xref: /openbmc/phosphor-power/pmbus.hpp (revision 070c1bc6)
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 constexpr auto ON_OFF_CONFIG = "on_off_config";
105 
106 // From PMBus Specification Part II Revsion 1.2:
107 // The ON_OFF_CONFIG command configures the combination of CONTROL pin input
108 // and serial bus commands needed to turn the unit on and off. This includes how
109 // the unit responds when power is applied.
110 // Bits [7:5] - 000 - Reserved
111 // Bit 4 - 1 - Unit does not power up until commanded by the CONTROL pin and
112 // OPERATION command (as programmed in bits [3:0]).
113 // Bit 3 - 0 - Unit ignores the on/off portion of the OPERATION command from
114 // serial bus.
115 // Bit 2 - 1 - Unit requires the CONTROL pin to be asserted to start the unit.
116 // Bit 1 - 0 - Polarity of the CONTROL pin. Active low (Pull pin low to start
117 // the unit).
118 // Bit 0 - 1 - Turn off the output and stop transferring energy to the output as
119 // fast as possible.
120 constexpr auto ON_OFF_CONFIG_CONTROL_PIN_ONLY = 0x15;
121 
122 /**
123  * Where the access should be done
124  */
125 enum class Type
126 {
127     Base,            // base device directory
128     Hwmon,           // hwmon directory
129     Debug,           // pmbus debug directory
130     DeviceDebug,     // device debug directory
131     HwmonDeviceDebug // hwmon device debug directory
132 };
133 
134 /**
135  * @class PMBusBase
136  *
137  * This is a base class for PMBus to assist with unit testing via mocking.
138  */
139 class PMBusBase
140 {
141   public:
142     virtual ~PMBusBase() = default;
143 
144     virtual uint64_t read(const std::string& name, Type type) = 0;
145     virtual std::string readString(const std::string& name, Type type) = 0;
146     virtual void writeBinary(const std::string& name, std::vector<uint8_t> data,
147                              Type type) = 0;
148     virtual const fs::path& path() const = 0;
149 };
150 
151 /**
152  * Wrapper function for PMBus
153  *
154  * @param[in] bus - I2C bus
155  * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
156  *
157  * @return PMBusBase pointer
158  */
159 std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
160                                        const std::string& address);
161 
162 /**
163  * @class PMBus
164  *
165  * This class is an interface to communicating with PMBus devices
166  * by reading and writing sysfs files.
167  *
168  * Based on the Type parameter, the accesses can either be done
169  * in the base device directory (the one passed into the constructor),
170  * or in the hwmon directory for the device.
171  */
172 class PMBus : public PMBusBase
173 {
174   public:
175     PMBus() = delete;
176     virtual ~PMBus() = default;
177     PMBus(const PMBus&) = default;
178     PMBus& operator=(const PMBus&) = default;
179     PMBus(PMBus&&) = default;
180     PMBus& operator=(PMBus&&) = default;
181 
182     /**
183      * Constructor
184      *
185      * @param[in] path - path to the sysfs directory
186      */
187     PMBus(const std::string& path) : basePath(path)
188     {
189         findHwmonDir();
190     }
191 
192     /**
193      * Constructor
194      *
195      * This version is required when DeviceDebug
196      * access will be used.
197      *
198      * @param[in] path - path to the sysfs directory
199      * @param[in] driverName - the device driver name
200      * @param[in] instance - chip instance number
201      */
202     PMBus(const std::string& path, const std::string& driverName,
203           size_t instance) :
204         basePath(path),
205         driverName(driverName), instance(instance)
206     {
207         findHwmonDir();
208     }
209 
210     /**
211      * Wrapper function for PMBus
212      *
213      * @param[in] bus - I2C bus
214      * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
215      *
216      * @return PMBusBase pointer
217      */
218     static std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
219                                                   const std::string& address);
220 
221     /**
222      * Reads a file in sysfs that represents a single bit,
223      * therefore doing a PMBus read.
224      *
225      * @param[in] name - path concatenated to
226      *                   basePath to read
227      * @param[in] type - Path type
228      *
229      * @return bool - false if result was 0, else true
230      */
231     bool readBit(const std::string& name, Type type);
232 
233     /**
234      * Reads a file in sysfs that represents a single bit,
235      * where the page number passed in is substituted
236      * into the name in place of the 'P' character in it.
237      *
238      * @param[in] name - path concatenated to
239      *                   basePath to read
240      * @param[in] page - page number
241      * @param[in] type - Path type
242      *
243      * @return bool - false if result was 0, else true
244      */
245     bool readBitInPage(const std::string& name, size_t page, Type type);
246     /**
247      * Checks if the file for the given name and type exists.
248      *
249      * @param[in] name   - path concatenated to basePath to read
250      * @param[in] type   - Path type
251      *
252      * @return bool - True if file exists, false if it does not.
253      */
254     bool exists(const std::string& name, Type type);
255 
256     /**
257      * Read byte(s) from file in sysfs.
258      *
259      * @param[in] name   - path concatenated to basePath to read
260      * @param[in] type   - Path type
261      *
262      * @return uint64_t - Up to 8 bytes of data read from file.
263      */
264     uint64_t read(const std::string& name, Type type) override;
265 
266     /**
267      * Read a string from file in sysfs.
268      *
269      * @param[in] name   - path concatenated to basePath to read
270      * @param[in] type   - Path type
271      *
272      * @return string - The data read from the file.
273      */
274     std::string readString(const std::string& name, Type type) override;
275 
276     /**
277      * Read data from a binary file in sysfs.
278      *
279      * @param[in] name   - path concatenated to basePath to read
280      * @param[in] type   - Path type
281      * @param[in] length - length of data to read, in bytes
282      *
283      * @return vector<uint8_t> - The data read from the file.
284      */
285     std::vector<uint8_t> readBinary(const std::string& name, Type type,
286                                     size_t length);
287 
288     /**
289      * Writes an integer value to the file, therefore doing
290      * a PMBus write.
291      *
292      * @param[in] name - path concatenated to
293      *                   basePath to write
294      * @param[in] value - the value to write
295      * @param[in] type - Path type
296      */
297     void write(const std::string& name, int value, Type type);
298 
299     /**
300      * Writes binary data to a file in sysfs.
301      *
302      * @param[in] name - path concatenated to basePath to write
303      * @param[in] data - The data to write to the file
304      * @param[in] type - Path type
305      */
306     void writeBinary(const std::string& name, std::vector<uint8_t> data,
307                      Type type) override;
308 
309     /**
310      * Returns the sysfs base path of this device
311      */
312     const fs::path& path() const override
313     {
314         return basePath;
315     }
316 
317     /**
318      * Replaces the 'P' in the string passed in with
319      * the page number passed in.
320      *
321      * For example:
322      *   insertPageNum("inP_enable", 42)
323      *   returns "in42_enable"
324      *
325      * @param[in] templateName - the name string, with a 'P' in it
326      * @param[in] page - the page number to insert where the P was
327      *
328      * @return string - the new string with the page number in it
329      */
330     static std::string insertPageNum(const std::string& templateName,
331                                      size_t page);
332 
333     /**
334      * Finds the path relative to basePath to the hwmon directory
335      * for the device and stores it in hwmonRelPath.
336      */
337     void findHwmonDir();
338 
339     /**
340      * Returns the path to use for the passed in type.
341      *
342      * @param[in] type - Path type
343      *
344      * @return fs::path - the full path
345      */
346     fs::path getPath(Type type);
347 
348   private:
349     /**
350      * Returns the device name
351      *
352      * This is found in the 'name' file in basePath.
353      *
354      * @return string - the device name
355      */
356     std::string getDeviceName();
357 
358     /**
359      * The sysfs device path
360      */
361     fs::path basePath;
362 
363     /**
364      * The directory name under the basePath hwmon directory
365      */
366     fs::path hwmonDir;
367 
368     /**
369      * The device driver name.  Used for finding the device
370      * debug directory.  Not required if that directory
371      * isn't used.
372      */
373     std::string driverName;
374 
375     /**
376      * The device instance number.
377      *
378      * Used in conjunction with the driver name for finding
379      * the debug directory.  Not required if that directory
380      * isn't used.
381      */
382     size_t instance = 0;
383 
384     /**
385      * The pmbus debug path with status files
386      */
387     const fs::path debugPath = "/sys/kernel/debug/";
388 };
389 
390 } // namespace pmbus
391 } // namespace phosphor
392