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 // The IBM CFF power supply driver does map this bit to in1_alarm, however, 49 // since a number of the other bits are not mapped that way for STATUS_WORD, 50 // this code will just read the entire STATUS_WORD and use bit masking to find 51 // out if that fault is on. 52 constexpr auto VIN_UV_FAULT = 0x0008; 53 54 } 55 56 /** 57 * If the access should be done in the base 58 * device directory, the hwmon directory, the 59 * pmbus debug directory, or the device debug 60 * directory. 61 */ 62 enum class Type 63 { 64 Base, 65 Hwmon, 66 Debug, 67 DeviceDebug 68 }; 69 70 /** 71 * @class PMBus 72 * 73 * This class is an interface to communicating with PMBus devices 74 * by reading and writing sysfs files. 75 * 76 * Based on the Type parameter, the accesses can either be done 77 * in the base device directory (the one passed into the constructor), 78 * or in the hwmon directory for the device. 79 */ 80 class PMBus 81 { 82 public: 83 84 PMBus() = delete; 85 ~PMBus() = default; 86 PMBus(const PMBus&) = default; 87 PMBus& operator=(const PMBus&) = default; 88 PMBus(PMBus&&) = default; 89 PMBus& operator=(PMBus&&) = default; 90 91 /** 92 * Constructor 93 * 94 * @param[in] path - path to the sysfs directory 95 */ 96 PMBus(const std::string& path) : 97 basePath(path) 98 { 99 findHwmonDir(); 100 } 101 102 /** 103 * Constructor 104 * 105 * This version is required when DeviceDebug 106 * access will be used. 107 * 108 * @param[in] path - path to the sysfs directory 109 * @param[in] driverName - the device driver name 110 * @param[in] instance - chip instance number 111 */ 112 PMBus(const std::string& path, 113 const std::string& driverName, 114 size_t instance) : 115 basePath(path), 116 driverName(driverName), 117 instance(instance) 118 { 119 findHwmonDir(); 120 } 121 122 /** 123 * Reads a file in sysfs that represents a single bit, 124 * therefore doing a PMBus read. 125 * 126 * @param[in] name - path concatenated to 127 * basePath to read 128 * @param[in] type - Path type 129 * 130 * @return bool - false if result was 0, else true 131 */ 132 bool readBit(const std::string& name, Type type); 133 134 /** 135 * Reads a file in sysfs that represents a single bit, 136 * where the page number passed in is substituted 137 * into the name in place of the 'P' character in it. 138 * 139 * @param[in] name - path concatenated to 140 * basePath to read 141 * @param[in] page - page number 142 * @param[in] type - Path type 143 * 144 * @return bool - false if result was 0, else true 145 */ 146 bool readBitInPage(const std::string& name, 147 size_t page, 148 Type type); 149 /** 150 * Read byte(s) from file in sysfs. 151 * 152 * @param[in] name - path concatenated to basePath to read 153 * @param[in] type - Path type 154 * 155 * @return uint64_t - Up to 8 bytes of data read from file. 156 */ 157 uint64_t read(const std::string& name, Type type); 158 159 /** 160 * Writes an integer value to the file, therefore doing 161 * a PMBus write. 162 * 163 * @param[in] name - path concatenated to 164 * basePath to write 165 * @param[in] value - the value to write 166 * @param[in] type - Path type 167 */ 168 void write(const std::string& name, int value, Type type); 169 170 /** 171 * Returns the sysfs base path of this device 172 */ 173 inline const auto& path() const 174 { 175 return basePath; 176 } 177 178 /** 179 * Replaces the 'P' in the string passed in with 180 * the page number passed in. 181 * 182 * For example: 183 * insertPageNum("inP_enable", 42) 184 * returns "in42_enable" 185 * 186 * @param[in] templateName - the name string, with a 'P' in it 187 * @param[in] page - the page number to insert where the P was 188 * 189 * @return string - the new string with the page number in it 190 */ 191 static std::string insertPageNum(const std::string& templateName, 192 size_t page); 193 194 /** 195 * Finds the path relative to basePath to the hwmon directory 196 * for the device and stores it in hwmonRelPath. 197 */ 198 void findHwmonDir(); 199 200 /** 201 * Returns the path to use for the passed in type. 202 * 203 * @param[in] type - Path type 204 * 205 * @return fs::path - the full path 206 */ 207 fs::path getPath(Type type); 208 209 private: 210 211 /** 212 * The sysfs device path 213 */ 214 fs::path basePath; 215 216 /** 217 * The directory name under the basePath hwmon directory 218 */ 219 fs::path hwmonDir; 220 221 /** 222 * The device driver name. Used for finding the device 223 * debug directory. Not required if that directory 224 * isn't used. 225 */ 226 std::string driverName; 227 228 /** 229 * The device instance number. 230 * 231 * Used in conjuction with the driver name for finding 232 * the debug directory. Not required if that directory 233 * isn't used. 234 */ 235 size_t instance = 0; 236 237 /** 238 * The pmbus debug path with status files 239 */ 240 const fs::path debugPath = "/sys/kernel/debug/"; 241 242 }; 243 244 } 245 } 246