On Thu, Nov 18, 2010 at 5:57 PM, Kevin Hilman <khil...@deeprootsystems.com> wrote: > "Nori, Sekhar" <nsek...@ti.com> writes: > >> Hi Michael, >> >> On Wed, Nov 17, 2010 at 02:12:53, Michael Williamson wrote: >>> >>> Help me out. Why do we need generic pin lists? >>> >> >> They might help in cases where all boards will use the same set of >> pins. For example, every one who uses I2C will most likely both the >> clock and data pins from the IP. For more complex peripherals with >> different pins options they serve a documentation purpose at best. >> >>> It seems to me that the "generic pin list" for da850.c isn't practical for >>> most >>> (if not all) of the peripherals. They should be done using __initdata in >>> each board file. >> >> Yes, agreed. >> >>> >>> Just a cursory glance at what's in da850.c highlights several items being >>> set >>> up for the EVM and not generically. For example: >>> >>> - da850_uart1_pins and da850_uart2_pins: I believe both have RTS/CTS pins >>> which >>> for a generic definition should be included as for UART0, but would then >>> be unused as the EVM doesn't use these pins in this function. >> >> Yes, the generic pin list should have RTS and CTS pins defined for UART1 >> and UART2. This needs fixing. >> >>> >>> - da850_mcasp_pins: if generic, must include all 16 AXR pins. I think you'd >>> be hard pressed to find a board configuration that would use all 16 AXR >>> pins >>> for the McASP. I'm fairly sure the EVM uses the pins called out, and uses >>> other pins for other functions. So it's likely this structure wouldn't >>> get used. >> >> Yes, the generic pin list should either be completed or removed >> altogether and the existing pin list da850_mcasp_pins should be >> copied into the board file and called da850_evm_mcasp_pins. >> >>> >>> - da850_mmcsd0_pins : includes 2 GPIO pins (specific to the EVM, though >>> possible for >>> other boards) for the card detect and write protect signals. These pins >>> are >>> completely arbitrary for that particular board design. I also believe that >>> the complete mmcsd0 port has 4 more data lines as part of it's >>> peripheral, although >>> the driver doesn't support using them. >> >> This is incorrect again. The generic pin list should be completed >> (or removed) and the existing list should be copied into the EVM board >> file as da850_evm_mmcsd0_pins. >> >>> >>> - da850_emif25_pins interface doesn't include the generic pins for some of >>> the SDRAM functions. >> >> Yes, this should be completed (or removed). This list is unused anyway. >> >>> >>> - da850_cpgmac_pins defines both RMII and MII pins. I don't think any board >>> would want to configure both sets at the same time. Seems like this >>> should >>> never get used... >> >> Agreed. >> >>> >>> It's also incomplete. What about the uPP pin list? Or the VPIF? Etc. >> >> These should be added as the drivers for these devices are >> supported. >> >>> >>> I think a board file author should be familiar enough with the SoC to >>> understand >>> what peripheral pins he should be configuring for his/her particular >>> hardware setup >>> and explicitly specify them in the board file. >> >> Agree. >> >>> >>> If you remove the common pin-mux lists and move them to a board file, then >>> once you >>> configure your specific platform, is there any more memory used than with >>> the common scheme? Of course, there would be replication of pin-mux code >>> in the board >> >> There is no memory wastage. All the pin lists are init data. >> >> I too prefer all generic pin lists which are most likely not >> going to be used at all to be removed. Unused stuff like this >> will only make code difficult to read. > > FWIW, I agree. > > Now, who wants to tackle it? > > Kevin >
I could but I will need a little help and from all of you. :) Regards Victor Rodriguez > _______________________________________________ > Davinci-linux-open-source mailing list > Davinci-linux-open-source@linux.davincidsp.com > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source > _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
