From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH 01/17] of: add dma-mask binding Date: Wed, 14 Nov 2012 14:56:14 -0600 Message-ID: <50A4056E.9090700@gmail.com> References: <1352710357-3265-1-git-send-email-wenyou.yang@atmel.com> <1352710357-3265-2-git-send-email-wenyou.yang@atmel.com> <50A3164C.3070301@gmail.com> <20121114060058.GM4576@game.jcrosoft.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121114060058.GM4576-RQcB7r2h9QmfDR2tN2SG5Ni2O/JbrIOy@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" To: Jean-Christophe PLAGNIOL-VILLARD Cc: JM.Lin-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, Wenyou Yang , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On 11/14/2012 12:00 AM, Jean-Christophe PLAGNIOL-VILLARD wrote: > On 21:55 Tue 13 Nov , Rob Herring wrote: >> On 11/12/2012 02:52 AM, Wenyou Yang wrote: >>> From: Jean-Christophe PLAGNIOL-VILLARD >>> >>> This will allow each device to specify its dma-mask for this we use the >>> coherent_dma_mask as pointer. By default the dma-mask will be set to >>> DMA_BIT_MASK(32). >> >> Do you really have a use case this is not DMA_BIT_MASK(32)? > yes as exmample on 64bit platfrom it will be 64 on x86 it's also 24, on power > pc 40 >> >>> The microblaze architecture hook is drop >>> >>> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD >>> Cc: grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org >>> Cc: rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org >>> Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org >>> --- >>> drivers/of/platform.c | 23 ++++++++++++++++------- >>> 1 file changed, 16 insertions(+), 7 deletions(-) >>> >>> diff --git a/drivers/of/platform.c b/drivers/of/platform.c >>> index b80891b..31ed405 100644 >>> --- a/drivers/of/platform.c >>> +++ b/drivers/of/platform.c >>> @@ -130,6 +130,21 @@ void of_device_make_bus_id(struct device *dev) >>> dev_set_name(dev, "%s.%d", node->name, magic - 1); >>> } >>> >>> +static void of_get_dma_mask(struct device *dev, struct device_node *np) >>> +{ >>> + const __be32 *prop; >>> + int len; >>> + >>> + prop = of_get_property(np, "dma-mask", &len); >> >> dma-ranges may work for this purpose. >> >>> + >>> + dev->dma_mask = &dev->coherent_dma_mask; >> >> I don't really know, but I suspect this is wrong. > no this is correct was suggest by Russell > we already do so on other ARM or SH as example > > the dma expect a pointer for dma_mask but the value is the same as coherent Okay. Then perhaps this part should be a separate patch as that is useful on its own for 32-bit machines with no DMA address restrictions (most modern ARM h/w). My comment on using dma-ranges still stands though. The form is . Normally, parent and child would be the same. I think the mask would be "parent address + size - 1". The simple case is <0 0 0> for all of 32-bit memory. I'm using 0 for full 32-bit size here as #size-cells is typically 1 and I can't imagine that 0 size would be useful. Rob >> >>> + >>> + if (!prop) >>> + dev->coherent_dma_mask = DMA_BIT_MASK(32); >>> + else >>> + dev->coherent_dma_mask = of_read_number(prop, len / 4); >>> +} >>> + >>> /** >>> * of_device_alloc - Allocate and initialize an of_device >>> * @np: device node to assign to device >>> @@ -171,10 +186,8 @@ struct platform_device *of_device_alloc(struct device_node *np, >>> WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq); >>> } >>> >>> + of_get_dma_mask(&dev->dev, np); >>> dev->dev.of_node = of_node_get(np); >>> -#if defined(CONFIG_MICROBLAZE) >>> - dev->dev.dma_mask = &dev->archdata.dma_mask; >>> -#endif >>> dev->dev.parent = parent; >>> >>> if (bus_id) >>> @@ -211,10 +224,6 @@ struct platform_device *of_platform_device_create_pdata( >>> if (!dev) >>> return NULL; >>> >>> -#if defined(CONFIG_MICROBLAZE) >>> - dev->archdata.dma_mask = 0xffffffffUL; >>> -#endif >>> - dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); >>> dev->dev.bus = &platform_bus_type; >>> dev->dev.platform_data = platform_data; >>> >>>