[PATCH v2 4/5] watchdog: rti_wdt: Add support for loading firmware

[Jan Kiszka]

On 07.06.21 13:44, Jan Kiszka wrote:
> On 07.06.21 13:40, Tom Rini wrote:
>> On Mon, Jun 07, 2021 at 03:33:52PM +0530, Lokesh Vutla wrote:
>>> +Tom,
>>>
>>> Hi Tom,
>>>
>>> On 02/06/21 3:07 pm, Jan Kiszka wrote:
>>>> From: Jan Kiszka <jan.kiszka at siemens.com>
>>>>
>>>> To avoid the need of extra boot scripting on AM65x for loading a
>>>> watchdog firmware, add the required rproc init and loading logic for the
>>>> first R5F core to the watchdog start handler. In case the R5F cluster is
>>>> in lock-step mode, also initialize the second core. The firmware itself
>>>> is embedded into U-Boot binary to ease access to it and ensure it is
>>>> properly hashed in case of secure boot.
>>>>
>>>> One possible firmware source is https://github.com/siemens/k3-rti-wdt.
>>>>
>>>> Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
>>>> ---
>>>>  drivers/watchdog/Kconfig      | 20 ++++++++++++
>>>>  drivers/watchdog/Makefile     |  5 +++
>>>>  drivers/watchdog/rti_wdt.c    | 58 ++++++++++++++++++++++++++++++++++-
>>>>  drivers/watchdog/rti_wdt_fw.S | 20 ++++++++++++
>>>>  4 files changed, 102 insertions(+), 1 deletion(-)
>>>>  create mode 100644 drivers/watchdog/rti_wdt_fw.S
>>>>
>>>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>>>> index f0ff2612a6..1a1fddfe9f 100644
>>>> --- a/drivers/watchdog/Kconfig
>>>> +++ b/drivers/watchdog/Kconfig
>>>> @@ -209,6 +209,26 @@ config WDT_K3_RTI
>>>>  	  Say Y here if you want to include support for the K3 watchdog
>>>>  	  timer (RTI module) available in the K3 generation of processors.
>>>>  
>>>> +if WDT_K3_RTI
>>>> +
>>>> +config WDT_K3_RTI_LOAD_FW
>>>> +	bool "Load watchdog firmware"
>>>> +	depends on REMOTEPROC
>>>> +	help
>>>> +	  Automatically load the specified firmware image into the MCU R5F
>>>> +	  core 0. On the AM65x, this firmware is supposed to handle the expiry
>>>> +	  of the watchdog timer, typically by resetting the system.
>>>> +
>>>> +config WDT_K3_RTI_FW_FILE
>>>> +	string "Watchdog firmware image file"
>>>> +	default "k3-rti-wdt.fw"
>>>> +	depends on WDT_K3_RTI_LOAD_FW
>>>> +	help
>>>> +	  Firmware image to be embedded into U-Boot and loaded on watchdog
>>>> +	  start.
>>>
>>> I need your input on this proach. Is it okay to include the linker file unders
>>> drivers?
>>
>> Maybe?  I suppose the first thing that springs to mind is why aren't we
>> using binman and including this blob (which I happily see is GPLv2)
>> similar to how we do things with x86 for one example.
>>
> 
> See https://www.mail-archive.com/u-boot@lists.denx.de/msg377894.html
> 
> Jan
> 

Did this help to answer open questions? Otherwise, please let me know.

I'd also like to avoid that his patch alone blocks 1-3 of the series
needless - but I would also not mind getting everything in at once.

Thanks,
Jan

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