From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from down.free-electrons.com ([37.187.137.238] helo=mail.free-electrons.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1b2DNc-0002KP-Tf for linux-mtd@lists.infradead.org; Mon, 16 May 2016 07:55:57 +0000 Date: Mon, 16 May 2016 09:55:34 +0200 From: Boris Brezillon To: Moritz Fischer Cc: dwmw2@infradead.org, computersforpeace@gmail.com, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, moritz.fischer.private@gmail.com Subject: Re: [PATCH] mtd: Adding of_mtd_info_get to get mtd_info from devicetree Message-ID: <20160516095534.727fcac6@bbrezillon> In-Reply-To: <1462988859-32240-1-git-send-email-moritz.fischer@ettus.com> References: <1462988859-32240-1-git-send-email-moritz.fischer@ettus.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Moritz, On Wed, 11 May 2016 10:47:39 -0700 Moritz Fischer wrote: > This allows for getting a struct mtd_info from a node pointer, > allowing mtd devices to e.g. store serial numbers or MAC addresses. Can you detail a bit what you'll do next. I guess you need to provide this information to in-kernel users, and those users will just call mtd_read() after retrieving the mtd_info pointer. Here are a few questions (I'm assuming the netdev + MAC address case): - how would you link the net/PHY device to the MTD partition storing the MAC address > > Signed-off-by: Moritz Fischer > --- > drivers/mtd/mtdcore.c | 21 +++++++++++++++++++++ > include/linux/mtd/mtd.h | 2 ++ > 2 files changed, 23 insertions(+) > > diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c > index 3096251..3d0ae65 100644 > --- a/drivers/mtd/mtdcore.c > +++ b/drivers/mtd/mtdcore.c > @@ -363,6 +363,27 @@ unsigned mtd_mmap_capabilities(struct mtd_info *mtd) > EXPORT_SYMBOL_GPL(mtd_mmap_capabilities); > #endif > > +static int mtd_of_node_match(struct device *dev, const void *data) > +{ > + return dev->of_node == data; > +} > + > +struct mtd_info *of_mtd_info_get(struct device_node *node) > +{ > + struct mtd_info *mtd; > + struct device *d; > + int ret = -ENODEV; > + > + d = class_find_device(&mtd_class, NULL, node, mtd_of_node_match); > + if (!d) > + return ERR_PTR(-ENODEV); > + > + mtd = container_of(d, struct mtd_info, dev); > + > + return mtd; > +} > +EXPORT_SYMBOL_GPL(of_mtd_info_get); > + > static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state, > void *cmd) > { > diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h > index 7712721..cce6cc7 100644 > --- a/include/linux/mtd/mtd.h > +++ b/include/linux/mtd/mtd.h > @@ -264,6 +264,8 @@ static inline struct device_node *mtd_get_of_node(struct mtd_info *mtd) > return mtd->dev.of_node; > } > > +struct mtd_info *of_mtd_info_get(struct device_node *node); > + > static inline int mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops) > { > return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize; -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com