kernel/drivers/hwmon/pmbus/ucd9200.c

   1 /*
   2  * Hardware monitoring driver for ucd9200 series Digital PWM System Controllers
   3  *
   4  * Copyright (C) 2011 Ericsson AB.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24 #include <linux/err.h>
  25 #include <linux/slab.h>
  26 #include <linux/i2c.h>
  27 #include <linux/i2c/pmbus.h>
  28 #include "pmbus.h"
  29
  30 #define UCD9200_PHASE_INFO      0xd2
  31 #define UCD9200_DEVICE_ID       0xfd
  32
  33 enum chips { ucd9200, ucd9220, ucd9222, ucd9224, ucd9240, ucd9244, ucd9246,
  34              ucd9248 };
  35
  36 static const struct i2c_device_id ucd9200_id[] = {
  37         {"ucd9200", ucd9200},
  38         {"ucd9220", ucd9220},
  39         {"ucd9222", ucd9222},
  40         {"ucd9224", ucd9224},
  41         {"ucd9240", ucd9240},
  42         {"ucd9244", ucd9244},
  43         {"ucd9246", ucd9246},
  44         {"ucd9248", ucd9248},
  45         {}
  46 };
  47 MODULE_DEVICE_TABLE(i2c, ucd9200_id);
  48
  49 static int ucd9200_probe(struct i2c_client *client,
  50                          const struct i2c_device_id *id)
  51 {
  52         u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
  53         struct pmbus_driver_info *info;
  54         const struct i2c_device_id *mid;
  55         int i, j, ret;
  56
  57         if (!i2c_check_functionality(client->adapter,
  58                                      I2C_FUNC_SMBUS_BYTE_DATA |
  59                                      I2C_FUNC_SMBUS_BLOCK_DATA))
  60                 return -ENODEV;
  61
  62         ret = i2c_smbus_read_block_data(client, UCD9200_DEVICE_ID,
  63                                         block_buffer);
  64         if (ret < 0) {
  65                 dev_err(&client->dev, "Failed to read device ID\n");
  66                 return ret;
  67         }
  68         block_buffer[ret] = '\0';
  69         dev_info(&client->dev, "Device ID %s\n", block_buffer);
  70
  71         for (mid = ucd9200_id; mid->name[0]; mid++) {
  72                 if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
  73                         break;
  74         }
  75         if (!mid->name[0]) {
  76                 dev_err(&client->dev, "Unsupported device\n");
  77                 return -ENODEV;
  78         }
  79         if (id->driver_data != ucd9200 && id->driver_data != mid->driver_data)
  80                 dev_notice(&client->dev,
  81                            "Device mismatch: Configured %s, detected %s\n",
  82                            id->name, mid->name);
  83
  84         info = devm_kzalloc(&client->dev, sizeof(struct pmbus_driver_info),
  85                             GFP_KERNEL);
  86         if (!info)
  87                 return -ENOMEM;
  88
  89         ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO,
  90                                         block_buffer);
  91         if (ret < 0) {
  92                 dev_err(&client->dev, "Failed to read phase information\n");
  93                 return ret;
  94         }
  95
  96         /*
  97          * Calculate number of configured pages (rails) from PHASE_INFO
  98          * register.
  99          * Rails have to be sequential, so we can abort after finding
 100          * the first unconfigured rail.
 101          */
 102         info->pages = 0;
 103         for (i = 0; i < ret; i++) {
 104                 if (!block_buffer[i])
 105                         break;
 106                 info->pages++;
 107         }
 108         if (!info->pages) {
 109                 dev_err(&client->dev, "No rails configured\n");
 110                 return -ENODEV;
 111         }
 112         dev_info(&client->dev, "%d rails configured\n", info->pages);
 113
 114         /*
 115          * Set PHASE registers on all pages to 0xff to ensure that phase
 116          * specific commands will apply to all phases of a given page (rail).
 117          * This only affects the READ_IOUT and READ_TEMPERATURE2 registers.
 118          * READ_IOUT will return the sum of currents of all phases of a rail,
 119          * and READ_TEMPERATURE2 will return the maximum temperature detected
 120          * for the the phases of the rail.
 121          */
 122         for (i = 0; i < info->pages; i++) {
 123                 /*
 124                  * Setting PAGE & PHASE fails once in a while for no obvious
 125                  * reason, so we need to retry a couple of times.
 126                  */
 127                 for (j = 0; j < 3; j++) {
 128                         ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
 129                         if (ret < 0)
 130                                 continue;
 131                         ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE,
 132                                                         0xff);
 133                         if (ret < 0)
 134                                 continue;
 135                         break;
 136                 }
 137                 if (ret < 0) {
 138                         dev_err(&client->dev,
 139                                 "Failed to initialize PHASE registers\n");
 140                         return ret;
 141                 }
 142         }
 143         if (info->pages > 1)
 144                 i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
 145
 146         info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
 147                         PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
 148                         PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 149                         PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
 150                         PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP |
 151                         PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 152
 153         for (i = 1; i < info->pages; i++)
 154                 info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 155                         PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
 156                         PMBUS_HAVE_POUT |
 157                         PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 158
 159         /* ucd9240 supports a single fan */
 160         if (mid->driver_data == ucd9240)
 161                 info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12;
 162
 163         return pmbus_do_probe(client, mid, info);
 164 }
 165
 166 /* This is the driver that will be inserted */
 167 static struct i2c_driver ucd9200_driver = {
 168         .driver = {
 169                 .name = "ucd9200",
 170         },
 171         .probe = ucd9200_probe,
 172         .remove = pmbus_do_remove,
 173         .id_table = ucd9200_id,
 174 };
 175
 176 module_i2c_driver(ucd9200_driver);
 177
 178 MODULE_AUTHOR("Guenter Roeck");
 179 MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");
 180 MODULE_LICENSE("GPL");