drivers/hwmon/pmbus/ibm-cffps.c

   1 /*
   2  * Copyright 2017 IBM Corp.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #include <linux/bitops.h>
  11 #include <linux/device.h>
  12 #include <linux/i2c.h>
  13 #include <linux/module.h>
  14
  15 #include "pmbus.h"
  16
  17 /* STATUS_MFR_SPECIFIC bits */
  18 #define CFFPS_MFR_FAN_FAULT                     BIT(0)
  19 #define CFFPS_MFR_THERMAL_FAULT                 BIT(1)
  20 #define CFFPS_MFR_OV_FAULT                      BIT(2)
  21 #define CFFPS_MFR_UV_FAULT                      BIT(3)
  22 #define CFFPS_MFR_PS_KILL                       BIT(4)
  23 #define CFFPS_MFR_OC_FAULT                      BIT(5)
  24 #define CFFPS_MFR_VAUX_FAULT                    BIT(6)
  25 #define CFFPS_MFR_CURRENT_SHARE_WARNING         BIT(7)
  26
  27 static int ibm_cffps_read_byte_data(struct i2c_client *client, int page,
  28                                     int reg)
  29 {
  30         int rc, mfr;
  31
  32         switch (reg) {
  33         case PMBUS_STATUS_VOUT:
  34         case PMBUS_STATUS_IOUT:
  35         case PMBUS_STATUS_TEMPERATURE:
  36         case PMBUS_STATUS_FAN_12:
  37                 rc = pmbus_read_byte_data(client, page, reg);
  38                 if (rc < 0)
  39                         return rc;
  40
  41                 mfr = pmbus_read_byte_data(client, page,
  42                                            PMBUS_STATUS_MFR_SPECIFIC);
  43                 if (mfr < 0)
  44                         /*
  45                          * Return the status register instead of an error,
  46                          * since we successfully read status.
  47                          */
  48                         return rc;
  49
  50                 /* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
  51                 if (reg == PMBUS_STATUS_FAN_12) {
  52                         if (mfr & CFFPS_MFR_FAN_FAULT)
  53                                 rc |= PB_FAN_FAN1_FAULT;
  54                 } else if (reg == PMBUS_STATUS_TEMPERATURE) {
  55                         if (mfr & CFFPS_MFR_THERMAL_FAULT)
  56                                 rc |= PB_TEMP_OT_FAULT;
  57                 } else if (reg == PMBUS_STATUS_VOUT) {
  58                         if (mfr & (CFFPS_MFR_OV_FAULT | CFFPS_MFR_VAUX_FAULT))
  59                                 rc |= PB_VOLTAGE_OV_FAULT;
  60                         if (mfr & CFFPS_MFR_UV_FAULT)
  61                                 rc |= PB_VOLTAGE_UV_FAULT;
  62                 } else if (reg == PMBUS_STATUS_IOUT) {
  63                         if (mfr & CFFPS_MFR_OC_FAULT)
  64                                 rc |= PB_IOUT_OC_FAULT;
  65                         if (mfr & CFFPS_MFR_CURRENT_SHARE_WARNING)
  66                                 rc |= PB_CURRENT_SHARE_FAULT;
  67                 }
  68                 break;
  69         default:
  70                 rc = -ENODATA;
  71                 break;
  72         }
  73
  74         return rc;
  75 }
  76
  77 static int ibm_cffps_read_word_data(struct i2c_client *client, int page,
  78                                     int reg)
  79 {
  80         int rc, mfr;
  81
  82         switch (reg) {
  83         case PMBUS_STATUS_WORD:
  84                 rc = pmbus_read_word_data(client, page, reg);
  85                 if (rc < 0)
  86                         return rc;
  87
  88                 mfr = pmbus_read_byte_data(client, page,
  89                                            PMBUS_STATUS_MFR_SPECIFIC);
  90                 if (mfr < 0)
  91                         /*
  92                          * Return the status register instead of an error,
  93                          * since we successfully read status.
  94                          */
  95                         return rc;
  96
  97                 if (mfr & CFFPS_MFR_PS_KILL)
  98                         rc |= PB_STATUS_OFF;
  99                 break;
 100         default:
 101                 rc = -ENODATA;
 102                 break;
 103         }
 104
 105         return rc;
 106 }
 107
 108 static struct pmbus_driver_info ibm_cffps_info = {
 109         .pages = 1,
 110         .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
 111                 PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
 112                 PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_VOUT |
 113                 PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT |
 114                 PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_STATUS_FAN12,
 115         .read_byte_data = ibm_cffps_read_byte_data,
 116         .read_word_data = ibm_cffps_read_word_data,
 117 };
 118
 119 static int ibm_cffps_probe(struct i2c_client *client,
 120                            const struct i2c_device_id *id)
 121 {
 122         return pmbus_do_probe(client, id, &ibm_cffps_info);
 123 }
 124
 125 static const struct i2c_device_id ibm_cffps_id[] = {
 126         { "ibm_cffps1", 1 },
 127         {}
 128 };
 129 MODULE_DEVICE_TABLE(i2c, ibm_cffps_id);
 130
 131 static const struct of_device_id ibm_cffps_of_match[] = {
 132         { .compatible = "ibm,cffps1" },
 133         {}
 134 };
 135 MODULE_DEVICE_TABLE(of, ibm_cffps_of_match);
 136
 137 static struct i2c_driver ibm_cffps_driver = {
 138         .driver = {
 139                 .name = "ibm-cffps",
 140                 .of_match_table = ibm_cffps_of_match,
 141         },
 142         .probe = ibm_cffps_probe,
 143         .remove = pmbus_do_remove,
 144         .id_table = ibm_cffps_id,
 145 };
 146
 147 module_i2c_driver(ibm_cffps_driver);
 148
 149 MODULE_AUTHOR("Eddie James");
 150 MODULE_DESCRIPTION("PMBus driver for IBM Common Form Factor power supplies");
 151 MODULE_LICENSE("GPL");