aboutsummaryrefslogtreecommitdiff
path: root/drivers/i2c/i2c-sensor-detect.c
blob: f99a8161a9f14020a3c93966cb3432de9103f141 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
/*
    i2c-sensor-detect.c - Part of lm_sensors, Linux kernel modules for hardware
            		  monitoring
    Copyright (c) 1998 - 2001 Frodo Looijaard <frodol@dds.nl> and
    Mark D. Studebaker <mdsxyz123@yahoo.com>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/i2c-sensor.h>

static unsigned short empty[] = {I2C_CLIENT_END};
static unsigned int empty_isa[] = {I2C_CLIENT_ISA_END};

/* Very inefficient for ISA detects, and won't work for 10-bit addresses! */
int i2c_detect(struct i2c_adapter *adapter,
	       struct i2c_address_data *address_data,
	       int (*found_proc) (struct i2c_adapter *, int, int))
{
	int addr, i, found, j, err;
	struct i2c_force_data *this_force;
	int is_isa = i2c_is_isa_adapter(adapter);
	int adapter_id =
	    is_isa ? ANY_I2C_ISA_BUS : i2c_adapter_id(adapter);
	unsigned short *normal_i2c;
	unsigned int *normal_isa;
	unsigned short *probe;
	unsigned short *ignore;

	/* Forget it if we can't probe using SMBUS_QUICK */
	if ((!is_isa) &&
	    !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK))
		return -1;
	
	/* Use default "empty" list if the adapter doesn't specify any */
	normal_i2c = probe = ignore = empty;
	normal_isa = empty_isa;
	if (address_data->normal_i2c)
		normal_i2c = address_data->normal_i2c;
	if (address_data->normal_isa)
		normal_isa = address_data->normal_isa;
	if (address_data->probe)
		probe = address_data->probe;
	if (address_data->ignore)
		ignore = address_data->ignore;

	for (addr = 0x00; addr <= (is_isa ? 0xffff : 0x7f); addr++) {
		if (!is_isa && i2c_check_addr(adapter, addr))
			continue;

		/* If it is in one of the force entries, we don't do any
		   detection at all */
		found = 0;
		for (i = 0; !found && (this_force = address_data->forces + i, this_force->force); i++) {
			for (j = 0; !found && (this_force->force[j] != I2C_CLIENT_END); j += 2) {
				if ( ((adapter_id == this_force->force[j]) ||
				      ((this_force->force[j] == ANY_I2C_BUS) && !is_isa)) &&
				      (addr == this_force->force[j + 1]) ) {
					dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n", adapter_id, addr);
					if ((err = found_proc(adapter, addr, this_force->kind)))
						return err;
					found = 1;
				}
			}
		}
		if (found)
			continue;

		/* If this address is in one of the ignores, we can forget about it
		   right now */
		for (i = 0; !found && (ignore[i] != I2C_CLIENT_END); i += 2) {
			if ( ((adapter_id == ignore[i]) ||
			      ((ignore[i] == ANY_I2C_BUS) &&
			       !is_isa)) &&
			      (addr == ignore[i + 1])) {
				dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, addr %04x\n", adapter_id, addr);
				found = 1;
			}
		}
		if (found)
			continue;

		/* Now, we will do a detection, but only if it is in the normal or 
		   probe entries */
		if (is_isa) {
			for (i = 0; !found && (normal_isa[i] != I2C_CLIENT_ISA_END); i += 1) {
				if (addr == normal_isa[i]) {
					dev_dbg(&adapter->dev, "found normal isa entry for adapter %d, addr %04x\n", adapter_id, addr);
					found = 1;
				}
			}
		} else {
			for (i = 0; !found && (normal_i2c[i] != I2C_CLIENT_END); i += 1) {
				if (addr == normal_i2c[i]) {
					found = 1;
					dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, addr %02x\n", adapter_id, addr);
				}
			}
		}

		for (i = 0;
		     !found && (probe[i] != I2C_CLIENT_END);
		     i += 2) {
			if (((adapter_id == probe[i]) ||
			     ((probe[i] == ANY_I2C_BUS) && !is_isa))
			    && (addr == probe[i + 1])) {
				dev_dbg(&adapter->dev, "found probe parameter for adapter %d, addr %04x\n", adapter_id, addr);
				found = 1;
			}
		}
		if (!found)
			continue;

		/* OK, so we really should examine this address. First check
		   whether there is some client here at all! */
		if (is_isa ||
		    (i2c_smbus_xfer (adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) >= 0))
			if ((err = found_proc(adapter, addr, -1)))
				return err;
	}
	return 0;
}

EXPORT_SYMBOL(i2c_detect);

MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
	      "Rudolf Marek <r.marek@sh.cvut.cz>");

MODULE_DESCRIPTION("i2c-sensor driver");
MODULE_LICENSE("GPL");