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