xref: /openbmc/phosphor-power/pmbus.hpp (revision 2fe5186e)
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 POWER_GOOD Negated bit of the STATUS_WORD.
56 constexpr auto POWER_GOOD_NEGATED = 0x0800;
57 
58 // The bit mask representing the FAN FAULT or WARNING bit of the STATUS_WORD.
59 // Bit 2 of the high byte of STATUS_WORD.
60 constexpr auto FAN_FAULT = 0x0400;
61 
62 // The bit mask representing the UNITI_IS_OFF bit of the STATUS_WORD.
63 constexpr auto UNIT_IS_OFF = 0x0040;
64 
65 // Bit 5 of the STATUS_BYTE, or lower byte of STATUS_WORD is used to indicate
66 // an output overvoltage fault.
67 constexpr auto VOUT_OV_FAULT = 0x0020;
68 
69 // The bit mask representing that an output overcurrent fault has occurred.
70 constexpr auto IOUT_OC_FAULT = 0x0010;
71 
72 // The IBM CFF power supply driver does map this bit to in1_alarm, however,
73 // since a number of the other bits are not mapped that way for STATUS_WORD,
74 // this code will just read the entire STATUS_WORD and use bit masking to find
75 // out if that fault is on.
76 constexpr auto VIN_UV_FAULT = 0x0008;
77 
78 // The bit mask representing the TEMPERATURE FAULT or WARNING bit of the
79 // STATUS_WORD. Bit 2 of the low byte (STATUS_BYTE).
80 constexpr auto TEMPERATURE_FAULT_WARN = 0x0004;
81 
82 } // namespace status_word
83 
84 namespace status_vout
85 {
86 // The IBM CFF power supply driver maps MFR's OV_FAULT and VAUX_FAULT to this
87 // bit.
88 constexpr auto OV_FAULT = 0x80;
89 
90 // The IBM CFF power supply driver maps MFR's UV_FAULT to this bit.
91 constexpr auto UV_FAULT = 0x10;
92 } // namespace status_vout
93 
94 namespace status_temperature
95 {
96 // Overtemperature Fault
97 constexpr auto OT_FAULT = 0x80;
98 } // namespace status_temperature
99 
100 /**
101  * Where the access should be done
102  */
103 enum class Type
104 {
105     Base,            // base device directory
106     Hwmon,           // hwmon directory
107     Debug,           // pmbus debug directory
108     DeviceDebug,     // device debug directory
109     HwmonDeviceDebug // hwmon device debug directory
110 };
111 
112 /**
113  * @class PMBus
114  *
115  * This class is an interface to communicating with PMBus devices
116  * by reading and writing sysfs files.
117  *
118  * Based on the Type parameter, the accesses can either be done
119  * in the base device directory (the one passed into the constructor),
120  * or in the hwmon directory for the device.
121  */
122 class PMBus
123 {
124   public:
125     PMBus() = delete;
126     ~PMBus() = default;
127     PMBus(const PMBus&) = default;
128     PMBus& operator=(const PMBus&) = default;
129     PMBus(PMBus&&) = default;
130     PMBus& operator=(PMBus&&) = default;
131 
132     /**
133      * Constructor
134      *
135      * @param[in] path - path to the sysfs directory
136      */
137     PMBus(const std::string& path) : basePath(path)
138     {
139         findHwmonDir();
140     }
141 
142     /**
143      * Constructor
144      *
145      * This version is required when DeviceDebug
146      * access will be used.
147      *
148      * @param[in] path - path to the sysfs directory
149      * @param[in] driverName - the device driver name
150      * @param[in] instance - chip instance number
151      */
152     PMBus(const std::string& path, const std::string& driverName,
153           size_t instance) :
154         basePath(path),
155         driverName(driverName), instance(instance)
156     {
157         findHwmonDir();
158     }
159 
160     /**
161      * Reads a file in sysfs that represents a single bit,
162      * therefore doing a PMBus read.
163      *
164      * @param[in] name - path concatenated to
165      *                   basePath to read
166      * @param[in] type - Path type
167      *
168      * @return bool - false if result was 0, else true
169      */
170     bool readBit(const std::string& name, Type type);
171 
172     /**
173      * Reads a file in sysfs that represents a single bit,
174      * where the page number passed in is substituted
175      * into the name in place of the 'P' character in it.
176      *
177      * @param[in] name - path concatenated to
178      *                   basePath to read
179      * @param[in] page - page number
180      * @param[in] type - Path type
181      *
182      * @return bool - false if result was 0, else true
183      */
184     bool readBitInPage(const std::string& name, size_t page, Type type);
185     /**
186      * Checks if the file for the given name and type exists.
187      *
188      * @param[in] name   - path concatenated to basePath to read
189      * @param[in] type   - Path type
190      *
191      * @return bool - True if file exists, false if it does not.
192      */
193     bool exists(const std::string& name, Type type);
194 
195     /**
196      * Read byte(s) from file in sysfs.
197      *
198      * @param[in] name   - path concatenated to basePath to read
199      * @param[in] type   - Path type
200      *
201      * @return uint64_t - Up to 8 bytes of data read from file.
202      */
203     uint64_t read(const std::string& name, Type type);
204 
205     /**
206      * Read a string from file in sysfs.
207      *
208      * @param[in] name   - path concatenated to basePath to read
209      * @param[in] type   - Path type
210      *
211      * @return string - The data read from the file.
212      */
213     std::string readString(const std::string& name, Type type);
214 
215     /**
216      * Read data from a binary file in sysfs.
217      *
218      * @param[in] name   - path concatenated to basePath to read
219      * @param[in] type   - Path type
220      * @param[in] length - length of data to read, in bytes
221      *
222      * @return vector<uint8_t> - The data read from the file.
223      */
224     std::vector<uint8_t> readBinary(const std::string& name, Type type,
225                                     size_t length);
226 
227     /**
228      * Writes an integer value to the file, therefore doing
229      * a PMBus write.
230      *
231      * @param[in] name - path concatenated to
232      *                   basePath to write
233      * @param[in] value - the value to write
234      * @param[in] type - Path type
235      */
236     void write(const std::string& name, int value, Type type);
237 
238     /**
239      * Returns the sysfs base path of this device
240      */
241     inline const auto& path() const
242     {
243         return basePath;
244     }
245 
246     /**
247      * Replaces the 'P' in the string passed in with
248      * the page number passed in.
249      *
250      * For example:
251      *   insertPageNum("inP_enable", 42)
252      *   returns "in42_enable"
253      *
254      * @param[in] templateName - the name string, with a 'P' in it
255      * @param[in] page - the page number to insert where the P was
256      *
257      * @return string - the new string with the page number in it
258      */
259     static std::string insertPageNum(const std::string& templateName,
260                                      size_t page);
261 
262     /**
263      * Finds the path relative to basePath to the hwmon directory
264      * for the device and stores it in hwmonRelPath.
265      */
266     void findHwmonDir();
267 
268     /**
269      * Returns the path to use for the passed in type.
270      *
271      * @param[in] type - Path type
272      *
273      * @return fs::path - the full path
274      */
275     fs::path getPath(Type type);
276 
277   private:
278     /**
279      * Returns the device name
280      *
281      * This is found in the 'name' file in basePath.
282      *
283      * @return string - the device name
284      */
285     std::string getDeviceName();
286 
287     /**
288      * The sysfs device path
289      */
290     fs::path basePath;
291 
292     /**
293      * The directory name under the basePath hwmon directory
294      */
295     fs::path hwmonDir;
296 
297     /**
298      * The device driver name.  Used for finding the device
299      * debug directory.  Not required if that directory
300      * isn't used.
301      */
302     std::string driverName;
303 
304     /**
305      * The device instance number.
306      *
307      * Used in conjunction with the driver name for finding
308      * the debug directory.  Not required if that directory
309      * isn't used.
310      */
311     size_t instance = 0;
312 
313     /**
314      * The pmbus debug path with status files
315      */
316     const fs::path debugPath = "/sys/kernel/debug/";
317 };
318 
319 } // namespace pmbus
320 } // namespace phosphor
321