[PATCH net-next 10/10] net: dsa: microchip: move the drive strength config out of the common section

["Bastien Curutchet (Schneider Electric)" <bastien.curutchet@bootlin.com>]

The drive strength configuration is done during the setup of all
switches through a common function that then has specific behavior
depending on the switch identity.

Split the common configuration in two functions: one is dedicated to the
KSZ8 family, the other is dedicated to the KSZ9477 family.
Remove the drive strength configuration from the lan937x_setup since
the LAN937x family doesn't support it.

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
 drivers/net/dsa/microchip/ksz8.c         | 127 ++++++++++++++++++++++-
 drivers/net/dsa/microchip/ksz9477.c      |  54 +++++++++-
 drivers/net/dsa/microchip/ksz_common.c   | 171 ++-----------------------------
 drivers/net/dsa/microchip/ksz_common.h   |  32 +++++-
 drivers/net/dsa/microchip/lan937x_main.c |   4 -
 5 files changed, 218 insertions(+), 170 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
index 472cc62ea747..c4c769028a20 100644
--- a/drivers/net/dsa/microchip/ksz8.c
+++ b/drivers/net/dsa/microchip/ksz8.c
@@ -36,6 +36,15 @@
 #include "ksz8_reg.h"
 #include "ksz8.h"
 
+/* ksz88x3_drive_strengths - Drive strength mapping for KSZ8863, KSZ8873, ..
+ *			     variants.
+ * This values are documented in KSZ8873 and KSZ8863 datasheets.
+ */
+static const struct ksz_drive_strength ksz88x3_drive_strengths[] = {
+	{ 0,  8000 },
+	{ KSZ8873_DRIVE_STRENGTH_16MA, 16000 },
+};
+
 struct ksz88xx_stats_raw {
 	u64 rx;
 	u64 rx_hi;
@@ -2291,6 +2300,122 @@ static void ksz88xx_r_mib_stats64(struct ksz_device *dev, int port)
 	spin_unlock(&mib->stats64_lock);
 }
 
+/**
+ * ksz88x3_drive_strength_write() - Set the drive strength configuration for
+ *				    KSZ8863 compatible chip variants.
+ * @dev:       ksz device
+ * @props:     Array of drive strength properties to be set
+ * @num_props: Number of properties in the array
+ *
+ * This function applies the specified drive strength settings to KSZ88X3 chip
+ * variants (KSZ8873, KSZ8863).
+ * It ensures the configurations align with what the chip variant supports and
+ * warns or errors out on unsupported settings.
+ *
+ * Return: 0 on success, error code otherwise
+ */
+static int ksz88x3_drive_strength_write(struct ksz_device *dev,
+					struct ksz_driver_strength_prop *props,
+					int num_props)
+{
+	size_t array_size = ARRAY_SIZE(ksz88x3_drive_strengths);
+	int microamp;
+	int i, ret;
+
+	for (i = 0; i < num_props; i++) {
+		if (props[i].value == -1 || i == KSZ_DRIVER_STRENGTH_IO)
+			continue;
+
+		dev_warn(dev->dev, "%s is not supported by this chip variant\n",
+			 props[i].name);
+	}
+
+	microamp = props[KSZ_DRIVER_STRENGTH_IO].value;
+	ret = ksz_drive_strength_to_reg(ksz88x3_drive_strengths, array_size,
+					microamp);
+	if (ret < 0) {
+		ksz_drive_strength_error(dev, ksz88x3_drive_strengths,
+					 array_size, microamp);
+		return ret;
+	}
+
+	return ksz_rmw8(dev, KSZ8873_REG_GLOBAL_CTRL_12,
+			KSZ8873_DRIVE_STRENGTH_16MA, ret);
+}
+
+/**
+ * ksz8_parse_drive_strength() - Extract and apply drive strength configurations
+ *				 from device tree properties.
+ * @dev:	ksz device
+ *
+ * This function reads the specified drive strength properties from the
+ * device tree, validates against the supported chip variants, and sets
+ * them accordingly. An error should be critical here, as the drive strength
+ * settings are crucial for EMI compliance.
+ *
+ * Return: 0 on success, error code otherwise
+ */
+static int ksz8_parse_drive_strength(struct ksz_device *dev)
+{
+	struct ksz_driver_strength_prop of_props[] = {
+		[KSZ_DRIVER_STRENGTH_HI] = {
+			.name = "microchip,hi-drive-strength-microamp",
+			.offset = SW_HI_SPEED_DRIVE_STRENGTH_S,
+			.value = -1,
+		},
+		[KSZ_DRIVER_STRENGTH_LO] = {
+			.name = "microchip,lo-drive-strength-microamp",
+			.offset = SW_LO_SPEED_DRIVE_STRENGTH_S,
+			.value = -1,
+		},
+		[KSZ_DRIVER_STRENGTH_IO] = {
+			.name = "microchip,io-drive-strength-microamp",
+			.offset = 0, /* don't care */
+			.value = -1,
+		},
+	};
+	struct device_node *np = dev->dev->of_node;
+	bool have_any_prop = false;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(of_props); i++) {
+		ret = of_property_read_u32(np, of_props[i].name,
+					   &of_props[i].value);
+		if (ret && ret != -EINVAL)
+			dev_warn(dev->dev, "Failed to read %s\n",
+				 of_props[i].name);
+		if (ret)
+			continue;
+
+		have_any_prop = true;
+	}
+
+	if (!have_any_prop)
+		return 0;
+
+	switch (dev->chip_id) {
+	case KSZ88X3_CHIP_ID:
+		return ksz88x3_drive_strength_write(dev, of_props,
+						    ARRAY_SIZE(of_props));
+	case KSZ8795_CHIP_ID:
+	case KSZ8794_CHIP_ID:
+	case KSZ8765_CHIP_ID:
+		return ksz_drive_strength_write(dev, of_props,
+						ARRAY_SIZE(of_props));
+	default:
+		/* KSZ8864, KSZ8895 */
+		for (i = 0; i < ARRAY_SIZE(of_props); i++) {
+			if (of_props[i].value == -1)
+				continue;
+
+			dev_warn(dev->dev, "%s is not supported by this chip variant\n",
+				 of_props[i].name);
+		}
+	}
+
+	return 0;
+}
+
 static int ksz8_setup(struct dsa_switch *ds)
 {
 	struct ksz_device *dev = ds->priv;
@@ -2313,7 +2438,7 @@ static int ksz8_setup(struct dsa_switch *ds)
 		return ret;
 	}
 
-	ret = ksz_parse_drive_strength(dev);
+	ret = ksz8_parse_drive_strength(dev);
 	if (ret)
 		return ret;
 
diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c
index 691b9b18c707..3ee995545c57 100644
--- a/drivers/net/dsa/microchip/ksz9477.c
+++ b/drivers/net/dsa/microchip/ksz9477.c
@@ -1615,6 +1615,58 @@ int ksz9477_enable_stp_addr(struct ksz_device *dev)
 	return 0;
 }
 
+/**
+ * ksz9477_parse_drive_strength() - Extract and apply drive strength
+ *				    configurations from device tree properties.
+ * @dev:	ksz device
+ *
+ * This function reads the specified drive strength properties from the
+ * device tree, validates against the supported chip variants, and sets
+ * them accordingly. An error should be critical here, as the drive strength
+ * settings are crucial for EMI compliance.
+ *
+ * Return: 0 on success, error code otherwise
+ */
+static int ksz9477_parse_drive_strength(struct ksz_device *dev)
+{
+	struct ksz_driver_strength_prop of_props[] = {
+		[KSZ_DRIVER_STRENGTH_HI] = {
+			.name = "microchip,hi-drive-strength-microamp",
+			.offset = SW_HI_SPEED_DRIVE_STRENGTH_S,
+			.value = -1,
+		},
+		[KSZ_DRIVER_STRENGTH_LO] = {
+			.name = "microchip,lo-drive-strength-microamp",
+			.offset = SW_LO_SPEED_DRIVE_STRENGTH_S,
+			.value = -1,
+		},
+		[KSZ_DRIVER_STRENGTH_IO] = {
+			.name = "microchip,io-drive-strength-microamp",
+			.offset = 0, /* don't care */
+			.value = -1,
+		},
+	};
+	struct device_node *np = dev->dev->of_node;
+	bool have_any_prop = false;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(of_props); i++) {
+		ret = of_property_read_u32(np, of_props[i].name,
+					   &of_props[i].value);
+		if (ret && ret != -EINVAL)
+			dev_warn(dev->dev, "Failed to read %s\n",
+				 of_props[i].name);
+		if (ret)
+			continue;
+
+		have_any_prop = true;
+	}
+
+	if (!have_any_prop)
+		return 0;
+
+	return ksz_drive_strength_write(dev, of_props, ARRAY_SIZE(of_props));
+}
 static int ksz9477_setup(struct dsa_switch *ds)
 {
 	struct ksz_device *dev = ds->priv;
@@ -1637,7 +1689,7 @@ static int ksz9477_setup(struct dsa_switch *ds)
 		return ret;
 	}
 
-	ret = ksz_parse_drive_strength(dev);
+	ret = ksz9477_parse_drive_strength(dev);
 	if (ret)
 		return ret;
 
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 15ed139564cb..67ab6ddb9e53 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -113,28 +113,6 @@ static const struct ksz_mib_names ksz9477_mib_names[] = {
 	{ 0x83, "tx_discards" },
 };
 
-struct ksz_driver_strength_prop {
-	const char *name;
-	int offset;
-	int value;
-};
-
-enum ksz_driver_strength_type {
-	KSZ_DRIVER_STRENGTH_HI,
-	KSZ_DRIVER_STRENGTH_LO,
-	KSZ_DRIVER_STRENGTH_IO,
-};
-
-/**
- * struct ksz_drive_strength - drive strength mapping
- * @reg_val:	register value
- * @microamp:	microamp value
- */
-struct ksz_drive_strength {
-	u32 reg_val;
-	u32 microamp;
-};
-
 /* ksz9477_drive_strengths - Drive strength mapping for KSZ9477 variants
  *
  * This values are not documented in KSZ9477 variants but confirmed by
@@ -170,15 +148,6 @@ static const struct ksz_drive_strength ksz9477_drive_strengths[] = {
 	{ SW_DRIVE_STRENGTH_28MA, 28000 },
 };
 
-/* ksz88x3_drive_strengths - Drive strength mapping for KSZ8863, KSZ8873, ..
- *			     variants.
- * This values are documented in KSZ8873 and KSZ8863 datasheets.
- */
-static const struct ksz_drive_strength ksz88x3_drive_strengths[] = {
-	{ 0,  8000 },
-	{ KSZ8873_DRIVE_STRENGTH_16MA, 16000 },
-};
-
 /**
  * ksz_phylink_mac_disable_tx_lpi() - Callback to signal LPI support (Dummy)
  * @config: phylink config structure
@@ -3785,8 +3754,8 @@ static void ksz_parse_rgmii_delay(struct ksz_device *dev, int port_num,
  * Returns: If found, the corresponding register value for that drive strength
  * is returned. Otherwise, -EINVAL is returned indicating an invalid value.
  */
-static int ksz_drive_strength_to_reg(const struct ksz_drive_strength *array,
-				     size_t array_size, int microamp)
+int ksz_drive_strength_to_reg(const struct ksz_drive_strength *array,
+			      size_t array_size, int microamp)
 {
 	int i;
 
@@ -3809,9 +3778,9 @@ static int ksz_drive_strength_to_reg(const struct ksz_drive_strength *array,
  * is detected. It lists out all the supported drive strength values for
  * reference in the error message.
  */
-static void ksz_drive_strength_error(struct ksz_device *dev,
-				     const struct ksz_drive_strength *array,
-				     size_t array_size, int microamp)
+void ksz_drive_strength_error(struct ksz_device *dev,
+			      const struct ksz_drive_strength *array,
+			      size_t array_size, int microamp)
 {
 	char supported_values[100];
 	size_t remaining_size;
@@ -3850,9 +3819,9 @@ static void ksz_drive_strength_error(struct ksz_device *dev,
  *
  * Return: 0 on successful configuration, a negative error code on failure.
  */
-static int ksz_drive_strength_write(struct ksz_device *dev,
-				    struct ksz_driver_strength_prop *props,
-				    int num_props)
+int ksz_drive_strength_write(struct ksz_device *dev,
+			     struct ksz_driver_strength_prop *props,
+			     int num_props)
 {
 	size_t array_size = ARRAY_SIZE(ksz9477_drive_strengths);
 	int i, ret, reg;
@@ -3889,130 +3858,6 @@ static int ksz_drive_strength_write(struct ksz_device *dev,
 	return ksz_rmw8(dev, reg, mask, val);
 }
 
-/**
- * ksz88x3_drive_strength_write() - Set the drive strength configuration for
- *				    KSZ8863 compatible chip variants.
- * @dev:       ksz device
- * @props:     Array of drive strength properties to be set
- * @num_props: Number of properties in the array
- *
- * This function applies the specified drive strength settings to KSZ88X3 chip
- * variants (KSZ8873, KSZ8863).
- * It ensures the configurations align with what the chip variant supports and
- * warns or errors out on unsupported settings.
- *
- * Return: 0 on success, error code otherwise
- */
-static int ksz88x3_drive_strength_write(struct ksz_device *dev,
-					struct ksz_driver_strength_prop *props,
-					int num_props)
-{
-	size_t array_size = ARRAY_SIZE(ksz88x3_drive_strengths);
-	int microamp;
-	int i, ret;
-
-	for (i = 0; i < num_props; i++) {
-		if (props[i].value == -1 || i == KSZ_DRIVER_STRENGTH_IO)
-			continue;
-
-		dev_warn(dev->dev, "%s is not supported by this chip variant\n",
-			 props[i].name);
-	}
-
-	microamp = props[KSZ_DRIVER_STRENGTH_IO].value;
-	ret = ksz_drive_strength_to_reg(ksz88x3_drive_strengths, array_size,
-					microamp);
-	if (ret < 0) {
-		ksz_drive_strength_error(dev, ksz88x3_drive_strengths,
-					 array_size, microamp);
-		return ret;
-	}
-
-	return ksz_rmw8(dev, KSZ8873_REG_GLOBAL_CTRL_12,
-			KSZ8873_DRIVE_STRENGTH_16MA, ret);
-}
-
-/**
- * ksz_parse_drive_strength() - Extract and apply drive strength configurations
- *				from device tree properties.
- * @dev:	ksz device
- *
- * This function reads the specified drive strength properties from the
- * device tree, validates against the supported chip variants, and sets
- * them accordingly. An error should be critical here, as the drive strength
- * settings are crucial for EMI compliance.
- *
- * Return: 0 on success, error code otherwise
- */
-int ksz_parse_drive_strength(struct ksz_device *dev)
-{
-	struct ksz_driver_strength_prop of_props[] = {
-		[KSZ_DRIVER_STRENGTH_HI] = {
-			.name = "microchip,hi-drive-strength-microamp",
-			.offset = SW_HI_SPEED_DRIVE_STRENGTH_S,
-			.value = -1,
-		},
-		[KSZ_DRIVER_STRENGTH_LO] = {
-			.name = "microchip,lo-drive-strength-microamp",
-			.offset = SW_LO_SPEED_DRIVE_STRENGTH_S,
-			.value = -1,
-		},
-		[KSZ_DRIVER_STRENGTH_IO] = {
-			.name = "microchip,io-drive-strength-microamp",
-			.offset = 0, /* don't care */
-			.value = -1,
-		},
-	};
-	struct device_node *np = dev->dev->of_node;
-	bool have_any_prop = false;
-	int i, ret;
-
-	for (i = 0; i < ARRAY_SIZE(of_props); i++) {
-		ret = of_property_read_u32(np, of_props[i].name,
-					   &of_props[i].value);
-		if (ret && ret != -EINVAL)
-			dev_warn(dev->dev, "Failed to read %s\n",
-				 of_props[i].name);
-		if (ret)
-			continue;
-
-		have_any_prop = true;
-	}
-
-	if (!have_any_prop)
-		return 0;
-
-	switch (dev->chip_id) {
-	case KSZ88X3_CHIP_ID:
-		return ksz88x3_drive_strength_write(dev, of_props,
-						    ARRAY_SIZE(of_props));
-	case KSZ8795_CHIP_ID:
-	case KSZ8794_CHIP_ID:
-	case KSZ8765_CHIP_ID:
-	case KSZ8563_CHIP_ID:
-	case KSZ8567_CHIP_ID:
-	case KSZ9477_CHIP_ID:
-	case KSZ9563_CHIP_ID:
-	case KSZ9567_CHIP_ID:
-	case KSZ9893_CHIP_ID:
-	case KSZ9896_CHIP_ID:
-	case KSZ9897_CHIP_ID:
-	case LAN9646_CHIP_ID:
-		return ksz_drive_strength_write(dev, of_props,
-						ARRAY_SIZE(of_props));
-	default:
-		for (i = 0; i < ARRAY_SIZE(of_props); i++) {
-			if (of_props[i].value == -1)
-				continue;
-
-			dev_warn(dev->dev, "%s is not supported by this chip variant\n",
-				 of_props[i].name);
-		}
-	}
-
-	return 0;
-}
-
 static int ksz8463_configure_straps_spi(struct ksz_device *dev)
 {
 	struct pinctrl *pinctrl;
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 029080838237..acaf70e6f393 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -511,7 +511,37 @@ int ksz_mdio_register(struct ksz_device *dev);
 int ksz_pirq_setup(struct ksz_device *dev, u8 p);
 int ksz_girq_setup(struct ksz_device *dev);
 void ksz_irq_free(struct ksz_irq *kirq);
-int ksz_parse_drive_strength(struct ksz_device *dev);
+
+struct ksz_driver_strength_prop {
+	const char *name;
+	int offset;
+	int value;
+};
+
+enum ksz_driver_strength_type {
+	KSZ_DRIVER_STRENGTH_HI,
+	KSZ_DRIVER_STRENGTH_LO,
+	KSZ_DRIVER_STRENGTH_IO,
+};
+
+/**
+ * struct ksz_drive_strength - drive strength mapping
+ * @reg_val:	register value
+ * @microamp:	microamp value
+ */
+struct ksz_drive_strength {
+	u32 reg_val;
+	u32 microamp;
+};
+
+void ksz_drive_strength_error(struct ksz_device *dev,
+			      const struct ksz_drive_strength *array,
+			      size_t array_size, int microamp);
+int ksz_drive_strength_to_reg(const struct ksz_drive_strength *array,
+			      size_t array_size, int microamp);
+int ksz_drive_strength_write(struct ksz_device *dev,
+			     struct ksz_driver_strength_prop *props,
+			     int num_props);
 
 /* Common register access functions */
 static inline struct regmap *ksz_regmap_8(struct ksz_device *dev)
diff --git a/drivers/net/dsa/microchip/lan937x_main.c b/drivers/net/dsa/microchip/lan937x_main.c
index f060fbc4c4f4..86ce3a86705f 100644
--- a/drivers/net/dsa/microchip/lan937x_main.c
+++ b/drivers/net/dsa/microchip/lan937x_main.c
@@ -787,10 +787,6 @@ static int lan937x_setup(struct dsa_switch *ds)
 		return ret;
 	}
 
-	ret = ksz_parse_drive_strength(dev);
-	if (ret)
-		return ret;
-
 	/* set broadcast storm protection 10% rate */
 	storm_mask = BROADCAST_STORM_RATE;
 	storm_rate = (BROADCAST_STORM_VALUE * BROADCAST_STORM_PROT_RATE) / 100;

-- 
2.54.0