From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Thu, 26 Feb 2015 13:57:15 +0100 Subject: [PATCH 1/3] mtd: atmel_nand: move the hsmc_clk from nfc node to nand node In-Reply-To: References: <1423548885-27589-1-git-send-email-josh.wu@atmel.com> <20150226101857.59104e97@bbrezillon> Message-ID: <20150226135715.7e6c199c@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Jean-Christophe, On Thu, 26 Feb 2015 19:49:09 +0800 Jean-Christophe PLAGNIOL-VILLARD wrote: > > > On Feb 26, 2015, at 5:18 PM, Boris Brezillon wrote: > > > > Hi Josh, > > > > On Tue, 10 Feb 2015 14:14:43 +0800 > > Josh Wu wrote: > > > >> Also add a new sama5d3_nand compatiable string for sama5d3 nand. > >> > >> For sama5d3, sama5d4 chip, the pmecc became part of HSMC, they need the > >> HSMC clock enabled to work. > >> The NFC is a sub feature for current nand driver, it can be disabled. > >> But if HSMC clock is controlled by NFC, so disable NFC will also disable > >> the HSMC clock. then, it will make the PMECC fail to work. > >> > >> So the solution is move the HSMC clock out of NFC to nand node. When > >> nand driver probed, it will check whether the chip has HSMC, if yes then > >> it will require a HSMC clock. > > > > Do you plan to use the NAND chip without the NFC (I mean, is there a > > reason for not using the NFC to access the NAND ?) ? > > If you don't, why don't you just wait for the NFC before probing the > > NAND chip it is attached to, so that the hmsc clk is properly claimed. > you can as you can have 2 Nand on the d3 but only 1 NFC I don't get your point ? You can control several NAND chips with the same NFC. -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com