1 #pragma once 2 3 #include <exception> 4 #include <fstream> 5 #include <string> 6 7 namespace sysfs { 8 9 /** 10 * @class DeviceBusyException 11 * 12 * An internal exception which will be thrown when 13 * readSysfsWithCallout() hits an EAGAIN. Will never bubble 14 * up to terminate the application, nor does it need to be 15 * reported. 16 */ 17 class DeviceBusyException : public std::runtime_error 18 { 19 public: 20 21 DeviceBusyException(const std::string& path) : 22 std::runtime_error(path + " busy") 23 { 24 } 25 }; 26 27 inline std::string make_sysfs_path(const std::string& path, 28 const std::string& type, 29 const std::string& id, 30 const std::string& entry) 31 { 32 using namespace std::literals; 33 34 return path + "/"s + type + id + "_"s + entry; 35 } 36 37 /** @brief Return the path to the phandle file matching value in io-channels. 38 * 39 * This function will take two passed in paths. 40 * One path is used to find the io-channels file. 41 * The other path is used to find the phandle file. 42 * The 4 byte phandle value is read from the phandle file(s). 43 * The 4 byte phandle value and 4 byte index value is read from io-channels. 44 * When a match is found, the path to the matching phandle file is returned. 45 * 46 * @param[in] iochanneldir - Path to file for getting phandle from io-channels 47 * @param[in] phandledir - Path to use for reading from phandle file 48 * 49 * @return Path to phandle file with value matching that in io-channels 50 */ 51 std::string findPhandleMatch( 52 const std::string& iochanneldir, 53 const std::string& phandledir); 54 55 /** @brief Find hwmon instances 56 * 57 * Look for a matching hwmon instance given an 58 * open firmware device path. 59 * 60 * @param[in] ofNode- The open firmware device path. 61 * 62 * @returns[in] - The hwmon instance path or an empty 63 * string if no match is found. 64 */ 65 std::string findHwmon(const std::string& ofNode); 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 /** @brief Read an hwmon sysfs value. 79 * 80 * Calls exit(3) with bad status on failure. 81 * 82 * @param[in] root - The hwmon class root. 83 * @param[in] instance - The hwmon instance (ex. hwmon1). 84 * @param[in] type - The hwmon type (ex. temp). 85 * @param[in] id - The hwmon id (ex. 1). 86 * @param[in] sensor - The hwmon sensor (ex. input). 87 * @param[in] throwDeviceBusy - will throw a DeviceBusyException 88 * on an EAGAIN errno instead of an error log exception. 89 * 90 * @returns - The read value. 91 */ 92 int readSysfsWithCallout(const std::string& root, 93 const std::string& instance, 94 const std::string& type, 95 const std::string& id, 96 const std::string& sensor, 97 bool throwDeviceBusy = true); 98 99 /** @brief Write a hwmon sysfs value 100 * 101 * Calls exit(3) with bad status on failure 102 * 103 * @param[in] value - The value to be written 104 * @param[in] root - The hwmon class root. 105 * @param[in] instance - The hwmon instance (ex. hwmon1). 106 * @param[in] type - The hwmon type (ex. fan). 107 * @param[in] id - The hwmon id (ex. 1). 108 * @param[in] sensor - The hwmon sensor (ex. target). 109 * 110 * @returns - The value written 111 */ 112 uint64_t writeSysfsWithCallout(const uint64_t& value, 113 const std::string& root, 114 const std::string& instance, 115 const std::string& type, 116 const std::string& id, 117 const std::string& sensor); 118 119 } 120 121 // vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4 122