net: dsa: mt7530-mdio: read PHY address of switch from device tree

Read the PHY address the switch listens on from the reg property of the
switch node on the device tree. This change brings support for MT7530
switches on boards with such bootstrapping configuration where the switch
listens on a different PHY address than the hardcoded PHY address on the
driver, 31.

As described on the "MT7621 Programming Guide v0.4" document, the MT7530
switch and its PHYs can be configured to listen on the range of 7-12,
15-20, 23-28, and 31 and 0-4 PHY addresses.

There are operations where the switch PHY registers are used. For the PHY
address of the control PHY, transform the MT753X_CTRL_PHY_ADDR constant
into a macro and use it. The PHY address for the control PHY is 0 when the
switch listens on 31. In any other case, it is one greater than the PHY
address the switch listens on.
Reviewed-by: Daniel Golle <daniel@makrotopia.org>
Tested-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/dsa/mt7530-mdio.c

@@ -18,7 +18,8 @@
 static int
 mt7530_regmap_write(void *context, unsigned int reg, unsigned int val)
 {
-	struct mii_bus *bus = context;
+	struct mt7530_priv *priv = context;
+	struct mii_bus *bus = priv->bus;
 	u16 page, r, lo, hi;
 	int ret;
 
@@ -27,36 +28,35 @@ mt7530_regmap_write(void *context, unsigned int reg, unsigned int val)
 	lo = val & 0xffff;
 	hi = val >> 16;
 
-	/* MT7530 uses 31 as the pseudo port */
-	ret = bus->write(bus, 0x1f, 0x1f, page);
+	ret = bus->write(bus, priv->mdiodev->addr, 0x1f, page);
 	if (ret < 0)
 		return ret;
 
-	ret = bus->write(bus, 0x1f, r,  lo);
+	ret = bus->write(bus, priv->mdiodev->addr, r, lo);
 	if (ret < 0)
 		return ret;
 
-	ret = bus->write(bus, 0x1f, 0x10, hi);
+	ret = bus->write(bus, priv->mdiodev->addr, 0x10, hi);
 	return ret;
 }
 
 static int
 mt7530_regmap_read(void *context, unsigned int reg, unsigned int *val)
 {
-	struct mii_bus *bus = context;
+	struct mt7530_priv *priv = context;
+	struct mii_bus *bus = priv->bus;
 	u16 page, r, lo, hi;
 	int ret;
 
 	page = (reg >> 6) & 0x3ff;
 	r = (reg >> 2) & 0xf;
 
-	/* MT7530 uses 31 as the pseudo port */
-	ret = bus->write(bus, 0x1f, 0x1f, page);
+	ret = bus->write(bus, priv->mdiodev->addr, 0x1f, page);
 	if (ret < 0)
 		return ret;
 
-	lo = bus->read(bus, 0x1f, r);
-	hi = bus->read(bus, 0x1f, 0x10);
+	lo = bus->read(bus, priv->mdiodev->addr, r);
+	hi = bus->read(bus, priv->mdiodev->addr, 0x10);
 
 	*val = (hi << 16) | (lo & 0xffff);
 
@@ -107,8 +107,7 @@ mt7531_create_sgmii(struct mt7530_priv *priv)
 		mt7531_pcs_config[i]->unlock = mt7530_mdio_regmap_unlock;
 		mt7531_pcs_config[i]->lock_arg = &priv->bus->mdio_lock;
 
-		regmap = devm_regmap_init(priv->dev,
-					  &mt7530_regmap_bus, priv->bus,
+		regmap = devm_regmap_init(priv->dev, &mt7530_regmap_bus, priv,
 					  mt7531_pcs_config[i]);
 		if (IS_ERR(regmap)) {
 			ret = PTR_ERR(regmap);
@@ -153,6 +152,7 @@ mt7530_probe(struct mdio_device *mdiodev)
 
 	priv->bus = mdiodev->bus;
 	priv->dev = &mdiodev->dev;
+	priv->mdiodev = mdiodev;
 
 	ret = mt7530_probe_common(priv);
 	if (ret)
@@ -203,8 +203,8 @@ mt7530_probe(struct mdio_device *mdiodev)
 	regmap_config->reg_stride = 4;
 	regmap_config->max_register = MT7530_CREV;
 	regmap_config->disable_locking = true;
-	priv->regmap = devm_regmap_init(priv->dev, &mt7530_regmap_bus,
-					priv->bus, regmap_config);
+	priv->regmap = devm_regmap_init(priv->dev, &mt7530_regmap_bus, priv,
+					regmap_config);
 	if (IS_ERR(priv->regmap))
 		return PTR_ERR(priv->regmap);
 

drivers/net/dsa/mt7530.c

@@ -86,22 +86,26 @@ core_read_mmd_indirect(struct mt7530_priv *priv, int prtad, int devad)
 	int value, ret;
 
 	/* Write the desired MMD Devad */
-	ret = bus->write(bus, 0, MII_MMD_CTRL, devad);
+	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+			 MII_MMD_CTRL, devad);
 	if (ret < 0)
 		goto err;
 
 	/* Write the desired MMD register address */
-	ret = bus->write(bus, 0, MII_MMD_DATA, prtad);
+	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+			 MII_MMD_DATA, prtad);
 	if (ret < 0)
 		goto err;
 
 	/* Select the Function : DATA with no post increment */
-	ret = bus->write(bus, 0, MII_MMD_CTRL, (devad | MII_MMD_CTRL_NOINCR));
+	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+			 MII_MMD_CTRL, devad | MII_MMD_CTRL_NOINCR);
 	if (ret < 0)
 		goto err;
 
 	/* Read the content of the MMD's selected register */
-	value = bus->read(bus, 0, MII_MMD_DATA);
+	value = bus->read(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+			  MII_MMD_DATA);
 
 	return value;
 err:
@@ -118,22 +122,26 @@ core_write_mmd_indirect(struct mt7530_priv *priv, int prtad,
 	int ret;
 
 	/* Write the desired MMD Devad */
-	ret = bus->write(bus, 0, MII_MMD_CTRL, devad);
+	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+			 MII_MMD_CTRL, devad);
 	if (ret < 0)
 		goto err;
 
 	/* Write the desired MMD register address */
-	ret = bus->write(bus, 0, MII_MMD_DATA, prtad);
+	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+			 MII_MMD_DATA, prtad);
 	if (ret < 0)
 		goto err;
 
 	/* Select the Function : DATA with no post increment */
-	ret = bus->write(bus, 0, MII_MMD_CTRL, (devad | MII_MMD_CTRL_NOINCR));
+	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+			 MII_MMD_CTRL, devad | MII_MMD_CTRL_NOINCR);
 	if (ret < 0)
 		goto err;
 
 	/* Write the data into MMD's selected register */
-	ret = bus->write(bus, 0, MII_MMD_DATA, data);
+	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+			 MII_MMD_DATA, data);
 err:
 	if (ret < 0)
 		dev_err(&bus->dev,
@@ -2679,16 +2687,19 @@ mt7531_setup(struct dsa_switch *ds)
 	 * phy_[read,write]_mmd_indirect is called, we provide our own
 	 * mt7531_ind_mmd_phy_[read,write] to complete this function.
 	 */
-	val = mt7531_ind_c45_phy_read(priv, MT753X_CTRL_PHY_ADDR,
+	val = mt7531_ind_c45_phy_read(priv,
+				      MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
 				      MDIO_MMD_VEND2, CORE_PLL_GROUP4);
 	val |= MT7531_RG_SYSPLL_DMY2 | MT7531_PHY_PLL_BYPASS_MODE;
 	val &= ~MT7531_PHY_PLL_OFF;
-	mt7531_ind_c45_phy_write(priv, MT753X_CTRL_PHY_ADDR, MDIO_MMD_VEND2,
-				 CORE_PLL_GROUP4, val);
+	mt7531_ind_c45_phy_write(priv,
+				 MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+				 MDIO_MMD_VEND2, CORE_PLL_GROUP4, val);
 
 	/* Disable EEE advertisement on the switch PHYs. */
-	for (i = MT753X_CTRL_PHY_ADDR;
-	     i < MT753X_CTRL_PHY_ADDR + MT7530_NUM_PHYS; i++) {
+	for (i = MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr);
+	     i < MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr) + MT7530_NUM_PHYS;
+	     i++) {
 		mt7531_ind_c45_phy_write(priv, i, MDIO_MMD_AN, MDIO_AN_EEE_ADV,
 					 0);
 	}

drivers/net/dsa/mt7530.h

@@ -629,7 +629,7 @@ enum mt7531_clk_skew {
 #define  MT7531_PHY_PLL_OFF		BIT(5)
 #define  MT7531_PHY_PLL_BYPASS_MODE	BIT(4)
 
-#define MT753X_CTRL_PHY_ADDR		0
+#define MT753X_CTRL_PHY_ADDR(addr)	((addr + 1) & 0x1f)
 
 #define CORE_PLL_GROUP5			0x404
 #define  RG_LCDDS_PCW_NCPO1(x)		((x) & 0xffff)
@@ -778,6 +778,7 @@ struct mt753x_info {
  * @irq_enable:		IRQ enable bits, synced to SYS_INT_EN
  * @create_sgmii:	Pointer to function creating SGMII PCS instance(s)
  * @active_cpu_ports:	Holding the active CPU ports
+ * @mdiodev:		The pointer to the MDIO device structure
  */
 struct mt7530_priv {
 	struct device		*dev;
@@ -804,6 +805,7 @@ struct mt7530_priv {
 	u32 irq_enable;
 	int (*create_sgmii)(struct mt7530_priv *priv);
 	u8 active_cpu_ports;
+	struct mdio_device *mdiodev;
 };
 
 struct mt7530_hw_vlan_entry {