linux/drivers/hwmon/pmbus/ibm-cffps.c
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   1/*
   2 * Copyright 2017 IBM Corp.
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License as published by
   6 * the Free Software Foundation; either version 2 of the License, or
   7 * (at your option) any later version.
   8 */
   9
  10#include <linux/bitops.h>
  11#include <linux/debugfs.h>
  12#include <linux/device.h>
  13#include <linux/fs.h>
  14#include <linux/i2c.h>
  15#include <linux/jiffies.h>
  16#include <linux/leds.h>
  17#include <linux/module.h>
  18#include <linux/mutex.h>
  19#include <linux/pmbus.h>
  20
  21#include "pmbus.h"
  22
  23#define CFFPS_FRU_CMD                           0x9A
  24#define CFFPS_PN_CMD                            0x9B
  25#define CFFPS_SN_CMD                            0x9E
  26#define CFFPS_CCIN_CMD                          0xBD
  27#define CFFPS_FW_CMD_START                      0xFA
  28#define CFFPS_FW_NUM_BYTES                      4
  29#define CFFPS_SYS_CONFIG_CMD                    0xDA
  30
  31#define CFFPS_INPUT_HISTORY_CMD                 0xD6
  32#define CFFPS_INPUT_HISTORY_SIZE                100
  33
  34/* STATUS_MFR_SPECIFIC bits */
  35#define CFFPS_MFR_FAN_FAULT                     BIT(0)
  36#define CFFPS_MFR_THERMAL_FAULT                 BIT(1)
  37#define CFFPS_MFR_OV_FAULT                      BIT(2)
  38#define CFFPS_MFR_UV_FAULT                      BIT(3)
  39#define CFFPS_MFR_PS_KILL                       BIT(4)
  40#define CFFPS_MFR_OC_FAULT                      BIT(5)
  41#define CFFPS_MFR_VAUX_FAULT                    BIT(6)
  42#define CFFPS_MFR_CURRENT_SHARE_WARNING         BIT(7)
  43
  44#define CFFPS_LED_BLINK                         BIT(0)
  45#define CFFPS_LED_ON                            BIT(1)
  46#define CFFPS_LED_OFF                           BIT(2)
  47#define CFFPS_BLINK_RATE_MS                     250
  48
  49enum {
  50        CFFPS_DEBUGFS_INPUT_HISTORY = 0,
  51        CFFPS_DEBUGFS_FRU,
  52        CFFPS_DEBUGFS_PN,
  53        CFFPS_DEBUGFS_SN,
  54        CFFPS_DEBUGFS_CCIN,
  55        CFFPS_DEBUGFS_FW,
  56        CFFPS_DEBUGFS_NUM_ENTRIES
  57};
  58
  59struct ibm_cffps_input_history {
  60        struct mutex update_lock;
  61        unsigned long last_update;
  62
  63        u8 byte_count;
  64        u8 data[CFFPS_INPUT_HISTORY_SIZE];
  65};
  66
  67struct ibm_cffps {
  68        struct i2c_client *client;
  69
  70        struct ibm_cffps_input_history input_history;
  71
  72        int debugfs_entries[CFFPS_DEBUGFS_NUM_ENTRIES];
  73
  74        char led_name[32];
  75        u8 led_state;
  76        struct led_classdev led;
  77};
  78
  79#define to_psu(x, y) container_of((x), struct ibm_cffps, debugfs_entries[(y)])
  80
  81static ssize_t ibm_cffps_read_input_history(struct ibm_cffps *psu,
  82                                            char __user *buf, size_t count,
  83                                            loff_t *ppos)
  84{
  85        int rc;
  86        u8 msgbuf0[1] = { CFFPS_INPUT_HISTORY_CMD };
  87        u8 msgbuf1[CFFPS_INPUT_HISTORY_SIZE + 1] = { 0 };
  88        struct i2c_msg msg[2] = {
  89                {
  90                        .addr = psu->client->addr,
  91                        .flags = psu->client->flags,
  92                        .len = 1,
  93                        .buf = msgbuf0,
  94                }, {
  95                        .addr = psu->client->addr,
  96                        .flags = psu->client->flags | I2C_M_RD,
  97                        .len = CFFPS_INPUT_HISTORY_SIZE + 1,
  98                        .buf = msgbuf1,
  99                },
 100        };
 101
 102        if (!*ppos) {
 103                mutex_lock(&psu->input_history.update_lock);
 104                if (time_after(jiffies, psu->input_history.last_update + HZ)) {
 105                        /*
 106                         * Use a raw i2c transfer, since we need more bytes
 107                         * than Linux I2C supports through smbus xfr (only 32).
 108                         */
 109                        rc = i2c_transfer(psu->client->adapter, msg, 2);
 110                        if (rc < 0) {
 111                                mutex_unlock(&psu->input_history.update_lock);
 112                                return rc;
 113                        }
 114
 115                        psu->input_history.byte_count = msgbuf1[0];
 116                        memcpy(psu->input_history.data, &msgbuf1[1],
 117                               CFFPS_INPUT_HISTORY_SIZE);
 118                        psu->input_history.last_update = jiffies;
 119                }
 120
 121                mutex_unlock(&psu->input_history.update_lock);
 122        }
 123
 124        return simple_read_from_buffer(buf, count, ppos,
 125                                       psu->input_history.data,
 126                                       psu->input_history.byte_count);
 127}
 128
 129static ssize_t ibm_cffps_debugfs_op(struct file *file, char __user *buf,
 130                                    size_t count, loff_t *ppos)
 131{
 132        u8 cmd;
 133        int i, rc;
 134        int *idxp = file->private_data;
 135        int idx = *idxp;
 136        struct ibm_cffps *psu = to_psu(idxp, idx);
 137        char data[I2C_SMBUS_BLOCK_MAX] = { 0 };
 138
 139        switch (idx) {
 140        case CFFPS_DEBUGFS_INPUT_HISTORY:
 141                return ibm_cffps_read_input_history(psu, buf, count, ppos);
 142        case CFFPS_DEBUGFS_FRU:
 143                cmd = CFFPS_FRU_CMD;
 144                break;
 145        case CFFPS_DEBUGFS_PN:
 146                cmd = CFFPS_PN_CMD;
 147                break;
 148        case CFFPS_DEBUGFS_SN:
 149                cmd = CFFPS_SN_CMD;
 150                break;
 151        case CFFPS_DEBUGFS_CCIN:
 152                rc = i2c_smbus_read_word_swapped(psu->client, CFFPS_CCIN_CMD);
 153                if (rc < 0)
 154                        return rc;
 155
 156                rc = snprintf(data, 5, "%04X", rc);
 157                goto done;
 158        case CFFPS_DEBUGFS_FW:
 159                for (i = 0; i < CFFPS_FW_NUM_BYTES; ++i) {
 160                        rc = i2c_smbus_read_byte_data(psu->client,
 161                                                      CFFPS_FW_CMD_START + i);
 162                        if (rc < 0)
 163                                return rc;
 164
 165                        snprintf(&data[i * 2], 3, "%02X", rc);
 166                }
 167
 168                rc = i * 2;
 169                goto done;
 170        default:
 171                return -EINVAL;
 172        }
 173
 174        rc = i2c_smbus_read_block_data(psu->client, cmd, data);
 175        if (rc < 0)
 176                return rc;
 177
 178done:
 179        data[rc] = '\n';
 180        rc += 2;
 181
 182        return simple_read_from_buffer(buf, count, ppos, data, rc);
 183}
 184
 185static const struct file_operations ibm_cffps_fops = {
 186        .llseek = noop_llseek,
 187        .read = ibm_cffps_debugfs_op,
 188        .open = simple_open,
 189};
 190
 191static int ibm_cffps_read_byte_data(struct i2c_client *client, int page,
 192                                    int reg)
 193{
 194        int rc, mfr;
 195
 196        switch (reg) {
 197        case PMBUS_STATUS_VOUT:
 198        case PMBUS_STATUS_IOUT:
 199        case PMBUS_STATUS_TEMPERATURE:
 200        case PMBUS_STATUS_FAN_12:
 201                rc = pmbus_read_byte_data(client, page, reg);
 202                if (rc < 0)
 203                        return rc;
 204
 205                mfr = pmbus_read_byte_data(client, page,
 206                                           PMBUS_STATUS_MFR_SPECIFIC);
 207                if (mfr < 0)
 208                        /*
 209                         * Return the status register instead of an error,
 210                         * since we successfully read status.
 211                         */
 212                        return rc;
 213
 214                /* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
 215                if (reg == PMBUS_STATUS_FAN_12) {
 216                        if (mfr & CFFPS_MFR_FAN_FAULT)
 217                                rc |= PB_FAN_FAN1_FAULT;
 218                } else if (reg == PMBUS_STATUS_TEMPERATURE) {
 219                        if (mfr & CFFPS_MFR_THERMAL_FAULT)
 220                                rc |= PB_TEMP_OT_FAULT;
 221                } else if (reg == PMBUS_STATUS_VOUT) {
 222                        if (mfr & (CFFPS_MFR_OV_FAULT | CFFPS_MFR_VAUX_FAULT))
 223                                rc |= PB_VOLTAGE_OV_FAULT;
 224                        if (mfr & CFFPS_MFR_UV_FAULT)
 225                                rc |= PB_VOLTAGE_UV_FAULT;
 226                } else if (reg == PMBUS_STATUS_IOUT) {
 227                        if (mfr & CFFPS_MFR_OC_FAULT)
 228                                rc |= PB_IOUT_OC_FAULT;
 229                        if (mfr & CFFPS_MFR_CURRENT_SHARE_WARNING)
 230                                rc |= PB_CURRENT_SHARE_FAULT;
 231                }
 232                break;
 233        default:
 234                rc = -ENODATA;
 235                break;
 236        }
 237
 238        return rc;
 239}
 240
 241static int ibm_cffps_read_word_data(struct i2c_client *client, int page,
 242                                    int reg)
 243{
 244        int rc, mfr;
 245
 246        switch (reg) {
 247        case PMBUS_STATUS_WORD:
 248                rc = pmbus_read_word_data(client, page, reg);
 249                if (rc < 0)
 250                        return rc;
 251
 252                mfr = pmbus_read_byte_data(client, page,
 253                                           PMBUS_STATUS_MFR_SPECIFIC);
 254                if (mfr < 0)
 255                        /*
 256                         * Return the status register instead of an error,
 257                         * since we successfully read status.
 258                         */
 259                        return rc;
 260
 261                if (mfr & CFFPS_MFR_PS_KILL)
 262                        rc |= PB_STATUS_OFF;
 263                break;
 264        default:
 265                rc = -ENODATA;
 266                break;
 267        }
 268
 269        return rc;
 270}
 271
 272static void ibm_cffps_led_brightness_set(struct led_classdev *led_cdev,
 273                                         enum led_brightness brightness)
 274{
 275        int rc;
 276        struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
 277
 278        if (brightness == LED_OFF) {
 279                psu->led_state = CFFPS_LED_OFF;
 280        } else {
 281                brightness = LED_FULL;
 282                if (psu->led_state != CFFPS_LED_BLINK)
 283                        psu->led_state = CFFPS_LED_ON;
 284        }
 285
 286        rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
 287                                       psu->led_state);
 288        if (rc < 0)
 289                return;
 290
 291        led_cdev->brightness = brightness;
 292}
 293
 294static int ibm_cffps_led_blink_set(struct led_classdev *led_cdev,
 295                                   unsigned long *delay_on,
 296                                   unsigned long *delay_off)
 297{
 298        int rc;
 299        struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
 300
 301        psu->led_state = CFFPS_LED_BLINK;
 302
 303        if (led_cdev->brightness == LED_OFF)
 304                return 0;
 305
 306        rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
 307                                       CFFPS_LED_BLINK);
 308        if (rc < 0)
 309                return rc;
 310
 311        *delay_on = CFFPS_BLINK_RATE_MS;
 312        *delay_off = CFFPS_BLINK_RATE_MS;
 313
 314        return 0;
 315}
 316
 317static void ibm_cffps_create_led_class(struct ibm_cffps *psu)
 318{
 319        int rc;
 320        struct i2c_client *client = psu->client;
 321        struct device *dev = &client->dev;
 322
 323        snprintf(psu->led_name, sizeof(psu->led_name), "%s-%02x", client->name,
 324                 client->addr);
 325        psu->led.name = psu->led_name;
 326        psu->led.max_brightness = LED_FULL;
 327        psu->led.brightness_set = ibm_cffps_led_brightness_set;
 328        psu->led.blink_set = ibm_cffps_led_blink_set;
 329
 330        rc = devm_led_classdev_register(dev, &psu->led);
 331        if (rc)
 332                dev_warn(dev, "failed to register led class: %d\n", rc);
 333}
 334
 335static struct pmbus_driver_info ibm_cffps_info = {
 336        .pages = 1,
 337        .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
 338                PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
 339                PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_VOUT |
 340                PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT |
 341                PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_STATUS_FAN12,
 342        .read_byte_data = ibm_cffps_read_byte_data,
 343        .read_word_data = ibm_cffps_read_word_data,
 344};
 345
 346static struct pmbus_platform_data ibm_cffps_pdata = {
 347        .flags = PMBUS_SKIP_STATUS_CHECK,
 348};
 349
 350static int ibm_cffps_probe(struct i2c_client *client,
 351                           const struct i2c_device_id *id)
 352{
 353        int i, rc;
 354        struct dentry *debugfs;
 355        struct dentry *ibm_cffps_dir;
 356        struct ibm_cffps *psu;
 357
 358        client->dev.platform_data = &ibm_cffps_pdata;
 359        rc = pmbus_do_probe(client, id, &ibm_cffps_info);
 360        if (rc)
 361                return rc;
 362
 363        /*
 364         * Don't fail the probe if there isn't enough memory for leds and
 365         * debugfs.
 366         */
 367        psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL);
 368        if (!psu)
 369                return 0;
 370
 371        psu->client = client;
 372        mutex_init(&psu->input_history.update_lock);
 373        psu->input_history.last_update = jiffies - HZ;
 374
 375        ibm_cffps_create_led_class(psu);
 376
 377        /* Don't fail the probe if we can't create debugfs */
 378        debugfs = pmbus_get_debugfs_dir(client);
 379        if (!debugfs)
 380                return 0;
 381
 382        ibm_cffps_dir = debugfs_create_dir(client->name, debugfs);
 383        if (!ibm_cffps_dir)
 384                return 0;
 385
 386        for (i = 0; i < CFFPS_DEBUGFS_NUM_ENTRIES; ++i)
 387                psu->debugfs_entries[i] = i;
 388
 389        debugfs_create_file("input_history", 0444, ibm_cffps_dir,
 390                            &psu->debugfs_entries[CFFPS_DEBUGFS_INPUT_HISTORY],
 391                            &ibm_cffps_fops);
 392        debugfs_create_file("fru", 0444, ibm_cffps_dir,
 393                            &psu->debugfs_entries[CFFPS_DEBUGFS_FRU],
 394                            &ibm_cffps_fops);
 395        debugfs_create_file("part_number", 0444, ibm_cffps_dir,
 396                            &psu->debugfs_entries[CFFPS_DEBUGFS_PN],
 397                            &ibm_cffps_fops);
 398        debugfs_create_file("serial_number", 0444, ibm_cffps_dir,
 399                            &psu->debugfs_entries[CFFPS_DEBUGFS_SN],
 400                            &ibm_cffps_fops);
 401        debugfs_create_file("ccin", 0444, ibm_cffps_dir,
 402                            &psu->debugfs_entries[CFFPS_DEBUGFS_CCIN],
 403                            &ibm_cffps_fops);
 404        debugfs_create_file("fw_version", 0444, ibm_cffps_dir,
 405                            &psu->debugfs_entries[CFFPS_DEBUGFS_FW],
 406                            &ibm_cffps_fops);
 407
 408        return 0;
 409}
 410
 411static const struct i2c_device_id ibm_cffps_id[] = {
 412        { "ibm_cffps1", 1 },
 413        {}
 414};
 415MODULE_DEVICE_TABLE(i2c, ibm_cffps_id);
 416
 417static const struct of_device_id ibm_cffps_of_match[] = {
 418        { .compatible = "ibm,cffps1" },
 419        {}
 420};
 421MODULE_DEVICE_TABLE(of, ibm_cffps_of_match);
 422
 423static struct i2c_driver ibm_cffps_driver = {
 424        .driver = {
 425                .name = "ibm-cffps",
 426                .of_match_table = ibm_cffps_of_match,
 427        },
 428        .probe = ibm_cffps_probe,
 429        .remove = pmbus_do_remove,
 430        .id_table = ibm_cffps_id,
 431};
 432
 433module_i2c_driver(ibm_cffps_driver);
 434
 435MODULE_AUTHOR("Eddie James");
 436MODULE_DESCRIPTION("PMBus driver for IBM Common Form Factor power supplies");
 437MODULE_LICENSE("GPL");
 438