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Detect the Philips PCA9556 (8-bit I/O expander).

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git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@2755 7894878c-1315-0410-8ee3-d5d059ff63e0
This commit is contained in:
Jean Delvare
2004-11-14 14:34:30 +00:00
parent 88bb42be00
commit dfe1645a5a
1 changed files with 36 additions and 1 deletions
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37
prog/detect/sensors-detect
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@@ -836,7 +836,7 @@ use subs qw(mtp008_detect lm78_detect lm78_isa_detect lm78_alias_detect
fscher_detect adm1029_detect adm1031_detect max6900_detect
m5879_detect pca9540_detect smartbatt_mgr_detect
smartbatt_chgr_detect adt7467_detect lm92_detect max1619_detect
lm93_detect lm77_detect lm63_detect);
lm93_detect lm77_detect lm63_detect pca9556_detect);
# This is a list of all recognized chips.
# Each entry must have the following fields:
@@ -1387,6 +1387,12 @@ use subs qw(mtp008_detect lm78_detect lm78_isa_detect lm78_alias_detect
i2c_addrs => [0x70],
i2c_detect => sub { pca9540_detect @_ },
},
{
name => "Philips Semiconductors PCA9556",
driver => "to-be-written",
i2c_addrs => [0x18..0x1f],
i2c_detect => sub { pca9556_detect @_ },
},
{
name => "Maxim MAX6900",
driver => "to-be-written",
@@ -4185,6 +4191,35 @@ sub pca9540_detect
return 1;
}
# $_[0]: A reference to the file descriptor to access this chip.
# We assume an i2c_set_slave_addr was already done.
# $_[1]: Address (unused)
# Returns: undef if not detected, 1 if detected
# Detection is rather difficult, since the PCA9556 only has 4 registers
# and no unused bit. We use the fact that the registers cycle over
# 4 addresses boundaries, and the logic rules between registers.
sub pca9556_detect
{
my ($file, $addr) = @_;
my $input = i2c_smbus_read_byte_data($file, 0x00);
my $output = i2c_smbus_read_byte_data($file, 0x01);
my $invert = i2c_smbus_read_byte_data($file, 0x02);
my $config = i2c_smbus_read_byte_data($file, 0x03);
# Pins configured for output (config = 0) must obey the following
# rule: input = output ^ invert
return unless ($input & ~$config) == (($output ^ $invert) & ~$config);
for (my $i = 5; $i < 254 ; $i+=4) {
return unless i2c_smbus_read_byte_data($file, $i) == $output;
return unless i2c_smbus_read_byte_data($file, $i+1) == $invert;
return unless i2c_smbus_read_byte_data($file, $i+2) == $config;
}
return 1;
}
# $_[0]: A reference to the file descriptor to access this chip.
# We may assume an i2c_set_slave_addr was already done.
# $_[1]: Address