Am 2022-03-22 11:54, schrieb Andre Przywara:
On Tue, 22 Mar 2022 17:19:53 +0800 Jim Liu jim.t90615@gmail.com wrote:
Hi,
Add watchdog controller driver for NPCM7xx/npcm8xx
So this is now the same as v4, with both compatible strings listed. Which *might* be right, but my question still stands:
Is the 845 watchdog compatible to the 740 version? Does the current Linux driver work?
If yes (and your driver suggests so, because you treat the two compatible strings the same), then you would not need to list both *in the driver*, but just do so in the .dts file.
So the driver just matches "nuvoton,npcm750-wdt" (as does the Linux driver), the nuvoton-common-npcm7xx.dtsi stays the same, but in the npcm845.dtsi you write: watchdog: watchdog@xxx { compatible = "nuvoton,npcm845-wdt", "nuvoton,npcm750-wdt"; interrupts = ... ... };
This way you don't need to change the (Linux) driver, and get away with one compatible string, for both devices.
Ahh didn't noticed that there are different compatible strings in the linux kernel driver.
And even
compatible = "nuvoton,npcm845-wdt", "nuvoton,npcm750-wdt";
would be undocumented if it is not upstreamed to linux.
So can you please confirm that both are compatible. I couldn't find any information on that.
Please just don't send another patch without answering the question ;-)
I'd suggest to convert the binding to yaml format so it is unambiguous what is supported and what isn't.
-michael