1 #pragma once 2 3 #include <chrono> 4 #include <exception> 5 #include <fstream> 6 #include <string> 7 8 namespace sysfs { 9 10 inline std::string make_sysfs_path(const std::string& path, 11 const std::string& type, 12 const std::string& id, 13 const std::string& entry) 14 { 15 using namespace std::literals; 16 17 if (entry.empty()) { 18 return path + "/"s + type + id; 19 } 20 21 return path + "/"s + type + id + "_"s + entry; 22 } 23 24 /** @brief Return the path to the phandle file matching value in io-channels. 25 * 26 * This function will take two passed in paths. 27 * One path is used to find the io-channels file. 28 * The other path is used to find the phandle file. 29 * The 4 byte phandle value is read from the phandle file(s). 30 * The 4 byte phandle value and 4 byte index value is read from io-channels. 31 * When a match is found, the path to the matching phandle file is returned. 32 * 33 * @param[in] iochanneldir - Path to file for getting phandle from io-channels 34 * @param[in] phandledir - Path to use for reading from phandle file 35 * 36 * @return Path to phandle file with value matching that in io-channels 37 */ 38 std::string findPhandleMatch( 39 const std::string& iochanneldir, 40 const std::string& phandledir); 41 42 /** @brief Find hwmon instances from an open-firmware device tree path 43 * 44 * Look for a matching hwmon instance given an 45 * open firmware device path. 46 * 47 * @param[in] ofNode- The open firmware device path. 48 * 49 * @returns[in] - The hwmon instance path or an empty 50 * string if no match is found. 51 */ 52 std::string findHwmonFromOFPath(const std::string& ofNode); 53 54 /** @brief Find hwmon instances from a device path 55 * 56 * Look for a matching hwmon instance given a device path that 57 * starts with /devices. This path is the DEVPATH udev attribute 58 * for the device except it has the '/hwmon/hwmonN' stripped off. 59 * 60 * @param[in] devPath - The device path. 61 * 62 * @return - The hwmon instance path or an empty 63 * string if no match is found. 64 */ 65 std::string findHwmonFromDevPath(const std::string& devPath); 66 67 /** @brief Return the path to use for a call out. 68 * 69 * Return an empty string if a callout path cannot be 70 * found. 71 * 72 * @param[in] instancePath - /sys/class/hwmon/hwmon<N> path. 73 * 74 * @return Path to use for call out 75 */ 76 std::string findCalloutPath(const std::string& instancePath); 77 78 namespace hwmonio 79 { 80 static constexpr auto retries = 10; 81 static constexpr auto delay = std::chrono::milliseconds{100}; 82 83 /** @class HwmonIO 84 * @brief Convenience wrappers for HWMON sysfs attribute IO. 85 * 86 * Unburden the rest of the application from having to check 87 * ENOENT after every hwmon attribute io operation. Hwmon 88 * device drivers can be unbound at any time; the program 89 * cannot always be terminated externally before we try to 90 * do an io. 91 */ 92 class HwmonIO 93 { 94 public: 95 HwmonIO() = delete; 96 HwmonIO(const HwmonIO&) = default; 97 HwmonIO(HwmonIO&&) = default; 98 HwmonIO& operator=(const HwmonIO&) = default; 99 HwmonIO& operator=(HwmonIO&&) = default; 100 ~HwmonIO() = default; 101 102 /** @brief Constructor 103 * 104 * @param[in] path - hwmon instance root - eg: 105 * /sys/class/hwmon/hwmon<N> 106 */ 107 explicit HwmonIO(const std::string& path); 108 109 /** @brief Perform formatted hwmon sysfs read. 110 * 111 * Propagates any exceptions other than ENOENT. 112 * ENOENT will result in a call to exit(0) in case 113 * the underlying hwmon driver is unbound and 114 * the program is inadvertently left running. 115 * 116 * For possibly transient errors will retry up to 117 * the specified number of times. 118 * 119 * @param[in] type - The hwmon type (ex. temp). 120 * @param[in] id - The hwmon id (ex. 1). 121 * @param[in] sensor - The hwmon sensor (ex. input). 122 * @param[in] retries - The number of times to retry. 123 * @param[in] delay - The time to sleep between retry attempts. 124 * 125 * @return val - The read value. 126 */ 127 int64_t read( 128 const std::string& type, 129 const std::string& id, 130 const std::string& sensor, 131 size_t retries, 132 std::chrono::milliseconds delay, 133 bool isOCC = false) const; 134 135 /** @brief Perform formatted hwmon sysfs write. 136 * 137 * Propagates any exceptions other than ENOENT. 138 * ENOENT will result in a call to exit(0) in case 139 * the underlying hwmon driver is unbound and 140 * the program is inadvertently left running. 141 * 142 * For possibly transient errors will retry up to 143 * the specified number of times. 144 * 145 * @param[in] val - The value to be written. 146 * @param[in] type - The hwmon type (ex. fan). 147 * @param[in] id - The hwmon id (ex. 1). 148 * @param[in] retries - The number of times to retry. 149 * @param[in] delay - The time to sleep between retry attempts. 150 */ 151 void write( 152 uint32_t val, 153 const std::string& type, 154 const std::string& id, 155 const std::string& sensor, 156 size_t retries, 157 std::chrono::milliseconds delay) const; 158 159 160 /** @brief Hwmon instance path access. 161 * 162 * @return path - The hwmon instance path. 163 */ 164 std::string path() const; 165 166 private: 167 std::string p; 168 }; 169 } // namespace hwmonio 170 } // namespace sysfs 171 172 // vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4 173