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 static unsigned int empty_isa[] = {I2C_CLIENT_ISA_END};
  29
  30 /* Very inefficient for ISA detects, and won't work for 10-bit addresses! */
  31 int i2c_detect(struct i2c_adapter *adapter,
  32                struct i2c_address_data *address_data,
  33                int (*found_proc) (struct i2c_adapter *, int, int))
  34 {
  35         int addr, i, found, j, err;
  36         struct i2c_force_data *this_force;
  37         int is_isa = i2c_is_isa_adapter(adapter);
  38         int adapter_id =
  39             is_isa ? ANY_I2C_ISA_BUS : i2c_adapter_id(adapter);
  40         unsigned short *normal_i2c;
  41         unsigned int *normal_isa;
  42         unsigned short *probe;
  43         unsigned short *ignore;
  44
  45         /* Forget it if we can't probe using SMBUS_QUICK */
  46         if ((!is_isa) &&
  47             !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK))
  48                 return -1;
  49
  50         /* Use default "empty" list if the adapter doesn't specify any */
  51         normal_i2c = probe = ignore = empty;
  52         normal_isa = empty_isa;
  53         if (address_data->normal_i2c)
  54                 normal_i2c = address_data->normal_i2c;
  55         if (address_data->normal_isa)
  56                 normal_isa = address_data->normal_isa;
  57         if (address_data->probe)
  58                 probe = address_data->probe;
  59         if (address_data->ignore)
  60                 ignore = address_data->ignore;
  61
  62         for (addr = 0x00; addr <= (is_isa ? 0xffff : 0x7f); addr++) {
  63                 if (!is_isa && i2c_check_addr(adapter, addr))
  64                         continue;
  65
  66                 /* If it is in one of the force entries, we don't do any
  67                    detection at all */
  68                 found = 0;
  69                 for (i = 0; !found && (this_force = address_data->forces + i, this_force->force); i++) {
  70                         for (j = 0; !found && (this_force->force[j] != I2C_CLIENT_END); j += 2) {
  71                                 if ( ((adapter_id == this_force->force[j]) ||
  72                                       ((this_force->force[j] == ANY_I2C_BUS) && !is_isa)) &&
  73                                       (addr == this_force->force[j + 1]) ) {
  74                                         dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n", adapter_id, addr);
  75                                         if ((err = found_proc(adapter, addr, this_force->kind)))
  76                                                 return err;
  77                                         found = 1;
  78                                 }
  79                         }
  80                 }
  81                 if (found)
  82                         continue;
  83
  84                 /* If this address is in one of the ignores, we can forget about it
  85                    right now */
  86                 for (i = 0; !found && (ignore[i] != I2C_CLIENT_END); i += 2) {
  87                         if ( ((adapter_id == ignore[i]) ||
  88                               ((ignore[i] == ANY_I2C_BUS) &&
  89                                !is_isa)) &&
  90                               (addr == ignore[i + 1])) {
  91                                 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, addr %04x\n", adapter_id, addr);
  92                                 found = 1;
  93                         }
  94                 }
  95                 if (found)
  96                         continue;
  97
  98                 /* Now, we will do a detection, but only if it is in the normal or
  99                    probe entries */
 100                 if (is_isa) {
 101                         for (i = 0; !found && (normal_isa[i] != I2C_CLIENT_ISA_END); i += 1) {
 102                                 if (addr == normal_isa[i]) {
 103                                         dev_dbg(&adapter->dev, "found normal isa entry for adapter %d, addr %04x\n", adapter_id, addr);
 104                                         found = 1;
 105                                 }
 106                         }
 107                 } else {
 108                         for (i = 0; !found && (normal_i2c[i] != I2C_CLIENT_END); i += 1) {
 109                                 if (addr == normal_i2c[i]) {
 110                                         found = 1;
 111                                         dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, addr %02x\n", adapter_id, addr);
 112                                 }
 113                         }
 114                 }
 115
 116                 for (i = 0;
 117                      !found && (probe[i] != I2C_CLIENT_END);
 118                      i += 2) {
 119                         if (((adapter_id == probe[i]) ||
 120                              ((probe[i] == ANY_I2C_BUS) && !is_isa))
 121                             && (addr == probe[i + 1])) {
 122                                 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, addr %04x\n", adapter_id, addr);
 123                                 found = 1;
 124                         }
 125                 }
 126                 if (!found)
 127                         continue;
 128
 129                 /* OK, so we really should examine this address. First check
 130                    whether there is some client here at all! */
 131                 if (is_isa ||
 132                     (i2c_smbus_xfer (adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) >= 0))
 133                         if ((err = found_proc(adapter, addr, -1)))
 134                                 return err;
 135         }
 136         return 0;
 137 }
 138
 139 EXPORT_SYMBOL(i2c_detect);
 140
 141 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 142               "Rudolf Marek <r.marek@sh.cvut.cz>");
 143
 144 MODULE_DESCRIPTION("i2c-sensor driver");
 145 MODULE_LICENSE("GPL");