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1408 | serge | 1 | /* ------------------------------------------------------------------------- */ |
2 | /* */ |
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3 | /* i2c.h - definitions for the i2c-bus interface */ |
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4 | /* */ |
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5 | /* ------------------------------------------------------------------------- */ |
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6 | /* Copyright (C) 1995-2000 Simon G. Vogl |
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7 | |||
8 | This program is free software; you can redistribute it and/or modify |
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9 | it under the terms of the GNU General Public License as published by |
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10 | the Free Software Foundation; either version 2 of the License, or |
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11 | (at your option) any later version. |
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12 | |||
13 | This program is distributed in the hope that it will be useful, |
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14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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16 | GNU General Public License for more details. |
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17 | |||
18 | You should have received a copy of the GNU General Public License |
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19 | along with this program; if not, write to the Free Software |
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20 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
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21 | /* ------------------------------------------------------------------------- */ |
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22 | |||
23 | /* With some changes from Kyösti Mälkki |
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24 | Frodo Looijaard |
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25 | |||
26 | #ifndef _LINUX_I2C_H |
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27 | #define _LINUX_I2C_H |
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28 | |||
1964 | serge | 29 | #include |
30 | #ifdef __KERNEL__ |
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1430 | serge | 31 | #include |
32 | #include |
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1964 | serge | 33 | #include |
1408 | serge | 34 | |
35 | |||
1964 | serge | 36 | /* --- General options ------------------------------------------------ */ |
1408 | serge | 37 | |
38 | struct i2c_msg; |
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39 | struct i2c_algorithm; |
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40 | struct i2c_adapter; |
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41 | struct i2c_client; |
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1964 | serge | 42 | struct i2c_driver; |
1408 | serge | 43 | union i2c_smbus_data; |
1964 | serge | 44 | struct i2c_board_info; |
1408 | serge | 45 | |
46 | |||
47 | /* Transfer num messages. |
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48 | */ |
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49 | extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, |
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50 | int num); |
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51 | |||
52 | /** |
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1430 | serge | 53 | * struct i2c_driver - represent an I2C device driver |
54 | * @class: What kind of i2c device we instantiate (for detect) |
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55 | * @attach_adapter: Callback for bus addition (for legacy drivers) |
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56 | * @detach_adapter: Callback for bus removal (for legacy drivers) |
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57 | * @probe: Callback for device binding |
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58 | * @remove: Callback for device unbinding |
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59 | * @shutdown: Callback for device shutdown |
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60 | * @suspend: Callback for device suspend |
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61 | * @resume: Callback for device resume |
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1964 | serge | 62 | * @alert: Alert callback, for example for the SMBus alert protocol |
1430 | serge | 63 | * @command: Callback for bus-wide signaling (optional) |
64 | * @driver: Device driver model driver |
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65 | * @id_table: List of I2C devices supported by this driver |
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66 | * @detect: Callback for device detection |
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67 | * @address_list: The I2C addresses to probe (for detect) |
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68 | * @clients: List of detected clients we created (for i2c-core use only) |
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69 | * |
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70 | * The driver.owner field should be set to the module owner of this driver. |
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71 | * The driver.name field should be set to the name of this driver. |
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72 | * |
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73 | * For automatic device detection, both @detect and @address_data must |
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74 | * be defined. @class should also be set, otherwise only devices forced |
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75 | * with module parameters will be created. The detect function must |
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76 | * fill at least the name field of the i2c_board_info structure it is |
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77 | * handed upon successful detection, and possibly also the flags field. |
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78 | * |
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79 | * If @detect is missing, the driver will still work fine for enumerated |
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80 | * devices. Detected devices simply won't be supported. This is expected |
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81 | * for the many I2C/SMBus devices which can't be detected reliably, and |
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82 | * the ones which can always be enumerated in practice. |
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83 | * |
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84 | * The i2c_client structure which is handed to the @detect callback is |
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85 | * not a real i2c_client. It is initialized just enough so that you can |
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86 | * call i2c_smbus_read_byte_data and friends on it. Don't do anything |
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87 | * else with it. In particular, calling dev_dbg and friends on it is |
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88 | * not allowed. |
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89 | */ |
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90 | struct i2c_driver { |
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91 | unsigned int class; |
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92 | |||
93 | /* Notifies the driver that a new bus has appeared or is about to be |
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1964 | serge | 94 | * removed. You should avoid using this, it will be removed in a |
95 | * near future. |
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1430 | serge | 96 | */ |
97 | int (*attach_adapter)(struct i2c_adapter *); |
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98 | int (*detach_adapter)(struct i2c_adapter *); |
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99 | |||
100 | /* Standard driver model interfaces */ |
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101 | int (*probe)(struct i2c_client *, const struct i2c_device_id *); |
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102 | int (*remove)(struct i2c_client *); |
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103 | |||
104 | /* driver model interfaces that don't relate to enumeration */ |
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105 | void (*shutdown)(struct i2c_client *); |
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106 | // int (*suspend)(struct i2c_client *, pm_message_t mesg); |
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107 | int (*resume)(struct i2c_client *); |
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108 | |||
109 | /* Alert callback, for example for the SMBus alert protocol. |
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110 | * The format and meaning of the data value depends on the protocol. |
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111 | * For the SMBus alert protocol, there is a single bit of data passed |
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112 | * as the alert response's low bit ("event flag"). |
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113 | */ |
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114 | void (*alert)(struct i2c_client *, unsigned int data); |
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115 | |||
116 | /* a ioctl like command that can be used to perform specific functions |
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117 | * with the device. |
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118 | */ |
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119 | int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); |
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120 | |||
121 | // struct device_driver driver; |
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122 | const struct i2c_device_id *id_table; |
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123 | |||
124 | /* Device detection callback for automatic device creation */ |
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125 | // int (*detect)(struct i2c_client *, struct i2c_board_info *); |
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126 | const unsigned short *address_list; |
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127 | struct list_head clients; |
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128 | }; |
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129 | #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) |
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130 | |||
131 | /** |
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1408 | serge | 132 | * struct i2c_client - represent an I2C slave device |
133 | * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; |
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134 | * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking |
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135 | * @addr: Address used on the I2C bus connected to the parent adapter. |
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136 | * @name: Indicates the type of the device, usually a chip name that's |
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137 | * generic enough to hide second-sourcing and compatible revisions. |
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138 | * @adapter: manages the bus segment hosting this I2C device |
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139 | * @driver: device's driver, hence pointer to access routines |
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140 | * @dev: Driver model device node for the slave. |
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141 | * @irq: indicates the IRQ generated by this device (if any) |
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142 | * @detected: member of an i2c_driver.clients list or i2c-core's |
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143 | * userspace_devices list |
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144 | * |
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145 | * An i2c_client identifies a single device (i.e. chip) connected to an |
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146 | * i2c bus. The behaviour exposed to Linux is defined by the driver |
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147 | * managing the device. |
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148 | */ |
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149 | struct i2c_client { |
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150 | unsigned short flags; /* div., see below */ |
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151 | unsigned short addr; /* chip address - NOTE: 7bit */ |
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152 | /* addresses are stored in the */ |
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153 | /* _LOWER_ 7 bits */ |
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154 | char name[I2C_NAME_SIZE]; |
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155 | struct i2c_adapter *adapter; /* the adapter we sit on */ |
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1430 | serge | 156 | struct i2c_driver *driver; /* and our access routines */ |
1964 | serge | 157 | struct device dev; /* the device structure */ |
158 | int irq; /* irq issued by device */ |
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1408 | serge | 159 | struct list_head detected; |
160 | }; |
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161 | #define to_i2c_client(d) container_of(d, struct i2c_client, dev) |
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162 | |||
1430 | serge | 163 | extern struct i2c_client *i2c_verify_client(struct device *dev); |
1408 | serge | 164 | |
1964 | serge | 165 | /** |
166 | * struct i2c_board_info - template for device creation |
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167 | * @type: chip type, to initialize i2c_client.name |
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168 | * @flags: to initialize i2c_client.flags |
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169 | * @addr: stored in i2c_client.addr |
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170 | * @platform_data: stored in i2c_client.dev.platform_data |
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171 | * @archdata: copied into i2c_client.dev.archdata |
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172 | * @of_node: pointer to OpenFirmware device node |
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173 | * @irq: stored in i2c_client.irq |
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174 | * |
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175 | * I2C doesn't actually support hardware probing, although controllers and |
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176 | * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's |
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177 | * a device at a given address. Drivers commonly need more information than |
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178 | * that, such as chip type, configuration, associated IRQ, and so on. |
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179 | * |
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180 | * i2c_board_info is used to build tables of information listing I2C devices |
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181 | * that are present. This information is used to grow the driver model tree. |
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182 | * For mainboards this is done statically using i2c_register_board_info(); |
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183 | * bus numbers identify adapters that aren't yet available. For add-on boards, |
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184 | * i2c_new_device() does this dynamically with the adapter already known. |
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185 | */ |
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186 | struct i2c_board_info { |
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187 | char type[I2C_NAME_SIZE]; |
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188 | unsigned short flags; |
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189 | unsigned short addr; |
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190 | void *platform_data; |
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191 | struct dev_archdata *archdata; |
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192 | #ifdef CONFIG_OF |
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193 | struct device_node *of_node; |
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194 | #endif |
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195 | int irq; |
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196 | }; |
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197 | |||
198 | /** |
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199 | * I2C_BOARD_INFO - macro used to list an i2c device and its address |
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200 | * @dev_type: identifies the device type |
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201 | * @dev_addr: the device's address on the bus. |
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202 | * |
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203 | * This macro initializes essential fields of a struct i2c_board_info, |
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204 | * declaring what has been provided on a particular board. Optional |
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205 | * fields (such as associated irq, or device-specific platform_data) |
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206 | * are provided using conventional syntax. |
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207 | */ |
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208 | #define I2C_BOARD_INFO(dev_type, dev_addr) \ |
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209 | .type = dev_type, .addr = (dev_addr) |
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1408 | serge | 210 | /* |
211 | * The following structs are for those who like to implement new bus drivers: |
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212 | * i2c_algorithm is the interface to a class of hardware solutions which can |
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213 | * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 |
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214 | * to name two of the most common. |
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215 | */ |
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216 | struct i2c_algorithm { |
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217 | /* If an adapter algorithm can't do I2C-level access, set master_xfer |
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218 | to NULL. If an adapter algorithm can do SMBus access, set |
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219 | smbus_xfer. If set to NULL, the SMBus protocol is simulated |
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220 | using common I2C messages */ |
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221 | /* master_xfer should return the number of messages successfully |
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222 | processed, or a negative value on error */ |
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223 | int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, |
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224 | int num); |
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225 | int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, |
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226 | unsigned short flags, char read_write, |
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227 | u8 command, int size, union i2c_smbus_data *data); |
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228 | |||
229 | /* To determine what the adapter supports */ |
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230 | u32 (*functionality) (struct i2c_adapter *); |
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231 | }; |
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232 | |||
233 | /* |
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234 | * i2c_adapter is the structure used to identify a physical i2c bus along |
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235 | * with the access algorithms necessary to access it. |
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236 | */ |
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237 | struct i2c_adapter { |
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1964 | serge | 238 | struct module *owner; |
1408 | serge | 239 | unsigned int class; /* classes to allow probing for */ |
240 | const struct i2c_algorithm *algo; /* the algorithm to access the bus */ |
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241 | void *algo_data; |
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242 | |||
243 | /* data fields that are valid for all devices */ |
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1430 | serge | 244 | // struct rt_mutex bus_lock; |
1408 | serge | 245 | |
246 | int timeout; /* in jiffies */ |
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247 | int retries; |
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1430 | serge | 248 | struct device dev; /* the adapter device */ |
1408 | serge | 249 | |
250 | int nr; |
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251 | char name[48]; |
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252 | }; |
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253 | #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) |
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254 | |||
1964 | serge | 255 | static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) |
1430 | serge | 256 | { |
257 | return dev_get_drvdata(&dev->dev); |
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258 | } |
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1408 | serge | 259 | |
1430 | serge | 260 | static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) |
261 | { |
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262 | dev_set_drvdata(&dev->dev, data); |
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263 | } |
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264 | |||
1964 | serge | 265 | /* Adapter locking functions, exported for shared pin cases */ |
266 | void i2c_lock_adapter(struct i2c_adapter *); |
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267 | void i2c_unlock_adapter(struct i2c_adapter *); |
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268 | |||
1408 | serge | 269 | /*flags for the client struct: */ |
270 | #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ |
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271 | #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ |
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272 | /* Must equal I2C_M_TEN below */ |
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273 | #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ |
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274 | |||
275 | /* i2c adapter classes (bitmask) */ |
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276 | #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ |
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277 | #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ |
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1964 | serge | 278 | #define I2C_CLASS_SPD (1<<7) /* Memory modules */ |
1408 | serge | 279 | |
280 | /* Internal numbers to terminate lists */ |
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281 | #define I2C_CLIENT_END 0xfffeU |
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282 | |||
283 | /* The numbers to use to set I2C bus address */ |
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284 | #define ANY_I2C_BUS 0xffff |
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285 | |||
286 | /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ |
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287 | #define I2C_ADDRS(addr, addrs...) \ |
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288 | ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) |
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289 | |||
290 | |||
1964 | serge | 291 | #endif /* __KERNEL__ */ |
1408 | serge | 292 | /** |
293 | * struct i2c_msg - an I2C transaction segment beginning with START |
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294 | * @addr: Slave address, either seven or ten bits. When this is a ten |
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295 | * bit address, I2C_M_TEN must be set in @flags and the adapter |
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296 | * must support I2C_FUNC_10BIT_ADDR. |
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297 | * @flags: I2C_M_RD is handled by all adapters. No other flags may be |
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298 | * provided unless the adapter exported the relevant I2C_FUNC_* |
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299 | * flags through i2c_check_functionality(). |
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300 | * @len: Number of data bytes in @buf being read from or written to the |
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301 | * I2C slave address. For read transactions where I2C_M_RECV_LEN |
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302 | * is set, the caller guarantees that this buffer can hold up to |
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303 | * 32 bytes in addition to the initial length byte sent by the |
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304 | * slave (plus, if used, the SMBus PEC); and this value will be |
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305 | * incremented by the number of block data bytes received. |
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306 | * @buf: The buffer into which data is read, or from which it's written. |
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307 | * |
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308 | * An i2c_msg is the low level representation of one segment of an I2C |
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309 | * transaction. It is visible to drivers in the @i2c_transfer() procedure, |
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310 | * to userspace from i2c-dev, and to I2C adapter drivers through the |
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311 | * @i2c_adapter.@master_xfer() method. |
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312 | * |
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313 | * Except when I2C "protocol mangling" is used, all I2C adapters implement |
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314 | * the standard rules for I2C transactions. Each transaction begins with a |
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315 | * START. That is followed by the slave address, and a bit encoding read |
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316 | * versus write. Then follow all the data bytes, possibly including a byte |
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317 | * with SMBus PEC. The transfer terminates with a NAK, or when all those |
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318 | * bytes have been transferred and ACKed. If this is the last message in a |
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319 | * group, it is followed by a STOP. Otherwise it is followed by the next |
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320 | * @i2c_msg transaction segment, beginning with a (repeated) START. |
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321 | * |
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322 | * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then |
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323 | * passing certain @flags may have changed those standard protocol behaviors. |
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324 | * Those flags are only for use with broken/nonconforming slaves, and with |
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325 | * adapters which are known to support the specific mangling options they |
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326 | * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR). |
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327 | */ |
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328 | struct i2c_msg { |
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1964 | serge | 329 | __u16 addr; /* slave address */ |
330 | __u16 flags; |
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1408 | serge | 331 | #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ |
332 | #define I2C_M_RD 0x0001 /* read data, from slave to master */ |
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333 | #define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_PROTOCOL_MANGLING */ |
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334 | #define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */ |
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335 | #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */ |
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336 | #define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */ |
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337 | #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ |
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1964 | serge | 338 | __u16 len; /* msg length */ |
339 | __u8 *buf; /* pointer to msg data */ |
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1408 | serge | 340 | }; |
341 | |||
342 | /* To determine what functionality is present */ |
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343 | |||
344 | #define I2C_FUNC_I2C 0x00000001 |
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345 | #define I2C_FUNC_10BIT_ADDR 0x00000002 |
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346 | #define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_NOSTART etc. */ |
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347 | #define I2C_FUNC_SMBUS_PEC 0x00000008 |
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348 | #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */ |
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349 | #define I2C_FUNC_SMBUS_QUICK 0x00010000 |
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350 | #define I2C_FUNC_SMBUS_READ_BYTE 0x00020000 |
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351 | #define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000 |
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352 | #define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000 |
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353 | #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000 |
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354 | #define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000 |
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355 | #define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000 |
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356 | #define I2C_FUNC_SMBUS_PROC_CALL 0x00800000 |
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357 | #define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000 |
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358 | #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000 |
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359 | #define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */ |
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360 | #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */ |
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361 | |||
362 | #define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \ |
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363 | I2C_FUNC_SMBUS_WRITE_BYTE) |
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364 | #define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \ |
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365 | I2C_FUNC_SMBUS_WRITE_BYTE_DATA) |
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366 | #define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \ |
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367 | I2C_FUNC_SMBUS_WRITE_WORD_DATA) |
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368 | #define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \ |
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369 | I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) |
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370 | #define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \ |
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371 | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK) |
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372 | |||
373 | #define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \ |
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374 | I2C_FUNC_SMBUS_BYTE | \ |
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375 | I2C_FUNC_SMBUS_BYTE_DATA | \ |
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376 | I2C_FUNC_SMBUS_WORD_DATA | \ |
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377 | I2C_FUNC_SMBUS_PROC_CALL | \ |
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378 | I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \ |
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379 | I2C_FUNC_SMBUS_I2C_BLOCK | \ |
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380 | I2C_FUNC_SMBUS_PEC) |
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381 | |||
382 | /* |
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383 | * Data for SMBus Messages |
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384 | */ |
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385 | #define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */ |
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386 | union i2c_smbus_data { |
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387 | __u8 byte; |
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388 | __u16 word; |
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389 | __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */ |
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390 | /* and one more for user-space compatibility */ |
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391 | }; |
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392 | |||
393 | /* i2c_smbus_xfer read or write markers */ |
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394 | #define I2C_SMBUS_READ 1 |
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395 | #define I2C_SMBUS_WRITE 0 |
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396 | |||
397 | /* SMBus transaction types (size parameter in the above functions) |
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398 | Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */ |
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399 | #define I2C_SMBUS_QUICK 0 |
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400 | #define I2C_SMBUS_BYTE 1 |
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401 | #define I2C_SMBUS_BYTE_DATA 2 |
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402 | #define I2C_SMBUS_WORD_DATA 3 |
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403 | #define I2C_SMBUS_PROC_CALL 4 |
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404 | #define I2C_SMBUS_BLOCK_DATA 5 |
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405 | #define I2C_SMBUS_I2C_BLOCK_BROKEN 6 |
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406 | #define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */ |
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407 | #define I2C_SMBUS_I2C_BLOCK_DATA 8 |
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408 | |||
409 | #endif /* _LINUX_I2C_H */7)><7)>3)><3)>0)><0)> |