[openwrt/openwrt] realtek: pcs: rtl93xx: provide proper SerDes polarity configuration

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/56e9a73d0b169ed2a7bb48fb5caddb70099d65c9

commit 56e9a73d0b169ed2a7bb48fb5caddb70099d65c9
Author: Jonas Jelonek <jelonek.jonas at gmail.com>
AuthorDate: Tue Nov 4 21:27:07 2025 +0000

    realtek: pcs: rtl93xx: provide proper SerDes polarity configuration
    
    The configuration code for RTL930X already provides setting the SerDes
    TX and RX PN polarity. This is covered by a function called
    '..._sds_mac_link_config'. But despite its name, this function only sets
    the SerDes polarity and nothing more.
    
    Moreover, this was called always with 'not inverted' in the SerDes setup
    code and thus not really allowing to be configured.
    
    At first, streamline the SerDes polarity configuration code. Rename the
    function to reflect what it actually does instead of giving the
    impression of doing more. Improve the implementation of this for better
    readability.
    
    As the implementation, page, register, bits, etc. are exactly the same
    for both RTL930X and RTL931X (compare [1] and [2]), move and name it
    accordingly so we can also add support for RTL931X.
    
    [1] https://github.com/plappermaul/realtek-doc/blob/69d2890a2e2d7a03df6e40e2cd2c32ff5b074dcf/sources/rtk-xgs1210/src/hal/phy/phy_rtl9300.c#L1384
    [2] https://github.com/plappermaul/realtek-doc/blob/69d2890a2e2d7a03df6e40e2cd2c32ff5b074dcf/sources/rtk-xgs1210/src/hal/phy/phy_rtl9310.c#L3479
    
    Signed-off-by: Jonas Jelonek <jelonek.jonas at gmail.com>
    Link: https://github.com/openwrt/openwrt/pull/20648
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
 .../files-6.12/drivers/net/pcs/pcs-rtl-otto.c      | 53 ++++++++++------------
 1 file changed, 25 insertions(+), 28 deletions(-)

diff --git a/target/linux/realtek/files-6.12/drivers/net/pcs/pcs-rtl-otto.c b/target/linux/realtek/files-6.12/drivers/net/pcs/pcs-rtl-otto.c
index d26b4aab80..bad34c046b 100644
--- a/target/linux/realtek/files-6.12/drivers/net/pcs/pcs-rtl-otto.c
+++ b/target/linux/realtek/files-6.12/drivers/net/pcs/pcs-rtl-otto.c
@@ -210,6 +210,27 @@ static struct rtpcs_link *rtpcs_phylink_pcs_to_link(struct phylink_pcs *pcs)
 
 /* Variant-specific functions */
 
+/* RTL93XX */
+
+static int rtpcs_93xx_sds_set_polarity(struct rtpcs_ctrl *ctrl, u32 sds,
+				       bool tx_inv, bool rx_inv)
+{
+	u8 rx_val = rx_inv ? 1 : 0;
+	u8 tx_val = tx_inv ? 1 : 0;
+	u32 val;
+	int ret;
+
+	/* 10GR */
+	val = (tx_val << 1) | rx_val;
+	ret = rtpcs_sds_write_bits(ctrl, sds, 0x6, 0x2, 14, 13, val);
+	if (ret)
+		return ret;
+
+	/* 1G */
+	val = (rx_val << 1) | tx_val;
+	return rtpcs_sds_write_bits(ctrl, sds, 0x0, 0x0, 9, 8, val);
+}
+
 /* RTL930X */
 
 /* The access registers for SDS_MODE_SEL and the LSB for each SDS within */
@@ -694,32 +715,6 @@ static int rtpcs_930x_sds_clock_wait(struct rtpcs_ctrl *ctrl, int timeout)
 	return 1;
 }
 
-static void rtpcs_930x_sds_mac_link_config(struct rtpcs_ctrl *ctrl, int sds,
-					   bool tx_normal, bool rx_normal)
-{
-	u32 v10, v1;
-
-	v10 = rtpcs_sds_read(ctrl, sds, 6, 2); /* 10GBit, page 6, reg 2 */
-	v1 = rtpcs_sds_read(ctrl, sds, 0, 0); /* 1GBit, page 0, reg 0 */
-	pr_info("%s: registers before %08x %08x\n", __func__, v10, v1);
-
-	v10 &= ~(BIT(13) | BIT(14));
-	v1 &= ~(BIT(8) | BIT(9));
-
-	v10 |= rx_normal ? 0 : BIT(13);
-	v1 |= rx_normal ? 0 : BIT(9);
-
-	v10 |= tx_normal ? 0 : BIT(14);
-	v1 |= tx_normal ? 0 : BIT(8);
-
-	rtpcs_sds_write(ctrl, sds, 6, 2, v10);
-	rtpcs_sds_write(ctrl, sds, 0, 0, v1);
-
-	v10 = rtpcs_sds_read(ctrl, sds, 6, 2);
-	v1 = rtpcs_sds_read(ctrl, sds, 0, 0);
-	pr_info("%s: registers after %08x %08x\n", __func__, v10, v1);
-}
-
 __attribute__((unused))
 static void rtpcs_930x_sds_rxcal_dcvs_manual(struct rtpcs_ctrl *ctrl, u32 sds_num,
 					     u32 dcvs_id, bool manual, u32 dvcs_list[])
@@ -1918,8 +1913,8 @@ static int rtpcs_930x_setup_serdes(struct rtpcs_ctrl *ctrl, int sds,
 	/* ----> dal_longan_sds_mode_set */
 	pr_info("%s: Configuring RTL9300 SERDES %d\n", __func__, sds);
 
-	/* Configure link to MAC */
-	rtpcs_930x_sds_mac_link_config(ctrl, sds, true, true);	/* MAC Construct */
+	/* Set SDS polarity */
+	rtpcs_93xx_sds_set_polarity(ctrl, sds, false, false);
 
 	/* Enable SDS in desired mode */
 	rtpcs_930x_sds_mode_set(ctrl, sds, phy_mode);
@@ -2498,6 +2493,8 @@ static int rtpcs_931x_setup_serdes(struct rtpcs_ctrl *ctrl, int sds,
 		}
 	}
 
+	rtpcs_93xx_sds_set_polarity(ctrl, sds, false, false);
+
 	val = ori & ~BIT(sds);
 	regmap_write(ctrl->map, RTL931X_PS_SERDES_OFF_MODE_CTRL_ADDR, val);
 	regmap_read(ctrl->map, RTL931X_PS_SERDES_OFF_MODE_CTRL_ADDR, &val);