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Commit a49d2536 authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman
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staging/atomisp: Add support for the Intel IPU v2 



This patch adds support for the Intel IPU v2 as found on Android and IoT
Baytrail-T and Baytrail-CR platforms (those with the IPU PCI mapped). You
will also need the firmware files from your device (Android usually puts
them into /etc) - or you can find them in the downloadable restore/upgrade
kits if you blew them away for some reason.

It may be possible to extend the driver to handle the BYT/T windows
platforms such as the ASUS T100TA. These platforms don't expose the IPU via
the PCI interface but via ACPI buried in the GPU description and with the
camera information somewhere unknown so would need a platform driver
interface adding to the codebase *IFF* the firmware works on such devices.

To get good results you also need a suitable support library such as
libxcam. The camera is intended to be driven from Android so it has a lot of
features that many desktop apps don't fully spport.

In theory all the pieces are there to build it with -DISP2401 and some
differing files to get CherryTrail/T support, but unifying the drivers
properlly is a work in progress.

The IPU driver represents the work of a lot of people within Intel over many
years. It's historical goal was portability rather than Linux upstream. Any
queries about the upstream aimed driver should be sent to me not to the
original authors.

Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 372499b5

drivers/staging/media/Kconfig

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@@ -34,4 +34,5 @@ source "drivers/staging/media/lirc/Kconfig" 


source "drivers/staging/media/st-cec/Kconfig"



source "drivers/staging/media/atomisp/Kconfig"

endif

drivers/staging/media/Makefile

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@@ -5,3 +5,4 @@ obj-$(CONFIG_LIRC_STAGING) += lirc/ 
obj-$(CONFIG_VIDEO_DM365_VPFE)	+= davinci_vpfe/

obj-$(CONFIG_VIDEO_OMAP4)	+= omap4iss/

obj-$(CONFIG_VIDEO_STI_HDMI_CEC) += st-cec/

obj-$(CONFIG_INTEL_ATOMISP)     += atomisp/

drivers/staging/media/atomisp/Kconfig

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menuconfig INTEL_ATOMISP

        bool "Enable support to Intel MIPI camera drivers"

        depends on X86

        help

          Enable support for the Intel ISP2 camera interfaces and MIPI

          sensor drivers.



if INTEL_ATOMISP

source "drivers/staging/media/atomisp/pci/Kconfig"

source "drivers/staging/media/atomisp/i2c/Kconfig"

endif

drivers/staging/media/atomisp/Makefile

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#

# Makefile for camera drivers.

#



obj-$(CONFIG_INTEL_ATOMISP) += pci/

obj-$(CONFIG_INTEL_ATOMISP) += i2c/

obj-$(CONFIG_INTEL_ATOMISP) += platform/

LINUXINCLUDE        += -I drivers/staging/media/atomisp/include/

drivers/staging/media/atomisp/TODO

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1. A single AtomISP driver needs to be implemented to support both BYT and

   CHT platforms. The current driver is a mechanical and hand combined merge

   of the two using an ifdef ISP2401 to select the CHT version, which at the

   moment is not enabled. Eventually this should become a runtime if check,

   but there are some quite tricky things that need sorting out before that

   will be possible.



2. The file structure needs to get tidied up to resemble a normal Linux

   driver.



3. Lots of the midlayer glue. unused code and abstraction needs removing.



3. The sensor drivers read MIPI settings from EFI variables or default to the

   settings hard-coded in the platform data file for different platforms.

   This isn't ideal but may be hard to improve as this is how existing

   platforms work.



4. The sensor drivers use the regulator framework API. In the ideal world it

   would be using ACPI but that's not how the existing devices work.



5. The AtomISP driver includes some special IOCTLS (ATOMISP_IOC_XXXX_XXXX)

   that may need some cleaning up.



6. Correct Coding Style. Please don't send coding style patches for this

   driver until the other work is done.



7. The ISP code depends on the exact FW version. The version defined in

   BYT: 

   drivers/staging/media/atomisp/pci/atomisp2/css2400/sh_css_firmware.c

   static const char *release_version = STR(irci_stable_candrpv_0415_20150521_0458);

   CHT:

   drivers/staging/media/atomisp/pci/atomisp2/css/sh_css_firmware.c

   static const char *release_version = STR(irci_ecr-master_20150911_0724);



   At some point we may need to round up a few driver versions and see if

   there are any specific things that can be done to fold in support for

   multiple firmware versions.





Limitations:



1. Currently the patch only support some camera sensors

   gc2235/gc0310/0v2680/ov2722/ov5693/mt9m114...



2. To test the patches, you also need the ISP firmware



   for BYT:/lib/firmware/shisp_2400b0_v21.bin

   for CHT:/lib/firmware/shisp_2401a0_v21.bin



   The firmware files will usually be found in /etc/firmware on an Android

   device but can also be extracted from the upgrade kit if you've managed

   to lose them somehow.



3. Without a 3A libary the capture behaviour is not very good. To take a good

   picture, you need tune ISP parameters by IOCTL functions or use a 3A libary

   such as libxcam.



4. The driver is intended to drive the PCI exposed versions of the device.

   It will not detect those devices enumerated via ACPI as a field of the

   i915 GPU driver.



5. The driver supports only v2 of the IPU/Camera. It will not work with the

   versions of the hardware in other SoCs.