Pull i2c changes from Wolfram Sang:
- new drivers for exynos5, bcm kona, and st micro
- bigger overhauls for drivers mxs and rcar
- typical driver bugfixes, cleanups, improvements
- got rid of the superfluous 'driver' member in i2c_client struct This
touches a few drivers in other subsystems. All acked.
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (38 commits)
i2c: bcm-kona: fix error return code in bcm_kona_i2c_probe()
i2c: i2c-eg20t: do not print error message in syslog if no ACK received
i2c: bcm-kona: Introduce Broadcom I2C Driver
i2c: cbus-gpio: Fix device tree binding
i2c: wmt: add missing clk_disable_unprepare() on error
i2c: designware: add new ACPI IDs
i2c: i801: Add Device IDs for Intel Wildcat Point-LP PCH
i2c: exynos5: Remove incorrect clk_disable_unprepare
i2c: i2c-st: Add ST I2C controller
i2c: exynos5: add High Speed I2C controller driver
i2c: rcar: fixup rcar type naming
i2c: scmi: remove some bogus NULL checks
i2c: sh_mobile & rcar: Enable the driver on all ARM platforms
i2c: sh_mobile: Convert to clk_prepare/unprepare
i2c: mux: gpio: use reg value for i2c_add_mux_adapter
i2c: mux: gpio: use gpio_set_value_cansleep()
i2c: Include linux/of.h header
i2c: mxs: Fix PIO mode on i.MX23
i2c: mxs: Rework the PIO mode operation
i2c: mxs: distinguish i.MX23 and i.MX28 based I2C controller
...
Fix to return a negative error code from the bus speed parse
error handling case instead of 0.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Using the i2c-eg20t driver and call i2cdetect or probe on the bus,
the driver will print a lot of error messages if there was no ACK
received.
i2cdetect normally print a table with all the available devices. If there
is no device on the address, the table will be empty.
Currently with the i2c-eg20t driver, the table is not visible because
the error messages destroy the table.
Error message: pch_i2c_getack return -71
This patch prevent the driver to print the messages to syslog.
The pch_i2c_wait_for_check_xfer function is the only one who is
calling pch_i2c_getack, so we can delete the function and add the
read to pch_i2c_wait_for_check_xfer.
If no ACK is received, the Message will be printed as a dbg
message.
Fixed print message to be a one liner so we can grep for the
error message.
Tested on Intel Atom E6xx and Eg20t Chipset.
Signed-off-by: Andreas Werner <wernerandy@gmx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Introduce support for Broadcom Serial Controller (BSC) I2C bus found
in the Kona family of Mobile SoCs. FIFO hardware is utilized but only
standard mode (100kHz), fast mode (400kHz), fast mode plus (1MHz), and
I2C high-speed (3.4 MHz) bus speeds are supported.
Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
[wsa: fixed Kconfig sorting, squashed broken out patches into one]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Looks like we're missing two lines needed to make it
work properly with device tree.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.
[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add the missing clk_disable_unprepare() before return
from wmt_i2c_reset_hardware() in the error handling case.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org # 3.11+
Newer Intel PCHs with LPSS have the same Designware I2C controllers than
Haswell but the ACPI IDs differ. Add these IDs to the driver list.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds the SMBus Device IDs for the Intel Wildcat Point-LP PCH.
Signed-off-by: James Ralston <james.d.ralston@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds support to SSC (Synchronous Serial Controller)
I2C driver. This IP also supports SPI protocol, but this is not
the aim of this driver.
This IP is embedded in all ST SoCs for Set-top box platorms, and
supports I2C Standard and Fast modes.
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Adds support for High Speed I2C driver found in Exynos5 and
later SoCs from Samsung.
Driver only supports Device Tree method.
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Taekgyun Ko <taeggyun.ko@samsung.com>
Reviewed-by: Simon Glass <sjg@google.com>
Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
Signed-off-by: Andrew Bresticker <abrestic@google.com>
[wsa: rebased to v3.12-rc4 (no of_i2c.h anymore)]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
b720423a26
(i2c: rcar: add rcar-H2 support)
added R-Car H2 support on i2c-rcar.
The R-Car I2C type is based on SoC generation
(Gen1 = E1/M1/H1, Gen2 = E2/M2/H2),
but added naming was H1/H2 instead of Gen1/Gen2.
Gen1/Gen2 is better naming on this driver.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
"obj" can't be NULL here.
We already know that "pkg->package.elements" gives us a valid pointer
so the next pointer after that is also non-NULL.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Renesas ARM platforms are transitioning from single-platform to
multi-platform kernels using the new ARCH_SHMOBILE_MULTI. Make the
driver available on all ARM platforms to enable it on both ARCH_SHMOBILE
and ARCH_SHMOBILE_MULTI, and increase build testing coverage with
COMPILE_TEST.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Turn clk_enable() and clk_disable() calls into clk_prepare_enable() and
clk_disable_unprepare() to get ready for the migration to the common
clock framework.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
'of_match_ptr' is defined in linux/of.h. Include it explicitly to
avoid build breakage in the future.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Replace some instances of of_irq_map_one()/irq_create_of_mapping() and
of_irq_to_resource() by the simpler equivalent irq_of_parse_and_map().
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
[grant.likely: resolved conflicts with core code renames]
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Initially commit cb527ede1b
"i2c-omap: Double clear of ARDY status in IRQ handler"
added a workaround for undocumented errata ProDB0017052.
But then commit 1d7afc9594
"i2c: omap: ack IRQ in parts" refactored code and missed
one of ARDY clearings. So current code violates errata.
It causes often i2c bus timeouts on my Pandaboard.
This patch adds a second clearing in place.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Taras Kondratiuk <taras.kondratiuk@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Subsystems like pinctrl and gpio rightfully make use of deferred probing at
core level. Now, deferred drivers won't be retried if they don't have a .probe
function specified in the driver struct. Fix this driver to have that, so the
devices it supports won't get lost in a deferred probe.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Subsystems like pinctrl and gpio rightfully make use of deferred probing at
core level. Now, deferred drivers won't be retried if they don't have a .probe
function specified in the driver struct. Fix this driver to have that, so the
devices it supports won't get lost in a deferred probe.
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Subsystems like pinctrl and gpio rightfully make use of deferred probing at
core level. Now, deferred drivers won't be retried if they don't have a .probe
function specified in the driver struct. Fix this driver to have that, so the
devices it supports won't get lost in a deferred probe.
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Subsystems like pinctrl and gpio rightfully make use of deferred probing at
core level. Now, deferred drivers won't be retried if they don't have a .probe
function specified in the driver struct. Fix this driver to have that, so the
devices it supports won't get lost in a deferred probe.
Reported-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Powerpc is a mess of implicit includes by prom.h. Add the necessary
explicit includes to drivers in preparation of prom.h cleanup.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
The i.MX23 I2C controller is also capable of PIO, but needs a little harder
push to behave. The controller needs to be reset after every PIO/DMA operation
for some reason, otherwise in rare cases, the controller can hang or emit
bytes onto the bus.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Analyze and rework the PIO mode operation. The PIO mode operation
was unreliable on MX28, by analyzing the bus with LA, the checks
for when data were available or were to be sent were wrong.
The PIO WRITE has to be completely reworked as it multiple problems.
The MX23 datasheet helped here, see comments in the code for details.
The problems boil down to:
- RUN bit in CTRL0 must be set after DATA register was written
- The PIO transfer must be 4 bytes long tops, otherwise use
clock stretching.
Both of these fixes are implemented.
The PIO READ operation can only be done for up to four bytes as
we are unable to read out the data from the DATA register fast
enough.
This patch also tries to document the investigation within the
code.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
It seems the PIO mode does not work, or at least not like it works
on a i.MX28. Each short transfer needs about one second (without an
error message) but does not send anything on the I2C lines.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Casting the return value which is a void pointer is redundant.
The conversion from void pointer to any other pointer type is
guaranteed by the C programming language.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Casting the return value which is a void pointer is redundant.
The conversion from void pointer to any other pointer type is
guaranteed by the C programming language.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Using the same clock for all device instances is non-portable and obtaining
clock references by an ID without using a device pointer is discouraged.
This is also not needed, because on platforms, where this driver is used,
suitable clocks are available for the I2C controllers, that are children of
the peripheral clock and just pass its rate 1-to-1 to controllers. This
patch switches the driver to obtain references to correct clocks.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When clk_get() fails, it returns an error code, not a NULL. This patch
fixes such an error handling bug.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds Device Tree support to the i2c-rcar driver and respective
documentation.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There is no need to repeatedly query clock frequency, where it is not
expected to change. The complete loop can also trivially be replaced with
a simple division. A further loop below the one, being simplified, could
also be replaced, but that would get more complicated.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
A recent patch added even more superfluous parenthesis to those, which
already were there. Remove them again.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds code to initialize the DMA buffer to compensate for
possible hardware data corruption.
Signed-off-by: James Ralston <james.d.ralston@intel.com>
[wsa: changed to use 'sizeof']
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
According to Designware I2C spec, if I2C_DYNAMIC_TAR_UPDATE is set to 1,
the 10-bit addressing mode is controlled by IC_10BITADDR_MASTER bit of
IC_TAR register instead of IC_CON register. The IC_10BITADDR_MASTER
in IC_CON register becomes read-only copy. Since I2C_DYNAMIC_TAR_UPDATE
value can't be detected from hardware register, so we will always set the
IC_10BITADDR_MASTER bit in both IC_CON and IC_TAR register whenever 10-bit
addresing mode is requested by user application.
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The driver is used on PowerPC which don't provide writel_relaxed(). This
breaks the c2k and prpmc2800 default configurations. To fix the build,
turn the calls to writel_relaxed() into writel(). The impacts for ARM
should be minimal.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Some functions and variables are only used if the configuration selects
HAVE_CLK. Protect them with a corresponding #ifdef CONFIG_HAVE_CLK block
to avoid compiler warnings.
Signed-off-by: Thierry Reding <treding@nvidia.com>
[wsa: added marker to #endif]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
commit d16933b339 "i2c: s3c2410: Move
location of clk_prepare_enable() call in probe function" refactored
clk_enable and clk_disable calls yet neglected to remove the
clk_disable_unprepare call in the module's remove().
It helps remove warnings on an arndale during unbind:
echo 12c90000.i2c > /sys/bus/platform/devices/12c90000.i2c/driver/unbind
------------[ cut here ]------------
WARNING: CPU: 0 PID: 2548 at drivers/clk/clk.c:842 clk_disable+0x18/0x24()
Modules linked in:
CPU: 0 PID: 2548 Comm: bash Not tainted 3.11.0-next-20130916-00003-gf4bddbc #6
[<c0014d48>] (unwind_backtrace+0x0/0xf8) from [<c00117d0>] (show_stack+0x10/0x14)
[<c00117d0>] (show_stack+0x10/0x14) from [<c0361be8>] (dump_stack+0x6c/0xac)
[<c0361be8>] (dump_stack+0x6c/0xac) from [<c001d864>] (warn_slowpath_common+0x64/0x88)
[<c001d864>] (warn_slowpath_common+0x64/0x88) from [<c001d8a4>] (warn_slowpath_null+0x1c/0x24)
[<c001d8a4>] (warn_slowpath_null+0x1c/0x24) from [<c02c4a64>] (clk_disable+0x18/0x24)
[<c02c4a64>] (clk_disable+0x18/0x24) from [<c028d0b0>] (s3c24xx_i2c_remove+0x28/0x70)
[<c028d0b0>] (s3c24xx_i2c_remove+0x28/0x70) from [<c0217a10>] (platform_drv_remove+0x18/0x1c)
[<c0217a10>] (platform_drv_remove+0x18/0x1c) from [<c0216358>] (__device_release_driver+0x58/0xb4)
[<c0216358>] (__device_release_driver+0x58/0xb4) from [<c02163d0>] (device_release_driver+0x1c/0x28)
[<c02163d0>] (device_release_driver+0x1c/0x28) from [<c02153c0>] (unbind_store+0x58/0x90)
[<c02153c0>] (unbind_store+0x58/0x90) from [<c0214c90>] (drv_attr_store+0x20/0x2c)
[<c0214c90>] (drv_attr_store+0x20/0x2c) from [<c01032c0>] (sysfs_write_file+0x168/0x198)
[<c01032c0>] (sysfs_write_file+0x168/0x198) from [<c00ae1c0>] (vfs_write+0xb0/0x194)
[<c00ae1c0>] (vfs_write+0xb0/0x194) from [<c00ae594>] (SyS_write+0x3c/0x70)
[<c00ae594>] (SyS_write+0x3c/0x70) from [<c000e3e0>] (ret_fast_syscall+0x0/0x30)
---[ end trace 4c9f9403066f57a6 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 2548 at drivers/clk/clk.c:751 clk_unprepare+0x14/0x1c()
Modules linked in:
CPU: 0 PID: 2548 Comm: bash Tainted: G W 3.11.0-next-20130916-00003-gf4bddbc #6
[<c0014d48>] (unwind_backtrace+0x0/0xf8) from [<c00117d0>] (show_stack+0x10/0x14)
[<c00117d0>] (show_stack+0x10/0x14) from [<c0361be8>] (dump_stack+0x6c/0xac)
[<c0361be8>] (dump_stack+0x6c/0xac) from [<c001d864>] (warn_slowpath_common+0x64/0x88)
[<c001d864>] (warn_slowpath_common+0x64/0x88) from [<c001d8a4>] (warn_slowpath_null+0x1c/0x24)
[<c001d8a4>] (warn_slowpath_null+0x1c/0x24) from [<c02c5834>] (clk_unprepare+0x14/0x1c)
[<c02c5834>] (clk_unprepare+0x14/0x1c) from [<c028d0b8>] (s3c24xx_i2c_remove+0x30/0x70)
[<c028d0b8>] (s3c24xx_i2c_remove+0x30/0x70) from [<c0217a10>] (platform_drv_remove+0x18/0x1c)
[<c0217a10>] (platform_drv_remove+0x18/0x1c) from [<c0216358>] (__device_release_driver+0x58/0xb4)
[<c0216358>] (__device_release_driver+0x58/0xb4) from [<c02163d0>] (device_release_driver+0x1c/0x28)
[<c02163d0>] (device_release_driver+0x1c/0x28) from [<c02153c0>] (unbind_store+0x58/0x90)
[<c02153c0>] (unbind_store+0x58/0x90) from [<c0214c90>] (drv_attr_store+0x20/0x2c)
[<c0214c90>] (drv_attr_store+0x20/0x2c) from [<c01032c0>] (sysfs_write_file+0x168/0x198)
[<c01032c0>] (sysfs_write_file+0x168/0x198) from [<c00ae1c0>] (vfs_write+0xb0/0x194)
[<c00ae1c0>] (vfs_write+0xb0/0x194) from [<c00ae594>] (SyS_write+0x3c/0x70)
[<c00ae594>] (SyS_write+0x3c/0x70) from [<c000e3e0>] (ret_fast_syscall+0x0/0x30)
---[ end trace 4c9f9403066f57a7 ]---
Signed-off-by: Kim Phillips <kim.phillips@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit 6d4028c644 (i2c: use dev_get_platdata()) did a bad conversion
of this one case:
drivers/i2c/busses/i2c-davinci.c: In function 'davinci_i2c_probe':
drivers/i2c/busses/i2c-davinci.c:665:2: warning: passing argument 1 of
'dev_get_platdata' from incompatible pointer type [enabled by default]
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
This patch modify I2C driver of rcar-H1 to usable on both rcar-H1 and rcar-H2.
Signed-off-by: Nguyen Viet Dung <nv-dung@jinso.co.jp>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
let i2c core retry 3 times as sometimes we get random noack and timeout
even when we access an existing i2c client.
Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
if users set I2C_M_REV_DIR_ADDR, revert the direction of address.
Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Rongjun Ying <rongjun.ying@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
there is a typo before, it makes the final bitrate wrong, this patch fixes
it.
Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
this fixes the issue that we lost to wait the i2c reset finished.
Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Due to hardware ANOMALY, we need to reset I2C earlier after
we get NOACK while accessing non-existing clients, otherwise
we will get errors even we access existing clients later
Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Some Intel LPSS I2C devices make the SDA hold time and *CNT parameters
available via SSCN (standard mode) and FMCN (fast mode) ACPI methods.
Implement support for this so that we check whether an ACPI method exists
and if it does, fill in the SDA hold time and *CNT values to the device
private structure for core to use.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
