From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751503AbaEBAtJ (ORCPT ); Thu, 1 May 2014 20:49:09 -0400 Received: from mail-ve0-f176.google.com ([209.85.128.176]:64815 "EHLO mail-ve0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751285AbaEBAtH (ORCPT ); Thu, 1 May 2014 20:49:07 -0400 MIME-Version: 1.0 In-Reply-To: <1398353407-2345-5-git-send-email-santosh.shilimkar@ti.com> References: <1398353407-2345-1-git-send-email-santosh.shilimkar@ti.com> <1398353407-2345-5-git-send-email-santosh.shilimkar@ti.com> Date: Thu, 1 May 2014 19:49:05 -0500 Message-ID: Subject: Re: [PATCH v3 4/7] of: configure the platform device dma parameters From: Rob Herring To: Santosh Shilimkar Cc: "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , Greg Kroah-Hartman , Russell King , Arnd Bergmann , Olof Johansson , Grant Likely , Rob Herring , Catalin Marinas , Linus Walleij , Grygorii Strashko Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 24, 2014 at 10:30 AM, Santosh Shilimkar wrote: > Retrieve DMA configuration from DT and setup platform device's DMA > parameters. The DMA configuration in DT has to be specified using > "dma-ranges" and "dma-coherent" properties if supported. > > We setup dma_pfn_offset using "dma-ranges" and dma_coherent_ops > using "dma-coherent" device tree properties. > > The set_arch_dma_coherent_ops macro has to be defined by arch if > it supports coherent dma_ops. Otherwise, set_arch_dma_coherent_ops() is > declared as nop. > [...] > + /* > + * if dma-ranges property doesn't exist - just return else > + * setup the dma offset > + */ > + ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size); > + if ((ret == -ENODEV) || (ret < 0)) { The 1st condition is redundant. > + dev_dbg(dev, "no dma range information to setup\n"); > + return; > + } > + > + /* DMA ranges found. Calculate and set dma_pfn_offset */ > + dev->dma_pfn_offset = PFN_DOWN(paddr - dma_addr); > + dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", dev->dma_pfn_offset); > +} > + > +/** > * of_platform_device_create_pdata - Alloc, initialize and register an of_device > * @np: pointer to node to create device for > * @bus_id: name to assign device > @@ -214,9 +258,7 @@ static struct platform_device *of_platform_device_create_pdata( > #if defined(CONFIG_MICROBLAZE) > dev->archdata.dma_mask = 0xffffffffUL; > #endif This is also dma related setup. Please move *all* dma setup into the function. > - dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); > - if (!dev->dev.dma_mask) > - dev->dev.dma_mask = &dev->dev.coherent_dma_mask; > + of_dma_configure(&dev->dev); > dev->dev.bus = &platform_bus_type; > dev->dev.platform_data = platform_data; > > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index fd4aee2..c7d9b1b 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -123,6 +123,13 @@ static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask) > > extern u64 dma_get_required_mask(struct device *dev); > > +#ifndef set_arch_dma_coherent_ops > +static inline int set_arch_dma_coherent_ops(struct device *dev) > +{ > + return 0; > +} > +#endif > + > static inline unsigned int dma_get_max_seg_size(struct device *dev) > { > return dev->dma_parms ? dev->dma_parms->max_segment_size : 65536; > -- > 1.7.9.5 >