From cad58377f01644d5390c1e915c978c1e0de1741a Mon Sep 17 00:00:00 2001
From: Thomas Cort <tcort@minix3.org>
Date: Thu, 22 Aug 2013 11:22:01 -0400
Subject: [PATCH] rc: start drivers for attached BeagleBone Capes

BeagleBone Capes add additional hardware to the BeagleBone to
improve functionality.

This patch probes the third i2c bus for capes and loads the
appropriate drivers for each detected cape. Currently only
the 'BeagleBone Weather' cape is supported.

Change-Id: Id8c133810db6de7c21625c2d5a794b8874673a0f
---
 etc/usr/rc | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/etc/usr/rc b/etc/usr/rc
index 7dfb42ffd..8045e0255 100644
--- a/etc/usr/rc
+++ b/etc/usr/rc
@@ -112,6 +112,70 @@ get_eth_labels() {
     grep -v '^vlan_'
 }
 
+# Detect expansion boards on the BeagleBone and load the proper drivers.
+capemgr() {
+
+    # Probe each possible cape EEPROM slave address for a BeagleBone cape.
+    for slave_addr in 54 55 56 57
+    do
+
+        # See if there is a readable EEPROM with address ${slave_addr}.
+        eepromread -f /dev/i2c-3 -a 0x${slave_addr} > /dev/null 2>&1
+        RESULT=$?
+	if [ $RESULT -eq 0 ]
+	then
+
+	    # Found an alive EEPROM. Try reading the cape name.
+            CAPE=`eepromread -i -f /dev/i2c-3 -a 0x${slave_addr} | \
+	        sed -n 's/^PART_NUMBER     : \(.*\)$/\1/p'`
+
+            # Load the drivers for the cape and do any other configuration.
+            case "${CAPE}" in
+
+                # Weather Cape
+	        BB-BONE-WTHR-01.)
+
+                    # CAT24C256 EEPROM
+		    test -e /dev/eepromb3s${slave_addr} || \
+		        (cd /dev && MAKEDEV eepromb3s${slave_addr})
+		    up cat24c256 -dev /dev/eepromb3s${slave_addr} \
+		        -label cat24c256.3.${slave_addr} \
+			-args "bus=3 address=0x${slave_addr}"
+
+                    # TSL2550 Ambient Light Sensor
+		    test -e /dev/tsl2550b3s39 || \
+		        (cd /dev && MAKEDEV tsl2550b3s39)
+		    up tsl2550 -dev /dev/tsl2550b3s39 \
+		        -label tsl2550.3.39 \
+			-args 'bus=3 address=0x39'
+
+		    # SHT21 Temperature and Humidity Sensor
+		    test -e /dev/sht21b3s40 || \
+		        (cd /dev && MAKEDEV sht21b3s40)
+		    up sht21 -dev /dev/sht21b3s40 \
+		        -label sht21.3.40 \
+			-args 'bus=3 address=0x40'
+
+		    # BMP085 Temperature and Pressure Sensor
+		    test -e /dev/bmp085b3s77 || \
+		        (cd /dev && MAKEDEV bmp085b3s77)
+		    up bmp085 -dev /dev/bmp085b3s77 \
+		        -label bmp085.3.77 \
+			-args 'bus=3 address=0x77'
+
+		    ;;
+
+                *)
+                    # Do nothing if the cape isn't recognized
+		    echo ""
+                    echo "** UNSUPPORTED CAPE: ${CAPE}"
+		    echo ""
+                    ;;
+	    esac
+	fi
+    done
+}
+
 DAEMONS=/etc/rc.daemons
 
 case $action in
@@ -230,6 +294,9 @@ start)
 				# fb hasn't been ported to AM335X yet.
 			fi
 
+			# Detect expansion boards and start drivers.
+			capemgr
+
 			;;
 
 		A335BNLT)
@@ -255,6 +322,9 @@ start)
 			#up fb -dev /dev/fb0 -args edid.0=tda19988.1.3470
 			# fb hasn't been ported to AM335X yet.
 
+			# Detect expansion boards and start drivers.
+			capemgr
+
 			;;
 
 		UNKNOWN)