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