drivers/hwmon/pmbus/bpa-rs600.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Hardware monitoring driver for BluTek BPA-RS600 Power Supplies
   4  *
   5  * Copyright 2021 Allied Telesis Labs
   6  */
   7
   8 #include <linux/i2c.h>
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/pmbus.h>
  13 #include "pmbus.h"
  14
  15 enum chips { bpa_rs600, bpd_rs600 };
  16
  17 static int bpa_rs600_read_byte_data(struct i2c_client *client, int page, int reg)
  18 {
  19         int ret;
  20
  21         if (page > 0)
  22                 return -ENXIO;
  23
  24         switch (reg) {
  25         case PMBUS_FAN_CONFIG_12:
  26                 /*
  27                  * Two fans are reported in PMBUS_FAN_CONFIG_12 but there is
  28                  * only one fan in the module. Mask out the FAN2 bits.
  29                  */
  30                 ret = pmbus_read_byte_data(client, 0, PMBUS_FAN_CONFIG_12);
  31                 if (ret >= 0)
  32                         ret &= ~(PB_FAN_2_INSTALLED | PB_FAN_2_PULSE_MASK);
  33                 break;
  34         default:
  35                 ret = -ENODATA;
  36                 break;
  37         }
  38
  39         return ret;
  40 }
  41
  42 /*
  43  * The BPA-RS600 violates the PMBus spec. Specifically it treats the
  44  * mantissa as unsigned. Deal with this here to allow the PMBus core
  45  * to work with correctly encoded data.
  46  */
  47 static int bpa_rs600_read_vin(struct i2c_client *client)
  48 {
  49         int ret, exponent, mantissa;
  50
  51         ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_READ_VIN);
  52         if (ret < 0)
  53                 return ret;
  54
  55         if (ret & BIT(10)) {
  56                 exponent = ret >> 11;
  57                 mantissa = ret & 0x7ff;
  58
  59                 exponent++;
  60                 mantissa >>= 1;
  61
  62                 ret = (exponent << 11) | mantissa;
  63         }
  64
  65         return ret;
  66 }
  67
  68 /*
  69  * Firmware V5.70 incorrectly reports 1640W for MFR_PIN_MAX.
  70  * Deal with this by returning a sensible value.
  71  */
  72 static int bpa_rs600_read_pin_max(struct i2c_client *client)
  73 {
  74         int ret;
  75
  76         ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_PIN_MAX);
  77         if (ret < 0)
  78                 return ret;
  79
  80         /* Detect invalid 1640W (linear encoding) */
  81         if (ret == 0x0b34)
  82                 /* Report 700W (linear encoding) */
  83                 return 0x095e;
  84
  85         return ret;
  86 }
  87
  88 static int bpa_rs600_read_word_data(struct i2c_client *client, int page, int phase, int reg)
  89 {
  90         int ret;
  91
  92         if (page > 0)
  93                 return -ENXIO;
  94
  95         switch (reg) {
  96         case PMBUS_VIN_UV_WARN_LIMIT:
  97         case PMBUS_VIN_OV_WARN_LIMIT:
  98         case PMBUS_VOUT_UV_WARN_LIMIT:
  99         case PMBUS_VOUT_OV_WARN_LIMIT:
 100         case PMBUS_IIN_OC_WARN_LIMIT:
 101         case PMBUS_IOUT_OC_WARN_LIMIT:
 102         case PMBUS_PIN_OP_WARN_LIMIT:
 103         case PMBUS_POUT_OP_WARN_LIMIT:
 104         case PMBUS_VIN_UV_FAULT_LIMIT:
 105         case PMBUS_VIN_OV_FAULT_LIMIT:
 106         case PMBUS_VOUT_UV_FAULT_LIMIT:
 107         case PMBUS_VOUT_OV_FAULT_LIMIT:
 108                 /* These commands return data but it is invalid/un-documented */
 109                 ret = -ENXIO;
 110                 break;
 111         case PMBUS_READ_VIN:
 112                 ret = bpa_rs600_read_vin(client);
 113                 break;
 114         case PMBUS_MFR_PIN_MAX:
 115                 ret = bpa_rs600_read_pin_max(client);
 116                 break;
 117         default:
 118                 if (reg >= PMBUS_VIRT_BASE)
 119                         ret = -ENXIO;
 120                 else
 121                         ret = -ENODATA;
 122                 break;
 123         }
 124
 125         return ret;
 126 }
 127
 128 static struct pmbus_driver_info bpa_rs600_info = {
 129         .pages = 1,
 130         .format[PSC_VOLTAGE_IN] = linear,
 131         .format[PSC_VOLTAGE_OUT] = linear,
 132         .format[PSC_CURRENT_IN] = linear,
 133         .format[PSC_CURRENT_OUT] = linear,
 134         .format[PSC_POWER] = linear,
 135         .format[PSC_TEMPERATURE] = linear,
 136         .format[PSC_FAN] = linear,
 137         .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
 138                 PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT |
 139                 PMBUS_HAVE_PIN | PMBUS_HAVE_POUT |
 140                 PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
 141                 PMBUS_HAVE_FAN12 |
 142                 PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
 143                 PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP |
 144                 PMBUS_HAVE_STATUS_FAN12,
 145         .read_byte_data = bpa_rs600_read_byte_data,
 146         .read_word_data = bpa_rs600_read_word_data,
 147 };
 148
 149 static const struct i2c_device_id bpa_rs600_id[] = {
 150         { "bpa-rs600", bpa_rs600 },
 151         { "bpd-rs600", bpd_rs600 },
 152         {},
 153 };
 154 MODULE_DEVICE_TABLE(i2c, bpa_rs600_id);
 155
 156 static int bpa_rs600_probe(struct i2c_client *client)
 157 {
 158         struct device *dev = &client->dev;
 159         u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
 160         int ret;
 161         const struct i2c_device_id *mid;
 162
 163         if (!i2c_check_functionality(client->adapter,
 164                                      I2C_FUNC_SMBUS_READ_BYTE_DATA
 165                                      | I2C_FUNC_SMBUS_READ_WORD_DATA
 166                                      | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
 167                 return -ENODEV;
 168
 169         ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
 170         if (ret < 0) {
 171                 dev_err(dev, "Failed to read Manufacturer Model\n");
 172                 return ret;
 173         }
 174
 175         for (mid = bpa_rs600_id; mid->name[0]; mid++) {
 176                 if (!strncasecmp(buf, mid->name, strlen(mid->name)))
 177                         break;
 178         }
 179         if (!mid->name[0]) {
 180                 buf[ret] = '\0';
 181                 dev_err(dev, "Unsupported Manufacturer Model '%s'\n", buf);
 182                 return -ENODEV;
 183         }
 184
 185         return pmbus_do_probe(client, &bpa_rs600_info);
 186 }
 187
 188 static const struct of_device_id __maybe_unused bpa_rs600_of_match[] = {
 189         { .compatible = "blutek,bpa-rs600" },
 190         {},
 191 };
 192 MODULE_DEVICE_TABLE(of, bpa_rs600_of_match);
 193
 194 static struct i2c_driver bpa_rs600_driver = {
 195         .driver = {
 196                 .name = "bpa-rs600",
 197                 .of_match_table = of_match_ptr(bpa_rs600_of_match),
 198         },
 199         .probe = bpa_rs600_probe,
 200         .id_table = bpa_rs600_id,
 201 };
 202
 203 module_i2c_driver(bpa_rs600_driver);
 204
 205 MODULE_AUTHOR("Chris Packham");
 206 MODULE_DESCRIPTION("PMBus driver for BluTek BPA-RS600");
 207 MODULE_LICENSE("GPL");
 208 MODULE_IMPORT_NS("PMBUS");