+For both Cherrytrail (CHT) and Baytrail (BHT) the driver
+requires the "candrpv_0415_20150521_0458" firmware version.
+It should be noticed that the firmware file is different,
+depending on the ISP model, so they're stored with different
+names:
+
+- for BHT: /lib/firmware/shisp_2400b0_v21.bin
+
+ Warning: The driver was not tested yet for BHT.
+
+- for CHT: /lib/firmware/shisp_2401a0_v21.bin
+
+ https://github.com/intel-aero/meta-intel-aero-base/blob/master/recipes-kernel/linux/linux-yocto/shisp_2401a0_v21.bin
+
NOTE:
=====
-While the driver probes the hardware and reports itself as a
-V4L2 driver, there are still some issues preventing it to
-stream (at least it doesn't with the standard V4L2 applications.
-Didn't test yet with some custom-made app for this driver).
-Solving the related bugs and issues preventing it to work is
-needed (items 6 and 7 from the list below).
+This driver currently doesn't work with most V4L2 applications,
+as there are still some issues with regards to implementing
+certain APIs at the standard way.
+
+Also, currently only USERPTR streaming mode is working.
+
+In order to test, it is needed to know what's the sensor's
+resolution. This can be checked with:
+
+$ v4l2-ctl --get-fmt-video
+ Format Video Capture:
+ Width/Height : 1600/1200
+ ...
+
+It is known to work with:
+
+- v4l2grab at contrib/test directory at https://git.linuxtv.org/v4l-utils.git/
+
+ The resolution should not be bigger than the max resolution
+ supported by the sensor, or it will fail. So, if the sensor
+ reports:
+
+ The driver can be tested with:
+
+ v4l2grab -f YUYV -x 1600 -y 1200 -d /dev/video2 -u
+
+- NVT at https://github.com/intel/nvt
+
+ $ ./v4l2n -o testimage_@.raw \
+ --device /dev/video2 \
+ --input 0 \
+ --exposure=30000,30000,30000,30000 \
+ --parm type=1,capturemode=CI_MODE_PREVIEW \
+ --fmt type=1,width=1600,height=1200,pixelformat=YUYV \
+ --reqbufs count=2,memory=USERPTR \
+ --parameters=wb_config.r=32768,wb_config.gr=21043,wb_config.gb=21043,wb_config.b=30863 \
+ --capture=20
+
+ As the output is in raw format, images need to be converted with:
+
+ $ for i in $(seq 0 19); do
+ name="testimage_$(printf "%03i" $i)"
+ ./raw2pnm -x$WIDTH -y$HEIGHT -f$FORMAT $name.raw $name.pnm
+ rm $name.raw
+ done
TODO
====
-1. The atomisp doesn't rely at the usual i2c stuff to discover the
- sensors. Instead, it calls a function from atomisp_gmin_platform.c.
- There are some hacks added there for it to wait for sensors to be
- probed (with a timeout of 2 seconds or so).
- This should be converted to the usual way, using V4L2 async subdev
- framework to wait for cameras to be probed;
+1. Fix support for MMAP streaming mode. This is required for most
+ V4L2 applications;
-2. Use ACPI _DSM table - DONE!
+2. Implement and/or fix V4L2 ioctls in order to allow a normal app to
+ use it;
-3. Switch the driver to use pm_runtime stuff. Right now, it probes the
- existing PMIC code and sensors call it directly.
+3. Ensure that the driver will pass v4l2-compliance tests;
-4. There's a problem at the sensor drivers: when trying to set a video
- format, the atomisp main driver calls the sensor drivers with the
- sensor turned off. This causes them to fail.
+4. Get manufacturer's authorization to redistribute the binaries for
+ the firmware files;
- The only exception is the atomisp-ov2880, which has a hack inside it
- to turn it on when VIDIOC_S_FMT is called.
+5. remove VIDEO_ATOMISP_ISP2401, making the driver to auto-detect the
+ register address differences between ISP2400 and ISP2401;
- The right fix seems to power on the sensor when a video device is
- opened (or at the first VIDIOC_ ioctl - except for VIDIOC_QUERYCAP),
- powering it down at close() syscall.
+6. Cleanup the driver code, removing the abstraction layers inside it;
- Such kind of control would need to be done inside the atomisp driver,
- not at the sensors code.
+7. The atomisp doesn't rely at the usual i2c stuff to discover the
+ sensors. Instead, it calls a function from atomisp_gmin_platform.c.
+ There are some hacks added there for it to wait for sensors to be
+ probed (with a timeout of 2 seconds or so). This should be converted
+ to the usual way, using V4L2 async subdev framework to wait for
+ cameras to be probed;
-5. There are several issues related to memory management, causing
- crashes. The atomisp splits the memory management on three separate
- regions:
+8. Switch to standard V4L2 sub-device API for sensor and lens. In
+ particular, the user space API needs to support V4L2 controls as
+ defined in the V4L2 spec and references to atomisp must be removed from
+ these drivers.
+
+9. Use LED flash API for flash LED drivers such as LM3554 (which already
+ has a LED class driver).
+
+10. Migrate the sensor drivers out of staging or re-using existing
+ drivers;
+
+11. Switch the driver to use pm_runtime stuff. Right now, it probes the
+ existing PMIC code and sensors call it directly.
+
+12. There's a problem on sensor drivers: when trying to set a video
+ format, the atomisp main driver calls the sensor drivers with the
+ sensor turned off. This causes them to fail.
+
+ This was fixed at atomisp-ov2880, which has a hack inside it
+ to turn it on when VIDIOC_S_FMT is called, but this has to be
+ cheked on other drivers as well.
+
+ The right fix seems to power on the sensor when a video device is
+ opened (or at the first VIDIOC_ ioctl - except for VIDIOC_QUERYCAP),
+ powering it down at close() syscall.
+
+ Such kind of control would need to be done inside the atomisp driver,
+ not at the sensors code.
+
+13. There are several issues related to memory management, that can
+ cause crashes and/or memory leaks. The atomisp splits the memory
+ management on three separate regions:
- dynamic pool;
- reserved pool;
- generic pool
- The code implementing it is at:
+ The code implementing it is at:
drivers/staging/media/atomisp/pci/hmm/
- It also has a separate code for managing DMA buffers at:
+ It also has a separate code for managing DMA buffers at:
drivers/staging/media/atomisp/pci/mmu/
- The code there is really dirty, ugly and probably wrong. I fixed
- one bug there already, but the best would be to just trash it and use
- something else. Maybe the code from the newer intel driver could
- serve as a model:
+ The code there is really dirty, ugly and probably wrong. I fixed
+ one bug there already, but the best would be to just trash it and use
+ something else. Maybe the code from the newer intel driver could
+ serve as a model:
drivers/staging/media/ipu3/ipu3-mmu.c
- But converting it to use something like that is painful and may
- cause some breakages.
-
-6. There is some issues at the frame receive logic, causing the
- DQBUF ioctls to fail.
-
-7. A single AtomISP driver needs to be implemented to support both
- Baytrail (BYT) and Cherrytail (CHT) platforms at the same time.
- The current driver is a mechanical and hand combined merge of the
- two using several runtime macros, plus some ifdef ISP2401 to select the
- CHT version. Yet, there are some ISP-specific headers that change the
- driver's behavior during compile time.
+ But converting it to use something like that is painful and may
+ cause some breakages.
-8. The file structure needs to get tidied up to resemble a normal Linux
- driver.
+14. The file structure needs to get tidied up to resemble a normal Linux
+ driver.
-9. Lots of the midlayer glue. unused code and abstraction needs removing.
+15. Lots of the midlayer glue. Unused code and abstraction needs removing.
-10. The AtomISP driver includes some special IOCTLS (ATOMISP_IOC_XXXX_XXXX)
+16. The AtomISP driver includes some special IOCTLS (ATOMISP_IOC_XXXX_XXXX)
and controls that require some cleanup. Some of those code may have
been removed during the cleanups. They could be needed in order to
- properly support 3A algorithms
+ properly support 3A algorithms.
Such IOCTL interface needs more documentation. The better would
be to use something close to the interface used by the IPU3 IMGU driver.
-11. The ISP code has some dependencies of the exact FW version.
+17. The ISP code has some dependencies of the exact FW version.
The version defined in pci/sh_css_firmware.c:
BYT (isp2400): "irci_stable_candrpv_0415_20150521_0458"
there are any specific things that can be done to fold in support for
multiple firmware versions.
-12. Switch to standard V4L2 sub-device API for sensor and lens. In
- particular, the user space API needs to support V4L2 controls as
- defined in the V4L2 spec and references to atomisp must be removed from
- these drivers.
-
-13. Use LED flash API for flash LED drivers such as LM3554 (which already
- has a LED class driver).
-14. Switch from videobuf1 to videobuf2. Videobuf1 is being removed!
+18. Switch from videobuf1 to videobuf2. Videobuf1 is being removed!
-15. Correct Coding Style. Please refrain sending coding style patches
+19. Correct Coding Style. Please refrain sending coding style patches
for this driver until the other work is done, as there will be a lot
of code churn until this driver becomes functional again.
-16. Fix private ioctls to not need a compat_ioctl handler for running
- 32-bit tasks. The compat code has been removed because of bugs,
- and should not be needed for modern drivers. Fixing this properly
- unfortunately means an incompatible ABI change.
+20. Remove the logic which sets up pipelines inside it, moving it to
+ libcamera and implement MC support.
+
Limitations
===========