From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751477AbaEBBG1 (ORCPT ); Thu, 1 May 2014 21:06:27 -0400 Received: from mail-vc0-f181.google.com ([209.85.220.181]:42002 "EHLO mail-vc0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751321AbaEBBG0 (ORCPT ); Thu, 1 May 2014 21:06:26 -0400 MIME-Version: 1.0 In-Reply-To: <1398353407-2345-3-git-send-email-santosh.shilimkar@ti.com> References: <1398353407-2345-1-git-send-email-santosh.shilimkar@ti.com> <1398353407-2345-3-git-send-email-santosh.shilimkar@ti.com> Date: Thu, 1 May 2014 20:06:25 -0500 Message-ID: Subject: Re: [PATCH v3 2/7] of: introduce of_dma_get_range() helper From: Rob Herring To: Santosh Shilimkar Cc: "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , Grygorii Strashko , Greg Kroah-Hartman , Russell King , Arnd Bergmann , Olof Johansson , Grant Likely , Rob Herring , Catalin Marinas , Linus Walleij 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: > From: Grygorii Strashko > > The of_dma_get_range() allows to find "dma-range" property for > the specified device and parse it. > dma-ranges format: > DMA addr (dma_addr) : naddr cells > CPU addr (phys_addr_t) : pna cells > size : nsize cells > > Cc: Greg Kroah-Hartman > Cc: Russell King > Cc: Arnd Bergmann > Cc: Olof Johansson > Cc: Grant Likely > Cc: Rob Herring > Cc: Catalin Marinas > Cc: Linus Walleij > Signed-off-by: Grygorii Strashko > Signed-off-by: Santosh Shilimkar Reviewed-by: Rob Herring > --- > drivers/of/address.c | 87 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of_address.h | 8 ++++ > 2 files changed, 95 insertions(+) > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index cb4242a..c54baee 100644 > --- a/drivers/of/address.c > +++ b/drivers/of/address.c > @@ -721,3 +721,90 @@ void __iomem *of_iomap(struct device_node *np, int index) > return ioremap(res.start, resource_size(&res)); > } > EXPORT_SYMBOL(of_iomap); > + > +/** > + * of_dma_get_range - Get DMA range info > + * @np: device node to get DMA range info > + * @dma_addr: pointer to store initial DMA address of DMA range > + * @paddr: pointer to store initial CPU address of DMA range > + * @size: pointer to store size of DMA range > + * > + * Look in bottom up direction for the first "dma-ranges" property > + * and parse it. > + * dma-ranges format: > + * DMA addr (dma_addr) : naddr cells > + * CPU addr (phys_addr_t) : pna cells > + * size : nsize cells > + * > + * It returns -ENODEV if "dma-ranges" property was not found > + * for this device in DT. > + */ > +int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size) > +{ > + struct device_node *node = of_node_get(np); > + const __be32 *ranges = NULL; > + int len, naddr, nsize, pna; > + int ret = 0; > + u64 dmaaddr; > + > + if (!node) > + return -EINVAL; > + > + while (1) { > + naddr = of_n_addr_cells(node); > + nsize = of_n_size_cells(node); > + node = of_get_next_parent(node); > + if (!node) > + break; > + > + ranges = of_get_property(node, "dma-ranges", &len); > + > + /* Ignore empty ranges, they imply no translation required */ > + if (ranges && len > 0) > + break; > + > + /* > + * At least empty ranges has to be defined for parent node if > + * DMA is supported > + */ > + if (!ranges) > + break; > + } > + > + if (!ranges) { > + pr_debug("%s: no dma-ranges found for node(%s)\n", > + __func__, np->full_name); > + ret = -ENODEV; > + goto out; > + } > + > + len /= sizeof(u32); > + > + pna = of_n_addr_cells(node); > + > + /* dma-ranges format: > + * DMA addr : naddr cells > + * CPU addr : pna cells > + * size : nsize cells > + */ > + dmaaddr = of_read_number(ranges, naddr); > + *paddr = of_translate_dma_address(np, ranges); > + if (*paddr == OF_BAD_ADDR) { > + pr_err("%s: translation of DMA address(%pad) to CPU address failed node(%s)\n", > + __func__, dma_addr, np->full_name); > + ret = -EINVAL; > + goto out; > + } > + *dma_addr = dmaaddr; > + > + *size = of_read_number(ranges + naddr + pna, nsize); > + > + pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n", > + *dma_addr, *paddr, *size); > + > +out: > + of_node_put(node); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(of_dma_get_range); > diff --git a/include/linux/of_address.h b/include/linux/of_address.h > index 5f6ed6b..4d7b325 100644 > --- a/include/linux/of_address.h > +++ b/include/linux/of_address.h > @@ -63,6 +63,8 @@ extern int of_pci_range_parser_init(struct of_pci_range_parser *parser, > extern struct of_pci_range *of_pci_range_parser_one( > struct of_pci_range_parser *parser, > struct of_pci_range *range); > +extern int of_dma_get_range(struct device_node *np, u64 *dma_addr, > + u64 *paddr, u64 *size); > #else /* CONFIG_OF_ADDRESS */ > static inline struct device_node *of_find_matching_node_by_address( > struct device_node *from, > @@ -90,6 +92,12 @@ static inline struct of_pci_range *of_pci_range_parser_one( > { > return NULL; > } > + > +static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr, > + u64 *paddr, u64 *size) > +{ > + return -ENODEV; > +} > #endif /* CONFIG_OF_ADDRESS */ > > #ifdef CONFIG_OF > -- > 1.7.9.5 >