xref: /openbmc/phosphor-power/pmbus.hpp (revision c3324424)
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 READ_VIN from pmbus.
15 constexpr auto READ_VIN = "in1_input";
16 
17 namespace in_input
18 {
19 // VIN thresholds in Volts
20 constexpr auto VIN_VOLTAGE_MIN = 20;
21 constexpr auto VIN_VOLTAGE_110_THRESHOLD = 160;
22 
23 // VIN actual values in Volts
24 // VIN_VOLTAGE_0:   VIN < VIN_VOLTAGE_MIN
25 // VIN_VOLTAGE_110: VIN_VOLTAGE_MIN < VIN < VIN_VOLTAGE_110_THRESHOLD
26 // VIN_VOLTAGE_220: VIN_VOLTAGE_110_THRESHOLD < VIN
27 constexpr auto VIN_VOLTAGE_0 = 0;
28 constexpr auto VIN_VOLTAGE_110 = 110;
29 constexpr auto VIN_VOLTAGE_220 = 220;
30 } // namespace in_input
31 
32 // The file name Linux uses to capture the STATUS_WORD from pmbus.
33 constexpr auto STATUS_WORD = "status0";
34 
35 // The file name Linux uses to capture the STATUS_INPUT from pmbus.
36 constexpr auto STATUS_INPUT = "status0_input";
37 
38 // Voltage out status.
39 // Overvoltage fault or warning, Undervoltage fault or warning, maximum or
40 // minimum warning, ....
41 // Uses Page substitution
42 constexpr auto STATUS_VOUT = "statusP_vout";
43 
44 namespace status_vout
45 {
46 // Mask of bits that are only warnings
47 constexpr auto WARNING_MASK = 0x6A;
48 } // namespace status_vout
49 
50 // Current output status bits.
51 constexpr auto STATUS_IOUT = "status0_iout";
52 
53 // Manufacturing specific status bits
54 constexpr auto STATUS_MFR = "status0_mfr";
55 
56 // Reports on the status of any fans installed in position 1 and 2.
57 constexpr auto STATUS_FANS_1_2 = "status0_fan12";
58 
59 // Reports on temperature faults or warnings. Overtemperature fault,
60 // overtemperature warning, undertemperature warning, undertemperature fault.
61 constexpr auto STATUS_TEMPERATURE = "status0_temp";
62 
63 // Reports on the communication, memory, logic fault(s).
64 constexpr auto STATUS_CML = "status0_cml";
65 
66 namespace status_word
67 {
68 constexpr auto VOUT_FAULT = 0x8000;
69 
70 // The IBM CFF power supply driver does map this bit to power1_alarm in the
71 // hwmon space, but since the other bits that need to be checked do not have
72 // a similar mapping, the code will just read STATUS_WORD and use bit masking
73 // to see if the INPUT FAULT OR WARNING bit is on.
74 constexpr auto INPUT_FAULT_WARN = 0x2000;
75 
76 // The bit mask representing the MFRSPECIFIC fault, bit 4 of STATUS_WORD high
77 // byte. A manufacturer specific fault or warning has occurred.
78 constexpr auto MFR_SPECIFIC_FAULT = 0x1000;
79 
80 // The bit mask representing the POWER_GOOD Negated bit of the STATUS_WORD.
81 constexpr auto POWER_GOOD_NEGATED = 0x0800;
82 
83 // The bit mask representing the FAN FAULT or WARNING bit of the STATUS_WORD.
84 // Bit 2 of the high byte of STATUS_WORD.
85 constexpr auto FAN_FAULT = 0x0400;
86 
87 // The bit mask representing the UNITI_IS_OFF bit of the STATUS_WORD.
88 constexpr auto UNIT_IS_OFF = 0x0040;
89 
90 // Bit 5 of the STATUS_BYTE, or lower byte of STATUS_WORD is used to indicate
91 // an output overvoltage fault.
92 constexpr auto VOUT_OV_FAULT = 0x0020;
93 
94 // The bit mask representing that an output overcurrent fault has occurred.
95 constexpr auto IOUT_OC_FAULT = 0x0010;
96 
97 // The IBM CFF power supply driver does map this bit to in1_alarm, however,
98 // since a number of the other bits are not mapped that way for STATUS_WORD,
99 // this code will just read the entire STATUS_WORD and use bit masking to find
100 // out if that fault is on.
101 constexpr auto VIN_UV_FAULT = 0x0008;
102 
103 // The bit mask representing the TEMPERATURE FAULT or WARNING bit of the
104 // STATUS_WORD. Bit 2 of the low byte (STATUS_BYTE).
105 constexpr auto TEMPERATURE_FAULT_WARN = 0x0004;
106 
107 // The bit mask representing the CML (Communication, Memory, and/or Logic) fault
108 // bit of the STATUS_WORD. Bit 1 of the low byte (STATUS_BYTE).
109 constexpr auto CML_FAULT = 0x0002;
110 } // namespace status_word
111 
112 namespace status_vout
113 {
114 // The IBM CFF power supply driver maps MFR's OV_FAULT and VAUX_FAULT to this
115 // bit.
116 constexpr auto OV_FAULT = 0x80;
117 
118 // The IBM CFF power supply driver maps MFR's UV_FAULT to this bit.
119 constexpr auto UV_FAULT = 0x10;
120 } // namespace status_vout
121 
122 namespace status_temperature
123 {
124 // Overtemperature Fault
125 constexpr auto OT_FAULT = 0x80;
126 } // namespace status_temperature
127 
128 constexpr auto ON_OFF_CONFIG = "on_off_config";
129 
130 // From PMBus Specification Part II Revsion 1.2:
131 // The ON_OFF_CONFIG command configures the combination of CONTROL pin input
132 // and serial bus commands needed to turn the unit on and off. This includes how
133 // the unit responds when power is applied.
134 // Bits [7:5] - 000 - Reserved
135 // Bit 4 - 1 - Unit does not power up until commanded by the CONTROL pin and
136 // OPERATION command (as programmed in bits [3:0]).
137 // Bit 3 - 0 - Unit ignores the on/off portion of the OPERATION command from
138 // serial bus.
139 // Bit 2 - 1 - Unit requires the CONTROL pin to be asserted to start the unit.
140 // Bit 1 - 0 - Polarity of the CONTROL pin. Active low (Pull pin low to start
141 // the unit).
142 // Bit 0 - 1 - Turn off the output and stop transferring energy to the output as
143 // fast as possible.
144 constexpr auto ON_OFF_CONFIG_CONTROL_PIN_ONLY = 0x15;
145 
146 /**
147  * Where the access should be done
148  */
149 enum class Type
150 {
151     Base,            // base device directory
152     Hwmon,           // hwmon directory
153     Debug,           // pmbus debug directory
154     DeviceDebug,     // device debug directory
155     HwmonDeviceDebug // hwmon device debug directory
156 };
157 
158 /**
159  * @class PMBusBase
160  *
161  * This is a base class for PMBus to assist with unit testing via mocking.
162  */
163 class PMBusBase
164 {
165   public:
166     virtual ~PMBusBase() = default;
167 
168     virtual uint64_t read(const std::string& name, Type type,
169                           bool errTrace = true) = 0;
170     virtual std::string readString(const std::string& name, Type type) = 0;
171     virtual std::vector<uint8_t> readBinary(const std::string& name, Type type,
172                                             size_t length) = 0;
173     virtual void writeBinary(const std::string& name, std::vector<uint8_t> data,
174                              Type type) = 0;
175     virtual void findHwmonDir() = 0;
176     virtual const fs::path& path() const = 0;
177     virtual std::string insertPageNum(const std::string& templateName,
178                                       size_t page) = 0;
179 };
180 
181 /**
182  * Wrapper function for PMBus
183  *
184  * @param[in] bus - I2C bus
185  * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
186  *
187  * @return PMBusBase pointer
188  */
189 std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
190                                        const std::string& address);
191 
192 /**
193  * @class PMBus
194  *
195  * This class is an interface to communicating with PMBus devices
196  * by reading and writing sysfs files.
197  *
198  * Based on the Type parameter, the accesses can either be done
199  * in the base device directory (the one passed into the constructor),
200  * or in the hwmon directory for the device.
201  */
202 class PMBus : public PMBusBase
203 {
204   public:
205     PMBus() = delete;
206     virtual ~PMBus() = default;
207     PMBus(const PMBus&) = default;
208     PMBus& operator=(const PMBus&) = default;
209     PMBus(PMBus&&) = default;
210     PMBus& operator=(PMBus&&) = default;
211 
212     /**
213      * Constructor
214      *
215      * @param[in] path - path to the sysfs directory
216      */
217     PMBus(const std::string& path) : basePath(path)
218     {
219         findHwmonDir();
220     }
221 
222     /**
223      * Constructor
224      *
225      * This version is required when DeviceDebug
226      * access will be used.
227      *
228      * @param[in] path - path to the sysfs directory
229      * @param[in] driverName - the device driver name
230      * @param[in] instance - chip instance number
231      */
232     PMBus(const std::string& path, const std::string& driverName,
233           size_t instance) :
234         basePath(path),
235         driverName(driverName), instance(instance)
236     {
237         findHwmonDir();
238     }
239 
240     /**
241      * Wrapper function for PMBus
242      *
243      * @param[in] bus - I2C bus
244      * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
245      *
246      * @return PMBusBase pointer
247      */
248     static std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
249                                                   const std::string& address);
250 
251     /**
252      * Reads a file in sysfs that represents a single bit,
253      * therefore doing a PMBus read.
254      *
255      * @param[in] name - path concatenated to
256      *                   basePath to read
257      * @param[in] type - Path type
258      *
259      * @return bool - false if result was 0, else true
260      */
261     bool readBit(const std::string& name, Type type);
262 
263     /**
264      * Reads a file in sysfs that represents a single bit,
265      * where the page number passed in is substituted
266      * into the name in place of the 'P' character in it.
267      *
268      * @param[in] name - path concatenated to
269      *                   basePath to read
270      * @param[in] page - page number
271      * @param[in] type - Path type
272      *
273      * @return bool - false if result was 0, else true
274      */
275     bool readBitInPage(const std::string& name, size_t page, Type type);
276     /**
277      * Checks if the file for the given name and type exists.
278      *
279      * @param[in] name   - path concatenated to basePath to read
280      * @param[in] type   - Path type
281      *
282      * @return bool - True if file exists, false if it does not.
283      */
284     bool exists(const std::string& name, Type type);
285 
286     /**
287      * Read byte(s) from file in sysfs.
288      *
289      * @param[in] name   - path concatenated to basePath to read
290      * @param[in] type   - Path type
291      * @param[in] errTrace - true to enable tracing error (defaults to true)
292      *
293      * @return uint64_t - Up to 8 bytes of data read from file.
294      */
295     uint64_t read(const std::string& name, Type type,
296                   bool errTrace = true) override;
297 
298     /**
299      * Read a string from file in sysfs.
300      *
301      * @param[in] name   - path concatenated to basePath to read
302      * @param[in] type   - Path type
303      *
304      * @return string - The data read from the file.
305      */
306     std::string readString(const std::string& name, Type type) override;
307 
308     /**
309      * Read data from a binary file in sysfs.
310      *
311      * @param[in] name   - path concatenated to basePath to read
312      * @param[in] type   - Path type
313      * @param[in] length - length of data to read, in bytes
314      *
315      * @return vector<uint8_t> - The data read from the file.
316      */
317     std::vector<uint8_t> readBinary(const std::string& name, Type type,
318                                     size_t length);
319 
320     /**
321      * Writes an integer value to the file, therefore doing
322      * a PMBus write.
323      *
324      * @param[in] name - path concatenated to
325      *                   basePath to write
326      * @param[in] value - the value to write
327      * @param[in] type - Path type
328      */
329     void write(const std::string& name, int value, Type type);
330 
331     /**
332      * Writes binary data to a file in sysfs.
333      *
334      * @param[in] name - path concatenated to basePath to write
335      * @param[in] data - The data to write to the file
336      * @param[in] type - Path type
337      */
338     void writeBinary(const std::string& name, std::vector<uint8_t> data,
339                      Type type) override;
340 
341     /**
342      * Returns the sysfs base path of this device
343      */
344     const fs::path& path() const override
345     {
346         return basePath;
347     }
348 
349     /**
350      * Replaces the 'P' in the string passed in with
351      * the page number passed in.
352      *
353      * For example:
354      *   insertPageNum("inP_enable", 42)
355      *   returns "in42_enable"
356      *
357      * @param[in] templateName - the name string, with a 'P' in it
358      * @param[in] page - the page number to insert where the P was
359      *
360      * @return string - the new string with the page number in it
361      */
362     std::string insertPageNum(const std::string& templateName,
363                               size_t page) override;
364 
365     /**
366      * Finds the path relative to basePath to the hwmon directory
367      * for the device and stores it in hwmonRelPath.
368      */
369     void findHwmonDir() override;
370 
371     /**
372      * Returns the path to use for the passed in type.
373      *
374      * @param[in] type - Path type
375      *
376      * @return fs::path - the full path
377      */
378     fs::path getPath(Type type);
379 
380   private:
381     /**
382      * Returns the device name
383      *
384      * This is found in the 'name' file in basePath.
385      *
386      * @return string - the device name
387      */
388     std::string getDeviceName();
389 
390     /**
391      * The sysfs device path
392      */
393     fs::path basePath;
394 
395     /**
396      * The directory name under the basePath hwmon directory
397      */
398     fs::path hwmonDir;
399 
400     /**
401      * The device driver name.  Used for finding the device
402      * debug directory.  Not required if that directory
403      * isn't used.
404      */
405     std::string driverName;
406 
407     /**
408      * The device instance number.
409      *
410      * Used in conjunction with the driver name for finding
411      * the debug directory.  Not required if that directory
412      * isn't used.
413      */
414     size_t instance = 0;
415 
416     /**
417      * The pmbus debug path with status files
418      */
419     const fs::path debugPath = "/sys/kernel/debug/";
420 };
421 
422 } // namespace pmbus
423 } // namespace phosphor
424