net: phy: microchip_t1s: add support for Microchip LAN865x Rev.B0 PHYs

Add support for the Microchip LAN865x Rev.B0 10BASE-T1S Internal PHYs
(LAN8650/1). The LAN865x combines a Media Access Controller (MAC) and an
internal 10BASE-T1S Ethernet PHY to access 10BASE‑T1S networks. As
LAN867X and LAN865X are using the same function for the read_status,
rename the function as lan86xx_read_status.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Parthiban Veerasooran <Parthiban.Veerasooran@microchip.com>
Reviewed-by: Ramón Nordin Rodriguez <ramon.nordin.rodriguez@ferroamp.se>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/phy/Kconfig

@@ -245,7 +245,8 @@ config MICREL_PHY
 config MICROCHIP_T1S_PHY
 	tristate "Microchip 10BASE-T1S Ethernet PHYs"
 	help
-	  Currently supports the LAN8670/1/2 Rev.B1
+	  Currently supports the LAN8670/1/2 Rev.B1 and LAN8650/1 Rev.B0 Internal
+	  PHYs.
 
 config MICROCHIP_PHY
 	tristate "Microchip PHYs"

drivers/net/phy/microchip_t1s.c

@@ -4,6 +4,7 @@
  *
  * Support: Microchip Phys:
  *  lan8670/1/2 Rev.B1
+ *  lan8650/1 Rev.B0 Internal PHYs
  */
 
 #include <linux/kernel.h>
@@ -11,11 +12,19 @@
 #include <linux/phy.h>
 
 #define PHY_ID_LAN867X_REVB1 0x0007C162
+#define PHY_ID_LAN865X_REVB0 0x0007C1B3
 
 #define LAN867X_REG_STS2 0x0019
 
 #define LAN867x_RESET_COMPLETE_STS BIT(11)
 
+#define LAN865X_REG_CFGPARAM_ADDR 0x00D8
+#define LAN865X_REG_CFGPARAM_DATA 0x00D9
+#define LAN865X_REG_CFGPARAM_CTRL 0x00DA
+#define LAN865X_REG_STS2 0x0019
+
+#define LAN865X_CFGPARAM_READ_ENABLE BIT(1)
+
 /* The arrays below are pulled from the following table from AN1699
  * Access MMD Address Value Mask
  * RMW 0x1F 0x00D0 0x0002 0x0E03
@@ -50,6 +59,160 @@ static const u16 lan867x_revb1_fixup_masks[12] = {
 	0x0600, 0x7F00, 0x2000, 0xFFFF,
 };
 
+/* LAN865x Rev.B0 configuration parameters from AN1760 */
+static const u32 lan865x_revb0_fixup_registers[28] = {
+	0x0091, 0x0081, 0x0043, 0x0044,
+	0x0045, 0x0053, 0x0054, 0x0055,
+	0x0040, 0x0050, 0x00D0, 0x00E9,
+	0x00F5, 0x00F4, 0x00F8, 0x00F9,
+	0x00B0, 0x00B1, 0x00B2, 0x00B3,
+	0x00B4, 0x00B5, 0x00B6, 0x00B7,
+	0x00B8, 0x00B9, 0x00BA, 0x00BB,
+};
+
+static const u16 lan865x_revb0_fixup_values[28] = {
+	0x9660, 0x00C0, 0x00FF, 0xFFFF,
+	0x0000, 0x00FF, 0xFFFF, 0x0000,
+	0x0002, 0x0002, 0x5F21, 0x9E50,
+	0x1CF8, 0xC020, 0x9B00, 0x4E53,
+	0x0103, 0x0910, 0x1D26, 0x002A,
+	0x0103, 0x070D, 0x1720, 0x0027,
+	0x0509, 0x0E13, 0x1C25, 0x002B,
+};
+
+static const u16 lan865x_revb0_fixup_cfg_regs[5] = {
+	0x0084, 0x008A, 0x00AD, 0x00AE, 0x00AF
+};
+
+/* Pulled from AN1760 describing 'indirect read'
+ *
+ * write_register(0x4, 0x00D8, addr)
+ * write_register(0x4, 0x00DA, 0x2)
+ * return (int8)(read_register(0x4, 0x00D9))
+ *
+ * 0x4 refers to memory map selector 4, which maps to MDIO_MMD_VEND2
+ */
+static int lan865x_revb0_indirect_read(struct phy_device *phydev, u16 addr)
+{
+	int ret;
+
+	ret = phy_write_mmd(phydev, MDIO_MMD_VEND2, LAN865X_REG_CFGPARAM_ADDR,
+			    addr);
+	if (ret)
+		return ret;
+
+	ret = phy_write_mmd(phydev, MDIO_MMD_VEND2, LAN865X_REG_CFGPARAM_CTRL,
+			    LAN865X_CFGPARAM_READ_ENABLE);
+	if (ret)
+		return ret;
+
+	return phy_read_mmd(phydev, MDIO_MMD_VEND2, LAN865X_REG_CFGPARAM_DATA);
+}
+
+/* This is pulled straight from AN1760 from 'calculation of offset 1' &
+ * 'calculation of offset 2'
+ */
+static int lan865x_generate_cfg_offsets(struct phy_device *phydev, s8 offsets[2])
+{
+	const u16 fixup_regs[2] = {0x0004, 0x0008};
+	int ret;
+
+	for (int i = 0; i < ARRAY_SIZE(fixup_regs); i++) {
+		ret = lan865x_revb0_indirect_read(phydev, fixup_regs[i]);
+		if (ret < 0)
+			return ret;
+		if (ret & BIT(4))
+			offsets[i] = ret | 0xE0;
+		else
+			offsets[i] = ret;
+	}
+
+	return 0;
+}
+
+static int lan865x_read_cfg_params(struct phy_device *phydev, u16 cfg_params[])
+{
+	int ret;
+
+	for (int i = 0; i < ARRAY_SIZE(lan865x_revb0_fixup_cfg_regs); i++) {
+		ret = phy_read_mmd(phydev, MDIO_MMD_VEND2,
+				   lan865x_revb0_fixup_cfg_regs[i]);
+		if (ret < 0)
+			return ret;
+		cfg_params[i] = (u16)ret;
+	}
+
+	return 0;
+}
+
+static int lan865x_write_cfg_params(struct phy_device *phydev, u16 cfg_params[])
+{
+	int ret;
+
+	for (int i = 0; i < ARRAY_SIZE(lan865x_revb0_fixup_cfg_regs); i++) {
+		ret = phy_write_mmd(phydev, MDIO_MMD_VEND2,
+				    lan865x_revb0_fixup_cfg_regs[i],
+				    cfg_params[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int lan865x_setup_cfgparam(struct phy_device *phydev)
+{
+	u16 cfg_params[ARRAY_SIZE(lan865x_revb0_fixup_cfg_regs)];
+	u16 cfg_results[5];
+	s8 offsets[2];
+	int ret;
+
+	ret = lan865x_generate_cfg_offsets(phydev, offsets);
+	if (ret)
+		return ret;
+
+	ret = lan865x_read_cfg_params(phydev, cfg_params);
+	if (ret)
+		return ret;
+
+	cfg_results[0] = (cfg_params[0] & 0x000F) |
+			  FIELD_PREP(GENMASK(15, 10), 9 + offsets[0]) |
+			  FIELD_PREP(GENMASK(15, 4), 14 + offsets[0]);
+	cfg_results[1] = (cfg_params[1] & 0x03FF) |
+			  FIELD_PREP(GENMASK(15, 10), 40 + offsets[1]);
+	cfg_results[2] = (cfg_params[2] & 0xC0C0) |
+			  FIELD_PREP(GENMASK(15, 8), 5 + offsets[0]) |
+			  (9 + offsets[0]);
+	cfg_results[3] = (cfg_params[3] & 0xC0C0) |
+			  FIELD_PREP(GENMASK(15, 8), 9 + offsets[0]) |
+			  (14 + offsets[0]);
+	cfg_results[4] = (cfg_params[4] & 0xC0C0) |
+			  FIELD_PREP(GENMASK(15, 8), 17 + offsets[0]) |
+			  (22 + offsets[0]);
+
+	return lan865x_write_cfg_params(phydev, cfg_results);
+}
+
+static int lan865x_revb0_config_init(struct phy_device *phydev)
+{
+	int ret;
+
+	/* Reference to AN1760
+	 * https://ww1.microchip.com/downloads/aemDocuments/documents/AIS/ProductDocuments/SupportingCollateral/AN-LAN8650-1-Configuration-60001760.pdf
+	 */
+	for (int i = 0; i < ARRAY_SIZE(lan865x_revb0_fixup_registers); i++) {
+		ret = phy_write_mmd(phydev, MDIO_MMD_VEND2,
+				    lan865x_revb0_fixup_registers[i],
+				    lan865x_revb0_fixup_values[i]);
+		if (ret)
+			return ret;
+	}
+	/* Function to calculate and write the configuration parameters in the
+	 * 0x0084, 0x008A, 0x00AD, 0x00AE and 0x00AF registers (from AN1760)
+	 */
+	return lan865x_setup_cfgparam(phydev);
+}
+
 static int lan867x_revb1_config_init(struct phy_device *phydev)
 {
 	int err;
@@ -90,7 +253,7 @@ static int lan867x_revb1_config_init(struct phy_device *phydev)
 	return 0;
 }
 
-static int lan867x_read_status(struct phy_device *phydev)
+static int lan86xx_read_status(struct phy_device *phydev)
 {
 	/* The phy has some limitations, namely:
 	 *  - always reports link up
@@ -111,17 +274,28 @@ static struct phy_driver microchip_t1s_driver[] = {
 		.name               = "LAN867X Rev.B1",
 		.features           = PHY_BASIC_T1S_P2MP_FEATURES,
 		.config_init        = lan867x_revb1_config_init,
-		.read_status        = lan867x_read_status,
+		.read_status        = lan86xx_read_status,
 		.get_plca_cfg	    = genphy_c45_plca_get_cfg,
 		.set_plca_cfg	    = genphy_c45_plca_set_cfg,
 		.get_plca_status    = genphy_c45_plca_get_status,
-	}
+	},
+	{
+		PHY_ID_MATCH_EXACT(PHY_ID_LAN865X_REVB0),
+		.name               = "LAN865X Rev.B0 Internal Phy",
+		.features           = PHY_BASIC_T1S_P2MP_FEATURES,
+		.config_init        = lan865x_revb0_config_init,
+		.read_status        = lan86xx_read_status,
+		.get_plca_cfg	    = genphy_c45_plca_get_cfg,
+		.set_plca_cfg	    = genphy_c45_plca_set_cfg,
+		.get_plca_status    = genphy_c45_plca_get_status,
+	},
 };
 
 module_phy_driver(microchip_t1s_driver);
 
 static struct mdio_device_id __maybe_unused tbl[] = {
 	{ PHY_ID_MATCH_EXACT(PHY_ID_LAN867X_REVB1) },
+	{ PHY_ID_MATCH_EXACT(PHY_ID_LAN865X_REVB0) },
 	{ }
 };