drivers/hwmon/pmbus/ucd9200.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Hardware monitoring driver for ucd9200 series Digital PWM System Controllers
   4  *
   5  * Copyright (C) 2011 Ericsson AB.
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/of_device.h>
  11 #include <linux/init.h>
  12 #include <linux/err.h>
  13 #include <linux/slab.h>
  14 #include <linux/i2c.h>
  15 #include <linux/pmbus.h>
  16 #include "pmbus.h"
  17
  18 #define UCD9200_PHASE_INFO      0xd2
  19 #define UCD9200_DEVICE_ID       0xfd
  20
  21 enum chips { ucd9200, ucd9220, ucd9222, ucd9224, ucd9240, ucd9244, ucd9246,
  22              ucd9248 };
  23
  24 static const struct i2c_device_id ucd9200_id[] = {
  25         {"ucd9200", ucd9200},
  26         {"ucd9220", ucd9220},
  27         {"ucd9222", ucd9222},
  28         {"ucd9224", ucd9224},
  29         {"ucd9240", ucd9240},
  30         {"ucd9244", ucd9244},
  31         {"ucd9246", ucd9246},
  32         {"ucd9248", ucd9248},
  33         {}
  34 };
  35 MODULE_DEVICE_TABLE(i2c, ucd9200_id);
  36
  37 static const struct of_device_id __maybe_unused ucd9200_of_match[] = {
  38         {
  39                 .compatible = "ti,cd9200",
  40                 .data = (void *)ucd9200
  41         },
  42         {
  43                 .compatible = "ti,cd9220",
  44                 .data = (void *)ucd9220
  45         },
  46         {
  47                 .compatible = "ti,cd9222",
  48                 .data = (void *)ucd9222
  49         },
  50         {
  51                 .compatible = "ti,cd9224",
  52                 .data = (void *)ucd9224
  53         },
  54         {
  55                 .compatible = "ti,cd9240",
  56                 .data = (void *)ucd9240
  57         },
  58         {
  59                 .compatible = "ti,cd9244",
  60                 .data = (void *)ucd9244
  61         },
  62         {
  63                 .compatible = "ti,cd9246",
  64                 .data = (void *)ucd9246
  65         },
  66         {
  67                 .compatible = "ti,cd9248",
  68                 .data = (void *)ucd9248
  69         },
  70         { },
  71 };
  72 MODULE_DEVICE_TABLE(of, ucd9200_of_match);
  73
  74 static int ucd9200_probe(struct i2c_client *client,
  75                          const struct i2c_device_id *id)
  76 {
  77         u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
  78         struct pmbus_driver_info *info;
  79         const struct i2c_device_id *mid;
  80         enum chips chip;
  81         int i, j, ret;
  82
  83         if (!i2c_check_functionality(client->adapter,
  84                                      I2C_FUNC_SMBUS_BYTE_DATA |
  85                                      I2C_FUNC_SMBUS_BLOCK_DATA))
  86                 return -ENODEV;
  87
  88         ret = i2c_smbus_read_block_data(client, UCD9200_DEVICE_ID,
  89                                         block_buffer);
  90         if (ret < 0) {
  91                 dev_err(&client->dev, "Failed to read device ID\n");
  92                 return ret;
  93         }
  94         block_buffer[ret] = '\0';
  95         dev_info(&client->dev, "Device ID %s\n", block_buffer);
  96
  97         for (mid = ucd9200_id; mid->name[0]; mid++) {
  98                 if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
  99                         break;
 100         }
 101         if (!mid->name[0]) {
 102                 dev_err(&client->dev, "Unsupported device\n");
 103                 return -ENODEV;
 104         }
 105
 106         if (client->dev.of_node)
 107                 chip = (enum chips)of_device_get_match_data(&client->dev);
 108         else
 109                 chip = id->driver_data;
 110
 111         if (chip != ucd9200 && chip != mid->driver_data)
 112                 dev_notice(&client->dev,
 113                            "Device mismatch: Configured %s, detected %s\n",
 114                            id->name, mid->name);
 115
 116         info = devm_kzalloc(&client->dev, sizeof(struct pmbus_driver_info),
 117                             GFP_KERNEL);
 118         if (!info)
 119                 return -ENOMEM;
 120
 121         ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO,
 122                                         block_buffer);
 123         if (ret < 0) {
 124                 dev_err(&client->dev, "Failed to read phase information\n");
 125                 return ret;
 126         }
 127
 128         /*
 129          * Calculate number of configured pages (rails) from PHASE_INFO
 130          * register.
 131          * Rails have to be sequential, so we can abort after finding
 132          * the first unconfigured rail.
 133          */
 134         info->pages = 0;
 135         for (i = 0; i < ret; i++) {
 136                 if (!block_buffer[i])
 137                         break;
 138                 info->pages++;
 139         }
 140         if (!info->pages) {
 141                 dev_err(&client->dev, "No rails configured\n");
 142                 return -ENODEV;
 143         }
 144         dev_info(&client->dev, "%d rails configured\n", info->pages);
 145
 146         /*
 147          * Set PHASE registers on all pages to 0xff to ensure that phase
 148          * specific commands will apply to all phases of a given page (rail).
 149          * This only affects the READ_IOUT and READ_TEMPERATURE2 registers.
 150          * READ_IOUT will return the sum of currents of all phases of a rail,
 151          * and READ_TEMPERATURE2 will return the maximum temperature detected
 152          * for the the phases of the rail.
 153          */
 154         for (i = 0; i < info->pages; i++) {
 155                 /*
 156                  * Setting PAGE & PHASE fails once in a while for no obvious
 157                  * reason, so we need to retry a couple of times.
 158                  */
 159                 for (j = 0; j < 3; j++) {
 160                         ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
 161                         if (ret < 0)
 162                                 continue;
 163                         ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE,
 164                                                         0xff);
 165                         if (ret < 0)
 166                                 continue;
 167                         break;
 168                 }
 169                 if (ret < 0) {
 170                         dev_err(&client->dev,
 171                                 "Failed to initialize PHASE registers\n");
 172                         return ret;
 173                 }
 174         }
 175         if (info->pages > 1)
 176                 i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
 177
 178         info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
 179                         PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
 180                         PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 181                         PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
 182                         PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP |
 183                         PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 184
 185         for (i = 1; i < info->pages; i++)
 186                 info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 187                         PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
 188                         PMBUS_HAVE_POUT |
 189                         PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 190
 191         /* ucd9240 supports a single fan */
 192         if (mid->driver_data == ucd9240)
 193                 info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12;
 194
 195         return pmbus_do_probe(client, mid, info);
 196 }
 197
 198 /* This is the driver that will be inserted */
 199 static struct i2c_driver ucd9200_driver = {
 200         .driver = {
 201                 .name = "ucd9200",
 202                 .of_match_table = of_match_ptr(ucd9200_of_match),
 203         },
 204         .probe = ucd9200_probe,
 205         .remove = pmbus_do_remove,
 206         .id_table = ucd9200_id,
 207 };
 208
 209 module_i2c_driver(ucd9200_driver);
 210
 211 MODULE_AUTHOR("Guenter Roeck");
 212 MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");
 213 MODULE_LICENSE("GPL");