[openwrt/openwrt] realtek: enhance RTL930x SerDes/PLL/CMU interoperability
LEDE Commits
lede-commits at lists.infradead.org
Fri Jul 11 01:05:56 PDT 2025
robimarko pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/d2108c2c5896dcc878c7d65d8c3cd9c5b616dfae
commit d2108c2c5896dcc878c7d65d8c3cd9c5b616dfae
Author: Markus Stockhausen <markus.stockhausen at gmx.de>
AuthorDate: Mon Jun 23 14:12:05 2025 -0400
realtek: enhance RTL930x SerDes/PLL/CMU interoperability
The operating mode of a SerDes must be aligned with the attached PHY or
SFP module. That does not only require to change the protocol (e.g. SGMII,
10Gbase-R, ...) but also the speed (e.g. 1.25G). For this the SerDes must
be re-initialized properly.
- It must be taken into power down
- The PLL speed must be set
- Maybe the CMU (clock management unit) must be resetted
- The new mode must be set
- The state machine must be resetted
- The power must be reactivated
Until now this sequence is bugged. First the driver relies on a clean
setup from U-Boot (rtk network on) and second trying to to change mode
and PLL speeds does not work at all. And not to forget: Currently two
adjacent SerDes cannot drive SGMII/HSGMII at the same time. Fix this by
taking care about the right SerDes/PLL/CMU command init order.
P.S. This code is inspired by the work of Jan Hofmann, who tried to
enable parallel SGMII/HSGMII mode. The only missing bit was a proper CMU
reset sequence.
Signed-off-by: Jan Hoffmann <jan at 3e8.eu>
Signed-off-by: Markus Stockhausen <markus.stockhausen at gmx.de>
Link: https://github.com/openwrt/openwrt/pull/19220
Signed-off-by: Robert Marko <robimarko at gmail.com>
---
.../files-6.12/drivers/net/phy/rtl83xx-phy.c | 343 +++++++++++++--------
1 file changed, 220 insertions(+), 123 deletions(-)
diff --git a/target/linux/realtek/files-6.12/drivers/net/phy/rtl83xx-phy.c b/target/linux/realtek/files-6.12/drivers/net/phy/rtl83xx-phy.c
index c38bc86924..f8eddaec4f 100644
--- a/target/linux/realtek/files-6.12/drivers/net/phy/rtl83xx-phy.c
+++ b/target/linux/realtek/files-6.12/drivers/net/phy/rtl83xx-phy.c
@@ -81,6 +81,12 @@ extern int phy_port_read_paged(struct phy_device *phydev, int port, int page, u3
#define RTL930X_SDS_OFF 0x1f
#define RTL930X_SDS_MASK 0x1f
+#define RTSDS_930X_PLL_1000 0x1
+#define RTSDS_930X_PLL_10000 0x5
+#define RTSDS_930X_PLL_2500 0x3
+#define RTSDS_930X_PLL_LC 0x3
+#define RTSDS_930X_PLL_RING 0x1
+
/* This lock protects the state of the SoC automatically polling the PHYs over the SMI
* bus to detect e.g. link and media changes. For operations on the PHYs such as
* patching or other configuration changes such as EEE, polling needs to be disabled
@@ -1610,167 +1616,258 @@ static void rtl930x_sds_rx_rst(int sds_num, phy_interface_t phy_if)
rtl9300_sds_field_w(sds_num, page, 0x15, 4, 4, 0x0);
}
-/* Force PHY modes on 10GBit Serdes
- */
-static void rtl9300_force_sds_mode(int sds, phy_interface_t phy_if)
+static void rtsds_930x_get_pll_data(int sds, int *pll, int *speed)
{
- int lc_value;
- int sds_mode;
- bool lc_on;
- int lane_0 = (sds % 2) ? sds - 1 : sds;
- u32 v;
+ int sbit, pbit = sds & 1 ? 6 : 4;
+ int base_sds = sds & ~1;
- pr_info("%s: SDS: %d, mode %d\n", __func__, sds, phy_if);
- switch (phy_if) {
- case PHY_INTERFACE_MODE_SGMII:
- sds_mode = RTL930X_SDS_MODE_SGMII;
- lc_on = false;
- lc_value = 0x1;
- break;
+ /*
+ * PLL data is shared between adjacent SerDes in the even lane. Each SerDes defines
+ * what PLL it needs (ring or LC) while the PLL itself stores the current speed.
+ */
- case PHY_INTERFACE_MODE_HSGMII:
- sds_mode = RTL930X_SDS_MODE_HSGMII;
- lc_value = 0x3;
- /* Configure LC */
- break;
+ *pll = rtl9300_sds_field_r(base_sds, 0x20, 0x12, pbit + 1, pbit);
+ sbit = *pll == RTSDS_930X_PLL_LC ? 8 : 12;
+ *speed = rtl9300_sds_field_r(base_sds, 0x20, 0x12, sbit + 3, sbit);
+}
- case PHY_INTERFACE_MODE_1000BASEX:
- sds_mode = RTL930X_SDS_MODE_1000BASEX;
- lc_on = false;
- break;
+static int rtsds_930x_set_pll_data(int sds, int pll, int speed)
+{
+ int sbit = pll == RTSDS_930X_PLL_LC ? 8 : 12;
+ int pbit = sds & 1 ? 6 : 4;
+ int base_sds = sds & ~1;
- case PHY_INTERFACE_MODE_2500BASEX:
- sds_mode = RTL930X_SDS_MODE_2500BASEX;
- lc_value = 0x3;
- /* Configure LC */
- break;
+ if ((speed != RTSDS_930X_PLL_1000) &&
+ (speed != RTSDS_930X_PLL_2500) &&
+ (speed != RTSDS_930X_PLL_10000))
+ return -EINVAL;
- case PHY_INTERFACE_MODE_10GBASER:
- sds_mode = RTL930X_SDS_MODE_10GBASER;
- lc_on = true;
- lc_value = 0x5;
- break;
+ if ((pll != RTSDS_930X_PLL_RING) && (pll != RTSDS_930X_PLL_LC))
+ return -EINVAL;
- case PHY_INTERFACE_MODE_NA:
- /* This will disable SerDes */
- sds_mode = RTL930X_SDS_OFF;
- break;
+ if ((pll == RTSDS_930X_PLL_RING) && (speed == RTSDS_930X_PLL_10000))
+ return -EINVAL;
- default:
- pr_err("%s: unknown serdes mode: %s\n",
- __func__, phy_modes(phy_if));
- return;
- }
+ /*
+ * A SerDes clock can either be taken from the low speed ring PLL or the high speed
+ * LC PLL. As it is unclear if disabling PLLs has any positive or negative effect,
+ * always activate both.
+ */
- pr_info("%s --------------------- serdes %d forcing to %x ...\n", __func__, sds, sds_mode);
- /* Power down SerDes */
- rtl9300_sds_field_w(sds, 0x20, 0, 7, 6, 0x3);
- if (sds == 5) pr_info("%s after %x\n", __func__, rtl930x_read_sds_phy(sds, 0x20, 0));
+ rtl9300_sds_field_w(base_sds, 0x20, 0x12, 3, 0, 0xf);
+ rtl9300_sds_field_w(base_sds, 0x20, 0x12, pbit + 1, pbit, pll);
+ rtl9300_sds_field_w(base_sds, 0x20, 0x12, sbit + 3, sbit, speed);
+
+ return 0;
+}
- if (sds == 5) pr_info("%s a %x\n", __func__, rtl930x_read_sds_phy(sds, 0x1f, 9));
- /* Force mode enable */
- rtl9300_sds_field_w(sds, 0x1f, 9, 6, 6, 0x1);
- if (sds == 5) pr_info("%s b %x\n", __func__, rtl930x_read_sds_phy(sds, 0x1f, 9));
+static void rtsds_930x_reset_cmu(int sds)
+{
+ int reset_sequence[4] = { 3, 2, 3, 1 };
+ int base_sds = sds & ~1;
+ int pll, speed, i, bit;
- /* SerDes off */
- rtl9300_sds_field_w(sds, 0x1f, 9, 11, 7, RTL930X_SDS_OFF);
+ /*
+ * After the PLL speed has changed, the CMU must take over the new values. The models
+ * of the Otto platform have different reset sequences. Luckily it always boils down
+ * to flipping two bits in a special sequence.
+ */
- if (phy_if == PHY_INTERFACE_MODE_NA)
- return;
+ rtsds_930x_get_pll_data(sds, &pll, &speed);
+ bit = pll == RTSDS_930X_PLL_LC ? 2 : 0;
- if (sds == 5) pr_info("%s c %x\n", __func__, rtl930x_read_sds_phy(sds, 0x20, 18));
- /* Enable LC and ring */
- rtl9300_sds_field_w(lane_0, 0x20, 18, 3, 0, 0xf);
+ for (i = 0; i < ARRAY_SIZE(reset_sequence); i++)
+ rtl9300_sds_field_w(base_sds, 0x21, 0x0b, bit + 1, bit, reset_sequence[i]);
+}
- if (sds == lane_0)
- rtl9300_sds_field_w(lane_0, 0x20, 18, 5, 4, 0x1);
- else
- rtl9300_sds_field_w(lane_0, 0x20, 18, 7, 6, 0x1);
+static int rtsds_930x_wait_clock_ready(int sds)
+{
+ int i, base_sds = sds & ~1, ready, ready_cnt = 0, bit = (sds & 1) + 4;
+
+ /*
+ * While reconfiguring a SerDes it might take some time until its clock is in sync with
+ * the PLL. During that timespan the ready signal might toggle randomly. According to
+ * GPL sources it is enough to verify that 3 consecutive clock ready checks say "ok".
+ */
- rtl9300_sds_field_w(sds, 0x20, 0, 5, 4, 0x3);
+ for (i = 0; i < 20; i++) {
+ usleep_range(10000, 15000);
- if (lc_on)
- rtl9300_sds_field_w(lane_0, 0x20, 18, 11, 8, lc_value);
- else
- rtl9300_sds_field_w(lane_0, 0x20, 18, 15, 12, lc_value);
+ rtl930x_write_sds_phy(base_sds, 0x1f, 0x02, 53);
+ ready = rtl9300_sds_field_r(base_sds, 0x1f, 0x14, bit, bit);
+
+ ready_cnt = ready ? ready_cnt + 1 : 0;
+ if (ready_cnt >= 3)
+ return 0;
+ }
- /* Force analog LC & ring on */
- rtl9300_sds_field_w(lane_0, 0x21, 11, 3, 0, 0xf);
+ return -EBUSY;
+}
- v = lc_on ? 0x3 : 0x1;
+static void rtsds_930x_set_internal_mode(int sds, int mode)
+{
+ rtl9300_sds_field_w(sds, 0x1f, 0x09, 6, 6, 0x1); /* Force mode enable */
+ rtl9300_sds_field_w(sds, 0x1f, 0x09, 11, 7, mode);
+}
- if (sds == lane_0)
- rtl9300_sds_field_w(lane_0, 0x20, 18, 5, 4, v);
- else
- rtl9300_sds_field_w(lane_0, 0x20, 18, 7, 6, v);
+static int rtsds_930x_get_internal_mode(int sds)
+{
+ return rtl9300_sds_field_r(sds, 0x1f, 0x09, 11, 7);
+}
- /* Force SerDes mode */
- rtl9300_sds_field_w(sds, 0x1f, 9, 6, 6, 1);
- rtl9300_sds_field_w(sds, 0x1f, 9, 11, 7, sds_mode);
+static void rtsds_930x_set_power(int sds, bool on)
+{
+ int power = on ? 0 : 3;
- /* Toggle LC or Ring */
- for (int i = 0; i < 20; i++) {
- u32 cr_0, cr_1, cr_2;
- u32 m_bit, l_bit;
+ rtl9300_sds_field_w(sds, 0x20, 0x00, 7, 6, power);
+}
- mdelay(200);
+static int rtsds_930x_config_pll(int sds, phy_interface_t interface)
+{
+ int neighbor_speed, neighbor_mode, neighbor_pll, neighbor = sds ^ 1;
+ bool speed_changed = true;
+ int pll, speed;
- rtl930x_write_sds_phy(lane_0, 0x1f, 2, 53);
+ /*
+ * A SerDes pair on the RTL930x is driven by two PLLs. A low speed ring PLL can generate
+ * signals of 1.25G and 3.125G for link speeds of 1G/2.5G. A high speed LC PLL can
+ * additionally generate a 10.3125G signal for 10G speeds. To drive the pair at different
+ * speeds each SerDes must use its own PLL. But what if the SerDess attached to the ring
+ * PLL suddenly needs 10G but the LC PLL is running at 1G? To avoid reconfiguring the
+ * "partner" SerDes we must choose wisely what assignment serves the current needs. The
+ * logic boils down to the following rules:
+ *
+ * - Use ring PLL for slow 1G speeds
+ * - Use LC PLL for fast 10G speeds
+ * - For 2.5G prefer ring over LC PLL
+ */
- m_bit = (lane_0 == sds) ? (4) : (5);
- l_bit = (lane_0 == sds) ? (4) : (5);
+ neighbor_mode = rtsds_930x_get_internal_mode(neighbor);
+ rtsds_930x_get_pll_data(neighbor, &neighbor_pll, &neighbor_speed);
+
+ if ((interface == PHY_INTERFACE_MODE_1000BASEX) ||
+ (interface == PHY_INTERFACE_MODE_SGMII))
+ speed = RTSDS_930X_PLL_1000;
+ else if ((interface == PHY_INTERFACE_MODE_2500BASEX) ||
+ (interface == PHY_INTERFACE_MODE_HSGMII))
+ speed = RTSDS_930X_PLL_2500;
+ else if (interface == PHY_INTERFACE_MODE_10GBASER)
+ speed = RTSDS_930X_PLL_10000;
+ else
+ return -ENOTSUPP;
+
+ if (!neighbor_mode)
+ pll = speed == RTSDS_930X_PLL_10000 ? RTSDS_930X_PLL_LC : RTSDS_930X_PLL_RING;
+ else if (speed == neighbor_speed) {
+ speed_changed = false;
+ pll = neighbor_pll;
+ } else if (neighbor_pll == RTSDS_930X_PLL_RING)
+ pll = RTSDS_930X_PLL_LC;
+ else if (speed == RTSDS_930X_PLL_10000)
+ return -ENOTSUPP; /* caller wants 10G but only ring PLL available */
+ else
+ pll = RTSDS_930X_PLL_RING;
- cr_0 = rtl9300_sds_field_r(lane_0, 0x1f, 20, m_bit, l_bit);
- mdelay(10);
- cr_1 = rtl9300_sds_field_r(lane_0, 0x1f, 20, m_bit, l_bit);
- mdelay(10);
- cr_2 = rtl9300_sds_field_r(lane_0, 0x1f, 20, m_bit, l_bit);
+ rtsds_930x_set_pll_data(sds, pll, speed);
- if (cr_0 && cr_1 && cr_2) {
- u32 t;
+ if (speed_changed)
+ rtsds_930x_reset_cmu(sds);
- if (phy_if != PHY_INTERFACE_MODE_10GBASER)
- break;
+ pr_info("%s: SDS %d using %s PLL for %s\n", __func__, sds,
+ pll == RTSDS_930X_PLL_LC ? "LC" : "ring", phy_modes(interface));
- t = rtl9300_sds_field_r(sds, 0x6, 0x1, 2, 2);
- rtl9300_sds_field_w(sds, 0x6, 0x1, 2, 2, 0x1);
+ return 0;
+}
+
+static void rtsds_930x_reset_state_machine(int sds)
+{
+ rtl9300_sds_field_w(sds, 0x06, 0x02, 12, 12, 0x01); /* SM_RESET bit */
+ usleep_range(10000, 20000);
+ rtl9300_sds_field_w(sds, 0x06, 0x02, 12, 12, 0x00);
+ usleep_range(10000, 20000);
+}
- /* Reset FSM */
- rtl9300_sds_field_w(sds, 0x6, 0x2, 12, 12, 0x1);
- mdelay(10);
- rtl9300_sds_field_w(sds, 0x6, 0x2, 12, 12, 0x0);
- mdelay(10);
+static int rtsds_930x_init_state_machine(int sds, phy_interface_t interface)
+{
+ int loopback, link, cnt = 20, ret = -EBUSY;
- /* Need to read this twice */
- v = rtl9300_sds_field_r(sds, 0x5, 0, 12, 12);
- v = rtl9300_sds_field_r(sds, 0x5, 0, 12, 12);
+ if (interface != PHY_INTERFACE_MODE_10GBASER)
+ return 0;
+ /*
+ * After a SerDes mode change it takes some time until the frontend state machine
+ * works properly for 10G. To verify operation readyness run a connection check via
+ * loopback.
+ */
+ loopback = rtl9300_sds_field_r(sds, 0x06, 0x01, 2, 2); /* CFG_AFE_LPK bit */
+ rtl9300_sds_field_w(sds, 0x06, 0x01, 2, 2, 0x01);
- rtl9300_sds_field_w(sds, 0x6, 0x1, 2, 2, t);
+ while (cnt-- && ret) {
+ rtsds_930x_reset_state_machine(sds);
+ link = rtl9300_sds_field_r(sds, 0x05, 0x00, 12, 12); /* 10G link state (latched) */
+ link = rtl9300_sds_field_r(sds, 0x05, 0x00, 12, 12);
+ if (link)
+ ret = 0;
+ }
- /* Reset FSM again */
- rtl9300_sds_field_w(sds, 0x6, 0x2, 12, 12, 0x1);
- mdelay(10);
- rtl9300_sds_field_w(sds, 0x6, 0x2, 12, 12, 0x0);
- mdelay(10);
+ rtl9300_sds_field_w(sds, 0x06, 0x01, 2, 2, loopback);
+ rtsds_930x_reset_state_machine(sds);
- if (v == 1)
- break;
- }
+ return ret;
+}
- m_bit = (phy_if == PHY_INTERFACE_MODE_10GBASER) ? 3 : 1;
- l_bit = (phy_if == PHY_INTERFACE_MODE_10GBASER) ? 2 : 0;
+static void rtsds_930x_force_mode(int sds, phy_interface_t interface)
+{
+ int mode;
- rtl9300_sds_field_w(lane_0, 0x21, 11, m_bit, l_bit, 0x2);
- mdelay(10);
- rtl9300_sds_field_w(lane_0, 0x21, 11, m_bit, l_bit, 0x3);
+ /*
+ * TODO: Usually one would expect that it is enough to modify the SDS_MODE_SEL_*
+ * registers (lets call it MAC setup). It seems as if this complex sequence is only
+ * needed for modes that cannot be set by the SoC itself. Additionally it is unclear
+ * if this sequence should quit early in case of errors.
+ */
+
+ switch (interface) {
+ case PHY_INTERFACE_MODE_SGMII:
+ mode = RTL930X_SDS_MODE_SGMII;
+ break;
+ case PHY_INTERFACE_MODE_HSGMII:
+ mode = RTL930X_SDS_MODE_HSGMII;
+ break;
+ case PHY_INTERFACE_MODE_1000BASEX:
+ mode = RTL930X_SDS_MODE_1000BASEX;
+ break;
+ case PHY_INTERFACE_MODE_2500BASEX:
+ mode = RTL930X_SDS_MODE_2500BASEX;
+ break;
+ case PHY_INTERFACE_MODE_10GBASER:
+ mode = RTL930X_SDS_MODE_10GBASER;
+ break;
+ case PHY_INTERFACE_MODE_NA:
+ mode = RTL930X_SDS_OFF;
+ break;
+ default:
+ pr_err("%s: SDS %d does not support %s\n", __func__, sds, phy_modes(interface));
+ return;
}
- rtl930x_sds_rx_rst(sds, phy_if);
+ rtsds_930x_set_power(sds, false);
+ rtsds_930x_set_internal_mode(sds, RTL930X_SDS_OFF);
+ if (interface == PHY_INTERFACE_MODE_NA)
+ return;
+
+ if (rtsds_930x_config_pll(sds, interface))
+ pr_err("%s: SDS %d could not configure PLL for %s\n", __func__,
+ sds, phy_modes(interface));
+
+ rtsds_930x_set_internal_mode(sds, mode);
+ if (rtsds_930x_wait_clock_ready(sds))
+ pr_err("%s: SDS %d could not sync clock\n", __func__, sds);
- /* Re-enable power */
- rtl9300_sds_field_w(sds, 0x20, 0, 7, 6, 0);
+ if (rtsds_930x_init_state_machine(sds, interface))
+ pr_err("%s: SDS %d could not reset state machine\n", __func__, sds);
- pr_info("%s --------------------- serdes %d forced to %x DONE\n", __func__, sds, sds_mode);
+ rtsds_930x_set_power(sds, true);
+ rtl930x_sds_rx_rst(sds, interface);
}
static void rtl9300_sds_tx_config(int sds, phy_interface_t phy_if)
@@ -2770,7 +2867,7 @@ int rtl9300_serdes_setup(int port, int sds_num, phy_interface_t phy_mode)
sw_w32_mask(1, 0, RTL930X_MAC_FORCE_MODE_CTRL + 4 * port);
/* Enable SDS in desired mode */
- rtl9300_force_sds_mode(sds_num, phy_mode);
+ rtsds_930x_force_mode(sds_num, phy_mode);
/* Enable Fiber RX */
rtl9300_sds_field_w(sds_num, 0x20, 2, 12, 12, 0);
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