mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2024-11-24 22:37:32 +02:00
fc54b9bf15
(stable-branch of Openmoko) git-svn-id: svn://svn.openwrt.org/openwrt/trunk@13613 3c298f89-4303-0410-b956-a3cf2f4a3e73
88 lines
2.9 KiB
Diff
88 lines
2.9 KiB
Diff
From ab6e925546e3d3361ab59c2b090eccf0cb411c7b Mon Sep 17 00:00:00 2001
|
|
From: Andy Green <andy@openmoko.com>
|
|
Date: Sun, 13 Apr 2008 07:25:48 +0100
|
|
Subject: [PATCH] introduce-fiq-hdq.patch
|
|
|
|
This adds a platform driver and device which performs HDQ
|
|
battery protocol using a single GPIO pin which is set
|
|
through platform data.
|
|
|
|
HDQ has some hard latency requirements which can't
|
|
be met if interrupts are enabled, so normally using
|
|
a GPIO for this will require blocking out all other
|
|
interrupts and processes for several milliseconds
|
|
per register being read or written.
|
|
|
|
This HDQ protocol engine is a FSM implemented inside the
|
|
the FIQ ISR and regulated by timer interrupts happening
|
|
at 20us intervals. The path through the FSM on any
|
|
"clock" is very short and should be over with in ~
|
|
1us. Because FIQ has guaranteed latencies of <1us,
|
|
it means we can service the HDQ protocol without
|
|
blocking interrupts or any other process other than
|
|
the caller that is waiting for the result. It's pretty
|
|
cool performance from 1 GPIO ;-)
|
|
|
|
Due to it being hard to do locking from the FIQ ISR
|
|
the code simply sleeps 10ms or whatever the scheduler
|
|
gives it and checks if the transfer took place yet.
|
|
|
|
This platform driver doesn't have any knowledge about
|
|
the device it is talking to, it just knows it is a
|
|
HDQ device. It exports three functions for read, write
|
|
and confirming HDQ is initialized. It also exports two
|
|
/sys nodes that are usable by humans, one dumps the whole
|
|
127 register HDQ register space
|
|
|
|
# cat /sys/devices/platform/gta02-hdq.0/hdq/dump
|
|
00 44 55 00 00 00 ba 04 a2 0d 50 00 00 00 00 00
|
|
00 00 9a 1a 00 00 ff ff ff ff 29 00 00 00 80 2b
|
|
00 00 00 00 00 00 ff ff 00 00 00 00 00 32 af 06
|
|
a0 d8 37 4e 00 00 00 00 00 00 00 34 2e 03 b4 e7
|
|
00 00 06 00 41 00 4c 02 00 00 00 00 00 00 00 00
|
|
83 02 00 00 94 09 59 b9 a5 0d 7f 21 00 00 7a ff
|
|
df ff 62 ff a7 04 2e 05 00 00 00 01 00 07 00 00
|
|
2a 78 36 67 7b b5 1b a9 af 19 38 89 63 57 42 7c
|
|
#
|
|
|
|
and the other allows to set one register
|
|
|
|
# echo 2 170 > /sys/devices/platform/gta02-hdq.0/hdq/write
|
|
|
|
writes 0xAA into register 2.
|
|
|
|
Signed-off-by: Andy Green <andy@openmoko.com>
|
|
---
|
|
defconfig-2.6.24 | 1 +
|
|
drivers/power/Kconfig | 8 ++++++++
|
|
2 files changed, 9 insertions(+), 0 deletions(-)
|
|
|
|
diff --git a/defconfig-2.6.24 b/defconfig-2.6.24
|
|
index 833e15e..6d750a5 100644
|
|
--- a/defconfig-2.6.24
|
|
+++ b/defconfig-2.6.24
|
|
@@ -1825,3 +1825,4 @@ CONFIG_TEXTSEARCH_FSM=m
|
|
CONFIG_PLIST=y
|
|
CONFIG_HAS_IOMEM=y
|
|
CONFIG_HAS_DMA=y
|
|
+CONFIG_GTA02_HDQ=y
|
|
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
|
|
index feb8b0a..5ace872 100644
|
|
--- a/drivers/power/Kconfig
|
|
+++ b/drivers/power/Kconfig
|
|
@@ -63,3 +63,11 @@ config GTA02_HDQ
|
|
at least BATTERY_BQ27000_HDQ as well
|
|
|
|
endif # POWER_SUPPLY
|
|
+
|
|
+config GTA02_HDQ
|
|
+ tristate "Neo Freerunner HDQ"
|
|
+ depends on MACH_NEO1973_GTA02 && FIQ && S3C2440_C_FIQ
|
|
+ help
|
|
+ Say Y to enable support for communicating with an HDQ battery
|
|
+ on the Neo Freerunner. You probably want to select
|
|
+ at least BATTERY_BQ27000_HDQ as well
|
|
--
|
|
1.5.6.5
|
|
|