[PATCH v2 2/3] watchdog: rti_wdt: Add support for loading firmware

[Jan Kiszka <jan.kiszka@siemens.com>]

On 23.06.20 13:50, Lokesh Vutla wrote:
> 
> 
> On 23/06/20 4:45 pm, Jan Kiszka wrote:
>> From: Jan Kiszka <jan.kiszka@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. The firmware itself is
>> embedded into U-Boot binary.
>>
>> One possible firmware source is https://github.com/siemens/k3-rti-wdt.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>> ---
>>   drivers/watchdog/Kconfig      | 20 ++++++++++++++++++++
>>   drivers/watchdog/Makefile     |  3 +++
>>   drivers/watchdog/rti_wdt.c    | 24 ++++++++++++++++++++++++
>>   drivers/watchdog/rti_wdt_fw.S | 20 ++++++++++++++++++++
>>   4 files changed, 67 insertions(+)
>>   create mode 100644 drivers/watchdog/rti_wdt_fw.S
>>
>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>> index ee99bd2af1..fd6ab9a85b 100644
>> --- a/drivers/watchdog/Kconfig
>> +++ b/drivers/watchdog/Kconfig
>> @@ -162,6 +162,26 @@ 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.
>> +
>> +endif
>> +
>>   config WDT_SANDBOX
>>   	bool "Enable Watchdog Timer support for Sandbox"
>>   	depends on SANDBOX && WDT
>> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
>> index 16bdbf4970..bf58684875 100644
>> --- a/drivers/watchdog/Makefile
>> +++ b/drivers/watchdog/Makefile
>> @@ -28,7 +28,10 @@ obj-$(CONFIG_WDT_MT7621) += mt7621_wdt.o
>>   obj-$(CONFIG_WDT_MTK) += mtk_wdt.o
>>   obj-$(CONFIG_WDT_OMAP3) += omap_wdt.o
>>   obj-$(CONFIG_WDT_K3_RTI) += rti_wdt.o
>> +obj-$(CONFIG_WDT_K3_RTI_LOAD_FW) += rti_wdt_fw.o
>>   obj-$(CONFIG_WDT_SP805) += sp805_wdt.o
>>   obj-$(CONFIG_WDT_STM32MP) += stm32mp_wdt.o
>>   obj-$(CONFIG_WDT_TANGIER) += tangier_wdt.o
>>   obj-$(CONFIG_WDT_XILINX) += xilinx_wwdt.o
>> +
>> +$(obj)/rti_wdt_fw.o: $(shell readlink -f $(CONFIG_WDT_K3_RTI_FW_FILE)) FORCE
>> diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
>> index ebe29c7409..38e82a6b6b 100644
>> --- a/drivers/watchdog/rti_wdt.c
>> +++ b/drivers/watchdog/rti_wdt.c
>> @@ -14,6 +14,7 @@
>>   #include <power-domain.h>
>>   #include <wdt.h>
>>   #include <asm/io.h>
>> +#include <remoteproc.h>
>>   
>>   /* Timer register set definition */
>>   #define RTIDWDCTRL		0x90
>> @@ -37,11 +38,16 @@
>>   
>>   #define WDT_PRELOAD_MAX		0xfff
>>   
>> +#define RTI_PROC_ID		0
> 
> Can we get the rproc id from DT?

You mean, resolve "mcu_r5fss0_core0" to the ID? Doable.

> 
>> +
>>   struct rti_wdt_priv {
>>   	phys_addr_t regs;
>>   	unsigned int clk_khz;
>>   };
>>   
>> +extern const u32 rti_wdt_fw[];
>> +extern const int rti_wdt_fw_size;
> 
> FIT is the preferred way of packing images in U-Boot. Can you try using it?

How does that work? Some example for me?

What benefit would that bring? There are other users of this pattern, 
e.g. board/xilinx/zynqmp/pm_cfg_obj.S.

Jan

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