LXR linux/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/i2c/pmbus.h>
  29#include "pmbus.h"
  30
  31/*
  32 * Find sensor groups and status registers on each page.
  33 */
  34static 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 */
  97static 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);
 163abort:
 164        return ret;
 165}
 166
 167static 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 */
 198static 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
 221MODULE_DEVICE_TABLE(i2c, pmbus_id);
 222
 223/* This is the driver that will be inserted */
 224static 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
 233module_i2c_driver(pmbus_driver);
 234
 235MODULE_AUTHOR("Guenter Roeck");
 236MODULE_DESCRIPTION("Generic PMBus driver");
 237MODULE_LICENSE("GPL");
 238