From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Christophe PLAGNIOL-VILLARD Subject: Re: [PATCH 1/1] of: add dma-mask binding Date: Wed, 7 Mar 2012 18:34:37 +0100 Message-ID: <20120307173437.GC17087@game.jcrosoft.org> References: <1331119575-6638-1-git-send-email-plagnioj@jcrosoft.com> <4F5793E9.9010100@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <4F5793E9.9010100-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Rob Herring Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On 10:59 Wed 07 Mar , Rob Herring wrote: > On 03/07/2012 05:26 AM, Jean-Christophe PLAGNIOL-VILLARD wrote: > > This will allow each device to specify its dma-mask > > The microblaze architecture hook is keep temporary if no dma-mask is specified > > int the DT > > > > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD > > --- > > drivers/of/platform.c | 26 +++++++++++++++++++++++++- > > 1 files changed, 25 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > > index cae9477..bb22194 100644 > > --- a/drivers/of/platform.c > > +++ b/drivers/of/platform.c > > @@ -121,6 +121,26 @@ void of_device_make_bus_id(struct device *dev) > > dev_set_name(dev, "%s.%d", node->name, magic - 1); > > } > > > > +static u64* of_get_dma_mask(struct device_node *np) > > +{ > > + const __be32 *prop; > > + int len; > > + u64 *dma_mask; > > + > > + prop = of_get_property(np, "dma-mask", &len); > > This would need some documentation. There is already "dma-ranges" > defined for OF which nay do what's needed. what is dma-ranges I see no doc about it but I don't think it could be used for the dma mask > > > + > > + if (!prop) > > + return NULL; > > + > > + dma_mask = kzalloc(sizeof(u64), GFP_KERNEL); > > This seems kind of wasteful for 1 u64. no choice dma_mask must be a pointer > > > + if (!dma_mask) > > + return NULL; > > + > > + *dma_mask = of_read_number(prop, len / 4); > > + > > + return dma_mask; > > +} > > + > > /** > > * of_device_alloc - Allocate and initialize an of_device > > * @np: device node to assign to device > > @@ -161,10 +181,14 @@ struct platform_device *of_device_alloc(struct device_node *np, > > WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq); > > } > > > > + dev->dev.dma_mask = of_get_dma_mask(np); > > dev->dev.of_node = of_node_get(np); > > + > > #if defined(CONFIG_MICROBLAZE) > > - dev->dev.dma_mask = &dev->archdata.dma_mask; > > And doing it this way for didn't get a warm reception either: > > http://lists.ozlabs.org/pipermail/devicetree-discuss/2011-April/005285.html > > Do you really need this to be something other than ~0UL and if so does > it need to be per device or system wide? > > You can solve this with bus notifiers in your at91 code. Here's an > example which I did (but no longer need): > > static u64 highbank_dma_mask = DMA_BIT_MASK(32); IIRC on at91 all of them that need it have a DMA_BIT_MASK(32) > > static int highbank_platform_notifier(struct notifier_block *nb, > unsigned long event, void *__dev) > { > struct device *dev = __dev; > > if (event != BUS_NOTIFY_ADD_DEVICE) > return NOTIFY_DONE; > > if (of_device_is_compatible(dev->of_node, "calxeda,hb-nfc")) > dev->dma_mask = &highbank_dma_mask; execpt as example today I need it on 2 node (OHCI & EHCI) and if more device need I don't want to end up with more fixup I really prefer to set it via DT Best Regards, J.