From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: [PATCH v3 4/7] of: address: Add support for the parent DMA bus Date: Mon, 11 Feb 2019 16:02:52 +0100 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Mark Rutland , Rob Herring , Frank Rowand , Chen-Yu Tsai , Maxime Ripard Cc: devicetree@vger.kernel.org, Thomas Petazzoni , Arnd Bergmann , dri-devel@lists.freedesktop.org, Georgi Djakov , Paul Kocialkowski , Yong Deng , Robin Murphy , Dave Martin , linux-arm-kernel@lists.infradead.org List-Id: dri-devel@lists.freedesktop.org Some SoCs have devices that are using a separate bus from the main bus to perform DMA. These buses might have some restrictions and/or different mapping than from the CPU side, so we'd need to express those using the usual dma-ranges, but using a different DT node than the node's parent. Now that the generic interconnect bindings are available, we can model an interconnect with the reserved name "dma" for those use-cases. Signed-off-by: Maxime Ripard --- drivers/of/address.c | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) diff --git a/drivers/of/address.c b/drivers/of/address.c index 4c5dc21c71ca..0e9d87a664f5 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -583,8 +583,8 @@ static u64 __of_translate_address(struct device_node *dev, /* Increase refcount at current level */ of_node_get(dev); + *host = NULL; if (!parent) { - *host = NULL; /* Get parent & match bus type */ parent = of_get_parent(dev); if (parent == NULL) @@ -678,12 +678,34 @@ u64 of_translate_address(struct device_node *dev, const __be32 *in_addr) } EXPORT_SYMBOL(of_translate_address); +static struct device_node *__of_get_dma_parent(struct device_node *np) +{ + struct of_phandle_args args; + unsigned int index; + int ret; + + ret = of_property_match_string(np, "interconnect-names", "dma"); + if (ret < 0) + return of_get_parent(np); + + ret = of_parse_phandle_with_args(np, "interconnects", + "#interconnect-cells", + index, &args); + if (ret < 0) + return of_get_parent(np); + + return of_node_get(args.np); +} + u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr) { + struct device_node *parent; struct device_node *host; u64 ret; - ret = __of_translate_address(dev, NULL, in_addr, "dma-ranges", &host); + parent = __of_get_dma_parent(dev); + ret = __of_translate_address(dev, parent, in_addr, "dma-ranges", &host); + of_node_put(parent); if (host) { of_node_put(host); @@ -911,9 +933,15 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz return -EINVAL; while (1) { + struct device_node *parent; + naddr = of_n_addr_cells(node); nsize = of_n_size_cells(node); - node = of_get_next_parent(node); + + parent = __of_get_dma_parent(node); + of_node_put(node); + + node = parent; if (!node) break; -- git-series 0.9.1