drivers/hwmon/pmbus/delta-ahe50dc-fan.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Delta AHE-50DC power shelf fan control module driver
   4  *
   5  * Copyright 2021 Zev Weiss <zev@bewilderbeest.net>
   6  */
   7
   8 #include <linux/i2c.h>
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/pmbus.h>
  12
  13 #include "pmbus.h"
  14
  15 #define AHE50DC_PMBUS_READ_TEMP4 0xd0
  16
  17 static int ahe50dc_fan_read_word_data(struct i2c_client *client, int page, int phase, int reg)
  18 {
  19         /* temp1 in (virtual) page 1 is remapped to mfr-specific temp4 */
  20         if (page == 1) {
  21                 if (reg == PMBUS_READ_TEMPERATURE_1)
  22                         return i2c_smbus_read_word_data(client, AHE50DC_PMBUS_READ_TEMP4);
  23                 return -EOPNOTSUPP;
  24         }
  25
  26         /*
  27          * There's a fairly limited set of commands this device actually
  28          * supports, so here we block attempts to read anything else (which
  29          * return 0xffff and would cause confusion elsewhere).
  30          */
  31         switch (reg) {
  32         case PMBUS_STATUS_WORD:
  33         case PMBUS_FAN_COMMAND_1:
  34         case PMBUS_FAN_COMMAND_2:
  35         case PMBUS_FAN_COMMAND_3:
  36         case PMBUS_FAN_COMMAND_4:
  37         case PMBUS_STATUS_FAN_12:
  38         case PMBUS_STATUS_FAN_34:
  39         case PMBUS_READ_VIN:
  40         case PMBUS_READ_TEMPERATURE_1:
  41         case PMBUS_READ_TEMPERATURE_2:
  42         case PMBUS_READ_TEMPERATURE_3:
  43         case PMBUS_READ_FAN_SPEED_1:
  44         case PMBUS_READ_FAN_SPEED_2:
  45         case PMBUS_READ_FAN_SPEED_3:
  46         case PMBUS_READ_FAN_SPEED_4:
  47                 return -ENODATA;
  48         default:
  49                 return -EOPNOTSUPP;
  50         }
  51 }
  52
  53 static struct pmbus_driver_info ahe50dc_fan_info = {
  54         .pages = 2,
  55         .format[PSC_FAN] = direct,
  56         .format[PSC_TEMPERATURE] = direct,
  57         .format[PSC_VOLTAGE_IN] = direct,
  58         .m[PSC_FAN] = 1,
  59         .b[PSC_FAN] = 0,
  60         .R[PSC_FAN] = 0,
  61         .m[PSC_TEMPERATURE] = 1,
  62         .b[PSC_TEMPERATURE] = 0,
  63         .R[PSC_TEMPERATURE] = 1,
  64         .m[PSC_VOLTAGE_IN] = 1,
  65         .b[PSC_VOLTAGE_IN] = 0,
  66         .R[PSC_VOLTAGE_IN] = 3,
  67         .func[0] = PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
  68                 PMBUS_HAVE_VIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_FAN34 |
  69                 PMBUS_HAVE_STATUS_FAN12 | PMBUS_HAVE_STATUS_FAN34 | PMBUS_PAGE_VIRTUAL,
  70         .func[1] = PMBUS_HAVE_TEMP | PMBUS_PAGE_VIRTUAL,
  71         .read_word_data = ahe50dc_fan_read_word_data,
  72 };
  73
  74 /*
  75  * CAPABILITY returns 0xff, which appears to be this device's way indicating
  76  * it doesn't support something (and if we enable I2C_CLIENT_PEC on seeing bit
  77  * 7 being set it generates bad PECs, so let's not go there).
  78  */
  79 static struct pmbus_platform_data ahe50dc_fan_data = {
  80         .flags = PMBUS_NO_CAPABILITY,
  81 };
  82
  83 static int ahe50dc_fan_probe(struct i2c_client *client)
  84 {
  85         client->dev.platform_data = &ahe50dc_fan_data;
  86         return pmbus_do_probe(client, &ahe50dc_fan_info);
  87 }
  88
  89 static const struct i2c_device_id ahe50dc_fan_id[] = {
  90         { "ahe50dc_fan" },
  91         { }
  92 };
  93 MODULE_DEVICE_TABLE(i2c, ahe50dc_fan_id);
  94
  95 static const struct of_device_id __maybe_unused ahe50dc_fan_of_match[] = {
  96         { .compatible = "delta,ahe50dc-fan" },
  97         { }
  98 };
  99 MODULE_DEVICE_TABLE(of, ahe50dc_fan_of_match);
 100
 101 static struct i2c_driver ahe50dc_fan_driver = {
 102         .driver = {
 103                    .name = "ahe50dc_fan",
 104                    .of_match_table = of_match_ptr(ahe50dc_fan_of_match),
 105         },
 106         .probe_new = ahe50dc_fan_probe,
 107         .id_table = ahe50dc_fan_id,
 108 };
 109 module_i2c_driver(ahe50dc_fan_driver);
 110
 111 MODULE_AUTHOR("Zev Weiss <zev@bewilderbeest.net>");
 112 MODULE_DESCRIPTION("Driver for Delta AHE-50DC power shelf fan control module");
 113 MODULE_LICENSE("GPL");
 114 MODULE_IMPORT_NS(PMBUS);