drivers/hwmon/pmbus/zl6100.c

   1 /*
   2  * Hardware monitoring driver for ZL6100 and compatibles
   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/ktime.h>
  28 #include <linux/delay.h>
  29 #include "pmbus.h"
  30
  31 enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105 };
  32
  33 struct zl6100_data {
  34         int id;
  35         ktime_t access;         /* chip access time */
  36         struct pmbus_driver_info info;
  37 };
  38
  39 #define to_zl6100_data(x)  container_of(x, struct zl6100_data, info)
  40
  41 #define ZL6100_MFR_CONFIG               0xd0
  42 #define ZL6100_DEVICE_ID                0xe4
  43
  44 #define ZL6100_MFR_XTEMP_ENABLE         (1 << 7)
  45
  46 #define ZL6100_WAIT_TIME                1000    /* uS   */
  47
  48 static ushort delay = ZL6100_WAIT_TIME;
  49 module_param(delay, ushort, 0644);
  50 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
  51
  52 /* Some chips need a delay between accesses */
  53 static inline void zl6100_wait(const struct zl6100_data *data)
  54 {
  55         if (delay) {
  56                 s64 delta = ktime_us_delta(ktime_get(), data->access);
  57                 if (delta < delay)
  58                         udelay(delay - delta);
  59         }
  60 }
  61
  62 static int zl6100_read_word_data(struct i2c_client *client, int page, int reg)
  63 {
  64         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
  65         struct zl6100_data *data = to_zl6100_data(info);
  66         int ret;
  67
  68         if (page || reg >= PMBUS_VIRT_BASE)
  69                 return -ENXIO;
  70
  71         if (data->id == zl2005) {
  72                 /*
  73                  * Limit register detection is not reliable on ZL2005.
  74                  * Make sure registers are not erroneously detected.
  75                  */
  76                 switch (reg) {
  77                 case PMBUS_VOUT_OV_WARN_LIMIT:
  78                 case PMBUS_VOUT_UV_WARN_LIMIT:
  79                 case PMBUS_IOUT_OC_WARN_LIMIT:
  80                         return -ENXIO;
  81                 }
  82         }
  83
  84         zl6100_wait(data);
  85         ret = pmbus_read_word_data(client, page, reg);
  86         data->access = ktime_get();
  87
  88         return ret;
  89 }
  90
  91 static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
  92 {
  93         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
  94         struct zl6100_data *data = to_zl6100_data(info);
  95         int ret;
  96
  97         if (page > 0)
  98                 return -ENXIO;
  99
 100         zl6100_wait(data);
 101         ret = pmbus_read_byte_data(client, page, reg);
 102         data->access = ktime_get();
 103
 104         return ret;
 105 }
 106
 107 static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
 108                                   u16 word)
 109 {
 110         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 111         struct zl6100_data *data = to_zl6100_data(info);
 112         int ret;
 113
 114         if (page || reg >= PMBUS_VIRT_BASE)
 115                 return -ENXIO;
 116
 117         zl6100_wait(data);
 118         ret = pmbus_write_word_data(client, page, reg, word);
 119         data->access = ktime_get();
 120
 121         return ret;
 122 }
 123
 124 static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
 125 {
 126         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 127         struct zl6100_data *data = to_zl6100_data(info);
 128         int ret;
 129
 130         if (page > 0)
 131                 return -ENXIO;
 132
 133         zl6100_wait(data);
 134         ret = pmbus_write_byte(client, page, value);
 135         data->access = ktime_get();
 136
 137         return ret;
 138 }
 139
 140 static const struct i2c_device_id zl6100_id[] = {
 141         {"bmr450", zl2005},
 142         {"bmr451", zl2005},
 143         {"bmr462", zl2008},
 144         {"bmr463", zl2008},
 145         {"bmr464", zl2008},
 146         {"zl2004", zl2004},
 147         {"zl2005", zl2005},
 148         {"zl2006", zl2006},
 149         {"zl2008", zl2008},
 150         {"zl2105", zl2105},
 151         {"zl2106", zl2106},
 152         {"zl6100", zl6100},
 153         {"zl6105", zl6105},
 154         { }
 155 };
 156 MODULE_DEVICE_TABLE(i2c, zl6100_id);
 157
 158 static int zl6100_probe(struct i2c_client *client,
 159                         const struct i2c_device_id *id)
 160 {
 161         int ret;
 162         struct zl6100_data *data;
 163         struct pmbus_driver_info *info;
 164         u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
 165         const struct i2c_device_id *mid;
 166
 167         if (!i2c_check_functionality(client->adapter,
 168                                      I2C_FUNC_SMBUS_READ_WORD_DATA
 169                                      | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
 170                 return -ENODEV;
 171
 172         ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
 173                                         device_id);
 174         if (ret < 0) {
 175                 dev_err(&client->dev, "Failed to read device ID\n");
 176                 return ret;
 177         }
 178         device_id[ret] = '\0';
 179         dev_info(&client->dev, "Device ID %s\n", device_id);
 180
 181         mid = NULL;
 182         for (mid = zl6100_id; mid->name[0]; mid++) {
 183                 if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
 184                         break;
 185         }
 186         if (!mid->name[0]) {
 187                 dev_err(&client->dev, "Unsupported device\n");
 188                 return -ENODEV;
 189         }
 190         if (id->driver_data != mid->driver_data)
 191                 dev_notice(&client->dev,
 192                            "Device mismatch: Configured %s, detected %s\n",
 193                            id->name, mid->name);
 194
 195         data = kzalloc(sizeof(struct zl6100_data), GFP_KERNEL);
 196         if (!data)
 197                 return -ENOMEM;
 198
 199         data->id = mid->driver_data;
 200
 201         /*
 202          * ZL2005, ZL2008, ZL2105, and ZL6100 are known to require a wait time
 203          * between I2C accesses. ZL2004 and ZL6105 are known to be safe.
 204          * Other chips have not yet been tested.
 205          *
 206          * Only clear the wait time for chips known to be safe. The wait time
 207          * can be cleared later for additional chips if tests show that it
 208          * is not needed (in other words, better be safe than sorry).
 209          */
 210         if (data->id == zl2004 || data->id == zl6105)
 211                 delay = 0;
 212
 213         /*
 214          * Since there was a direct I2C device access above, wait before
 215          * accessing the chip again.
 216          */
 217         data->access = ktime_get();
 218         zl6100_wait(data);
 219
 220         info = &data->info;
 221
 222         info->pages = 1;
 223         info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 224           | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 225           | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 226           | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 227
 228         ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
 229         if (ret < 0)
 230                 goto err_mem;
 231         if (ret & ZL6100_MFR_XTEMP_ENABLE)
 232                 info->func[0] |= PMBUS_HAVE_TEMP2;
 233
 234         data->access = ktime_get();
 235         zl6100_wait(data);
 236
 237         info->read_word_data = zl6100_read_word_data;
 238         info->read_byte_data = zl6100_read_byte_data;
 239         info->write_word_data = zl6100_write_word_data;
 240         info->write_byte = zl6100_write_byte;
 241
 242         ret = pmbus_do_probe(client, mid, info);
 243         if (ret)
 244                 goto err_mem;
 245         return 0;
 246
 247 err_mem:
 248         kfree(data);
 249         return ret;
 250 }
 251
 252 static int zl6100_remove(struct i2c_client *client)
 253 {
 254         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 255         const struct zl6100_data *data = to_zl6100_data(info);
 256
 257         pmbus_do_remove(client);
 258         kfree(data);
 259         return 0;
 260 }
 261
 262 static struct i2c_driver zl6100_driver = {
 263         .driver = {
 264                    .name = "zl6100",
 265                    },
 266         .probe = zl6100_probe,
 267         .remove = zl6100_remove,
 268         .id_table = zl6100_id,
 269 };
 270
 271 static int __init zl6100_init(void)
 272 {
 273         return i2c_add_driver(&zl6100_driver);
 274 }
 275
 276 static void __exit zl6100_exit(void)
 277 {
 278         i2c_del_driver(&zl6100_driver);
 279 }
 280
 281 MODULE_AUTHOR("Guenter Roeck");
 282 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
 283 MODULE_LICENSE("GPL");
 284 module_init(zl6100_init);
 285 module_exit(zl6100_exit);