[PATCH net-next v4] net: phy: realtek: Add support for JLSemi JL2101 and JL2121 PHYs

[Pufan Jin <cyan2254650260@gmail.com>]

JLSemi (JingLue Semiconductor) JL2101 and JL2121 Gigabit Ethernet PHYs
are register-compatible second-source alternatives to the Realtek
RTL8211F. They share the same paged register layout (page select at
register 0x1f), RGMII TX/RX internal delay registers (page 0xd08
regs 11/15), and specific status register (0x1a). Wake-on-LAN (WoL)
events (page 0xd8a regs 16/17 and page 0xd8c reg 16) and LED control
registers (page 0xd04 reg 0x10) match RTL8211F.

In the IEEE 802.3 PHY ID allocation, JL2101 (0x937c4032) and JL2121
(0x937c4030) share the same Model number 0x03 (bits [9:4] of register 3),
differing only in revision number bits [3:0] (0x2 vs 0x0). Both chips
share identical operational characteristics. Consolidate them under a
single PHY_ID_MATCH_MODEL(0x937c4030) entry covering all revisions of
this model.

Unlike RTL8211F where PHYSR (0x1a) can be read directly on page 0,
JL21xx requires reading PHYSR from page 0xa43 via phy_read_paged().
Reading 0x1a on page 0 yields 0x0000, which causes rtlgen_decode_physr()
to erroneously downshift to 10Mbps half duplex. Introduce
jlsemi_read_status() to read PHYSR from page 0xa43.

Extend the Realtek PHY driver to bind JLSemi JL21xx by its Model ID to
the RTL8211F-compatible driver operations, and add the ID to the MDIO
module device table.

Signed-off-by: Pufan Jin <cyan2254650260@gmail.com>
---
Changes in v4:
- Consolidate JL2101 (0x937c4032) and JL2121 (0x937c4030) into a single
  PHY_ID_MATCH_MODEL(0x937c4030) entry as both share Model number 0x03
  and differ only in revision number (Andrew Lunn).

Changes in v3:
- Drop standalone driver drivers/net/phy/jlsemi.c and extend the Realtek
  PHY driver directly as suggested by Andrew Lunn.
- Add jlsemi_read_status() to read PHYSR (0x1a) via phy_read_paged()
  from page 0xa43, avoiding false downshift to 10Mbps half duplex (verified
  on physical ALINX AX7Z020B board).

Changes in v2:
- Drop redundant phy_interface_is_rgmii() check in jlsemi_config_init()
  (Andrew Lunn)
- Change speed check in jlsemi_read_status() to '>= SPEED_1000' since
  JL21xx only supports up to 1000M and 100BASE-TX does not use Master/Slave
  clock resolution (Andrew Lunn)
- Check device_can_wakeup() and configure wakeup capability and wake IRQ
  in probe() when 'wakeup-source' is present (Andrew Lunn)
- Drop redundant .features = PHY_GBIT_FEATURES (Andrew Lunn)
- Use PHY_ID_MATCH_VENDOR() for generic driver and mdio table (Andrew Lunn)
 drivers/net/phy/realtek/realtek_main.c | 40 ++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/net/phy/realtek/realtek_main.c b/drivers/net/phy/realtek/realtek_main.c
index 177b62a7b..13039d9f8 100644
--- a/drivers/net/phy/realtek/realtek_main.c
+++ b/drivers/net/phy/realtek/realtek_main.c
@@ -259,6 +259,9 @@
 #define RTL_8261C				0x001cc890
 #define RTL_8261C_CG				0x001cc898
 
+#define JLSEMI_JL21XX_PHYID			0x937c4030
+#define JLSEMI_STATUS_PAGE			0xa43
+
 #define RTL8261C_CE_MODEL		0x00
 #define RTL8261D_MODEL			0x81
 #define RTL8261X_INT_AUTONEG_ERROR	BIT(0)
@@ -1731,6 +1734,23 @@ static int rtlgen_read_status(struct phy_device *phydev)
 	return 0;
 }
 
+static int jlsemi_read_status(struct phy_device *phydev)
+{
+	int ret, val;
+
+	ret = genphy_read_status(phydev);
+	if (ret < 0 || !phydev->link)
+		return ret;
+
+	val = phy_read_paged(phydev, JLSEMI_STATUS_PAGE, RTL_PHYSR);
+	if (val < 0)
+		return val;
+
+	rtlgen_decode_physr(phydev, val);
+
+	return 0;
+}
+
 static int rtlgen_read_vend2(struct phy_device *phydev, int regnum)
 {
 	return __mdiobus_c45_read(phydev->mdio.bus, 0, MDIO_MMD_VEND2, regnum);
@@ -3192,6 +3212,25 @@ static struct phy_driver realtek_drvs[] = {
 		.led_hw_control_get = rtl8211f_led_hw_control_get,
 		.led_hw_control_set = rtl8211f_led_hw_control_set,
 		.disable_autonomous_eee = rtl8211f_disable_autonomous_eee,
+	}, {
+		PHY_ID_MATCH_MODEL(JLSEMI_JL21XX_PHYID),
+		.name		= "JLSemi JL2101/JL2121 Gigabit Ethernet",
+		.probe		= rtl8211f_probe,
+		.config_init	= &rtl8211f_config_init,
+		.read_status	= jlsemi_read_status,
+		.config_intr	= &rtl8211f_config_intr,
+		.handle_interrupt = rtl8211f_handle_interrupt,
+		.set_wol	= rtl8211f_set_wol,
+		.get_wol	= rtl8211f_get_wol,
+		.suspend	= rtl8211f_suspend,
+		.resume		= rtl8211f_resume,
+		.read_page	= rtl821x_read_page,
+		.write_page	= rtl821x_write_page,
+		.flags		= PHY_ALWAYS_CALL_SUSPEND,
+		.led_hw_is_supported = rtl8211x_led_hw_is_supported,
+		.led_hw_control_get = rtl8211f_led_hw_control_get,
+		.led_hw_control_set = rtl8211f_led_hw_control_set,
+		.disable_autonomous_eee = rtl8211f_disable_autonomous_eee,
 	}, {
 		.name		= "Generic FE-GE Realtek PHY",
 		.match_phy_device = rtlgen_match_phy_device,
@@ -3420,6 +3459,7 @@ module_phy_driver(realtek_drvs);
 
 static const struct mdio_device_id __maybe_unused realtek_tbl[] = {
 	{ PHY_ID_MATCH_VENDOR(0x001cc800) },
+	{ PHY_ID_MATCH_MODEL(JLSEMI_JL21XX_PHYID) },
 	{ }
 };
 
-- 
2.56.0