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/drivers/i2c/i2c-sensor-detect.c

https://bitbucket.org/evzijst/gittest
C | 145 lines | 100 code | 14 blank | 31 comment | 52 complexity | 01d0df59f22f705b3cb05326d04c17d8 MD5 | raw file
  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
 27static unsigned short empty[] = {I2C_CLIENT_END};
 28static unsigned int empty_isa[] = {I2C_CLIENT_ISA_END};
 29
 30/* Very inefficient for ISA detects, and won't work for 10-bit addresses! */
 31int 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
139EXPORT_SYMBOL(i2c_detect);
140
141MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
142	      "Rudolf Marek <r.marek@sh.cvut.cz>");
143
144MODULE_DESCRIPTION("i2c-sensor driver");
145MODULE_LICENSE("GPL");