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