The implementation of the gain calculation for this sensor is incorrect.
It is only working for the first 127 values.
The reason is, that the gain cannot be set directly by writing a value
into the gain registers of the sensor. The gain register work this way
(see datasheet page 24): bits 0 to 6 are called "initial gain". These
are linear. But bits 7 and 8 ("analog multiplicative factors") and bits
9 and 10 ("digital multiplicative factors") work completely different:
Each of these bits increase the gain by the factor 2. So if the bits
7-10 are 0011, 0110, 1100 or 0101 for example, the gain from bits 0-6 is
multiplied by 4. The order of the bits 7-10 is not important for the
resulting gain. (But there are some recommended values for low noise)
The current driver doesn't do this correctly: If the current gain is 000
0111 1111 (127) and the gain is increased by 1, you would expect the
image to become brighter. But the image is completly dark, because the
new gain is 000 1000 0000 (128). This means: Initial gain of 0,
multiplied by 2. The result is 0.
This patch adds a new function which does the gain calculation and also
fixes the same bug for red_balance and blue_balance. Additionally, the
driver follows the recommendation from the datasheet, which says, that
the gain should always be above 0x0020.
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Johannes Obermaier <johannes.obermaier@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
There are problems when you use this camera/sensor in a very bright room
or outside. The image is completely white, because it is overexposed.
The driver uses a default value which is not suitable for all
environments.
This patch makes it possible to adjust the exposure time by youself. I
found out by logging the i2c-data, that the windows driver for this
sensor is doing this, too. I tested the camera on a sunny day and after
adjusting the exposure time, I was able to see a very good image.
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Johannes Obermaier <johannes.obermaier@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
According to the datasheet (page 8), the first optical clear
pixel-column is not at position 14. The correct/recommended value is 20.
Without this patch there is a dark line on the left side of the image.
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Johannes Obermaier <johannes.obermaier@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The core.s_config op was meant for legacy drivers that needed to work with old
pre-2.6.26 kernels. This is no longer relevant. Unfortunately, this op was
incorrectly called from several drivers.
Replace those occurences with proper i2c_board_info structs and call
v4l2_i2c_new_subdev_board.
After these changes v4l2_i2c_new_subdev_cfg() was no longer used, so remove
that function as well.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Note that this driver is only used by em28xx and that em28xx does not
actually call the enum/try/s_fmt ops of mt9v011. So these functions
have never been tested.
And in fact the driver really implements cropping instead of scaling. So it
seems to be doing the wrong thing :-(
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Implement g_parm/s_parm ioctls. Those are used to check the current
frame rate (in fps) and to set it to a value. In practice, there are
only 15 possible different speeds, due to chip limits.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Some mt9v011 webcams report 0x8332 chip version, instead of 0x8243. From
the revision history at the mt9v011 datasheet, it seems that the chip
version has changed from the first release of the chip.
Thanks-to hermann pitton <hermann-pitton@arcor.de> for pointing this to
me, on his tests with a Silvercrest webcam.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Since frames per second is a function of cristal frequency, and this is
device-specific, add a function that allows adjusting it, via
subdev->core->s_config callback.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
It is possible to adjust the fps rate by changing some register values.
This is function of the connected Xtal at the camera sensor, being a 27
MHz cristal needed, in order to support 640x480 at 30 fps.
For now, it will only calculate the values for fps. Later patches may
introduce V4L2 ioctls, to allow frequency rate adjustments.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The original driver for Silvercrest cameras were using some values that
are different from what datasheet says. As result, it was taken very
less snapshots per second than expected.
A test with the datasheet values showed that they work fine and give a
better frame rate. So, let's stick with datasheet values.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Instead of working with a table of precalculated values, fill them with
the proper values. Also, adds format functions that allow changing the
resolution, by cropping the image to the center of the sensor.
While here, move the sensor version check to the probe routine, to
indicate to the caller if the sensor is not supported by this driver.
Also, fixes a stupid bug where we're using &buffer[] instead of
buffer[].
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Adds driver for mt9v011 based on its datasheet, available at:
http://download.micron.com/pdf/datasheets/imaging/MT9V011.pdf
The driver was tested with a webcam that will be added on a next patch.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Johannes Obermaier