drivers/hwmon/pmbus/ibm-cffps.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2017 IBM Corp.
   4  */
   5
   6 #include <linux/bitops.h>
   7 #include <linux/debugfs.h>
   8 #include <linux/device.h>
   9 #include <linux/fs.h>
  10 #include <linux/i2c.h>
  11 #include <linux/jiffies.h>
  12 #include <linux/leds.h>
  13 #include <linux/module.h>
  14 #include <linux/mutex.h>
  15 #include <linux/pmbus.h>
  16
  17 #include "pmbus.h"
  18
  19 #define CFFPS_FRU_CMD                           0x9A
  20 #define CFFPS_PN_CMD                            0x9B
  21 #define CFFPS_SN_CMD                            0x9E
  22 #define CFFPS_CCIN_CMD                          0xBD
  23 #define CFFPS_FW_CMD_START                      0xFA
  24 #define CFFPS_FW_NUM_BYTES                      4
  25 #define CFFPS_SYS_CONFIG_CMD                    0xDA
  26
  27 #define CFFPS_INPUT_HISTORY_CMD                 0xD6
  28 #define CFFPS_INPUT_HISTORY_SIZE                100
  29
  30 /* STATUS_MFR_SPECIFIC bits */
  31 #define CFFPS_MFR_FAN_FAULT                     BIT(0)
  32 #define CFFPS_MFR_THERMAL_FAULT                 BIT(1)
  33 #define CFFPS_MFR_OV_FAULT                      BIT(2)
  34 #define CFFPS_MFR_UV_FAULT                      BIT(3)
  35 #define CFFPS_MFR_PS_KILL                       BIT(4)
  36 #define CFFPS_MFR_OC_FAULT                      BIT(5)
  37 #define CFFPS_MFR_VAUX_FAULT                    BIT(6)
  38 #define CFFPS_MFR_CURRENT_SHARE_WARNING         BIT(7)
  39
  40 #define CFFPS_LED_BLINK                         BIT(0)
  41 #define CFFPS_LED_ON                            BIT(1)
  42 #define CFFPS_LED_OFF                           BIT(2)
  43 #define CFFPS_BLINK_RATE_MS                     250
  44
  45 enum {
  46         CFFPS_DEBUGFS_INPUT_HISTORY = 0,
  47         CFFPS_DEBUGFS_FRU,
  48         CFFPS_DEBUGFS_PN,
  49         CFFPS_DEBUGFS_SN,
  50         CFFPS_DEBUGFS_CCIN,
  51         CFFPS_DEBUGFS_FW,
  52         CFFPS_DEBUGFS_NUM_ENTRIES
  53 };
  54
  55 struct ibm_cffps_input_history {
  56         struct mutex update_lock;
  57         unsigned long last_update;
  58
  59         u8 byte_count;
  60         u8 data[CFFPS_INPUT_HISTORY_SIZE];
  61 };
  62
  63 struct ibm_cffps {
  64         struct i2c_client *client;
  65
  66         struct ibm_cffps_input_history input_history;
  67
  68         int debugfs_entries[CFFPS_DEBUGFS_NUM_ENTRIES];
  69
  70         char led_name[32];
  71         u8 led_state;
  72         struct led_classdev led;
  73 };
  74
  75 #define to_psu(x, y) container_of((x), struct ibm_cffps, debugfs_entries[(y)])
  76
  77 static ssize_t ibm_cffps_read_input_history(struct ibm_cffps *psu,
  78                                             char __user *buf, size_t count,
  79                                             loff_t *ppos)
  80 {
  81         int rc;
  82         u8 msgbuf0[1] = { CFFPS_INPUT_HISTORY_CMD };
  83         u8 msgbuf1[CFFPS_INPUT_HISTORY_SIZE + 1] = { 0 };
  84         struct i2c_msg msg[2] = {
  85                 {
  86                         .addr = psu->client->addr,
  87                         .flags = psu->client->flags,
  88                         .len = 1,
  89                         .buf = msgbuf0,
  90                 }, {
  91                         .addr = psu->client->addr,
  92                         .flags = psu->client->flags | I2C_M_RD,
  93                         .len = CFFPS_INPUT_HISTORY_SIZE + 1,
  94                         .buf = msgbuf1,
  95                 },
  96         };
  97
  98         if (!*ppos) {
  99                 mutex_lock(&psu->input_history.update_lock);
 100                 if (time_after(jiffies, psu->input_history.last_update + HZ)) {
 101                         /*
 102                          * Use a raw i2c transfer, since we need more bytes
 103                          * than Linux I2C supports through smbus xfr (only 32).
 104                          */
 105                         rc = i2c_transfer(psu->client->adapter, msg, 2);
 106                         if (rc < 0) {
 107                                 mutex_unlock(&psu->input_history.update_lock);
 108                                 return rc;
 109                         }
 110
 111                         psu->input_history.byte_count = msgbuf1[0];
 112                         memcpy(psu->input_history.data, &msgbuf1[1],
 113                                CFFPS_INPUT_HISTORY_SIZE);
 114                         psu->input_history.last_update = jiffies;
 115                 }
 116
 117                 mutex_unlock(&psu->input_history.update_lock);
 118         }
 119
 120         return simple_read_from_buffer(buf, count, ppos,
 121                                        psu->input_history.data,
 122                                        psu->input_history.byte_count);
 123 }
 124
 125 static ssize_t ibm_cffps_debugfs_op(struct file *file, char __user *buf,
 126                                     size_t count, loff_t *ppos)
 127 {
 128         u8 cmd;
 129         int i, rc;
 130         int *idxp = file->private_data;
 131         int idx = *idxp;
 132         struct ibm_cffps *psu = to_psu(idxp, idx);
 133         char data[I2C_SMBUS_BLOCK_MAX] = { 0 };
 134
 135         switch (idx) {
 136         case CFFPS_DEBUGFS_INPUT_HISTORY:
 137                 return ibm_cffps_read_input_history(psu, buf, count, ppos);
 138         case CFFPS_DEBUGFS_FRU:
 139                 cmd = CFFPS_FRU_CMD;
 140                 break;
 141         case CFFPS_DEBUGFS_PN:
 142                 cmd = CFFPS_PN_CMD;
 143                 break;
 144         case CFFPS_DEBUGFS_SN:
 145                 cmd = CFFPS_SN_CMD;
 146                 break;
 147         case CFFPS_DEBUGFS_CCIN:
 148                 rc = i2c_smbus_read_word_swapped(psu->client, CFFPS_CCIN_CMD);
 149                 if (rc < 0)
 150                         return rc;
 151
 152                 rc = snprintf(data, 5, "%04X", rc);
 153                 goto done;
 154         case CFFPS_DEBUGFS_FW:
 155                 for (i = 0; i < CFFPS_FW_NUM_BYTES; ++i) {
 156                         rc = i2c_smbus_read_byte_data(psu->client,
 157                                                       CFFPS_FW_CMD_START + i);
 158                         if (rc < 0)
 159                                 return rc;
 160
 161                         snprintf(&data[i * 2], 3, "%02X", rc);
 162                 }
 163
 164                 rc = i * 2;
 165                 goto done;
 166         default:
 167                 return -EINVAL;
 168         }
 169
 170         rc = i2c_smbus_read_block_data(psu->client, cmd, data);
 171         if (rc < 0)
 172                 return rc;
 173
 174 done:
 175         data[rc] = '\n';
 176         rc += 2;
 177
 178         return simple_read_from_buffer(buf, count, ppos, data, rc);
 179 }
 180
 181 static const struct file_operations ibm_cffps_fops = {
 182         .llseek = noop_llseek,
 183         .read = ibm_cffps_debugfs_op,
 184         .open = simple_open,
 185 };
 186
 187 static int ibm_cffps_read_byte_data(struct i2c_client *client, int page,
 188                                     int reg)
 189 {
 190         int rc, mfr;
 191
 192         switch (reg) {
 193         case PMBUS_STATUS_VOUT:
 194         case PMBUS_STATUS_IOUT:
 195         case PMBUS_STATUS_TEMPERATURE:
 196         case PMBUS_STATUS_FAN_12:
 197                 rc = pmbus_read_byte_data(client, page, reg);
 198                 if (rc < 0)
 199                         return rc;
 200
 201                 mfr = pmbus_read_byte_data(client, page,
 202                                            PMBUS_STATUS_MFR_SPECIFIC);
 203                 if (mfr < 0)
 204                         /*
 205                          * Return the status register instead of an error,
 206                          * since we successfully read status.
 207                          */
 208                         return rc;
 209
 210                 /* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
 211                 if (reg == PMBUS_STATUS_FAN_12) {
 212                         if (mfr & CFFPS_MFR_FAN_FAULT)
 213                                 rc |= PB_FAN_FAN1_FAULT;
 214                 } else if (reg == PMBUS_STATUS_TEMPERATURE) {
 215                         if (mfr & CFFPS_MFR_THERMAL_FAULT)
 216                                 rc |= PB_TEMP_OT_FAULT;
 217                 } else if (reg == PMBUS_STATUS_VOUT) {
 218                         if (mfr & (CFFPS_MFR_OV_FAULT | CFFPS_MFR_VAUX_FAULT))
 219                                 rc |= PB_VOLTAGE_OV_FAULT;
 220                         if (mfr & CFFPS_MFR_UV_FAULT)
 221                                 rc |= PB_VOLTAGE_UV_FAULT;
 222                 } else if (reg == PMBUS_STATUS_IOUT) {
 223                         if (mfr & CFFPS_MFR_OC_FAULT)
 224                                 rc |= PB_IOUT_OC_FAULT;
 225                         if (mfr & CFFPS_MFR_CURRENT_SHARE_WARNING)
 226                                 rc |= PB_CURRENT_SHARE_FAULT;
 227                 }
 228                 break;
 229         default:
 230                 rc = -ENODATA;
 231                 break;
 232         }
 233
 234         return rc;
 235 }
 236
 237 static int ibm_cffps_read_word_data(struct i2c_client *client, int page,
 238                                     int reg)
 239 {
 240         int rc, mfr;
 241
 242         switch (reg) {
 243         case PMBUS_STATUS_WORD:
 244                 rc = pmbus_read_word_data(client, page, reg);
 245                 if (rc < 0)
 246                         return rc;
 247
 248                 mfr = pmbus_read_byte_data(client, page,
 249                                            PMBUS_STATUS_MFR_SPECIFIC);
 250                 if (mfr < 0)
 251                         /*
 252                          * Return the status register instead of an error,
 253                          * since we successfully read status.
 254                          */
 255                         return rc;
 256
 257                 if (mfr & CFFPS_MFR_PS_KILL)
 258                         rc |= PB_STATUS_OFF;
 259                 break;
 260         default:
 261                 rc = -ENODATA;
 262                 break;
 263         }
 264
 265         return rc;
 266 }
 267
 268 static void ibm_cffps_led_brightness_set(struct led_classdev *led_cdev,
 269                                          enum led_brightness brightness)
 270 {
 271         int rc;
 272         struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
 273
 274         if (brightness == LED_OFF) {
 275                 psu->led_state = CFFPS_LED_OFF;
 276         } else {
 277                 brightness = LED_FULL;
 278                 if (psu->led_state != CFFPS_LED_BLINK)
 279                         psu->led_state = CFFPS_LED_ON;
 280         }
 281
 282         rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
 283                                        psu->led_state);
 284         if (rc < 0)
 285                 return;
 286
 287         led_cdev->brightness = brightness;
 288 }
 289
 290 static int ibm_cffps_led_blink_set(struct led_classdev *led_cdev,
 291                                    unsigned long *delay_on,
 292                                    unsigned long *delay_off)
 293 {
 294         int rc;
 295         struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
 296
 297         psu->led_state = CFFPS_LED_BLINK;
 298
 299         if (led_cdev->brightness == LED_OFF)
 300                 return 0;
 301
 302         rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
 303                                        CFFPS_LED_BLINK);
 304         if (rc < 0)
 305                 return rc;
 306
 307         *delay_on = CFFPS_BLINK_RATE_MS;
 308         *delay_off = CFFPS_BLINK_RATE_MS;
 309
 310         return 0;
 311 }
 312
 313 static void ibm_cffps_create_led_class(struct ibm_cffps *psu)
 314 {
 315         int rc;
 316         struct i2c_client *client = psu->client;
 317         struct device *dev = &client->dev;
 318
 319         snprintf(psu->led_name, sizeof(psu->led_name), "%s-%02x", client->name,
 320                  client->addr);
 321         psu->led.name = psu->led_name;
 322         psu->led.max_brightness = LED_FULL;
 323         psu->led.brightness_set = ibm_cffps_led_brightness_set;
 324         psu->led.blink_set = ibm_cffps_led_blink_set;
 325
 326         rc = devm_led_classdev_register(dev, &psu->led);
 327         if (rc)
 328                 dev_warn(dev, "failed to register led class: %d\n", rc);
 329 }
 330
 331 static struct pmbus_driver_info ibm_cffps_info = {
 332         .pages = 1,
 333         .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
 334                 PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
 335                 PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_VOUT |
 336                 PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT |
 337                 PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_STATUS_FAN12,
 338         .read_byte_data = ibm_cffps_read_byte_data,
 339         .read_word_data = ibm_cffps_read_word_data,
 340 };
 341
 342 static struct pmbus_platform_data ibm_cffps_pdata = {
 343         .flags = PMBUS_SKIP_STATUS_CHECK,
 344 };
 345
 346 static int ibm_cffps_probe(struct i2c_client *client,
 347                            const struct i2c_device_id *id)
 348 {
 349         int i, rc;
 350         struct dentry *debugfs;
 351         struct dentry *ibm_cffps_dir;
 352         struct ibm_cffps *psu;
 353
 354         client->dev.platform_data = &ibm_cffps_pdata;
 355         rc = pmbus_do_probe(client, id, &ibm_cffps_info);
 356         if (rc)
 357                 return rc;
 358
 359         /*
 360          * Don't fail the probe if there isn't enough memory for leds and
 361          * debugfs.
 362          */
 363         psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL);
 364         if (!psu)
 365                 return 0;
 366
 367         psu->client = client;
 368         mutex_init(&psu->input_history.update_lock);
 369         psu->input_history.last_update = jiffies - HZ;
 370
 371         ibm_cffps_create_led_class(psu);
 372
 373         /* Don't fail the probe if we can't create debugfs */
 374         debugfs = pmbus_get_debugfs_dir(client);
 375         if (!debugfs)
 376                 return 0;
 377
 378         ibm_cffps_dir = debugfs_create_dir(client->name, debugfs);
 379         if (!ibm_cffps_dir)
 380                 return 0;
 381
 382         for (i = 0; i < CFFPS_DEBUGFS_NUM_ENTRIES; ++i)
 383                 psu->debugfs_entries[i] = i;
 384
 385         debugfs_create_file("input_history", 0444, ibm_cffps_dir,
 386                             &psu->debugfs_entries[CFFPS_DEBUGFS_INPUT_HISTORY],
 387                             &ibm_cffps_fops);
 388         debugfs_create_file("fru", 0444, ibm_cffps_dir,
 389                             &psu->debugfs_entries[CFFPS_DEBUGFS_FRU],
 390                             &ibm_cffps_fops);
 391         debugfs_create_file("part_number", 0444, ibm_cffps_dir,
 392                             &psu->debugfs_entries[CFFPS_DEBUGFS_PN],
 393                             &ibm_cffps_fops);
 394         debugfs_create_file("serial_number", 0444, ibm_cffps_dir,
 395                             &psu->debugfs_entries[CFFPS_DEBUGFS_SN],
 396                             &ibm_cffps_fops);
 397         debugfs_create_file("ccin", 0444, ibm_cffps_dir,
 398                             &psu->debugfs_entries[CFFPS_DEBUGFS_CCIN],
 399                             &ibm_cffps_fops);
 400         debugfs_create_file("fw_version", 0444, ibm_cffps_dir,
 401                             &psu->debugfs_entries[CFFPS_DEBUGFS_FW],
 402                             &ibm_cffps_fops);
 403
 404         return 0;
 405 }
 406
 407 static const struct i2c_device_id ibm_cffps_id[] = {
 408         { "ibm_cffps1", 1 },
 409         {}
 410 };
 411 MODULE_DEVICE_TABLE(i2c, ibm_cffps_id);
 412
 413 static const struct of_device_id ibm_cffps_of_match[] = {
 414         { .compatible = "ibm,cffps1" },
 415         {}
 416 };
 417 MODULE_DEVICE_TABLE(of, ibm_cffps_of_match);
 418
 419 static struct i2c_driver ibm_cffps_driver = {
 420         .driver = {
 421                 .name = "ibm-cffps",
 422                 .of_match_table = ibm_cffps_of_match,
 423         },
 424         .probe = ibm_cffps_probe,
 425         .remove = pmbus_do_remove,
 426         .id_table = ibm_cffps_id,
 427 };
 428
 429 module_i2c_driver(ibm_cffps_driver);
 430
 431 MODULE_AUTHOR("Eddie James");
 432 MODULE_DESCRIPTION("PMBus driver for IBM Common Form Factor power supplies");
 433 MODULE_LICENSE("GPL");