netdev - [PATCH net-next v2] net: sfp: clean up i2c-bus property parsing

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Message-Id: <E1p1OIG-0098J4-EV@rmk-PC.armlinux.org.uk>
Date:   Sat, 03 Dec 2022 08:54:44 +0000
From:   "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>
To:     Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>
Cc:     "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>
Subject: [PATCH net-next v2] net: sfp: clean up i2c-bus property parsing

We currently have some complicated code in sfp_probe() which gets the
I2C bus depending on whether the sfp node is DT or ACPI, and we use
completely separate lookup functions.

This could do with being in a separate function to make the code more
readable, so move it to a new function, sfp_i2c_get(). We can also use
fwnode_find_reference() to lookup the I2C bus fwnode before then
decending into fwnode-type specific parsing.

A future cleanup would be to move the fwnode-type specific parsing into
the i2c layer, which is where it really should be.

Signed-off-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>
---
v2: actually send version with ACPI build error fixed (doesn't show up unless
 ACPI is enabled.)

 drivers/net/phy/sfp.c | 74 +++++++++++++++++++++++--------------------
 1 file changed, 40 insertions(+), 34 deletions(-)

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 39fd1811375c..09c1d10f5b5d 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -2642,10 +2642,46 @@ static void sfp_cleanup(void *data)
 	kfree(sfp);
 }
 
+static int sfp_i2c_get(struct sfp *sfp)
+{
+	struct acpi_handle *acpi_handle;
+	struct fwnode_handle *h;
+	struct i2c_adapter *i2c;
+	struct device_node *np;
+	int err;
+
+	h = fwnode_find_reference(dev_fwnode(sfp->dev), "i2c-bus", 0);
+	if (IS_ERR(h)) {
+		dev_err(sfp->dev, "missing 'i2c-bus' property\n");
+		return -ENODEV;
+	}
+
+	if (is_acpi_device_node(h)) {
+		acpi_handle = ACPI_HANDLE_FWNODE(h);
+		i2c = i2c_acpi_find_adapter_by_handle(acpi_handle);
+	} else if ((np = to_of_node(h)) != NULL) {
+		i2c = of_find_i2c_adapter_by_node(np);
+	} else {
+		err = -EINVAL;
+		goto put;
+	}
+
+	if (!i2c) {
+		err = -EPROBE_DEFER;
+		goto put;
+	}
+
+	err = sfp_i2c_configure(sfp, i2c);
+	if (err)
+		i2c_put_adapter(i2c);
+put:
+	fwnode_handle_put(h);
+	return err;
+}
+
 static int sfp_probe(struct platform_device *pdev)
 {
 	const struct sff_data *sff;
-	struct i2c_adapter *i2c;
 	char *sfp_irq_name;
 	struct sfp *sfp;
 	int err, i;
@@ -2665,49 +2701,19 @@ static int sfp_probe(struct platform_device *pdev)
 	if (pdev->dev.of_node) {
 		struct device_node *node = pdev->dev.of_node;
 		const struct of_device_id *id;
-		struct device_node *np;
 
 		id = of_match_node(sfp_of_match, node);
 		if (WARN_ON(!id))
 			return -EINVAL;
 
 		sff = sfp->type = id->data;
-
-		np = of_parse_phandle(node, "i2c-bus", 0);
-		if (!np) {
-			dev_err(sfp->dev, "missing 'i2c-bus' property\n");
-			return -ENODEV;
-		}
-
-		i2c = of_find_i2c_adapter_by_node(np);
-		of_node_put(np);
-	} else if (has_acpi_companion(&pdev->dev)) {
-		struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
-		struct fwnode_handle *fw = acpi_fwnode_handle(adev);
-		struct fwnode_reference_args args;
-		struct acpi_handle *acpi_handle;
-		int ret;
-
-		ret = acpi_node_get_property_reference(fw, "i2c-bus", 0, &args);
-		if (ret || !is_acpi_device_node(args.fwnode)) {
-			dev_err(&pdev->dev, "missing 'i2c-bus' property\n");
-			return -ENODEV;
-		}
-
-		acpi_handle = ACPI_HANDLE_FWNODE(args.fwnode);
-		i2c = i2c_acpi_find_adapter_by_handle(acpi_handle);
-	} else {
+	} else if (!has_acpi_companion(&pdev->dev)) {
 		return -EINVAL;
 	}
 
-	if (!i2c)
-		return -EPROBE_DEFER;
-
-	err = sfp_i2c_configure(sfp, i2c);
-	if (err < 0) {
-		i2c_put_adapter(i2c);
+	err = sfp_i2c_get(sfp);
+	if (err)
 		return err;
-	}
 
 	for (i = 0; i < GPIO_MAX; i++)
 		if (sff->gpios & BIT(i)) {
-- 
2.30.2