xref: /openbmc/phosphor-power/pmbus.hpp (revision cd9ab087)
1 #pragma once
2 
3 #include <filesystem>
4 #include <string>
5 #include <vector>
6 
7 namespace phosphor
8 {
9 namespace pmbus
10 {
11 
12 namespace fs = std::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 namespace status_vout
27 {
28 // Mask of bits that are only warnings
29 constexpr auto WARNING_MASK = 0x6A;
30 } // namespace status_vout
31 
32 // Current output status bits.
33 constexpr auto STATUS_IOUT = "status0_iout";
34 
35 // Manufacturing specific status bits
36 constexpr auto STATUS_MFR = "status0_mfr";
37 
38 // Reports on the status of any fans installed in position 1 and 2.
39 constexpr auto STATUS_FANS_1_2 = "status0_fans12";
40 
41 // Reports on temperature faults or warnings. Overtemperature fault,
42 // overtemperature warning, undertemperature warning, undertemperature fault.
43 constexpr auto STATUS_TEMPERATURE = "status0_temp";
44 
45 namespace status_word
46 {
47 constexpr auto VOUT_FAULT = 0x8000;
48 
49 // The IBM CFF power supply driver does map this bit to power1_alarm in the
50 // hwmon space, but since the other bits that need to be checked do not have
51 // a similar mapping, the code will just read STATUS_WORD and use bit masking
52 // to see if the INPUT FAULT OR WARNING bit is on.
53 constexpr auto INPUT_FAULT_WARN = 0x2000;
54 
55 // The bit mask representing the MFRSPECIFIC fault, bit 4 of STATUS_WORD high
56 // byte. A manufacturer specific fault or warning has occurred.
57 constexpr auto MFR_SPECIFIC_FAULT = 0x1000;
58 
59 // The bit mask representing the POWER_GOOD Negated bit of the STATUS_WORD.
60 constexpr auto POWER_GOOD_NEGATED = 0x0800;
61 
62 // The bit mask representing the FAN FAULT or WARNING bit of the STATUS_WORD.
63 // Bit 2 of the high byte of STATUS_WORD.
64 constexpr auto FAN_FAULT = 0x0400;
65 
66 // The bit mask representing the UNITI_IS_OFF bit of the STATUS_WORD.
67 constexpr auto UNIT_IS_OFF = 0x0040;
68 
69 // Bit 5 of the STATUS_BYTE, or lower byte of STATUS_WORD is used to indicate
70 // an output overvoltage fault.
71 constexpr auto VOUT_OV_FAULT = 0x0020;
72 
73 // The bit mask representing that an output overcurrent fault has occurred.
74 constexpr auto IOUT_OC_FAULT = 0x0010;
75 
76 // The IBM CFF power supply driver does map this bit to in1_alarm, however,
77 // since a number of the other bits are not mapped that way for STATUS_WORD,
78 // this code will just read the entire STATUS_WORD and use bit masking to find
79 // out if that fault is on.
80 constexpr auto VIN_UV_FAULT = 0x0008;
81 
82 // The bit mask representing the TEMPERATURE FAULT or WARNING bit of the
83 // STATUS_WORD. Bit 2 of the low byte (STATUS_BYTE).
84 constexpr auto TEMPERATURE_FAULT_WARN = 0x0004;
85 
86 } // namespace status_word
87 
88 namespace status_vout
89 {
90 // The IBM CFF power supply driver maps MFR's OV_FAULT and VAUX_FAULT to this
91 // bit.
92 constexpr auto OV_FAULT = 0x80;
93 
94 // The IBM CFF power supply driver maps MFR's UV_FAULT to this bit.
95 constexpr auto UV_FAULT = 0x10;
96 } // namespace status_vout
97 
98 namespace status_temperature
99 {
100 // Overtemperature Fault
101 constexpr auto OT_FAULT = 0x80;
102 } // namespace status_temperature
103 
104 /**
105  * Where the access should be done
106  */
107 enum class Type
108 {
109     Base,            // base device directory
110     Hwmon,           // hwmon directory
111     Debug,           // pmbus debug directory
112     DeviceDebug,     // device debug directory
113     HwmonDeviceDebug // hwmon device debug directory
114 };
115 
116 /**
117  * @class PMBusBase
118  *
119  * This is a base class for PMBus to assist with unit testing via mocking.
120  */
121 class PMBusBase
122 {
123   public:
124     virtual ~PMBusBase() = default;
125 
126     virtual uint64_t read(const std::string& name, Type type) = 0;
127 };
128 
129 /**
130  * Wrapper function for PMBus
131  *
132  * @param[in] bus - I2C bus
133  * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
134  *
135  * @return PMBusBase pointer
136  */
137 std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
138                                        const std::string& address);
139 
140 /**
141  * @class PMBus
142  *
143  * This class is an interface to communicating with PMBus devices
144  * by reading and writing sysfs files.
145  *
146  * Based on the Type parameter, the accesses can either be done
147  * in the base device directory (the one passed into the constructor),
148  * or in the hwmon directory for the device.
149  */
150 class PMBus : public PMBusBase
151 {
152   public:
153     PMBus() = delete;
154     virtual ~PMBus() = default;
155     PMBus(const PMBus&) = default;
156     PMBus& operator=(const PMBus&) = default;
157     PMBus(PMBus&&) = default;
158     PMBus& operator=(PMBus&&) = default;
159 
160     /**
161      * Constructor
162      *
163      * @param[in] path - path to the sysfs directory
164      */
165     PMBus(const std::string& path) : basePath(path)
166     {
167         findHwmonDir();
168     }
169 
170     /**
171      * Constructor
172      *
173      * This version is required when DeviceDebug
174      * access will be used.
175      *
176      * @param[in] path - path to the sysfs directory
177      * @param[in] driverName - the device driver name
178      * @param[in] instance - chip instance number
179      */
180     PMBus(const std::string& path, const std::string& driverName,
181           size_t instance) :
182         basePath(path),
183         driverName(driverName), instance(instance)
184     {
185         findHwmonDir();
186     }
187 
188     /**
189      * Wrapper function for PMBus
190      *
191      * @param[in] bus - I2C bus
192      * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
193      *
194      * @return PMBusBase pointer
195      */
196     static std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
197                                                   const std::string& address);
198 
199     /**
200      * Reads a file in sysfs that represents a single bit,
201      * therefore doing a PMBus read.
202      *
203      * @param[in] name - path concatenated to
204      *                   basePath to read
205      * @param[in] type - Path type
206      *
207      * @return bool - false if result was 0, else true
208      */
209     bool readBit(const std::string& name, Type type);
210 
211     /**
212      * Reads a file in sysfs that represents a single bit,
213      * where the page number passed in is substituted
214      * into the name in place of the 'P' character in it.
215      *
216      * @param[in] name - path concatenated to
217      *                   basePath to read
218      * @param[in] page - page number
219      * @param[in] type - Path type
220      *
221      * @return bool - false if result was 0, else true
222      */
223     bool readBitInPage(const std::string& name, size_t page, Type type);
224     /**
225      * Checks if the file for the given name and type exists.
226      *
227      * @param[in] name   - path concatenated to basePath to read
228      * @param[in] type   - Path type
229      *
230      * @return bool - True if file exists, false if it does not.
231      */
232     bool exists(const std::string& name, Type type);
233 
234     /**
235      * Read byte(s) from file in sysfs.
236      *
237      * @param[in] name   - path concatenated to basePath to read
238      * @param[in] type   - Path type
239      *
240      * @return uint64_t - Up to 8 bytes of data read from file.
241      */
242     uint64_t read(const std::string& name, Type type) override;
243 
244     /**
245      * Read a string from file in sysfs.
246      *
247      * @param[in] name   - path concatenated to basePath to read
248      * @param[in] type   - Path type
249      *
250      * @return string - The data read from the file.
251      */
252     std::string readString(const std::string& name, Type type);
253 
254     /**
255      * Read data from a binary file in sysfs.
256      *
257      * @param[in] name   - path concatenated to basePath to read
258      * @param[in] type   - Path type
259      * @param[in] length - length of data to read, in bytes
260      *
261      * @return vector<uint8_t> - The data read from the file.
262      */
263     std::vector<uint8_t> readBinary(const std::string& name, Type type,
264                                     size_t length);
265 
266     /**
267      * Writes an integer value to the file, therefore doing
268      * a PMBus write.
269      *
270      * @param[in] name - path concatenated to
271      *                   basePath to write
272      * @param[in] value - the value to write
273      * @param[in] type - Path type
274      */
275     void write(const std::string& name, int value, Type type);
276 
277     /**
278      * Returns the sysfs base path of this device
279      */
280     inline const auto& path() const
281     {
282         return basePath;
283     }
284 
285     /**
286      * Replaces the 'P' in the string passed in with
287      * the page number passed in.
288      *
289      * For example:
290      *   insertPageNum("inP_enable", 42)
291      *   returns "in42_enable"
292      *
293      * @param[in] templateName - the name string, with a 'P' in it
294      * @param[in] page - the page number to insert where the P was
295      *
296      * @return string - the new string with the page number in it
297      */
298     static std::string insertPageNum(const std::string& templateName,
299                                      size_t page);
300 
301     /**
302      * Finds the path relative to basePath to the hwmon directory
303      * for the device and stores it in hwmonRelPath.
304      */
305     void findHwmonDir();
306 
307     /**
308      * Returns the path to use for the passed in type.
309      *
310      * @param[in] type - Path type
311      *
312      * @return fs::path - the full path
313      */
314     fs::path getPath(Type type);
315 
316   private:
317     /**
318      * Returns the device name
319      *
320      * This is found in the 'name' file in basePath.
321      *
322      * @return string - the device name
323      */
324     std::string getDeviceName();
325 
326     /**
327      * The sysfs device path
328      */
329     fs::path basePath;
330 
331     /**
332      * The directory name under the basePath hwmon directory
333      */
334     fs::path hwmonDir;
335 
336     /**
337      * The device driver name.  Used for finding the device
338      * debug directory.  Not required if that directory
339      * isn't used.
340      */
341     std::string driverName;
342 
343     /**
344      * The device instance number.
345      *
346      * Used in conjunction with the driver name for finding
347      * the debug directory.  Not required if that directory
348      * isn't used.
349      */
350     size_t instance = 0;
351 
352     /**
353      * The pmbus debug path with status files
354      */
355     const fs::path debugPath = "/sys/kernel/debug/";
356 };
357 
358 } // namespace pmbus
359 } // namespace phosphor
360