From mboxrd@z Thu Jan 1 00:00:00 1970 From: vm.rod25@gmail.com (Victor Rodriguez) Date: Fri, 19 Nov 2010 10:23:31 -0600 Subject: [PATCH v8 4/9] davinci: McASP configuration for Omapl138-Hawkboard In-Reply-To: References: <1289601535-6746-1-git-send-email-vm.rod25@gmail.com> <1289601535-6746-5-git-send-email-vm.rod25@gmail.com> <4CE124AE.4080301@mvista.com> <4CE1560F.6080705@mvista.com> <4CE2AB73.3050109@mvista.com> <4CE2ECCD.8090603@criticallink.com> <87fwuyfanl.fsf@deeprootsystems.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Nov 18, 2010 at 6:17 PM, Victor Rodriguez wrote: > On Thu, Nov 18, 2010 at 5:57 PM, Kevin Hilman > wrote: >> "Nori, Sekhar" 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 > Hey I have sent the first patch in order to fix UARTs on da850. please check if this is right Regards Victor Rodriguez >> _______________________________________________ >> Davinci-linux-open-source mailing list >> Davinci-linux-open-source at linux.davincidsp.com >> http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source >> >