drivers/hwmon/pmbus/pmbus.c

   1 /*
   2  * Hardware monitoring driver for PMBus devices
   3  *
   4  * Copyright (c) 2010, 2011 Ericsson AB.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24 #include <linux/err.h>
  25 #include <linux/slab.h>
  26 #include <linux/mutex.h>
  27 #include <linux/i2c.h>
  28 #include <linux/pmbus.h>
  29 #include "pmbus.h"
  30
  31 /*
  32  * Find sensor groups and status registers on each page.
  33  */
  34 static void pmbus_find_sensor_groups(struct i2c_client *client,
  35                                      struct pmbus_driver_info *info)
  36 {
  37         int page;
  38
  39         /* Sensors detected on page 0 only */
  40         if (pmbus_check_word_register(client, 0, PMBUS_READ_VIN))
  41                 info->func[0] |= PMBUS_HAVE_VIN;
  42         if (pmbus_check_word_register(client, 0, PMBUS_READ_VCAP))
  43                 info->func[0] |= PMBUS_HAVE_VCAP;
  44         if (pmbus_check_word_register(client, 0, PMBUS_READ_IIN))
  45                 info->func[0] |= PMBUS_HAVE_IIN;
  46         if (pmbus_check_word_register(client, 0, PMBUS_READ_PIN))
  47                 info->func[0] |= PMBUS_HAVE_PIN;
  48         if (info->func[0]
  49             && pmbus_check_byte_register(client, 0, PMBUS_STATUS_INPUT))
  50                 info->func[0] |= PMBUS_HAVE_STATUS_INPUT;
  51         if (pmbus_check_byte_register(client, 0, PMBUS_FAN_CONFIG_12) &&
  52             pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_1)) {
  53                 info->func[0] |= PMBUS_HAVE_FAN12;
  54                 if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_12))
  55                         info->func[0] |= PMBUS_HAVE_STATUS_FAN12;
  56         }
  57         if (pmbus_check_byte_register(client, 0, PMBUS_FAN_CONFIG_34) &&
  58             pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_3)) {
  59                 info->func[0] |= PMBUS_HAVE_FAN34;
  60                 if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_34))
  61                         info->func[0] |= PMBUS_HAVE_STATUS_FAN34;
  62         }
  63         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_1))
  64                 info->func[0] |= PMBUS_HAVE_TEMP;
  65         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_2))
  66                 info->func[0] |= PMBUS_HAVE_TEMP2;
  67         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_3))
  68                 info->func[0] |= PMBUS_HAVE_TEMP3;
  69         if (info->func[0] & (PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
  70                              | PMBUS_HAVE_TEMP3)
  71             && pmbus_check_byte_register(client, 0,
  72                                          PMBUS_STATUS_TEMPERATURE))
  73                         info->func[0] |= PMBUS_HAVE_STATUS_TEMP;
  74
  75         /* Sensors detected on all pages */
  76         for (page = 0; page < info->pages; page++) {
  77                 if (pmbus_check_word_register(client, page, PMBUS_READ_VOUT)) {
  78                         info->func[page] |= PMBUS_HAVE_VOUT;
  79                         if (pmbus_check_byte_register(client, page,
  80                                                       PMBUS_STATUS_VOUT))
  81                                 info->func[page] |= PMBUS_HAVE_STATUS_VOUT;
  82                 }
  83                 if (pmbus_check_word_register(client, page, PMBUS_READ_IOUT)) {
  84                         info->func[page] |= PMBUS_HAVE_IOUT;
  85                         if (pmbus_check_byte_register(client, 0,
  86                                                       PMBUS_STATUS_IOUT))
  87                                 info->func[page] |= PMBUS_HAVE_STATUS_IOUT;
  88                 }
  89                 if (pmbus_check_word_register(client, page, PMBUS_READ_POUT))
  90                         info->func[page] |= PMBUS_HAVE_POUT;
  91         }
  92 }
  93
  94 /*
  95  * Identify chip parameters.
  96  */
  97 static int pmbus_identify(struct i2c_client *client,
  98                           struct pmbus_driver_info *info)
  99 {
 100         int ret = 0;
 101
 102         if (!info->pages) {
 103                 /*
 104                  * Check if the PAGE command is supported. If it is,
 105                  * keep setting the page number until it fails or until the
 106                  * maximum number of pages has been reached. Assume that
 107                  * this is the number of pages supported by the chip.
 108                  */
 109                 if (pmbus_check_byte_register(client, 0, PMBUS_PAGE)) {
 110                         int page;
 111
 112                         for (page = 1; page < PMBUS_PAGES; page++) {
 113                                 if (pmbus_set_page(client, page) < 0)
 114                                         break;
 115                         }
 116                         pmbus_set_page(client, 0);
 117                         info->pages = page;
 118                 } else {
 119                         info->pages = 1;
 120                 }
 121         }
 122
 123         if (pmbus_check_byte_register(client, 0, PMBUS_VOUT_MODE)) {
 124                 int vout_mode;
 125
 126                 vout_mode = pmbus_read_byte_data(client, 0, PMBUS_VOUT_MODE);
 127                 if (vout_mode >= 0 && vout_mode != 0xff) {
 128                         switch (vout_mode >> 5) {
 129                         case 0:
 130                                 break;
 131                         case 1:
 132                                 info->format[PSC_VOLTAGE_OUT] = vid;
 133                                 info->vrm_version = vr11;
 134                                 break;
 135                         case 2:
 136                                 info->format[PSC_VOLTAGE_OUT] = direct;
 137                                 break;
 138                         default:
 139                                 ret = -ENODEV;
 140                                 goto abort;
 141                         }
 142                 }
 143         }
 144
 145         /*
 146          * We should check if the COEFFICIENTS register is supported.
 147          * If it is, and the chip is configured for direct mode, we can read
 148          * the coefficients from the chip, one set per group of sensor
 149          * registers.
 150          *
 151          * To do this, we will need access to a chip which actually supports the
 152          * COEFFICIENTS command, since the command is too complex to implement
 153          * without testing it. Until then, abort if a chip configured for direct
 154          * mode was detected.
 155          */
 156         if (info->format[PSC_VOLTAGE_OUT] == direct) {
 157                 ret = -ENODEV;
 158                 goto abort;
 159         }
 160
 161         /* Try to find sensor groups  */
 162         pmbus_find_sensor_groups(client, info);
 163 abort:
 164         return ret;
 165 }
 166
 167 static int pmbus_probe(struct i2c_client *client,
 168                        const struct i2c_device_id *id)
 169 {
 170         struct pmbus_driver_info *info;
 171         struct pmbus_platform_data *pdata = NULL;
 172         struct device *dev = &client->dev;
 173
 174         info = devm_kzalloc(dev, sizeof(struct pmbus_driver_info), GFP_KERNEL);
 175         if (!info)
 176                 return -ENOMEM;
 177
 178         if (!strcmp(id->name, "dps460") || !strcmp(id->name, "dps800") ||
 179             !strcmp(id->name, "sgd009")) {
 180                 pdata = devm_kzalloc(dev, sizeof(struct pmbus_platform_data),
 181                                      GFP_KERNEL);
 182                 if (!pdata)
 183                         return -ENOMEM;
 184
 185                 pdata->flags = PMBUS_SKIP_STATUS_CHECK;
 186         }
 187
 188         info->pages = id->driver_data;
 189         info->identify = pmbus_identify;
 190         dev->platform_data = pdata;
 191
 192         return pmbus_do_probe(client, id, info);
 193 }
 194
 195 /*
 196  * Use driver_data to set the number of pages supported by the chip.
 197  */
 198 static const struct i2c_device_id pmbus_id[] = {
 199         {"adp4000", 1},
 200         {"bmr453", 1},
 201         {"bmr454", 1},
 202         {"dps460", 1},
 203         {"dps800", 1},
 204         {"mdt040", 1},
 205         {"ncp4200", 1},
 206         {"ncp4208", 1},
 207         {"pdt003", 1},
 208         {"pdt006", 1},
 209         {"pdt012", 1},
 210         {"pmbus", 0},
 211         {"sgd009", 1},
 212         {"tps40400", 1},
 213         {"tps544b20", 1},
 214         {"tps544b25", 1},
 215         {"tps544c20", 1},
 216         {"tps544c25", 1},
 217         {"udt020", 1},
 218         {}
 219 };
 220
 221 MODULE_DEVICE_TABLE(i2c, pmbus_id);
 222
 223 /* This is the driver that will be inserted */
 224 static struct i2c_driver pmbus_driver = {
 225         .driver = {
 226                    .name = "pmbus",
 227                    },
 228         .probe = pmbus_probe,
 229         .remove = pmbus_do_remove,
 230         .id_table = pmbus_id,
 231 };
 232
 233 module_i2c_driver(pmbus_driver);
 234
 235 MODULE_AUTHOR("Guenter Roeck");
 236 MODULE_DESCRIPTION("Generic PMBus driver");
 237 MODULE_LICENSE("GPL");