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 "pmbus.h"
  29
  30 /*
  31  * Find sensor groups and status registers on each page.
  32  */
  33 static void pmbus_find_sensor_groups(struct i2c_client *client,
  34                                      struct pmbus_driver_info *info)
  35 {
  36         int page;
  37
  38         /* Sensors detected on page 0 only */
  39         if (pmbus_check_word_register(client, 0, PMBUS_READ_VIN))
  40                 info->func[0] |= PMBUS_HAVE_VIN;
  41         if (pmbus_check_word_register(client, 0, PMBUS_READ_VCAP))
  42                 info->func[0] |= PMBUS_HAVE_VCAP;
  43         if (pmbus_check_word_register(client, 0, PMBUS_READ_IIN))
  44                 info->func[0] |= PMBUS_HAVE_IIN;
  45         if (pmbus_check_word_register(client, 0, PMBUS_READ_PIN))
  46                 info->func[0] |= PMBUS_HAVE_PIN;
  47         if (info->func[0]
  48             && pmbus_check_byte_register(client, 0, PMBUS_STATUS_INPUT))
  49                 info->func[0] |= PMBUS_HAVE_STATUS_INPUT;
  50         if (pmbus_check_byte_register(client, 0, PMBUS_FAN_CONFIG_12) &&
  51             pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_1)) {
  52                 info->func[0] |= PMBUS_HAVE_FAN12;
  53                 if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_12))
  54                         info->func[0] |= PMBUS_HAVE_STATUS_FAN12;
  55         }
  56         if (pmbus_check_byte_register(client, 0, PMBUS_FAN_CONFIG_34) &&
  57             pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_3)) {
  58                 info->func[0] |= PMBUS_HAVE_FAN34;
  59                 if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_34))
  60                         info->func[0] |= PMBUS_HAVE_STATUS_FAN34;
  61         }
  62         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_1))
  63                 info->func[0] |= PMBUS_HAVE_TEMP;
  64         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_2))
  65                 info->func[0] |= PMBUS_HAVE_TEMP2;
  66         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_3))
  67                 info->func[0] |= PMBUS_HAVE_TEMP3;
  68         if (info->func[0] & (PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
  69                              | PMBUS_HAVE_TEMP3)
  70             && pmbus_check_byte_register(client, 0,
  71                                          PMBUS_STATUS_TEMPERATURE))
  72                         info->func[0] |= PMBUS_HAVE_STATUS_TEMP;
  73
  74         /* Sensors detected on all pages */
  75         for (page = 0; page < info->pages; page++) {
  76                 if (pmbus_check_word_register(client, page, PMBUS_READ_VOUT)) {
  77                         info->func[page] |= PMBUS_HAVE_VOUT;
  78                         if (pmbus_check_byte_register(client, page,
  79                                                       PMBUS_STATUS_VOUT))
  80                                 info->func[page] |= PMBUS_HAVE_STATUS_VOUT;
  81                 }
  82                 if (pmbus_check_word_register(client, page, PMBUS_READ_IOUT)) {
  83                         info->func[page] |= PMBUS_HAVE_IOUT;
  84                         if (pmbus_check_byte_register(client, 0,
  85                                                       PMBUS_STATUS_IOUT))
  86                                 info->func[page] |= PMBUS_HAVE_STATUS_IOUT;
  87                 }
  88                 if (pmbus_check_word_register(client, page, PMBUS_READ_POUT))
  89                         info->func[page] |= PMBUS_HAVE_POUT;
  90         }
  91 }
  92
  93 /*
  94  * Identify chip parameters.
  95  */
  96 static int pmbus_identify(struct i2c_client *client,
  97                           struct pmbus_driver_info *info)
  98 {
  99         int ret = 0;
 100
 101         if (!info->pages) {
 102                 /*
 103                  * Check if the PAGE command is supported. If it is,
 104                  * keep setting the page number until it fails or until the
 105                  * maximum number of pages has been reached. Assume that
 106                  * this is the number of pages supported by the chip.
 107                  */
 108                 if (pmbus_check_byte_register(client, 0, PMBUS_PAGE)) {
 109                         int page;
 110
 111                         for (page = 1; page < PMBUS_PAGES; page++) {
 112                                 if (pmbus_set_page(client, page) < 0)
 113                                         break;
 114                         }
 115                         pmbus_set_page(client, 0);
 116                         info->pages = page;
 117                 } else {
 118                         info->pages = 1;
 119                 }
 120         }
 121
 122         if (pmbus_check_byte_register(client, 0, PMBUS_VOUT_MODE)) {
 123                 int vout_mode;
 124
 125                 vout_mode = pmbus_read_byte_data(client, 0, PMBUS_VOUT_MODE);
 126                 if (vout_mode >= 0 && vout_mode != 0xff) {
 127                         switch (vout_mode >> 5) {
 128                         case 0:
 129                                 break;
 130                         case 1:
 131                                 info->format[PSC_VOLTAGE_OUT] = vid;
 132                                 break;
 133                         case 2:
 134                                 info->format[PSC_VOLTAGE_OUT] = direct;
 135                                 break;
 136                         default:
 137                                 ret = -ENODEV;
 138                                 goto abort;
 139                         }
 140                 }
 141         }
 142
 143         /*
 144          * We should check if the COEFFICIENTS register is supported.
 145          * If it is, and the chip is configured for direct mode, we can read
 146          * the coefficients from the chip, one set per group of sensor
 147          * registers.
 148          *
 149          * To do this, we will need access to a chip which actually supports the
 150          * COEFFICIENTS command, since the command is too complex to implement
 151          * without testing it. Until then, abort if a chip configured for direct
 152          * mode was detected.
 153          */
 154         if (info->format[PSC_VOLTAGE_OUT] == direct) {
 155                 ret = -ENODEV;
 156                 goto abort;
 157         }
 158
 159         /* Try to find sensor groups  */
 160         pmbus_find_sensor_groups(client, info);
 161 abort:
 162         return ret;
 163 }
 164
 165 static int pmbus_probe(struct i2c_client *client,
 166                        const struct i2c_device_id *id)
 167 {
 168         struct pmbus_driver_info *info;
 169         int ret;
 170
 171         info = kzalloc(sizeof(struct pmbus_driver_info), GFP_KERNEL);
 172         if (!info)
 173                 return -ENOMEM;
 174
 175         info->pages = id->driver_data;
 176         info->identify = pmbus_identify;
 177
 178         ret = pmbus_do_probe(client, id, info);
 179         if (ret < 0)
 180                 goto out;
 181         return 0;
 182
 183 out:
 184         kfree(info);
 185         return ret;
 186 }
 187
 188 static int pmbus_remove(struct i2c_client *client)
 189 {
 190         int ret;
 191         const struct pmbus_driver_info *info;
 192
 193         info = pmbus_get_driver_info(client);
 194         ret = pmbus_do_remove(client);
 195         kfree(info);
 196         return ret;
 197 }
 198
 199 /*
 200  * Use driver_data to set the number of pages supported by the chip.
 201  */
 202 static const struct i2c_device_id pmbus_id[] = {
 203         {"adp4000", 1},
 204         {"bmr450", 1},
 205         {"bmr451", 1},
 206         {"bmr453", 1},
 207         {"bmr454", 1},
 208         {"ltc2978", 8},
 209         {"ncp4200", 1},
 210         {"ncp4208", 1},
 211         {"pmbus", 0},
 212         {}
 213 };
 214
 215 MODULE_DEVICE_TABLE(i2c, pmbus_id);
 216
 217 /* This is the driver that will be inserted */
 218 static struct i2c_driver pmbus_driver = {
 219         .driver = {
 220                    .name = "pmbus",
 221                    },
 222         .probe = pmbus_probe,
 223         .remove = pmbus_remove,
 224         .id_table = pmbus_id,
 225 };
 226
 227 static int __init pmbus_init(void)
 228 {
 229         return i2c_add_driver(&pmbus_driver);
 230 }
 231
 232 static void __exit pmbus_exit(void)
 233 {
 234         i2c_del_driver(&pmbus_driver);
 235 }
 236
 237 MODULE_AUTHOR("Guenter Roeck");
 238 MODULE_DESCRIPTION("Generic PMBus driver");
 239 MODULE_LICENSE("GPL");
 240 module_init(pmbus_init);
 241 module_exit(pmbus_exit);