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From:   Rob Herring <robh@kernel.org>
To:     Michael Ellerman <mpe@ellerman.id.au>,
        Nicholas Piggin <npiggin@gmail.com>,
        Christophe Leroy <christophe.leroy@csgroup.eu>
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH] powerpc: fsl_rio: Use of_range_to_resource() for "ranges" parsing
Date:   Fri,  9 Jun 2023 12:32:44 -0600
Message-Id: <20230609183244.1767325-1-robh@kernel.org>
MIME-Version: 1.0
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Precedence: bulk

"ranges" is a standard property with common parsing functions. Users
shouldn't be implementing their own parsing of it. Refactor the FSL RapidIO
"ranges" parsing to use of_range_to_resource() instead.

One change is the original code would look for "#size-cells" and
"#address-cells" in the parent node if not found in the port child
nodes. That is non-standard behavior and not necessary AFAICT. In 2011
in commit 54986964c13c ("powerpc/85xx: Update SRIO device tree nodes")
there was an ABI break. The upstream .dts files have been correct since
at least that point.

Signed-off-by: Rob Herring <robh@kernel.org>
---
 arch/powerpc/sysdev/fsl_rio.c | 34 ++++++++--------------------------
 1 file changed, 8 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/sysdev/fsl_rio.c b/arch/powerpc/sysdev/fsl_rio.c
index f8e492ee54cc..18176d0df612 100644
--- a/arch/powerpc/sysdev/fsl_rio.c
+++ b/arch/powerpc/sysdev/fsl_rio.c
@@ -453,8 +453,8 @@ int fsl_rio_setup(struct platform_device *dev)
 	struct device_node *np, *rmu_node;
 	int rlen;
 	u32 ccsr;
-	u64 range_start, range_size;
-	int paw, aw, sw;
+	u64 range_start;
+	int aw;
 	u32 i;
 	static int tmp;
 	struct device_node *rmu_np[MAX_MSG_UNIT_NUM] = {NULL};
@@ -569,6 +569,8 @@ int fsl_rio_setup(struct platform_device *dev)
 
 	/*set up ports node*/
 	for_each_child_of_node(dev->dev.of_node, np) {
+		struct resource res;
+
 		port_index = of_get_property(np, "cell-index", NULL);
 		if (!port_index) {
 			dev_err(&dev->dev, "Can't get %pOF property 'cell-index'\n",
@@ -576,32 +578,14 @@ int fsl_rio_setup(struct platform_device *dev)
 			continue;
 		}
 
-		dt_range = of_get_property(np, "ranges", &rlen);
-		if (!dt_range) {
+		if (of_range_to_resource(np, 0, &res)) {
 			dev_err(&dev->dev, "Can't get %pOF property 'ranges'\n",
 					np);
 			continue;
 		}
 
-		/* Get node address wide */
-		cell = of_get_property(np, "#address-cells", NULL);
-		if (cell)
-			aw = *cell;
-		else
-			aw = of_n_addr_cells(np);
-		/* Get node size wide */
-		cell = of_get_property(np, "#size-cells", NULL);
-		if (cell)
-			sw = *cell;
-		else
-			sw = of_n_size_cells(np);
-		/* Get parent address wide wide */
-		paw = of_n_addr_cells(np);
-		range_start = of_read_number(dt_range + aw, paw);
-		range_size = of_read_number(dt_range + aw + paw, sw);
-
-		dev_info(&dev->dev, "%pOF: LAW start 0x%016llx, size 0x%016llx.\n",
-				np, range_start, range_size);
+		dev_info(&dev->dev, "%pOF: LAW %pR\n",
+				np, &res);
 
 		port = kzalloc(sizeof(struct rio_mport), GFP_KERNEL);
 		if (!port)
@@ -624,9 +608,7 @@ int fsl_rio_setup(struct platform_device *dev)
 		}
 
 		INIT_LIST_HEAD(&port->dbells);
-		port->iores.start = range_start;
-		port->iores.end = port->iores.start + range_size - 1;
-		port->iores.flags = IORESOURCE_MEM;
+		port->iores = res;	/* struct copy */
 		port->iores.name = "rio_io_win";
 
 		if (request_resource(&iomem_resource, &port->iores) < 0) {
-- 
2.39.2