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 {
  76         u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
  77         struct pmbus_driver_info *info;
  78         const struct i2c_device_id *mid;
  79         enum chips chip;
  80         int i, j, ret;
  81
  82         if (!i2c_check_functionality(client->adapter,
  83                                      I2C_FUNC_SMBUS_BYTE_DATA |
  84                                      I2C_FUNC_SMBUS_BLOCK_DATA))
  85                 return -ENODEV;
  86
  87         ret = i2c_smbus_read_block_data(client, UCD9200_DEVICE_ID,
  88                                         block_buffer);
  89         if (ret < 0) {
  90                 dev_err(&client->dev, "Failed to read device ID\n");
  91                 return ret;
  92         }
  93         block_buffer[ret] = '\0';
  94         dev_info(&client->dev, "Device ID %s\n", block_buffer);
  95
  96         for (mid = ucd9200_id; mid->name[0]; mid++) {
  97                 if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
  98                         break;
  99         }
 100         if (!mid->name[0]) {
 101                 dev_err(&client->dev, "Unsupported device\n");
 102                 return -ENODEV;
 103         }
 104
 105         if (client->dev.of_node)
 106                 chip = (enum chips)of_device_get_match_data(&client->dev);
 107         else
 108                 chip = mid->driver_data;
 109
 110         if (chip != ucd9200 && strcmp(client->name, mid->name) != 0)
 111                 dev_notice(&client->dev,
 112                            "Device mismatch: Configured %s, detected %s\n",
 113                            client->name, mid->name);
 114
 115         info = devm_kzalloc(&client->dev, sizeof(struct pmbus_driver_info),
 116                             GFP_KERNEL);
 117         if (!info)
 118                 return -ENOMEM;
 119
 120         ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO,
 121                                         block_buffer);
 122         if (ret < 0) {
 123                 dev_err(&client->dev, "Failed to read phase information\n");
 124                 return ret;
 125         }
 126
 127         /*
 128          * Calculate number of configured pages (rails) from PHASE_INFO
 129          * register.
 130          * Rails have to be sequential, so we can abort after finding
 131          * the first unconfigured rail.
 132          */
 133         info->pages = 0;
 134         for (i = 0; i < ret; i++) {
 135                 if (!block_buffer[i])
 136                         break;
 137                 info->pages++;
 138         }
 139         if (!info->pages) {
 140                 dev_err(&client->dev, "No rails configured\n");
 141                 return -ENODEV;
 142         }
 143         dev_info(&client->dev, "%d rails configured\n", info->pages);
 144
 145         /*
 146          * Set PHASE registers on all pages to 0xff to ensure that phase
 147          * specific commands will apply to all phases of a given page (rail).
 148          * This only affects the READ_IOUT and READ_TEMPERATURE2 registers.
 149          * READ_IOUT will return the sum of currents of all phases of a rail,
 150          * and READ_TEMPERATURE2 will return the maximum temperature detected
 151          * for the the phases of the rail.
 152          */
 153         for (i = 0; i < info->pages; i++) {
 154                 /*
 155                  * Setting PAGE & PHASE fails once in a while for no obvious
 156                  * reason, so we need to retry a couple of times.
 157                  */
 158                 for (j = 0; j < 3; j++) {
 159                         ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
 160                         if (ret < 0)
 161                                 continue;
 162                         ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE,
 163                                                         0xff);
 164                         if (ret < 0)
 165                                 continue;
 166                         break;
 167                 }
 168                 if (ret < 0) {
 169                         dev_err(&client->dev,
 170                                 "Failed to initialize PHASE registers\n");
 171                         return ret;
 172                 }
 173         }
 174         if (info->pages > 1)
 175                 i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
 176
 177         info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
 178                         PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
 179                         PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 180                         PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
 181                         PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP |
 182                         PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 183
 184         for (i = 1; i < info->pages; i++)
 185                 info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 186                         PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
 187                         PMBUS_HAVE_POUT |
 188                         PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 189
 190         /* ucd9240 supports a single fan */
 191         if (mid->driver_data == ucd9240)
 192                 info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12;
 193
 194         return pmbus_do_probe(client, info);
 195 }
 196
 197 /* This is the driver that will be inserted */
 198 static struct i2c_driver ucd9200_driver = {
 199         .driver = {
 200                 .name = "ucd9200",
 201                 .of_match_table = of_match_ptr(ucd9200_of_match),
 202         },
 203         .probe_new = ucd9200_probe,
 204         .id_table = ucd9200_id,
 205 };
 206
 207 module_i2c_driver(ucd9200_driver);
 208
 209 MODULE_AUTHOR("Guenter Roeck");
 210 MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");
 211 MODULE_LICENSE("GPL");