From 8c52a7cf8e066d7ce202e38863c225a7d4d0bfeb Mon Sep 17 00:00:00 2001
From: Andreas Kemnade <andreas@kemnade.info>
Date: Fri, 1 Nov 2013 16:29:06 +0100
Subject: usb: various hacks related to otg

- start switch to b_host role via sysfs
- control vbus output power
  - can be used to start charging when a charger with ID
    grounded is first connected to the device and then to the
    wall outlet
  - enable/disable pulldown resistors via sysfs,
    can be used to emulate a connection to a usb host,
    useful for switching to b_host when using y-cables
  - script for entering b_host mode

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
 GTA04/README            |  5 +++++
 GTA04/scripts/b_host.sh | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100755 GTA04/scripts/b_host.sh

(limited to 'GTA04')

diff --git a/GTA04/README b/GTA04/README
index dad8c0a..fcb638d 100644
--- a/GTA04/README
+++ b/GTA04/README
@@ -28,3 +28,8 @@
   simple tasks
 
   + vibra.py shows how to program the vibrator as a rumble effect.
+  + b_host.sh helps to switch to b_host otg state (GTA04 is external
+    powered but plays the role of an usb host, the id pin is
+    not grounded in that situation). First apply power or switch on
+    software-controlled charging, run that script, then also connect
+    the usb data lines
diff --git a/GTA04/scripts/b_host.sh b/GTA04/scripts/b_host.sh
new file mode 100755
index 0000000..16e04c1
--- /dev/null
+++ b/GTA04/scripts/b_host.sh
@@ -0,0 +1,35 @@
+#!/bin/sh
+# if not in software-controlled charging mode, Vbus (and only that)
+# has to be applied before running the script
+#MUSB_MODE=/sys/bus/platform/devices/musb-hdrc/mode
+#MUSB_MODE=/sys/bus/platform/devices/musb-hdrc.0/mode
+MUSB_MODE=/sys/bus/platform/devices/musb-hdrc.1.auto/mode
+
+MUSB_M=`cat $MUSB_MODE`
+echo "$MUSB_M"
+if [ "$MUSB_M" != b_idle ] ; then
+	echo Invalid mode at start
+        exit
+fi
+# trigger a transition from b_idle to b_peripheral by simulating
+# a connection to a host (enable pull-down resistors)
+echo on > /sys/bus/platform/devices/twl4030_usb/fake_host
+sleep 0.2
+cat $MUSB_MODE
+# trigger a transition from b_peripheral to b_hnp_enable
+echo host >$MUSB_MODE
+cat $MUSB_MODE
+sleep 0.2
+# simulate a disconnection from host
+echo off > /sys/bus/platform/devices/twl4030_usb/fake_host
+sleep 0.2
+cat $MUSB_MODE
+# be a host by ourselfs (if we wouldn't mess with this bit,
+# it would be already set here)
+echo on > /sys/bus/platform/devices/twl4030_usb/fake_host
+MUSB_M=`cat $MUSB_MODE`
+echo "$MUSB_M"
+
+if [ "$MUSB_M" = b_wait_acon ] ; then
+	echo "Prepared for being usb host, time to attach your device"
+fi
-- 
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