 159 | } |
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| 160 | if (ret >= 0) |
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| 161 | ret = num; |
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| 162 | i2c_algo_dp_aux_stop(adapter, reading); |
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| 163 | DRM_DEBUG_KMS("dp_aux_xfer return %d\n", ret); |
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| 164 | return ret; |
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| 165 | } |
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| 166 | |||
| 167 | static u32 |
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| 168 | i2c_algo_dp_aux_functionality(struct i2c_adapter *adapter) |
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| 169 | { |
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| 170 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | |
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| 171 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | |
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| 172 | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | |
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| 173 | I2C_FUNC_10BIT_ADDR; |
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| 174 | } |
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| 175 | |||
| 176 | static const struct i2c_algorithm i2c_dp_aux_algo = { |
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| 177 | .master_xfer = i2c_algo_dp_aux_xfer, |
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| 178 | .functionality = i2c_algo_dp_aux_functionality, |
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| 179 | }; |
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| 180 | |||
| 181 | static void |
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| 182 | i2c_dp_aux_reset_bus(struct i2c_adapter *adapter) |
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| 183 | { |
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| 184 | (void) i2c_algo_dp_aux_address(adapter, 0, false); |
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| 185 | (void) i2c_algo_dp_aux_stop(adapter, false); |
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| 186 | |||
| 187 | } |
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| 188 | |||
| 189 | static int |
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| 190 | i2c_dp_aux_prepare_bus(struct i2c_adapter *adapter) |
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| 191 | { |
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| 192 | adapter->algo = &i2c_dp_aux_algo; |
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| 193 | adapter->retries = 3; |
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| 194 | i2c_dp_aux_reset_bus(adapter); |
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| 195 | return 0; |
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| 196 | } |
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| 197 | |||
| 198 | int |
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| 199 | i2c_dp_aux_add_bus(struct i2c_adapter *adapter) |
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| 200 | { |
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| 201 | int error; |
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| 202 | |||
| 203 | error = i2c_dp_aux_prepare_bus(adapter); |
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| 204 | if (error) |
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| 205 | return error; |
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| 206 | // error = i2c_add_adapter(adapter); |
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| 207 | return error; |
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| 208 | } |
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| 209 | EXPORT_SYMBOL(i2c_dp_aux_add_bus); |