Panda How to kernel 2 6 39rel

Introduction
The 2.6.39 kernel has been released, There were many Pandaboard related changes during the release candidate phase, including HDMI, DVI and wl21xx support.

-rc1
* hdmi & dvi are broken due to some dss clocking issues, see: https://patchwork.kernel.org/patch/674062/ for details, a fix for dvi is available, see below. * abe sound is not supported. * Dave Anders patch to not configure the unused power regulators of VUSIM and VAUX1 is included. * wl12xx support is working to the extent that one can associate with an access point, get an IP address and ping out to the internet.

-rc3
* Rebooting is broken (there was a post suggesting that it was broken in -rc2 as well) follow this thread for more info: http://www.spinics.net/lists/linux-omap/msg49746.html. ** a simple fix is to turn off OMAP2 support, which is done in the .config below for -rc3. * What at first looked like interesting changes to /arch/arm/mach-omap2/ /drivers/net/wireless/wl12xx/ /drivers/video/omap2/dss/ seemed to really be typo fixes in comments, Hopefully, some real fixes will be in -rc3. * New in -rc3 is that the usb ethernet adapter appears as eth0 rather than usb0.

-rc6
* lots of (real) changes for omap, see http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.39-rc6 for details. * Rebooting is still broken, so beware of using omap2plus_defconfig without changes. (see -rc3 above) * patching is still neccessary to get dvi working * wlan and ethernet both seem to work as in -rc3, -rc4 and -rc5 * i2c chararacter device driver is still broken, the patch below still applies cleanly and resolves the issue.

-rc7
* No specific PandaBoard changes, but there was work done on /drivers/usb/host/ehci-omap.c * A new version of wlan firmware (see below) became available which might have working bluetooth. unfortunately, there is no BT support in the board file /arch/arm/mach-omap2/board-omap4panda.c * looks like some PandaBoard & OMAP4 specific changes queued up for the next .39-rcx (or maybe .40-rc1)

Wlan
The proper firmware for wl12xx support is available from: git://git.kernel.org/pub/scm/linux/kernel/git/dwmw2/linux-firmware.git, just clone that repository and copy the ti-connectivity directory to /lib/firmware/.


 * this firmware includes a Bluetooth init script, which contains binary patches to the firmware that resides in ROM.
 * This OMAP35xx user guide has useful info: http://processors.wiki.ti.com/index.php/OMAP35x_Wireless_Connectivity_System_Test_Guidelines_User%27s_Guide
 * This OMAP35xx App note also is interesting: http://processors.wiki.ti.com/index.php/OMAP35x_Wireless_Connectivity_WLAN_Bluetooth_Coexistence_Application_Note
 * The firmware and wl1271 hardware is the same as on the PandaBoard, but there is no support in /arch/arm/mach-omap2/board-omap4panda.c for the gpio's that control BT_EN (GPIO46) or BT_WAKEUP (GPIO49), as well as the bt audio interface to MCBSP1. In addition, the latest Bluez (4.93) source for hidattach_ti.c still assumes that the firmware (and bt init script) are in /lib/firmware/ rather than in /lib/firmware/ti-connectivity/.

/lib/firmware/ti-connectivity total 1385 drwxr-xr-x   2 root     root          1024 May  9  2011. drwxr-xr-x   3 root     root          1024 Dec 31 17:36 .. -rw-r--r--   1 root     root         48909 May  9  2011 TIInit_7.2.31.bts -rw-r--r--   1 root     root        273252 May  9  2011 wl1271-fw-2.bin -rw-r--r--   1 root     root        272784 May  9  2011 wl1271-fw-ap.bin -rw-r--r--   1 root     root        271832 May  9  2011 wl1271-fw.bin -rwxr-xr-x   1 root     root          1113 May  9  2011 wl1271-nvs-example-wl128x.bin -rw-r--r--   1 root     root           912 May  9  2011 wl1271-nvs.bin -rw-r--r--   1 root     root        265196 May  9  2011 wl128x-fw-ap.bin -rwxr-xr-x   1 root     root        272748 May  9  2011 wl128x-fw.bin
 * 1) pwd
 * 1) ls -la

Building
Building 2.6.39 is basically the same as How to build 2.6.38 kernel, but of course you need the released sources. The omap2plus_defconfig works, but does not enable anything interesting. [[Media:config.2.6.39-rc1|config.2.6.39-rc1]] enables USB, its' ethernet adapter, and wl12xx support. [[Media:config.2.6.39-rc1.2|config.2.6.39-rc1.2]] enables USB, it's ethernet adapter, wl12xx support, and dvi support,. However using that config requires that the kernel sources be patched with [[Media:0001-omap4-pandaboard-fix-dvi-support.patch|0001-omap4-pandaboard-fix-dvi-support.patch]] The patch also provices panda_dvi_defconfig which just enables dvi. The patche applies cleanly to the released sources.

DVI Patch
Apply it like so: (from inside the kernel sources directory)

patch -p1 < 0001-omap4-pandaboard-fix-dvi-support.patch

Then use either of the above configs or

make ARCH=arm omap2plus_defconfig or make ARCH=arm panda_dvi_defconfig

Then compile with

make ARCH=arm CROSS_COMPILE=Path_to_your/arm-2009q3/bin/arm-none-linux-gnueabi- uImage or make ARCH=arm CROSS_COMPILE=Path_to_your/arm-2010q1/bin/arm-none-linux-gnueabi- uImage

i2c character device driver
Ever since 2.6.38, the i2c character device driver support from user space has been broken for OMAP44xx. * A fix has been submitted for the linux-omap-2.6 branch, but it may be a while till it gets into an -rcx. See http://git.kernel.org/?p=linux/kernel/git/tmlind/linux-omap-2.6.git;a=commit;h=39fe1a6fafe1e85c183379af9f3ceda7cd24bd65 for the commit. * A quick fix for this issue is available

I2C Patch
Apply it like so: (from inside the kernel sources directory)

patch -p1 < Omap44xx-i2c-fix.patch

Then compile as above.

Testing
After booting run fbtest to see a nice test pattern from the dvi port.



Then you can run i2cdetect and the results should look like this:

0 1  2  3  4  5  6  7  8  9  a  b  c  d  e  f 00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --  30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --  40: -- -- -- -- -- -- -- -- UU UU UU UU -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --  70: -- -- -- -- -- -- -- --
 * 1) i2cdetect -y -r 1

Stay tuned for the 2.6.40-rcx series where there should be some new features as well as some more bug squashing.