drivers/hwmon/pmbus/lt7182s.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Hardware monitoring driver for Analog Devices LT7182S
   4  *
   5  * Copyright (c) 2022 Guenter Roeck
   6  *
   7  */
   8
   9 #include <linux/bits.h>
  10 #include <linux/err.h>
  11 #include <linux/i2c.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include "pmbus.h"
  17
  18 #define LT7182S_NUM_PAGES       2
  19
  20 #define MFR_READ_EXTVCC         0xcd
  21 #define MFR_READ_ITH            0xce
  22 #define MFR_CONFIG_ALL_LT7182S  0xd1
  23 #define MFR_IOUT_PEAK           0xd7
  24 #define MFR_ADC_CONTROL_LT7182S 0xd8
  25
  26 #define MFR_DEBUG_TELEMETRY     BIT(0)
  27
  28 #define MFR_VOUT_PEAK           0xdd
  29 #define MFR_VIN_PEAK            0xde
  30 #define MFR_TEMPERATURE_1_PEAK  0xdf
  31 #define MFR_CLEAR_PEAKS         0xe3
  32
  33 #define MFR_CONFIG_IEEE         BIT(8)
  34
  35 static int lt7182s_read_word_data(struct i2c_client *client, int page, int phase, int reg)
  36 {
  37         int ret;
  38
  39         switch (reg) {
  40         case PMBUS_VIRT_READ_VMON:
  41                 if (page == 0 || page == 1)
  42                         ret = pmbus_read_word_data(client, page, phase, MFR_READ_ITH);
  43                 else
  44                         ret = pmbus_read_word_data(client, 0, phase, MFR_READ_EXTVCC);
  45                 break;
  46         case PMBUS_VIRT_READ_IOUT_MAX:
  47                 ret = pmbus_read_word_data(client, page, phase, MFR_IOUT_PEAK);
  48                 break;
  49         case PMBUS_VIRT_READ_VOUT_MAX:
  50                 ret = pmbus_read_word_data(client, page, phase, MFR_VOUT_PEAK);
  51                 break;
  52         case PMBUS_VIRT_READ_VIN_MAX:
  53                 ret = pmbus_read_word_data(client, page, phase, MFR_VIN_PEAK);
  54                 break;
  55         case PMBUS_VIRT_READ_TEMP_MAX:
  56                 ret = pmbus_read_word_data(client, page, phase, MFR_TEMPERATURE_1_PEAK);
  57                 break;
  58         case PMBUS_VIRT_RESET_VIN_HISTORY:
  59                 ret = (page == 0) ? 0 : -ENODATA;
  60                 break;
  61         default:
  62                 ret = -ENODATA;
  63                 break;
  64         }
  65         return ret;
  66 }
  67
  68 static int lt7182s_write_word_data(struct i2c_client *client, int page, int reg, u16 word)
  69 {
  70         int ret;
  71
  72         switch (reg) {
  73         case PMBUS_VIRT_RESET_VIN_HISTORY:
  74                 ret = pmbus_write_byte(client, 0, MFR_CLEAR_PEAKS);
  75                 break;
  76         default:
  77                 ret = -ENODATA;
  78                 break;
  79         }
  80         return ret;
  81 }
  82
  83 static struct pmbus_driver_info lt7182s_info = {
  84         .pages = LT7182S_NUM_PAGES,
  85         .format[PSC_VOLTAGE_IN] = linear,
  86         .format[PSC_VOLTAGE_OUT] = linear,
  87         .format[PSC_CURRENT_IN] = linear,
  88         .format[PSC_CURRENT_OUT] = linear,
  89         .format[PSC_TEMPERATURE] = linear,
  90         .format[PSC_POWER] = linear,
  91         .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
  92           PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
  93           PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
  94           PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
  95         .func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
  96           PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
  97           PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
  98           PMBUS_HAVE_STATUS_INPUT,
  99         .read_word_data = lt7182s_read_word_data,
 100         .write_word_data = lt7182s_write_word_data,
 101 };
 102
 103 static int lt7182s_probe(struct i2c_client *client)
 104 {
 105         struct device *dev = &client->dev;
 106         struct pmbus_driver_info *info;
 107         u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
 108         int ret;
 109
 110         if (!i2c_check_functionality(client->adapter,
 111                                      I2C_FUNC_SMBUS_READ_BYTE_DATA |
 112                                      I2C_FUNC_SMBUS_READ_WORD_DATA |
 113                                      I2C_FUNC_SMBUS_READ_BLOCK_DATA))
 114                 return -ENODEV;
 115
 116         ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
 117         if (ret < 0) {
 118                 dev_err(dev, "Failed to read PMBUS_MFR_ID\n");
 119                 return ret;
 120         }
 121         if (ret != 3 || strncmp(buf, "ADI", 3)) {
 122                 buf[ret] = '\0';
 123                 dev_err(dev, "Manufacturer '%s' not supported\n", buf);
 124                 return -ENODEV;
 125         }
 126
 127         ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
 128         if (ret < 0) {
 129                 dev_err(dev, "Failed to read PMBUS_MFR_MODEL\n");
 130                 return ret;
 131         }
 132         if (ret != 7 || strncmp(buf, "LT7182S", 7)) {
 133                 buf[ret] = '\0';
 134                 dev_err(dev, "Model '%s' not supported\n", buf);
 135                 return -ENODEV;
 136         }
 137
 138         info = devm_kmemdup(dev, &lt7182s_info,
 139                             sizeof(struct pmbus_driver_info), GFP_KERNEL);
 140         if (!info)
 141                 return -ENOMEM;
 142
 143         /* Set data format to IEEE754 if configured */
 144         ret = i2c_smbus_read_word_data(client, MFR_CONFIG_ALL_LT7182S);
 145         if (ret < 0)
 146                 return ret;
 147         if (ret & MFR_CONFIG_IEEE) {
 148                 info->format[PSC_VOLTAGE_IN] = ieee754;
 149                 info->format[PSC_VOLTAGE_OUT] = ieee754;
 150                 info->format[PSC_CURRENT_IN] = ieee754;
 151                 info->format[PSC_CURRENT_OUT] = ieee754;
 152                 info->format[PSC_TEMPERATURE] = ieee754;
 153                 info->format[PSC_POWER] = ieee754;
 154         }
 155
 156         /* Enable VMON output if configured */
 157         ret = i2c_smbus_read_byte_data(client, MFR_ADC_CONTROL_LT7182S);
 158         if (ret < 0)
 159                 return ret;
 160         if (ret & MFR_DEBUG_TELEMETRY) {
 161                 info->pages = 3;
 162                 info->func[0] |= PMBUS_HAVE_VMON;
 163                 info->func[1] |= PMBUS_HAVE_VMON;
 164                 info->func[2] = PMBUS_HAVE_VMON;
 165         }
 166
 167         return pmbus_do_probe(client, info);
 168 }
 169
 170 static const struct i2c_device_id lt7182s_id[] = {
 171         { "lt7182s" },
 172         {}
 173 };
 174 MODULE_DEVICE_TABLE(i2c, lt7182s_id);
 175
 176 static const struct of_device_id __maybe_unused lt7182s_of_match[] = {
 177         { .compatible = "adi,lt7182s" },
 178         {}
 179 };
 180
 181 static struct i2c_driver lt7182s_driver = {
 182         .driver = {
 183                 .name = "lt7182s",
 184                 .of_match_table = of_match_ptr(lt7182s_of_match),
 185         },
 186         .probe = lt7182s_probe,
 187         .id_table = lt7182s_id,
 188 };
 189
 190 module_i2c_driver(lt7182s_driver);
 191
 192 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
 193 MODULE_DESCRIPTION("PMBus driver for Analog Devices LT7182S");
 194 MODULE_LICENSE("GPL");
 195 MODULE_IMPORT_NS(PMBUS);