On Tue, Oct 06, 2015 at 10:21:34AM +0200, Olliver Schinagl wrote: > Hey Thierry, > > thans for your quick reply :) > > On 06-10-15 09:38, Thierry Reding wrote: > >On Tue, Oct 06, 2015 at 09:20:53AM +0200, Olliver Schinagl wrote: > >>Hey Thierry, list, > >> > >>While working on something in the pwm framework, I noticed that the void > >>*data in the pwm_device struct is called chip_data. Why is it not called > >>device_data, since it is the data associated with a PWM device, rather then > >>the chip, and on that note, if it really is chip related data (thus covering > >>the whole chip, not just the single pwm device) why is there no chip_data in > >>pwm_chip? > >The reason for the name is that it's chip-specific data associated with > >a struct pwm_device. That is, a PWM chip implementation (i.e. driver) > >can use it to keep per-PWM data that's not in struct pwm_device itself. > Then I have to wrap my head around what is a chip and what is a device :) > > To me, it seems that a chip can hold X number of pwm devices, and each > pwm_device has a unique set of properties, duty, plarity, period. So it > seems that some device specific data could go here as well, where i'm bad at > examples now
I think we're really talking about the same thing here. This is used for device-specific data. The chip_ prefix merely means that the chip driver "owns" the data. > >>Again, is this something worth my time to add a device_data and rename > >>chip_data? > >device_data would be redundant because it's already part of struct > >pwm_device. Plain data might be okay, but I like the chip_ prefix > >because it marks the data as being chip-specific data rather than > >generic. > well here i'd imagine the chip specific data (not allready in the struct). Data specific to a chip is what you're supposed to embed in your driver- specific data structure (which embeds struct pwm_chip). Like you said it is data that pertains to the whole chip, so doesn't need to be per-PWM. Thierry
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