LXR linux/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
  18struct pmbus_device_info {
  19        int pages;
  20        u32 flags;
  21};
  22
  23static const struct i2c_device_id pmbus_id[];
  24
  25/*
  26 * Find sensor groups and status registers on each page.
  27 */
  28static 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 */
  91static 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);
 160abort:
 161        return ret;
 162}
 163
 164static 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
 192static const struct pmbus_device_info pmbus_info_one = {
 193        .pages = 1,
 194        .flags = 0
 195};
 196static const struct pmbus_device_info pmbus_info_zero = {
 197        .pages = 0,
 198        .flags = 0
 199};
 200static 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 */
 208static 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
 233MODULE_DEVICE_TABLE(i2c, pmbus_id);
 234
 235/* This is the driver that will be inserted */
 236static 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
 245module_i2c_driver(pmbus_driver);
 246
 247MODULE_AUTHOR("Guenter Roeck");
 248MODULE_DESCRIPTION("Generic PMBus driver");
 249MODULE_LICENSE("GPL");
 250