On 19/09/2024 14:39, Christian Marangi wrote: > On Thu, Sep 19, 2024 at 02:35:02PM +0200, Krzysztof Kozlowski wrote: >> On 19/09/2024 14:26, Christian Marangi wrote: >>> Document watchdog for Airoha EN7581. This SoC implement a simple >>> watchdog that supports a max timeout of 28 seconds. >>> >>> The watchdog ticks on half the BUS clock and require the BUS frequency >>> to be provided. >> >> Clock provider should implement clk_get_rate()... >> > > The BUS clock is internal and not exposed to the system hence > clk_get_rate is not possible saddly. > >>> >> >> ... >> >>> +maintainers: >>> + - Christian Marangi <ansuelsmth@xxxxxxxxx> >>> + >>> +allOf: >>> + - $ref: watchdog.yaml# >>> + >>> +properties: >>> + compatible: >>> + const: airoha,en7581-wdt >>> + >>> + reg: >>> + maxItems: 1 >>> + >>> + clock-frequency: >>> + description: BUS frequency in Hz (timer ticks at half the BUS freq) >>> + const: 300000000 >> >> Which bus frequency? Aren't you missing here clock input? > > I'm putting here property to describe the internal clock to what the > watchdog is attached. Should I drop this and just hardcode it > internally to the driver or maybe declare the clock to be 150000000 > directly? If this stays, then please mention "internal watchdog bus frequency". If this is internal and it is part of an SoC (so not board!) why would we need it in DT? I would imagine this is fixed per SoC, thus deduced from the compatible. clock-frequency property is legacy and in general discouraged. This might be an exception, but for that I would like to see more of explanations. > > Tick frequency is already not well defined so I tought it was a good > idea to describe it in DT. > Best regards, Krzysztof
