drivers/i2c/i2c-sensor-detect.c

   1 /*
   2     i2c-sensor-detect.c - Part of lm_sensors, Linux kernel modules for hardware
   3                           monitoring
   4     Copyright (c) 1998 - 2001 Frodo Looijaard <frodol@dds.nl> and
   5     Mark D. Studebaker <mdsxyz123@yahoo.com>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include <linux/module.h>
  23 #include <linux/kernel.h>
  24 #include <linux/i2c.h>
  25 #include <linux/i2c-sensor.h>
  26
  27 static unsigned short empty[] = {I2C_CLIENT_END};
  28
  29 /* Won't work for 10-bit addresses! */
  30 int i2c_detect(struct i2c_adapter *adapter,
  31                struct i2c_client_address_data *address_data,
  32                int (*found_proc) (struct i2c_adapter *, int, int))
  33 {
  34         int addr, i, found, j, err;
  35         int adapter_id = i2c_adapter_id(adapter);
  36         unsigned short *normal_i2c;
  37         unsigned short *probe;
  38         unsigned short *ignore;
  39
  40         /* Forget it if we can't probe using SMBUS_QUICK */
  41         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK))
  42                 return -1;
  43
  44         /* Use default "empty" list if the adapter doesn't specify any */
  45         normal_i2c = probe = ignore = empty;
  46         if (address_data->normal_i2c)
  47                 normal_i2c = address_data->normal_i2c;
  48         if (address_data->probe)
  49                 probe = address_data->probe;
  50         if (address_data->ignore)
  51                 ignore = address_data->ignore;
  52
  53         for (addr = 0x00; addr <= 0x7f; addr++) {
  54                 if (i2c_check_addr(adapter, addr))
  55                         continue;
  56
  57                 /* If it is in one of the force entries, we don't do any
  58                    detection at all */
  59                 found = 0;
  60                 for (i = 0; address_data->forces[i]; i++) {
  61                         for (j = 0; !found && (address_data->forces[i][j] != I2C_CLIENT_END); j += 2) {
  62                                 if ( ((adapter_id == address_data->forces[i][j]) ||
  63                                       (address_data->forces[i][j] == ANY_I2C_BUS)) &&
  64                                       (addr == address_data->forces[i][j + 1]) ) {
  65                                         dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n", adapter_id, addr);
  66                                         if ((err = found_proc(adapter, addr, i)))
  67                                                 return err;
  68                                         found = 1;
  69                                 }
  70                         }
  71                 }
  72                 if (found)
  73                         continue;
  74
  75                 /* If this address is in one of the ignores, we can forget about it
  76                    right now */
  77                 for (i = 0; !found && (ignore[i] != I2C_CLIENT_END); i += 2) {
  78                         if ( ((adapter_id == ignore[i]) ||
  79                               (ignore[i] == ANY_I2C_BUS)) &&
  80                               (addr == ignore[i + 1])) {
  81                                 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, addr %04x\n", adapter_id, addr);
  82                                 found = 1;
  83                         }
  84                 }
  85                 if (found)
  86                         continue;
  87
  88                 /* Now, we will do a detection, but only if it is in the normal or
  89                    probe entries */
  90                 for (i = 0; !found && (normal_i2c[i] != I2C_CLIENT_END); i += 1) {
  91                         if (addr == normal_i2c[i]) {
  92                                 found = 1;
  93                                 dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, addr %02x\n", adapter_id, addr);
  94                         }
  95                 }
  96
  97                 for (i = 0;
  98                      !found && (probe[i] != I2C_CLIENT_END);
  99                      i += 2) {
 100                         if (((adapter_id == probe[i]) ||
 101                              (probe[i] == ANY_I2C_BUS))
 102                             && (addr == probe[i + 1])) {
 103                                 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, addr %04x\n", adapter_id, addr);
 104                                 found = 1;
 105                         }
 106                 }
 107                 if (!found)
 108                         continue;
 109
 110                 /* OK, so we really should examine this address. First check
 111                    whether there is some client here at all! */
 112                 if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) >= 0)
 113                         if ((err = found_proc(adapter, addr, -1)))
 114                                 return err;
 115         }
 116         return 0;
 117 }
 118
 119 EXPORT_SYMBOL(i2c_detect);
 120
 121 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 122               "Rudolf Marek <r.marek@sh.cvut.cz>");
 123
 124 MODULE_DESCRIPTION("i2c-sensor driver");
 125 MODULE_LICENSE("GPL");