xref: /openbmc/phosphor-power/pmbus.cpp (revision cd9ab087)
1 /**
2  * Copyright © 2017 IBM Corporation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 #include "pmbus.hpp"
17 
18 #include <phosphor-logging/elog-errors.hpp>
19 #include <phosphor-logging/elog.hpp>
20 #include <xyz/openbmc_project/Common/Device/error.hpp>
21 #include <xyz/openbmc_project/Common/error.hpp>
22 
23 #include <filesystem>
24 #include <fstream>
25 
26 namespace phosphor
27 {
28 namespace pmbus
29 {
30 
31 using namespace phosphor::logging;
32 using namespace sdbusplus::xyz::openbmc_project::Common::Error;
33 using namespace sdbusplus::xyz::openbmc_project::Common::Device::Error;
34 namespace fs = std::filesystem;
35 
36 /**
37  * @brief Helper to close a file handle
38  */
39 struct FileCloser
40 {
41     void operator()(FILE* fp) const
42     {
43         fclose(fp);
44     }
45 };
46 
47 std::string PMBus::insertPageNum(const std::string& templateName, size_t page)
48 {
49     auto name = templateName;
50 
51     // insert the page where the P was
52     auto pos = name.find('P');
53     if (pos != std::string::npos)
54     {
55         name.replace(pos, 1, std::to_string(page));
56     }
57 
58     return name;
59 }
60 
61 fs::path PMBus::getPath(Type type)
62 {
63     switch (type)
64     {
65         default:
66         /* fall through */
67         case Type::Base:
68             return basePath;
69             break;
70         case Type::Hwmon:
71             return basePath / "hwmon" / hwmonDir;
72             break;
73         case Type::Debug:
74             return debugPath / "pmbus" / hwmonDir;
75             break;
76         case Type::DeviceDebug:
77         {
78             auto dir = driverName + "." + std::to_string(instance);
79             return debugPath / dir;
80             break;
81         }
82         case Type::HwmonDeviceDebug:
83             return debugPath / "pmbus" / hwmonDir / getDeviceName();
84             break;
85     }
86 }
87 
88 std::string PMBus::getDeviceName()
89 {
90     std::string name;
91     std::ifstream file;
92     auto path = basePath / "name";
93 
94     file.exceptions(std::ifstream::failbit | std::ifstream::badbit |
95                     std::ifstream::eofbit);
96     try
97     {
98         file.open(path);
99         file >> name;
100     }
101     catch (std::exception& e)
102     {
103         log<level::ERR>("Unable to read PMBus device name",
104                         entry("PATH=%s", path.c_str()));
105     }
106 
107     return name;
108 }
109 
110 bool PMBus::readBitInPage(const std::string& name, size_t page, Type type)
111 {
112     auto pagedBit = insertPageNum(name, page);
113     return readBit(pagedBit, type);
114 }
115 
116 bool PMBus::readBit(const std::string& name, Type type)
117 {
118     unsigned long int value = 0;
119     std::ifstream file;
120     fs::path path = getPath(type);
121 
122     path /= name;
123 
124     file.exceptions(std::ifstream::failbit | std::ifstream::badbit |
125                     std::ifstream::eofbit);
126 
127     try
128     {
129         char* err = NULL;
130         std::string val{1, '\0'};
131 
132         file.open(path);
133         file.read(&val[0], 1);
134 
135         value = strtoul(val.c_str(), &err, 10);
136 
137         if (*err)
138         {
139             log<level::ERR>("Invalid character in sysfs file",
140                             entry("FILE=%s", path.c_str()),
141                             entry("CONTENTS=%s", val.c_str()));
142 
143             // Catch below and handle as a read failure
144             elog<InternalFailure>();
145         }
146     }
147     catch (std::exception& e)
148     {
149         auto rc = errno;
150 
151         log<level::ERR>("Failed to read sysfs file",
152                         entry("FILENAME=%s", path.c_str()));
153 
154         using metadata = xyz::openbmc_project::Common::Device::ReadFailure;
155 
156         elog<ReadFailure>(
157             metadata::CALLOUT_ERRNO(rc),
158             metadata::CALLOUT_DEVICE_PATH(fs::canonical(basePath).c_str()));
159     }
160 
161     return value != 0;
162 }
163 
164 bool PMBus::exists(const std::string& name, Type type)
165 {
166     auto path = getPath(type);
167     path /= name;
168     return fs::exists(path);
169 }
170 
171 uint64_t PMBus::read(const std::string& name, Type type)
172 {
173     uint64_t data = 0;
174     std::ifstream file;
175     auto path = getPath(type);
176     path /= name;
177 
178     file.exceptions(std::ifstream::failbit | std::ifstream::badbit |
179                     std::ifstream::eofbit);
180 
181     try
182     {
183         file.open(path);
184         file >> std::hex >> data;
185     }
186     catch (std::exception& e)
187     {
188         auto rc = errno;
189         log<level::ERR>("Failed to read sysfs file",
190                         entry("FILENAME=%s", path.c_str()));
191 
192         using metadata = xyz::openbmc_project::Common::Device::ReadFailure;
193 
194         elog<ReadFailure>(
195             metadata::CALLOUT_ERRNO(rc),
196             metadata::CALLOUT_DEVICE_PATH(fs::canonical(basePath).c_str()));
197     }
198 
199     return data;
200 }
201 
202 std::string PMBus::readString(const std::string& name, Type type)
203 {
204     std::string data;
205     std::ifstream file;
206     auto path = getPath(type);
207     path /= name;
208 
209     file.exceptions(std::ifstream::failbit | std::ifstream::badbit |
210                     std::ifstream::eofbit);
211 
212     try
213     {
214         file.open(path);
215         file >> data;
216     }
217     catch (std::exception& e)
218     {
219         auto rc = errno;
220         log<level::ERR>("Failed to read sysfs file",
221                         entry("FILENAME=%s", path.c_str()));
222 
223         using metadata = xyz::openbmc_project::Common::Device::ReadFailure;
224 
225         elog<ReadFailure>(
226             metadata::CALLOUT_ERRNO(rc),
227             metadata::CALLOUT_DEVICE_PATH(fs::canonical(basePath).c_str()));
228     }
229 
230     return data;
231 }
232 
233 std::vector<uint8_t> PMBus::readBinary(const std::string& name, Type type,
234                                        size_t length)
235 {
236     auto path = getPath(type) / name;
237 
238     // Use C style IO because it's easier to handle telling the difference
239     // between hitting EOF or getting an actual error.
240     std::unique_ptr<FILE, FileCloser> file{fopen(path.c_str(), "rb")};
241 
242     if (file)
243     {
244         std::vector<uint8_t> data(length, 0);
245 
246         auto bytes =
247             fread(data.data(), sizeof(decltype(data[0])), length, file.get());
248 
249         if (bytes != length)
250         {
251             // If hit EOF, just return the amount of data that was read.
252             if (feof(file.get()))
253             {
254                 data.erase(data.begin() + bytes, data.end());
255             }
256             else if (ferror(file.get()))
257             {
258                 auto rc = errno;
259                 log<level::ERR>("Failed to read sysfs file",
260                                 entry("FILENAME=%s", path.c_str()));
261 
262                 using metadata =
263                     xyz::openbmc_project::Common::Device::ReadFailure;
264 
265                 elog<ReadFailure>(metadata::CALLOUT_ERRNO(rc),
266                                   metadata::CALLOUT_DEVICE_PATH(
267                                       fs::canonical(basePath).c_str()));
268             }
269         }
270         return data;
271     }
272 
273     return std::vector<uint8_t>{};
274 }
275 
276 void PMBus::write(const std::string& name, int value, Type type)
277 {
278     std::ofstream file;
279     fs::path path = getPath(type);
280 
281     path /= name;
282 
283     file.exceptions(std::ofstream::failbit | std::ofstream::badbit |
284                     std::ofstream::eofbit);
285 
286     try
287     {
288         file.open(path);
289         file << value;
290     }
291     catch (const std::exception& e)
292     {
293         auto rc = errno;
294 
295         log<level::ERR>("Failed to write sysfs file",
296                         entry("FILENAME=%s", path.c_str()));
297 
298         using metadata = xyz::openbmc_project::Common::Device::WriteFailure;
299 
300         elog<WriteFailure>(
301             metadata::CALLOUT_ERRNO(rc),
302             metadata::CALLOUT_DEVICE_PATH(fs::canonical(basePath).c_str()));
303     }
304 }
305 
306 void PMBus::findHwmonDir()
307 {
308     fs::path path{basePath};
309     path /= "hwmon";
310 
311     // Make sure the directory exists, otherwise for things that can be
312     // dynamically present or not present an exception will be thrown if the
313     // hwmon directory is not there, resulting in a program termination.
314     if (fs::is_directory(path))
315     {
316         // look for <basePath>/hwmon/hwmonN/
317         for (auto& f : fs::directory_iterator(path))
318         {
319             if ((f.path().filename().string().find("hwmon") !=
320                  std::string::npos) &&
321                 (fs::is_directory(f.path())))
322             {
323                 hwmonDir = f.path().filename();
324                 break;
325             }
326         }
327     }
328 
329     // Don't really want to crash here, just log it
330     // and let accesses fail later
331     if (hwmonDir.empty())
332     {
333         log<level::INFO>("Unable to find hwmon directory "
334                          "in device base path",
335                          entry("DEVICE_PATH=%s", basePath.c_str()));
336     }
337 }
338 
339 std::unique_ptr<PMBusBase> PMBus::createPMBus(std::uint8_t bus,
340                                               const std::string& address)
341 {
342     const std::string physpath = {"/sys/bus/i2c/devices/" +
343                                   std::to_string(bus) + "-" + address};
344     auto interface = std::make_unique<PMBus>(physpath);
345 
346     return interface;
347 }
348 
349 std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
350                                        const std::string& address)
351 {
352     return PMBus::createPMBus(bus, address);
353 }
354 
355 } // namespace pmbus
356 } // namespace phosphor
357