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sensors-detect: Check i2c adapter functionalities before probing, so that

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we don't use SMBus transactions the adapter doesn't support. This could
be extended to the transactions used during detection itself.


git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@4086 7894878c-1315-0410-8ee3-d5d059ff63e0
This commit is contained in:
Jean Delvare
2006-08-09 06:45:48 +00:00
parent 6e2060e7ad
commit 0d09dd4dfe
2 changed files with 41 additions and 4 deletions
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44
prog/detect/sensors-detect
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@@ -2437,6 +2437,7 @@ sub find_adapter_driver
# These are copied from <linux/i2c-dev.h>
use constant IOCTL_I2C_SLAVE => 0x0703;
use constant IOCTL_I2C_FUNCS => 0x0705;
use constant IOCTL_I2C_SMBUS => 0x0720;
use constant SMBUS_READ => 1;
@@ -2447,6 +2448,23 @@ use constant SMBUS_BYTE => 1;
use constant SMBUS_BYTE_DATA => 2;
use constant SMBUS_WORD_DATA => 3;
use constant I2C_FUNC_SMBUS_QUICK => 0x00010000;
use constant I2C_FUNC_SMBUS_READ_BYTE => 0x00020000;
# Get the i2c adapter's functionalities
# $_[0]: Reference to an opened filehandle
# Returns: -1 on failure, functionality bitfield on success.
sub i2c_get_funcs($)
{
my $file = shift;
my $funcs;
ioctl $file, IOCTL_I2C_FUNCS, $funcs='' or return -1;
$funcs = unpack "L", $funcs;
return $funcs;
}
# Select the device to communicate with through its address.
# $_[0]: Reference to an opened filehandle
# $_[1]: Address to select
@@ -2532,13 +2550,14 @@ sub i2c_smbus_read_word_data
# $_[0]: Reference to an opened filehandle
# $_[1]: Address
# $_[2]: Functionalities of this i2c adapter
# Returns: 1 on successful probing, 0 else.
# This function is meant to prevent AT24RF08 corruption and write-only
# chips locks. This is done by choosing the best probing method depending
# on the address range.
sub i2c_probe
sub i2c_probe($$$)
{
my ($file, $addr) = @_;
my ($file, $addr, $funcs) = @_;
my $data = [];
if (($addr >= 0x50 && $addr <= 0x5F)
|| ($addr >= 0x30 && $addr <= 0x37)) {
@@ -2547,8 +2566,10 @@ sub i2c_probe
# this, because they ack on write only, but this is probably better since
# some EEPROMs write-protect themselves permanently on almost any write to
# their page protection address.
return 0 unless ($funcs & I2C_FUNC_SMBUS_READ_BYTE);
return i2c_smbus_access($file, SMBUS_READ, 0, SMBUS_BYTE, $data);
} else {
return 0 unless ($funcs & I2C_FUNC_SMBUS_QUICK);
return i2c_smbus_access($file, SMBUS_WRITE, 0, SMBUS_QUICK, $data);
}
}
@@ -2799,7 +2820,7 @@ sub add_isa_to_chips_detected
sub scan_adapter
{
my ($adapter_nr, $adapter_name, $adapter_driver, $not_to_scan) = @_;
my ($chip, $addr, $conf,@chips,$new_hash,$other_addr);
my ($funcs, $chip, $addr, $conf, @chips, $new_hash, $other_addr);
# As we modify it, we need a copy
my @not_to_scan = @$not_to_scan;
@@ -2808,6 +2829,21 @@ sub scan_adapter
(print "Can't open $dev_i2c$adapter_nr\n"), return;
binmode FILE;
# Can we probe this adapter?
$funcs = i2c_get_funcs(\*FILE);
if ($funcs < 0) {
print "Adapter failed to provide its functionalities, skipping.\n";
return;
}
if (!($funcs & (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_READ_BYTE))) {
print "Adapter cannot be probed, skipping.\n";
return;
}
if (~$funcs & (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_READ_BYTE)) {
print "Adapter doesn't support all probing functions.\n",
"Some addresses won't be probed.\n";
}
# Now scan each address in turn
foreach $addr (0x03..0x77) {
# As the not_to_scan list is sorted, we can check it fast
@@ -2855,7 +2891,7 @@ sub scan_adapter
next;
}
next unless i2c_probe(\*FILE, $addr);
next unless i2c_probe(\*FILE, $addr, $funcs);
printf "Client found at address 0x%02x\n",$addr;
foreach $chip (@chip_ids) {