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_address_data *address_data,
  32                int (*found_proc) (struct i2c_adapter *, int, int))
  33 {
  34         int addr, i, found, j, err;
  35         struct i2c_force_data *this_force;
  36         int adapter_id = i2c_adapter_id(adapter);
  37         unsigned short *normal_i2c;
  38         unsigned short *probe;
  39         unsigned short *ignore;
  40
  41         /* Forget it if we can't probe using SMBUS_QUICK */
  42         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK))
  43                 return -1;
  44
  45         /* Use default "empty" list if the adapter doesn't specify any */
  46         normal_i2c = probe = ignore = empty;
  47         if (address_data->normal_i2c)
  48                 normal_i2c = address_data->normal_i2c;
  49         if (address_data->probe)
  50                 probe = address_data->probe;
  51         if (address_data->ignore)
  52                 ignore = address_data->ignore;
  53
  54         for (addr = 0x00; addr <= 0x7f; addr++) {
  55                 if (i2c_check_addr(adapter, addr))
  56                         continue;
  57
  58                 /* If it is in one of the force entries, we don't do any
  59                    detection at all */
  60                 found = 0;
  61                 for (i = 0; !found && (this_force = address_data->forces + i, this_force->force); i++) {
  62                         for (j = 0; !found && (this_force->force[j] != I2C_CLIENT_END); j += 2) {
  63                                 if ( ((adapter_id == this_force->force[j]) ||
  64                                       (this_force->force[j] == ANY_I2C_BUS)) &&
  65                                       (addr == this_force->force[j + 1]) ) {
  66                                         dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n", adapter_id, addr);
  67                                         if ((err = found_proc(adapter, addr, this_force->kind)))
  68                                                 return err;
  69                                         found = 1;
  70                                 }
  71                         }
  72                 }
  73                 if (found)
  74                         continue;
  75
  76                 /* If this address is in one of the ignores, we can forget about it
  77                    right now */
  78                 for (i = 0; !found && (ignore[i] != I2C_CLIENT_END); i += 2) {
  79                         if ( ((adapter_id == ignore[i]) ||
  80                               (ignore[i] == ANY_I2C_BUS)) &&
  81                               (addr == ignore[i + 1])) {
  82                                 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, addr %04x\n", adapter_id, addr);
  83                                 found = 1;
  84                         }
  85                 }
  86                 if (found)
  87                         continue;
  88
  89                 /* Now, we will do a detection, but only if it is in the normal or
  90                    probe entries */
  91                 for (i = 0; !found && (normal_i2c[i] != I2C_CLIENT_END); i += 1) {
  92                         if (addr == normal_i2c[i]) {
  93                                 found = 1;
  94                                 dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, addr %02x\n", adapter_id, addr);
  95                         }
  96                 }
  97
  98                 for (i = 0;
  99                      !found && (probe[i] != I2C_CLIENT_END);
 100                      i += 2) {
 101                         if (((adapter_id == probe[i]) ||
 102                              (probe[i] == ANY_I2C_BUS))
 103                             && (addr == probe[i + 1])) {
 104                                 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, addr %04x\n", adapter_id, addr);
 105                                 found = 1;
 106                         }
 107                 }
 108                 if (!found)
 109                         continue;
 110
 111                 /* OK, so we really should examine this address. First check
 112                    whether there is some client here at all! */
 113                 if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) >= 0)
 114                         if ((err = found_proc(adapter, addr, -1)))
 115                                 return err;
 116         }
 117         return 0;
 118 }
 119
 120 EXPORT_SYMBOL(i2c_detect);
 121
 122 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 123               "Rudolf Marek <r.marek@sh.cvut.cz>");
 124
 125 MODULE_DESCRIPTION("i2c-sensor driver");
 126 MODULE_LICENSE("GPL");