On Fri, Feb 21, 2014 at 3:59 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Friday 21 February 2014 15:48:04 Jonas Gorski wrote: >> >> There already is a (non-OF) user for this driver that exports a >> "periph" clock, which is where the name comes from. It currently does >> all clock lookups purely based on the clock name, not the device name >> itself. Of course we can just make it get a different named clock when >> of_node is present; that should satisfy both. > > I think you are referring to arch/mips/bcm63xx/clk.c, but that doesn't > actually use clkdev at all and instead expects device drivers to know > the name of *output* of the clock controllers. You can't use that > name in the binding for a device, which needs to know the name of > the *input* from the clock consumer point of view. That's why I was suggesting making the driver do a lookup on the input name in case of probing through OF (having an of_node), and using the "legacy" output name else. That way the binding is not limited to the output name of bcm63xx/mips anymore. > An easy solution would be to register a clkdev lookup table in > the above clock driver. Requiring bcm63xx/mips to implement clkdev would be IMHO an unnecessary burden just so bcm63xx/arm using OF can reuse this driver. Letting bcm63xx use a clkdev lookup table (or rather tables, as each chip is different) is good mid or long term goal, but it should not block other users. >> Technically on BCM6345 there are actually two clocks (more or less), >> the "periph" for the reference clock rate, and a clock bit in the >> clock controller register for the uart block. All later chips do not >> expose a uart clock bit anymore, and the bootloader is expected to >> enable it on systems with the clock, so we can probably pretend that >> it does not exist. Also it's quite unlikely that BCM6345 will ever >> receive proper OF support, and if it does, we can add the second >> optional clock then if we find devices that need it. > > That seems fine, but it does mean things would get tricky we use > an anonymous clock and then later need to add the second clock > after all, e.g. if the uart gets reused in a new product that > requires you to program both clocks. Right, so let's just not use an anonymous clock to begin with. Regards Jonas -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
