From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Quadros Subject: Re: [PATCH 14/36] ARM: OMAP2+: gpmc: Allow drivers to reconfigure GPMC settings & timings Date: Fri, 13 Jun 2014 10:44:37 +0300 Message-ID: <539AABE5.10907@ti.com> References: <1402477001-31132-1-git-send-email-rogerq@ti.com> <1402477001-31132-15-git-send-email-rogerq@ti.com> <20140613072550.GM17845@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140613072550.GM17845@atomide.com> Sender: linux-kernel-owner@vger.kernel.org To: Tony Lindgren Cc: dwmw2@infradead.org, computersforpeace@gmail.com, kyungmin.park@samsung.com, pekon@ti.com, ezequiel.garcia@free-electrons.com, javier@dowhile0.org, nsekhar@ti.com, linux-omap@vger.kernel.org, linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org On 06/13/2014 10:25 AM, Tony Lindgren wrote: > * Roger Quadros [140611 01:58]: >> Some devices (e.g. TUSB6010, omap-onenand) need to reconfigure the GPMC >> timings in order to operate with different peripheral clock frequencies. >> Introduce omap_gpmc_retime() to allow them to do that. The driver >> needs to pass the chips select number, GPMC settings and Device timings to >> omap_gpmc_retime(). >> >> NOTE: Device tree and board code must still pass the most conservative >> timings to GPMC so that the device can be probed by the respective driver. >> e.g. Onenand must operate in asynchronous mode at bootup. The device driver >> can then request for more optimal timings via omap_gpmc_retime(). > > Hmm but many of the devices are Linux generic like sms91x and 8250 so it's > not nice to start stuffing omap bus specific data there. Those drivers should never need to use this function. Hopefully they will work with a one time setup where we specify the timings in the DT. This function is primarily for use by omap-onenand and tusb6010, which are both OMAP specific. cheers, -roger > > I wonder if we should just keep device specific gpmc-smc91x.c etc > in drivers/memory? > > Regards, > > Tony >