Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754997AbaDSOeo (ORCPT ); Sat, 19 Apr 2014 10:34:44 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:38771 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754209AbaDSOeZ (ORCPT ); Sat, 19 Apr 2014 10:34:25 -0400 From: Santosh Shilimkar To: CC: , , Grygorii Strashko , Greg Kroah-Hartman , Russell King , Arnd Bergmann , Olof Johansson , Grant Likely , Rob Herring , Catalin Marinas , Linus Walleij , Santosh Shilimkar Subject: [PATCH v2 2/7] of: introduce of_dma_get_range() helper Date: Sat, 19 Apr 2014 10:32:47 -0400 Message-ID: <1397917972-6293-3-git-send-email-santosh.shilimkar@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1397917972-6293-1-git-send-email-santosh.shilimkar@ti.com> References: <1397917972-6293-1-git-send-email-santosh.shilimkar@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/of/platform.c | 85 +++++++++++++++++++++++++++++++++++++++++++ include/linux/of_platform.h | 8 ++++ 2 files changed, 93 insertions(+) diff --git a/drivers/of/platform.c b/drivers/of/platform.c index 404d1da..2265a55 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -485,4 +485,89 @@ int of_platform_populate(struct device_node *root, return rc; } EXPORT_SYMBOL_GPL(of_platform_populate); + +/** + * 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-range" 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. + */ +extern int of_dma_get_range(struct device_node *np, dma_addr_t *dma_addr, + phys_addr_t *paddr, phys_addr_t *size) +{ + struct device_node *node = np; + const u32 *ranges = NULL; + int len, naddr, nsize, pna; + int ret = 0; + + 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 + */ + *dma_addr = 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; + } + + *size = of_read_number(ranges + naddr + pna, nsize); + + pr_debug("dma_addr(%pad) cpu_addr(%pa) size(%pa)\n", + dma_addr, paddr, size); + +out: + of_node_put(node); + + return ret; +} +EXPORT_SYMBOL_GPL(of_dma_get_range); #endif /* CONFIG_OF_ADDRESS */ diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h index 05cb4a9..ba7d3dc 100644 --- a/include/linux/of_platform.h +++ b/include/linux/of_platform.h @@ -72,6 +72,8 @@ extern int of_platform_populate(struct device_node *root, const struct of_device_id *matches, const struct of_dev_auxdata *lookup, struct device *parent); +extern int of_dma_get_range(struct device_node *np, dma_addr_t *dma_addr, + phys_addr_t *paddr, phys_addr_t *size); #else static inline int of_platform_populate(struct device_node *root, const struct of_device_id *matches, @@ -80,6 +82,12 @@ static inline int of_platform_populate(struct device_node *root, { return -ENODEV; } + +static inline int of_dma_get_range(struct device_node *np, dma_addr_t *dma_addr, + phys_addr_t *paddr, phys_addr_t *size) +{ + return -ENODEV; +} #endif #endif /* _LINUX_OF_PLATFORM_H */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/