From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <55A3B931.1050706@ti.com> Date: Mon, 13 Jul 2015 16:12:17 +0300 From: Roger Quadros MIME-Version: 1.0 To: nick , Tony Lindgren CC: , , , , , , , Subject: Re: [PATCH 03/12] mtd: nand: omap: Move IRQ handling from GPMC to NAND driver References: <1436531019-18088-1-git-send-email-rogerq@ti.com> <1436531019-18088-4-git-send-email-rogerq@ti.com> <20150713071008.GC26485@atomide.com> <55A38D2E.9010500@ti.com> <20150713124059.GF26485@atomide.com> <55A3B467.8030409@gmail.com> <20150713130109.GG26485@atomide.com> <55A3B73C.9040604@gmail.com> In-Reply-To: <55A3B73C.9040604@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 13/07/15 16:03, nick wrote: > > > On 2015-07-13 09:01 AM, Tony Lindgren wrote: >> * nick [150713 05:54]: >>> On 2015-07-13 08:40 AM, Tony Lindgren wrote: >>>> * Roger Quadros [150713 03:07]: >>>> >>>>> What is the best map we should use for irqchip? >>>>> Some Socs have 4 WAIT pins, some have 3 and some have 2. >>>>> >>>>> Should we start with 0,1,2, for the wait pins and use the next >>>>> available free one for the NAND? >>>> >>>> Maybe we can just use the bits defined for each SoC in the >>>> GPMC_IRQSTATUS register for the mapping? >>>> Regards, >>> >>> Is that a good idea as to my knowledge of OMAP platforms that register is hardware >>> dependent and therefore that may be an issue unless your idea is to create device >>> tables like the way they do in the nand subsystems to support various vendor's >>> nand flash expect here for the pins on OMAP SOCs. >> >> Do you mean mapping irqs based on the GPMC_IRQSTATUS register >> bits? If so, that's pretty much how all the GPIO drivers >> handle them. We can have a SoC specific irqmask of the valid >> bits passed from the dts files, and if necessary we can also >> add custom SoC specific IRQ handlers to the GPMC driver if >> needed. >> >> The idea is that the NAND driver can just request the irq >> from the GPMC driver and do whatever it wants with the >> interrupt. >> >> Regards, >> >> Tony >> > Tony, > That is what I was hoping the code was doing. So what appears to be the problem with the > patches related to irq requesting from the GPMC driver. > Cheers, > Nick > The problem with this patch is that it expects GPMC_IRQ registers to be accessible by the NAND driver and looses the 2 to 4 pins of WAIT pin edge detection interrupt capability if it is needed for generic use. (not NAND/GPMC memory specific) cheers, -roger