From 0fb8b6f04b699a2158b8700a8350bf488e2c1d42 Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Fri, 19 Mar 2004 18:22:30 +0000
Subject: [PATCH] Add support for the PCA9540.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@2367 7894878c-1315-0410-8ee3-d5d059ff63e0
---
 prog/detect/sensors-detect | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/prog/detect/sensors-detect b/prog/detect/sensors-detect
index c41d8e97..b1aeca04 100755
--- a/prog/detect/sensors-detect
+++ b/prog/detect/sensors-detect
@@ -780,7 +780,7 @@ use subs qw(mtp008_detect lm78_detect lm78_isa_detect lm78_alias_detect
             adm1026_detect w83l785ts_detect lm83_detect lm90_detect
             saa1064_detect w83l784r_detect mozart_detect max6650_detect
 			fscher_detect adm1029_detect adm1031_detect max6900_detect
-			m5879_detect);
+			m5879_detect pca9540_detect);
 
 # This is a list of all recognized chips. 
 # Each entry must have the following fields:
@@ -1252,6 +1252,12 @@ use subs qw(mtp008_detect lm78_detect lm78_isa_detect lm78_alias_detect
        i2c_addrs => [0x38..0x3b],
        i2c_detect => sub { saa1064_detect @_ },
      },
+     {
+       name => "Philips Semiconductors PCA9540",
+       driver => "pca9540",
+       i2c_addrs => [0x70],
+       i2c_detect => sub { pca9540_detect @_ },
+     },
      {
        name => "Maxim MAX6900",
        driver => "to-be-written",
@@ -3806,6 +3812,25 @@ sub saa1064_detect
 	return 4;
 }
 
+# $_[0]: A reference to the file descriptor to access this chip.
+#        We may assume an i2c_set_slave_addr was already done.
+# $_[1]: Address
+# Returns: undef if not detected, 1 if detected
+# Detection is rather difficult, since the PCA9540 has a single register.
+# Fortunately, no other device is known to live at this address.
+sub pca9540_detect
+{
+	my ($file, $addr) = @_;
+	my $reg = i2c_smbus_read_byte($file);
+
+	return if ($reg & 0xf7);
+	return if $reg != i2c_smbus_read_byte($file);
+	return if $reg != i2c_smbus_read_byte($file);
+	return if $reg != i2c_smbus_read_byte($file);
+
+	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