>-----Original Message----- >From: Tony Lindgren [mailto:tony@xxxxxxxxxxx] >Sent: Friday, November 19, 2010 2:56 AM >To: Cousson, Benoit >Cc: R, Sricharan; linux-omap@xxxxxxxxxxxxxxx >Subject: Re: [PATCH 0/5] OMAP4: mux: Initialise OMAP4 mux pins. > >* Cousson, Benoit <b-cousson@xxxxxx> [101118 12:56]: >> On 11/18/2010 8:06 PM, Tony Lindgren wrote: >> >* sricharan<r.sricharan@xxxxxx> [101114 23:26]: >> >>This series updates the core device drivers to use mux framework >> >>for OMAP4 SDP and PANDA board. It's generated against the >> >>linux-omap master branch. It has a dependency on the Benoit's >> >>omap4 mux data series. >> > >> ><snip> >> > >> >>2. Do PAD configuration independently for each module >> >>Pros: >> >> a. Avoids repetition of similar data for different boards. >> >> b. Gives a knowledge of how pins are configured for a module >> >> to the respective owners. >> >> c. Pads are not initialised unless they are really needed. >> >>Cons: >> >> a. Can become difficult to maintain if lot of data tend to be >> >> different across boards. >> > >> >For the common modules, we should have generic platform init code >> >using hwmod. And that init code is the logical place to do the muxing. >> > >> >We also need to consider that the pin muxing is board specific. >> >So in cases where the are alternative signal paths, we need to pass >> >the signal names from board-*.c file to the platform driver init code. >> >> What about the omap_board_mux array in board file? Do you want to >> get rid of it, or is the plan is to use that for pads that does not >> belong to any driver or pads that are purely board specific? > >Well we might as well keep it around for now as that's the way >some people prefer to do the muxing. But yeah, eventually that >could be for only board specific unused pads. > >I'll post some sample patches related to the uart (re)muxing >within next few days, then let's see how that will work for >other devices. > >Here's the rough plan in case you have some ideas on it: > >1. board-*.c code calls omap_serial_init_port with struct omap_device_mux > array that contains the pin names > >2. serial.c init code muxes the pins the right way and sets > wake-up events for omap3 & 4. It also populates the runtime > remux values needed for omap2 uart > >3. serial.c init code saves the struct omap_device_mux pointer > to the related hwmod entry > >4. omap_device_idle/shutdown can then call omap_remux if the > omap_device_mux entry exists > ... > >This should solve how devices need to initialize the pads. >It should also work for all devices that may require runtime >remuxing, like some USB transceivers and eMMC. Ok . This means that the pin muxing introduced would be applicable for omap 2 ,3 and 4 also, with the board file passing the respective data if they are different ? >Regards, > >Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
