1 #pragma once 2 3 #include <experimental/filesystem> 4 #include <string> 5 #include <vector> 6 7 namespace witherspoon 8 { 9 namespace pmbus 10 { 11 12 namespace fs = std::experimental::filesystem; 13 14 // The file name Linux uses to capture the STATUS_WORD from pmbus. 15 constexpr auto STATUS_WORD = "status0"; 16 17 // The file name Linux uses to capture the STATUS_INPUT from pmbus. 18 constexpr auto STATUS_INPUT = "status0_input"; 19 20 // Voltage out status. 21 // Overvoltage fault or warning, Undervoltage fault or warning, maximum or 22 // minimum warning, .... 23 // Uses Page substitution 24 constexpr auto STATUS_VOUT = "statusP_vout"; 25 26 // Current output status bits. 27 constexpr auto STATUS_IOUT = "status0_iout"; 28 29 // Manufacturing specific status bits 30 constexpr auto STATUS_MFR = "status0_mfr"; 31 32 namespace status_word 33 { 34 constexpr auto VOUT_FAULT = 0x8000; 35 36 // The IBM CFF power supply driver does map this bit to power1_alarm in the 37 // hwmon space, but since the other bits that need to be checked do not have 38 // a similar mapping, the code will just read STATUS_WORD and use bit masking 39 // to see if the INPUT FAULT OR WARNING bit is on. 40 constexpr auto INPUT_FAULT_WARN = 0x2000; 41 42 // The bit mask representing the POWER_GOOD Negated bit of the STATUS_WORD. 43 constexpr auto POWER_GOOD_NEGATED = 0x0800; 44 45 // The bit mask representing the UNITI_IS_OFF bit of the STATUS_WORD. 46 constexpr auto UNIT_IS_OFF = 0x0040; 47 48 // Bit 5 of the STATUS_BYTE, or lower byte of STATUS_WORD is used to indicate 49 // an output overvoltage fault. 50 constexpr auto VOUT_OV_FAULT = 0x0020; 51 52 // The bit mask representing that an output overcurrent fault has occurred. 53 constexpr auto IOUT_OC_FAULT = 0x0010; 54 55 // The IBM CFF power supply driver does map this bit to in1_alarm, however, 56 // since a number of the other bits are not mapped that way for STATUS_WORD, 57 // this code will just read the entire STATUS_WORD and use bit masking to find 58 // out if that fault is on. 59 constexpr auto VIN_UV_FAULT = 0x0008; 60 61 } 62 63 /** 64 * If the access should be done in the base 65 * device directory, the hwmon directory, the 66 * pmbus debug directory, or the device debug 67 * directory. 68 */ 69 enum class Type 70 { 71 Base, 72 Hwmon, 73 Debug, 74 DeviceDebug 75 }; 76 77 /** 78 * @class PMBus 79 * 80 * This class is an interface to communicating with PMBus devices 81 * by reading and writing sysfs files. 82 * 83 * Based on the Type parameter, the accesses can either be done 84 * in the base device directory (the one passed into the constructor), 85 * or in the hwmon directory for the device. 86 */ 87 class PMBus 88 { 89 public: 90 91 PMBus() = delete; 92 ~PMBus() = default; 93 PMBus(const PMBus&) = default; 94 PMBus& operator=(const PMBus&) = default; 95 PMBus(PMBus&&) = default; 96 PMBus& operator=(PMBus&&) = default; 97 98 /** 99 * Constructor 100 * 101 * @param[in] path - path to the sysfs directory 102 */ 103 PMBus(const std::string& path) : 104 basePath(path) 105 { 106 findHwmonDir(); 107 } 108 109 /** 110 * Constructor 111 * 112 * This version is required when DeviceDebug 113 * access will be used. 114 * 115 * @param[in] path - path to the sysfs directory 116 * @param[in] driverName - the device driver name 117 * @param[in] instance - chip instance number 118 */ 119 PMBus(const std::string& path, 120 const std::string& driverName, 121 size_t instance) : 122 basePath(path), 123 driverName(driverName), 124 instance(instance) 125 { 126 findHwmonDir(); 127 } 128 129 /** 130 * Reads a file in sysfs that represents a single bit, 131 * therefore doing a PMBus read. 132 * 133 * @param[in] name - path concatenated to 134 * basePath to read 135 * @param[in] type - Path type 136 * 137 * @return bool - false if result was 0, else true 138 */ 139 bool readBit(const std::string& name, Type type); 140 141 /** 142 * Reads a file in sysfs that represents a single bit, 143 * where the page number passed in is substituted 144 * into the name in place of the 'P' character in it. 145 * 146 * @param[in] name - path concatenated to 147 * basePath to read 148 * @param[in] page - page number 149 * @param[in] type - Path type 150 * 151 * @return bool - false if result was 0, else true 152 */ 153 bool readBitInPage(const std::string& name, 154 size_t page, 155 Type type); 156 /** 157 * Read byte(s) from file in sysfs. 158 * 159 * @param[in] name - path concatenated to basePath to read 160 * @param[in] type - Path type 161 * 162 * @return uint64_t - Up to 8 bytes of data read from file. 163 */ 164 uint64_t read(const std::string& name, Type type); 165 166 /** 167 * Writes an integer value to the file, therefore doing 168 * a PMBus write. 169 * 170 * @param[in] name - path concatenated to 171 * basePath to write 172 * @param[in] value - the value to write 173 * @param[in] type - Path type 174 */ 175 void write(const std::string& name, int value, Type type); 176 177 /** 178 * Returns the sysfs base path of this device 179 */ 180 inline const auto& path() const 181 { 182 return basePath; 183 } 184 185 /** 186 * Replaces the 'P' in the string passed in with 187 * the page number passed in. 188 * 189 * For example: 190 * insertPageNum("inP_enable", 42) 191 * returns "in42_enable" 192 * 193 * @param[in] templateName - the name string, with a 'P' in it 194 * @param[in] page - the page number to insert where the P was 195 * 196 * @return string - the new string with the page number in it 197 */ 198 static std::string insertPageNum(const std::string& templateName, 199 size_t page); 200 201 /** 202 * Finds the path relative to basePath to the hwmon directory 203 * for the device and stores it in hwmonRelPath. 204 */ 205 void findHwmonDir(); 206 207 /** 208 * Returns the path to use for the passed in type. 209 * 210 * @param[in] type - Path type 211 * 212 * @return fs::path - the full path 213 */ 214 fs::path getPath(Type type); 215 216 private: 217 218 /** 219 * The sysfs device path 220 */ 221 fs::path basePath; 222 223 /** 224 * The directory name under the basePath hwmon directory 225 */ 226 fs::path hwmonDir; 227 228 /** 229 * The device driver name. Used for finding the device 230 * debug directory. Not required if that directory 231 * isn't used. 232 */ 233 std::string driverName; 234 235 /** 236 * The device instance number. 237 * 238 * Used in conjuction with the driver name for finding 239 * the debug directory. Not required if that directory 240 * isn't used. 241 */ 242 size_t instance = 0; 243 244 /** 245 * The pmbus debug path with status files 246 */ 247 const fs::path debugPath = "/sys/kernel/debug/"; 248 249 }; 250 251 } 252 } 253