drivers/hwmon/pmbus/pmbus.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Hardware monitoring driver for PMBus devices
   4  *
   5  * Copyright (c) 2010, 2011 Ericsson AB.
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/init.h>
  11 #include <linux/err.h>
  12 #include <linux/slab.h>
  13 #include <linux/mutex.h>
  14 #include <linux/i2c.h>
  15 #include <linux/pmbus.h>
  16 #include "pmbus.h"
  17
  18 struct pmbus_device_info {
  19         int pages;
  20         u32 flags;
  21 };
  22
  23 static const struct i2c_device_id pmbus_id[];
  24
  25 /*
  26  * Find sensor groups and status registers on each page.
  27  */
  28 static void pmbus_find_sensor_groups(struct i2c_client *client,
  29                                      struct pmbus_driver_info *info)
  30 {
  31         int page;
  32
  33         /* Sensors detected on page 0 only */
  34         if (pmbus_check_word_register(client, 0, PMBUS_READ_VIN))
  35                 info->func[0] |= PMBUS_HAVE_VIN;
  36         if (pmbus_check_word_register(client, 0, PMBUS_READ_VCAP))
  37                 info->func[0] |= PMBUS_HAVE_VCAP;
  38         if (pmbus_check_word_register(client, 0, PMBUS_READ_IIN))
  39                 info->func[0] |= PMBUS_HAVE_IIN;
  40         if (pmbus_check_word_register(client, 0, PMBUS_READ_PIN))
  41                 info->func[0] |= PMBUS_HAVE_PIN;
  42         if (info->func[0]
  43             && pmbus_check_byte_register(client, 0, PMBUS_STATUS_INPUT))
  44                 info->func[0] |= PMBUS_HAVE_STATUS_INPUT;
  45         if (pmbus_check_byte_register(client, 0, PMBUS_FAN_CONFIG_12) &&
  46             pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_1)) {
  47                 info->func[0] |= PMBUS_HAVE_FAN12;
  48                 if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_12))
  49                         info->func[0] |= PMBUS_HAVE_STATUS_FAN12;
  50         }
  51         if (pmbus_check_byte_register(client, 0, PMBUS_FAN_CONFIG_34) &&
  52             pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_3)) {
  53                 info->func[0] |= PMBUS_HAVE_FAN34;
  54                 if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_34))
  55                         info->func[0] |= PMBUS_HAVE_STATUS_FAN34;
  56         }
  57         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_1))
  58                 info->func[0] |= PMBUS_HAVE_TEMP;
  59         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_2))
  60                 info->func[0] |= PMBUS_HAVE_TEMP2;
  61         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_3))
  62                 info->func[0] |= PMBUS_HAVE_TEMP3;
  63         if (info->func[0] & (PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
  64                              | PMBUS_HAVE_TEMP3)
  65             && pmbus_check_byte_register(client, 0,
  66                                          PMBUS_STATUS_TEMPERATURE))
  67                         info->func[0] |= PMBUS_HAVE_STATUS_TEMP;
  68
  69         /* Sensors detected on all pages */
  70         for (page = 0; page < info->pages; page++) {
  71                 if (pmbus_check_word_register(client, page, PMBUS_READ_VOUT)) {
  72                         info->func[page] |= PMBUS_HAVE_VOUT;
  73                         if (pmbus_check_byte_register(client, page,
  74                                                       PMBUS_STATUS_VOUT))
  75                                 info->func[page] |= PMBUS_HAVE_STATUS_VOUT;
  76                 }
  77                 if (pmbus_check_word_register(client, page, PMBUS_READ_IOUT)) {
  78                         info->func[page] |= PMBUS_HAVE_IOUT;
  79                         if (pmbus_check_byte_register(client, 0,
  80                                                       PMBUS_STATUS_IOUT))
  81                                 info->func[page] |= PMBUS_HAVE_STATUS_IOUT;
  82                 }
  83                 if (pmbus_check_word_register(client, page, PMBUS_READ_POUT))
  84                         info->func[page] |= PMBUS_HAVE_POUT;
  85         }
  86 }
  87
  88 /*
  89  * Identify chip parameters.
  90  */
  91 static int pmbus_identify(struct i2c_client *client,
  92                           struct pmbus_driver_info *info)
  93 {
  94         int ret = 0;
  95
  96         if (!info->pages) {
  97                 /*
  98                  * Check if the PAGE command is supported. If it is,
  99                  * keep setting the page number until it fails or until the
 100                  * maximum number of pages has been reached. Assume that
 101                  * this is the number of pages supported by the chip.
 102                  */
 103                 if (pmbus_check_byte_register(client, 0, PMBUS_PAGE)) {
 104                         int page;
 105
 106                         for (page = 1; page < PMBUS_PAGES; page++) {
 107                                 if (pmbus_set_page(client, page, 0xff) < 0)
 108                                         break;
 109                         }
 110                         pmbus_set_page(client, 0, 0xff);
 111                         info->pages = page;
 112                 } else {
 113                         info->pages = 1;
 114                 }
 115
 116                 pmbus_clear_faults(client);
 117         }
 118
 119         if (pmbus_check_byte_register(client, 0, PMBUS_VOUT_MODE)) {
 120                 int vout_mode, i;
 121
 122                 vout_mode = pmbus_read_byte_data(client, 0, PMBUS_VOUT_MODE);
 123                 if (vout_mode >= 0 && vout_mode != 0xff) {
 124                         switch (vout_mode >> 5) {
 125                         case 0:
 126                                 break;
 127                         case 1:
 128                                 info->format[PSC_VOLTAGE_OUT] = vid;
 129                                 for (i = 0; i < info->pages; i++)
 130                                         info->vrm_version[i] = vr11;
 131                                 break;
 132                         case 2:
 133                                 info->format[PSC_VOLTAGE_OUT] = direct;
 134                                 break;
 135                         default:
 136                                 ret = -ENODEV;
 137                                 goto abort;
 138                         }
 139                 }
 140         }
 141
 142         /*
 143          * We should check if the COEFFICIENTS register is supported.
 144          * If it is, and the chip is configured for direct mode, we can read
 145          * the coefficients from the chip, one set per group of sensor
 146          * registers.
 147          *
 148          * To do this, we will need access to a chip which actually supports the
 149          * COEFFICIENTS command, since the command is too complex to implement
 150          * without testing it. Until then, abort if a chip configured for direct
 151          * mode was detected.
 152          */
 153         if (info->format[PSC_VOLTAGE_OUT] == direct) {
 154                 ret = -ENODEV;
 155                 goto abort;
 156         }
 157
 158         /* Try to find sensor groups  */
 159         pmbus_find_sensor_groups(client, info);
 160 abort:
 161         return ret;
 162 }
 163
 164 static int pmbus_probe(struct i2c_client *client)
 165 {
 166         struct pmbus_driver_info *info;
 167         struct pmbus_platform_data *pdata = NULL;
 168         struct device *dev = &client->dev;
 169         struct pmbus_device_info *device_info;
 170
 171         info = devm_kzalloc(dev, sizeof(struct pmbus_driver_info), GFP_KERNEL);
 172         if (!info)
 173                 return -ENOMEM;
 174
 175         device_info = (struct pmbus_device_info *)i2c_match_id(pmbus_id, client)->driver_data;
 176         if (device_info->flags & PMBUS_SKIP_STATUS_CHECK) {
 177                 pdata = devm_kzalloc(dev, sizeof(struct pmbus_platform_data),
 178                                      GFP_KERNEL);
 179                 if (!pdata)
 180                         return -ENOMEM;
 181
 182                 pdata->flags = PMBUS_SKIP_STATUS_CHECK;
 183         }
 184
 185         info->pages = device_info->pages;
 186         info->identify = pmbus_identify;
 187         dev->platform_data = pdata;
 188
 189         return pmbus_do_probe(client, info);
 190 }
 191
 192 static const struct pmbus_device_info pmbus_info_one = {
 193         .pages = 1,
 194         .flags = 0
 195 };
 196 static const struct pmbus_device_info pmbus_info_zero = {
 197         .pages = 0,
 198         .flags = 0
 199 };
 200 static const struct pmbus_device_info pmbus_info_one_skip = {
 201         .pages = 1,
 202         .flags = PMBUS_SKIP_STATUS_CHECK
 203 };
 204
 205 /*
 206  * Use driver_data to set the number of pages supported by the chip.
 207  */
 208 static const struct i2c_device_id pmbus_id[] = {
 209         {"adp4000", (kernel_ulong_t)&pmbus_info_one},
 210         {"bmr453", (kernel_ulong_t)&pmbus_info_one},
 211         {"bmr454", (kernel_ulong_t)&pmbus_info_one},
 212         {"dps460", (kernel_ulong_t)&pmbus_info_one_skip},
 213         {"dps650ab", (kernel_ulong_t)&pmbus_info_one_skip},
 214         {"dps800", (kernel_ulong_t)&pmbus_info_one_skip},
 215         {"max20796", (kernel_ulong_t)&pmbus_info_one},
 216         {"mdt040", (kernel_ulong_t)&pmbus_info_one},
 217         {"ncp4200", (kernel_ulong_t)&pmbus_info_one},
 218         {"ncp4208", (kernel_ulong_t)&pmbus_info_one},
 219         {"pdt003", (kernel_ulong_t)&pmbus_info_one},
 220         {"pdt006", (kernel_ulong_t)&pmbus_info_one},
 221         {"pdt012", (kernel_ulong_t)&pmbus_info_one},
 222         {"pmbus", (kernel_ulong_t)&pmbus_info_zero},
 223         {"sgd009", (kernel_ulong_t)&pmbus_info_one_skip},
 224         {"tps40400", (kernel_ulong_t)&pmbus_info_one},
 225         {"tps544b20", (kernel_ulong_t)&pmbus_info_one},
 226         {"tps544b25", (kernel_ulong_t)&pmbus_info_one},
 227         {"tps544c20", (kernel_ulong_t)&pmbus_info_one},
 228         {"tps544c25", (kernel_ulong_t)&pmbus_info_one},
 229         {"udt020", (kernel_ulong_t)&pmbus_info_one},
 230         {}
 231 };
 232
 233 MODULE_DEVICE_TABLE(i2c, pmbus_id);
 234
 235 /* This is the driver that will be inserted */
 236 static struct i2c_driver pmbus_driver = {
 237         .driver = {
 238                    .name = "pmbus",
 239                    },
 240         .probe_new = pmbus_probe,
 241         .remove = pmbus_do_remove,
 242         .id_table = pmbus_id,
 243 };
 244
 245 module_i2c_driver(pmbus_driver);
 246
 247 MODULE_AUTHOR("Guenter Roeck");
 248 MODULE_DESCRIPTION("Generic PMBus driver");
 249 MODULE_LICENSE("GPL");