From mboxrd@z Thu Jan 1 00:00:00 1970 From: joshc@eso.teric.us (Josh Cartwright) Date: Mon, 12 Oct 2015 16:54:59 -0500 Subject: [PATCH 3/5] mtd: brcmnand: Optional DT flag to reset IPROC NAND controller In-Reply-To: <39063E8F96E11742B35A201CC5D095B7AD8ADD@SJEXCHMB10.corp.ad.broadcom.com> References: <1443808606-21203-1-git-send-email-anup.patel@broadcom.com> <1443808606-21203-4-git-send-email-anup.patel@broadcom.com> <20151004214943.GA28904@localhost> <39063E8F96E11742B35A201CC5D095B7AD54C1@SJEXCHMB10.corp.ad.broadcom.com> <20151006134119.GB26818@localhost> <56144A62.70300@broadcom.com> <5614574C.2060701@gmail.com> <39063E8F96E11742B35A201CC5D095B7AD8ADD@SJEXCHMB10.corp.ad.broadcom.com> Message-ID: <20151012215459.GA8843@kryptos> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Oct 07, 2015 at 03:33:50AM +0000, Anup Patel wrote: > From: Florian Fainelli [mailto:f.fainelli at gmail.com] > > On 06/10/15 15:25, Scott Branden wrote: [..] > > Then instead of adding a "reset flag" to Device Tree, another approach could be > > to put the desired or currently configured exhaustive list of NAND timings in > > Device Tree, and based on that you could have this: > > > > - the NAND controller driver finds that these timings match the current > > configuration, you are good to go > > > > - the NAND controller drivers finds a difference in how current timings are > > configured vs. desired timings, and issues a controller reset, prior to applying > > new timing configuration > > To add to this ... > > The mechanism to reset is BRCM NAND controller is SOC specific so the > SoC independent BRCM NAND driver (i.e. brcmnand.c) does not know how > to reset the NAND controller. > > For iProc SoC family, the NAND controller reset is through IDM register > space which is only iomap'ed by iproc_nand.c. > > We might end-up having one more SoC specific callback which will be > Provided by iproc_nand.c to brcmnand.c. Not that I'm familiar with these SoCs, but I did want to chime in and make sure you are aware of the existing reset_controller_dev abstraction, which is intended to solve exactly this problem. Including a reset_control_get_optional() that might fit your use case. See include/linux/reset{,-controller}.h. Josh -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 473 bytes Desc: not available URL: