soc: qcom: smem: Move RPM message ram out of smem DT node

SMEM is a software construct built on top of a DDR reserved region
and sometimes a device memory region called RPM message ram. Having
the RPM message ram in the smem DT node's reg property leads to the
smem node being located in different places depending on if the
message ram is being used or not. Let's add a qcom specific
property, qcom,rpm-msg-ram, and point to the device memory from
the SMEM node via a phandle.  As SMEM is a software construct, it
really needs to reside at the root of the DT regardless of whether
it's using the message ram or not.

Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Andy Gross <agross@codeaurora.org>

arch/arm/boot/dts/qcom-msm8974.dtsi

@@ -100,6 +100,15 @@ timer {
 		clock-frequency = <19200000>;
 	};
 
+	smem {
+		compatible = "qcom,smem";
+
+		memory-region = <&smem_region>;
+		qcom,rpm-msg-ram = <&rpm_msg_ram>;
+
+		hwlocks = <&tcsr_mutex 3>;
+	};
+
 	soc: soc {
 		#address-cells = <1>;
 		#size-cells = <1>;
@@ -250,13 +259,9 @@ tcsr_mutex: tcsr-mutex {
 			#hwlock-cells = <1>;
 		};
 
-		smem@fa00000 {
-			compatible = "qcom,smem";
-
-			memory-region = <&smem_region>;
+		rpm_msg_ram: memory@fc428000 {
+			compatible = "qcom,rpm-msg-ram";
 			reg = <0xfc428000 0x4000>;
-
-			hwlocks = <&tcsr_mutex 3>;
 		};
 
 		blsp1_uart2: serial@f991e000 {

drivers/soc/qcom/smem.c

@@ -664,37 +664,47 @@ static int qcom_smem_enumerate_partitions(struct qcom_smem *smem,
 	return 0;
 }
 
-static int qcom_smem_count_mem_regions(struct platform_device *pdev)
+static int qcom_smem_map_memory(struct qcom_smem *smem, struct device *dev,
+				const char *name, int i)
 {
-	struct resource *res;
-	int num_regions = 0;
-	int i;
-
-	for (i = 0; i < pdev->num_resources; i++) {
-		res = &pdev->resource[i];
+	struct device_node *np;
+	struct resource r;
+	int ret;
 
-		if (resource_type(res) == IORESOURCE_MEM)
-			num_regions++;
+	np = of_parse_phandle(dev->of_node, name, 0);
+	if (!np) {
+		dev_err(dev, "No %s specified\n", name);
+		return -EINVAL;
 	}
 
-	return num_regions;
+	ret = of_address_to_resource(np, 0, &r);
+	of_node_put(np);
+	if (ret)
+		return ret;
+
+	smem->regions[i].aux_base = (u32)r.start;
+	smem->regions[i].size = resource_size(&r);
+	smem->regions[i].virt_base = devm_ioremap_nocache(dev, r.start,
+							  resource_size(&r));
+	if (!smem->regions[i].virt_base)
+		return -ENOMEM;
+
+	return 0;
 }
 
 static int qcom_smem_probe(struct platform_device *pdev)
 {
 	struct smem_header *header;
-	struct device_node *np;
 	struct qcom_smem *smem;
-	struct resource *res;
-	struct resource r;
 	size_t array_size;
-	int num_regions = 0;
+	int num_regions;
 	int hwlock_id;
 	u32 version;
 	int ret;
-	int i;
 
-	num_regions = qcom_smem_count_mem_regions(pdev) + 1;
+	num_regions = 1;
+	if (of_find_property(pdev->dev.of_node, "qcom,rpm-msg-ram", NULL))
+		num_regions++;
 
 	array_size = num_regions * sizeof(struct smem_region);
 	smem = devm_kzalloc(&pdev->dev, sizeof(*smem) + array_size, GFP_KERNEL);
@@ -704,36 +714,13 @@ static int qcom_smem_probe(struct platform_device *pdev)
 	smem->dev = &pdev->dev;
 	smem->num_regions = num_regions;
 
-	np = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
-	if (!np) {
-		dev_err(&pdev->dev, "No memory-region specified\n");
-		return -EINVAL;
-	}
-
-	ret = of_address_to_resource(np, 0, &r);
-	of_node_put(np);
+	ret = qcom_smem_map_memory(smem, &pdev->dev, "memory-region", 0);
 	if (ret)
 		return ret;
 
-	smem->regions[0].aux_base = (u32)r.start;
-	smem->regions[0].size = resource_size(&r);
-	smem->regions[0].virt_base = devm_ioremap_nocache(&pdev->dev,
-							  r.start,
-							  resource_size(&r));
-	if (!smem->regions[0].virt_base)
-		return -ENOMEM;
-
-	for (i = 1; i < num_regions; i++) {
-		res = platform_get_resource(pdev, IORESOURCE_MEM, i - 1);
-
-		smem->regions[i].aux_base = (u32)res->start;
-		smem->regions[i].size = resource_size(res);
-		smem->regions[i].virt_base = devm_ioremap_nocache(&pdev->dev,
-								  res->start,
-								  resource_size(res));
-		if (!smem->regions[i].virt_base)
-			return -ENOMEM;
-	}
+	if (num_regions > 1 && (ret = qcom_smem_map_memory(smem, &pdev->dev,
+					"qcom,rpm-msg-ram", 1)))
+		return ret;
 
 	header = smem->regions[0].virt_base;
 	if (le32_to_cpu(header->initialized) != 1 ||