drivers/hwmon/pmbus/ibm-cffps.c

   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
  49 enum {
  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
  59 struct 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
  67 struct 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
  81 static 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
 129 static 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
 178 done:
 179         data[rc] = '\n';
 180         rc += 2;
 181
 182         return simple_read_from_buffer(buf, count, ppos, data, rc);
 183 }
 184
 185 static const struct file_operations ibm_cffps_fops = {
 186         .llseek = noop_llseek,
 187         .read = ibm_cffps_debugfs_op,
 188         .open = simple_open,
 189 };
 190
 191 static 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
 241 static 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
 272 static 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
 294 static 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
 317 static 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
 335 static 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
 346 static struct pmbus_platform_data ibm_cffps_pdata = {
 347         .flags = PMBUS_SKIP_STATUS_CHECK,
 348 };
 349
 350 static 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
 411 static const struct i2c_device_id ibm_cffps_id[] = {
 412         { "ibm_cffps1", 1 },
 413         {}
 414 };
 415 MODULE_DEVICE_TABLE(i2c, ibm_cffps_id);
 416
 417 static const struct of_device_id ibm_cffps_of_match[] = {
 418         { .compatible = "ibm,cffps1" },
 419         {}
 420 };
 421 MODULE_DEVICE_TABLE(of, ibm_cffps_of_match);
 422
 423 static 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
 433 module_i2c_driver(ibm_cffps_driver);
 434
 435 MODULE_AUTHOR("Eddie James");
 436 MODULE_DESCRIPTION("PMBus driver for IBM Common Form Factor power supplies");
 437 MODULE_LICENSE("GPL");