On 10.09.20 18:53, Guenter Roeck wrote:
> Hi Jan,
>
> On 9/10/20 9:34 AM, Jan Kiszka wrote:
>> On 10.09.20 18:31, Guenter Roeck wrote:
>>> On Family 17h (Ryzen) devices, the WatchdogTmrEn bit of PmDecodeEn not only
>>> enables watchdog memory decoding at 0xfeb00000, it also enables the
>>> watchdog hardware itself. Use this information to enable the watchdog if
>>> it is not already enabled.
>>>
>>> Cc: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>>> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>>> ---
>>> drivers/watchdog/sp5100_tco.c | 18 ++++++++++++++++++
>>> 1 file changed, 18 insertions(+)
>>>
>>> diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c
>>> index 85e9664318c9..a730ecbf78cd 100644
>>> --- a/drivers/watchdog/sp5100_tco.c
>>> +++ b/drivers/watchdog/sp5100_tco.c
>>> @@ -17,6 +17,12 @@
>>> * AMD Publication 51192 "AMD Bolton FCH Register Reference Guide"
>>> * AMD Publication 52740 "BIOS and Kernel Developer’s Guide (BKDG)
>>> * for AMD Family 16h Models 30h-3Fh Processors"
>>> + * AMD Publication 55570-B1-PUB "Processor Programming Reference (PPR)
>>> + * for AMD Family 17h Model 18h, Revision B1
>>> + * Processors (PUB)
>>> + * AMD Publication 55772-A1-PUB "Processor Programming Reference (PPR)
>>> + * for AMD Family 17h Model 20h, Revision A1
>>> + * Processors (PUB)
>>> */
>>>
>>> /*
>>> @@ -241,6 +247,18 @@ static int sp5100_tco_setupdevice(struct device *dev,
>>> break;
>>> case efch:
>>> dev_name = SB800_DEVNAME;
>>> + /*
>>> + * On Family 17h devices, the EFCH_PM_DECODEEN_WDT_TMREN bit of
>>> + * EFCH_PM_DECODEEN not only enables the EFCH_PM_WDT_ADDR memory
>>> + * region, it also enables the watchdog itself.
>>> + */
>>> + if (boot_cpu_data.x86 == 0x17) {
>>> + val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
>>> + if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) {
>>> + sp5100_tco_update_pm_reg8(EFCH_PM_DECODEEN, 0xff,
>>> + EFCH_PM_DECODEEN_WDT_TMREN);
>>> + }
>>> + }
>>> val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
>>> if (val & EFCH_PM_DECODEEN_WDT_TMREN)
>>> mmio_addr = EFCH_PM_WDT_ADDR;
>>>
>>
>> Won't that bring us EFCH_PM_WDT_ADDR as address, rather than
>> EFCH_PM_ACPI_MMIO_ADDR which worked in my case? Or is one an alias of
>> the other.
>>
>
> Yes, it does use EFCH_PM_WDT_ADDR. EFCH_PM_ACPI_MMIO_ADDR works as well,
> but is meant to be a fallback. Both point to the watchdog memory space.
>
OK, will test, possibly only on the weekend, and confirm this also on my
board.
Jan
--
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux
