[PATCH v4 0/5] phy: phy-can-transceiver: Ad-hoc cleanups and refactoring

[PATCH v4 0/5] phy: phy-can-transceiver: Ad-hoc cleanups and refactoring

[Andy Shevchenko]

The driver does two things that need to be addressed:
- includes subject to remove gpio.h
- checks for error code from device property APIs when it can be done in
  a robust way

This series addresses the above and adds a couple of additional refactoring.

On top of that it fixes potential NULL pointer dereference when driver_override
is in use.

Changelog v4:
- prepended the series with match and driver data check (Sashiko, Vinod)
- made the max_bitrate==0 warning only when property is present (Sashiko, Vinod)
- rebased the rest accordingly

v3: 20260504070054.29508-1-andriy.shevchenko@linux.intel.com

Changelog v3:
- fixed commit message in patch 1 (Josua)
- dropped stray change (Vinod)
- collected tags (Josua)

v2: 20260317203001.2108568-1-andriy.shevchenko@linux.intel.com

Changelog v2:
- rebased on top of the latest changes in the driver
- Cc'ed to Ulf and Josua due to above
- elaborated dropping of_node parameter (Vladimir)

v1: 20260219202910.2304440-1-andriy.shevchenko@linux.intel.com

Andy Shevchenko (5):
  phy: phy-can-transceiver: Check driver match and driver data against
    NULL
  phy: phy-can-transceiver: use device_get_match_data()
  phy: phy-can-transceiver: Move OF ID table closer to their user
  phy: phy-can-transceiver: Don't check for specific errors when parsing
    properties
  phy: phy-can-transceiver: Drop unused include

 drivers/phy/phy-can-transceiver.c | 89 +++++++++++++++++--------------
 1 file changed, 49 insertions(+), 40 deletions(-)

-- 
2.50.1

[PATCH v4 1/5] phy: phy-can-transceiver: Check driver match and driver data against NULL

[Andy Shevchenko]

Every platform driver can be forced to match a device that doesn't
match its list of device IDs because of device_match_driver_override()
so platform drivers that rely on the existence of a device's driver
data need to verify its presence.

Accordingly, add requisite match and driver data checks against NULL
to the driver where they are missing.

Fixes: a4a86d273ff1 ("phy: phy-can-transceiver: Add support for generic CAN transceiver driver")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/phy/phy-can-transceiver.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
index 2b52e47f247a..1808f903c057 100644
--- a/drivers/phy/phy-can-transceiver.c
+++ b/drivers/phy/phy-can-transceiver.c
@@ -162,6 +162,9 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
 	int err, i, num_ch = 1;
 
 	match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node);
+	if (!match || !match->data)
+		return -ENODEV;
+
 	drvdata = match->data;
 	if (drvdata->flags & CAN_TRANSCEIVER_DUAL_CH)
 		num_ch = 2;
-- 
2.50.1

[PATCH v4 2/5] phy: phy-can-transceiver: use device_get_match_data()

[Andy Shevchenko]

Use the generic firmware node interface for retrieving
device match data instead of the OF-specific one.

While at it, drop unneeded argument to devm_phy_create() which
extracts device node from the given device by default.

Reviewed-by: Josua Mayer <josua@solid-run.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/phy/phy-can-transceiver.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
index 1808f903c057..5cfd09735204 100644
--- a/drivers/phy/phy-can-transceiver.c
+++ b/drivers/phy/phy-can-transceiver.c
@@ -5,9 +5,9 @@
  * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com
  *
  */
-#include <linux/of.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 #include <linux/module.h>
 #include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
@@ -152,7 +152,6 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
 	struct can_transceiver_phy *can_transceiver_phy;
 	struct can_transceiver_priv *priv;
 	const struct can_transceiver_data *drvdata;
-	const struct of_device_id *match;
 	struct phy *phy;
 	struct gpio_desc *silent_gpio;
 	struct gpio_desc *standby_gpio;
@@ -161,11 +160,10 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
 	u32 max_bitrate = 0;
 	int err, i, num_ch = 1;
 
-	match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node);
-	if (!match || !match->data)
+	drvdata = device_get_match_data(dev);
+	if (drvdata)
 		return -ENODEV;
 
-	drvdata = match->data;
 	if (drvdata->flags & CAN_TRANSCEIVER_DUAL_CH)
 		num_ch = 2;
 
@@ -190,7 +188,7 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
 		can_transceiver_phy = &priv->can_transceiver_phy[i];
 		can_transceiver_phy->priv = priv;
 
-		phy = devm_phy_create(dev, dev->of_node, &can_transceiver_phy_ops);
+		phy = devm_phy_create(dev, NULL, &can_transceiver_phy_ops);
 		if (IS_ERR(phy)) {
 			dev_err(dev, "failed to create can transceiver phy\n");
 			return PTR_ERR(phy);
-- 
2.50.1

[PATCH v4 3/5] phy: phy-can-transceiver: Move OF ID table closer to their user

[Andy Shevchenko]

There is no code that uses ID table directly, except the
struct device_driver at the end of the file. Hence, move
table closer to its user. It's always possible to access
them via a pointer.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/phy/phy-can-transceiver.c | 58 +++++++++++++++----------------
 1 file changed, 29 insertions(+), 29 deletions(-)

diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
index 5cfd09735204..23655956ace8 100644
--- a/drivers/phy/phy-can-transceiver.c
+++ b/drivers/phy/phy-can-transceiver.c
@@ -97,35 +97,6 @@ static const struct can_transceiver_data tja1057_drvdata = {
 	.flags = CAN_TRANSCEIVER_SILENT_PRESENT,
 };
 
-static const struct of_device_id can_transceiver_phy_ids[] = {
-	{
-		.compatible = "ti,tcan1042",
-		.data = &tcan1042_drvdata
-	},
-	{
-		.compatible = "ti,tcan1043",
-		.data = &tcan1043_drvdata
-	},
-	{
-		.compatible = "nxp,tja1048",
-		.data = &tja1048_drvdata
-	},
-	{
-		.compatible = "nxp,tja1051",
-		.data = &tja1051_drvdata
-	},
-	{
-		.compatible = "nxp,tja1057",
-		.data = &tja1057_drvdata
-	},
-	{
-		.compatible = "nxp,tjr1443",
-		.data = &tcan1043_drvdata
-	},
-	{ }
-};
-MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids);
-
 static struct phy *can_transceiver_phy_xlate(struct device *dev,
 					     const struct of_phandle_args *args)
 {
@@ -232,6 +203,35 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
 	return PTR_ERR_OR_ZERO(phy_provider);
 }
 
+static const struct of_device_id can_transceiver_phy_ids[] = {
+	{
+		.compatible = "ti,tcan1042",
+		.data = &tcan1042_drvdata
+	},
+	{
+		.compatible = "ti,tcan1043",
+		.data = &tcan1043_drvdata
+	},
+	{
+		.compatible = "nxp,tja1048",
+		.data = &tja1048_drvdata
+	},
+	{
+		.compatible = "nxp,tja1051",
+		.data = &tja1051_drvdata
+	},
+	{
+		.compatible = "nxp,tja1057",
+		.data = &tja1057_drvdata
+	},
+	{
+		.compatible = "nxp,tjr1443",
+		.data = &tcan1043_drvdata
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids);
+
 static struct platform_driver can_transceiver_phy_driver = {
 	.probe = can_transceiver_phy_probe,
 	.driver = {
-- 
2.50.1

[PATCH v4 4/5] phy: phy-can-transceiver: Don't check for specific errors when parsing properties

[Andy Shevchenko]

Instead of checking for the specific error codes (that can be considered
a layering violation to some extent) check for the property existence first
and then either parse it, or apply a default value.

With that, return an error when parsing of the existing property fails.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/phy/phy-can-transceiver.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
index 23655956ace8..973cc7ce651f 100644
--- a/drivers/phy/phy-can-transceiver.c
+++ b/drivers/phy/phy-can-transceiver.c
@@ -128,8 +128,9 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
 	struct gpio_desc *standby_gpio;
 	struct gpio_desc *enable_gpio;
 	struct mux_state *mux_state;
-	u32 max_bitrate = 0;
 	int err, i, num_ch = 1;
+	const char *propname;
+	u32 max_bitrate;
 
 	drvdata = device_get_match_data(dev);
 	if (drvdata)
@@ -151,9 +152,17 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
 
 	priv->mux_state = mux_state;
 
-	err = device_property_read_u32(dev, "max-bitrate", &max_bitrate);
-	if ((err != -EINVAL) && !max_bitrate)
-		dev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n");
+	propname = "max-bitrate";
+	if (device_property_present(dev, propname)) {
+		err = device_property_read_u32(dev, propname, &max_bitrate);
+		if (err)
+			return dev_err_probe(dev, err, "failed to parse %s\n", propname);
+
+		if (max_bitrate == 0)
+			dev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n");
+	} else {
+		max_bitrate = 0;
+	}
 
 	for (i = 0; i < num_ch; i++) {
 		can_transceiver_phy = &priv->can_transceiver_phy[i];
-- 
2.50.1

[PATCH v4 5/5] phy: phy-can-transceiver: Drop unused include

[Andy Shevchenko]

This file does not use the symbols from the legacy
<linux/gpio.h> header, so let's drop it.

Reviewed-by: Josua Mayer <josua@solid-run.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/phy/phy-can-transceiver.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
index 973cc7ce651f..534a4fc482aa 100644
--- a/drivers/phy/phy-can-transceiver.c
+++ b/drivers/phy/phy-can-transceiver.c
@@ -5,12 +5,11 @@
  * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com
  *
  */
+#include <linux/gpio/consumer.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/module.h>
-#include <linux/gpio.h>
-#include <linux/gpio/consumer.h>
 #include <linux/mux/consumer.h>
 
 struct can_transceiver_data {
-- 
2.50.1