xref: /openbmc/phosphor-power/pmbus.hpp (revision a2a830b1)
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_fans12";
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) = 0;
169     virtual std::string readString(const std::string& name, Type type) = 0;
170     virtual void writeBinary(const std::string& name, std::vector<uint8_t> data,
171                              Type type) = 0;
172     virtual void findHwmonDir() = 0;
173     virtual const fs::path& path() const = 0;
174     virtual std::string insertPageNum(const std::string& templateName,
175                                       size_t page) = 0;
176 };
177 
178 /**
179  * Wrapper function for PMBus
180  *
181  * @param[in] bus - I2C bus
182  * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
183  *
184  * @return PMBusBase pointer
185  */
186 std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
187                                        const std::string& address);
188 
189 /**
190  * @class PMBus
191  *
192  * This class is an interface to communicating with PMBus devices
193  * by reading and writing sysfs files.
194  *
195  * Based on the Type parameter, the accesses can either be done
196  * in the base device directory (the one passed into the constructor),
197  * or in the hwmon directory for the device.
198  */
199 class PMBus : public PMBusBase
200 {
201   public:
202     PMBus() = delete;
203     virtual ~PMBus() = default;
204     PMBus(const PMBus&) = default;
205     PMBus& operator=(const PMBus&) = default;
206     PMBus(PMBus&&) = default;
207     PMBus& operator=(PMBus&&) = default;
208 
209     /**
210      * Constructor
211      *
212      * @param[in] path - path to the sysfs directory
213      */
214     PMBus(const std::string& path) : basePath(path)
215     {
216         findHwmonDir();
217     }
218 
219     /**
220      * Constructor
221      *
222      * This version is required when DeviceDebug
223      * access will be used.
224      *
225      * @param[in] path - path to the sysfs directory
226      * @param[in] driverName - the device driver name
227      * @param[in] instance - chip instance number
228      */
229     PMBus(const std::string& path, const std::string& driverName,
230           size_t instance) :
231         basePath(path),
232         driverName(driverName), instance(instance)
233     {
234         findHwmonDir();
235     }
236 
237     /**
238      * Wrapper function for PMBus
239      *
240      * @param[in] bus - I2C bus
241      * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
242      *
243      * @return PMBusBase pointer
244      */
245     static std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
246                                                   const std::string& address);
247 
248     /**
249      * Reads a file in sysfs that represents a single bit,
250      * therefore doing a PMBus read.
251      *
252      * @param[in] name - path concatenated to
253      *                   basePath to read
254      * @param[in] type - Path type
255      *
256      * @return bool - false if result was 0, else true
257      */
258     bool readBit(const std::string& name, Type type);
259 
260     /**
261      * Reads a file in sysfs that represents a single bit,
262      * where the page number passed in is substituted
263      * into the name in place of the 'P' character in it.
264      *
265      * @param[in] name - path concatenated to
266      *                   basePath to read
267      * @param[in] page - page number
268      * @param[in] type - Path type
269      *
270      * @return bool - false if result was 0, else true
271      */
272     bool readBitInPage(const std::string& name, size_t page, Type type);
273     /**
274      * Checks if the file for the given name and type exists.
275      *
276      * @param[in] name   - path concatenated to basePath to read
277      * @param[in] type   - Path type
278      *
279      * @return bool - True if file exists, false if it does not.
280      */
281     bool exists(const std::string& name, Type type);
282 
283     /**
284      * Read byte(s) from file in sysfs.
285      *
286      * @param[in] name   - path concatenated to basePath to read
287      * @param[in] type   - Path type
288      *
289      * @return uint64_t - Up to 8 bytes of data read from file.
290      */
291     uint64_t read(const std::string& name, Type type) override;
292 
293     /**
294      * Read a string from file in sysfs.
295      *
296      * @param[in] name   - path concatenated to basePath to read
297      * @param[in] type   - Path type
298      *
299      * @return string - The data read from the file.
300      */
301     std::string readString(const std::string& name, Type type) override;
302 
303     /**
304      * Read data from a binary file in sysfs.
305      *
306      * @param[in] name   - path concatenated to basePath to read
307      * @param[in] type   - Path type
308      * @param[in] length - length of data to read, in bytes
309      *
310      * @return vector<uint8_t> - The data read from the file.
311      */
312     std::vector<uint8_t> readBinary(const std::string& name, Type type,
313                                     size_t length);
314 
315     /**
316      * Writes an integer value to the file, therefore doing
317      * a PMBus write.
318      *
319      * @param[in] name - path concatenated to
320      *                   basePath to write
321      * @param[in] value - the value to write
322      * @param[in] type - Path type
323      */
324     void write(const std::string& name, int value, Type type);
325 
326     /**
327      * Writes binary data to a file in sysfs.
328      *
329      * @param[in] name - path concatenated to basePath to write
330      * @param[in] data - The data to write to the file
331      * @param[in] type - Path type
332      */
333     void writeBinary(const std::string& name, std::vector<uint8_t> data,
334                      Type type) override;
335 
336     /**
337      * Returns the sysfs base path of this device
338      */
339     const fs::path& path() const override
340     {
341         return basePath;
342     }
343 
344     /**
345      * Replaces the 'P' in the string passed in with
346      * the page number passed in.
347      *
348      * For example:
349      *   insertPageNum("inP_enable", 42)
350      *   returns "in42_enable"
351      *
352      * @param[in] templateName - the name string, with a 'P' in it
353      * @param[in] page - the page number to insert where the P was
354      *
355      * @return string - the new string with the page number in it
356      */
357     std::string insertPageNum(const std::string& templateName,
358                               size_t page) override;
359 
360     /**
361      * Finds the path relative to basePath to the hwmon directory
362      * for the device and stores it in hwmonRelPath.
363      */
364     void findHwmonDir() override;
365 
366     /**
367      * Returns the path to use for the passed in type.
368      *
369      * @param[in] type - Path type
370      *
371      * @return fs::path - the full path
372      */
373     fs::path getPath(Type type);
374 
375   private:
376     /**
377      * Returns the device name
378      *
379      * This is found in the 'name' file in basePath.
380      *
381      * @return string - the device name
382      */
383     std::string getDeviceName();
384 
385     /**
386      * The sysfs device path
387      */
388     fs::path basePath;
389 
390     /**
391      * The directory name under the basePath hwmon directory
392      */
393     fs::path hwmonDir;
394 
395     /**
396      * The device driver name.  Used for finding the device
397      * debug directory.  Not required if that directory
398      * isn't used.
399      */
400     std::string driverName;
401 
402     /**
403      * The device instance number.
404      *
405      * Used in conjunction with the driver name for finding
406      * the debug directory.  Not required if that directory
407      * isn't used.
408      */
409     size_t instance = 0;
410 
411     /**
412      * The pmbus debug path with status files
413      */
414     const fs::path debugPath = "/sys/kernel/debug/";
415 };
416 
417 } // namespace pmbus
418 } // namespace phosphor
419