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From:   Anup Patel <apatel@ventanamicro.com>
To:     Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Frank Rowand <frowand.list@gmail.com>,
        Conor Dooley <conor+dt@kernel.org>
Cc:     Atish Patra <atishp@atishpatra.org>,
        Andrew Jones <ajones@ventanamicro.com>,
        Sunil V L <sunilvl@ventanamicro.com>,
        Saravana Kannan <saravanak@google.com>,
        Anup Patel <anup@brainfault.org>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, Anup Patel <apatel@ventanamicro.com>
Subject: [PATCH v7 02/15] of: property: Add fw_devlink support for msi-parent
Date:   Wed,  2 Aug 2023 20:30:05 +0530
Message-Id: <20230802150018.327079-3-apatel@ventanamicro.com>
In-Reply-To: <20230802150018.327079-1-apatel@ventanamicro.com>
References: <20230802150018.327079-1-apatel@ventanamicro.com>
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This allows fw_devlink to create device links between consumers of
a MSI and the supplier of the MSI.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/of/property.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/of/property.c b/drivers/of/property.c
index ddc75cd50825..bc20535deed7 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1325,6 +1325,37 @@ static struct device_node *parse_interrupts(struct device_node *np,
 	return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
 }
 
+static struct device_node *parse_msi_parent(struct device_node *np,
+					    const char *prop_name, int index)
+{
+	struct of_phandle_args sup_args;
+	struct device_node *msi_np;
+
+	if (IS_ENABLED(CONFIG_SPARC))
+		return NULL;
+
+	if (strcmp(prop_name, "msi-parent"))
+		return NULL;
+
+	msi_np = of_parse_phandle(np, prop_name, 0);
+	if (msi_np) {
+		if (!of_property_read_bool(msi_np, "#msi-cells")) {
+			if (index) {
+				of_node_put(msi_np);
+				return NULL;
+			}
+			return msi_np;
+		}
+		of_node_put(msi_np);
+	}
+
+	if (of_parse_phandle_with_args(np, prop_name, "#msi-cells", index,
+				       &sup_args))
+		return NULL;
+
+	return sup_args.np;
+}
+
 static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_clocks, },
 	{ .parse_prop = parse_interconnects, },
@@ -1359,6 +1390,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_regulators, },
 	{ .parse_prop = parse_gpio, },
 	{ .parse_prop = parse_gpios, },
+	{ .parse_prop = parse_msi_parent, },
 	{}
 };
 
-- 
2.34.1