[PATCH net-next v5 09/11] net: stmmac: dwmac-rk: add SGMII support for RK3568
From: Coia Prant <hidden>
Date: 2026-09-13 19:01:15
Also in:
linux-arm-kernel, linux-phy, linux-renesas-soc, linux-rockchip, lkml, netdev
Subsystem:
arm/rockchip soc support, networking drivers, stmmac ethernet driver, the rest · Maintainers:
Heiko Stuebner, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Maxime Chevallier, Linus Torvalds
The RK3568 SoC integrates a Synopsys DesignWare XPCS that can be connected to GMAC0 or GMAC1 in SGMII mode. Add the necessary glue logic to support this configuration. The current dwmac-rk driver does not support SGMII mode. SGMII requires a PCS to handle auto-negotiation and link state reporting, but the existing driver only supports RGMII and RMII. Add a set_to_sgmii() callback to configure the GMAC GRF register for SGMII mode (bit 7 set, interface selection bits 4:6 ignored when set). Also add a set_to_rmii() callback for rk3568 to explicitly clear bit 7, since the new SGMII path leaves it set and the RMII branch previously relied on the SoC reset value. Provide pcs_init/pcs_exit callbacks to create/destroy the XPCS via xpcs_rk_create() from the Rockchip XPCS platform driver, and a select_pcs callback to return the XPCS to phylink. Reorder rk_gmac_powerup() so that gmac_clk_enable() is called before the SGMII check. The SGMII path skips rk_get_phy_intf_sel(), so the clock must be enabled earlier to cover all register accesses in that path. While at it, unify the error unwinding into a single clk_disable label and add error handling for the default (unhandled interface) case. SGMII In-band vs Out-of-band ============================ On RK3568, the MAC clock is fixed at 125 MHz and cannot be dynamically changed by the stmmac core's set_clk_tx_rate callback. In-band mode works because the PCS handles rate adaptation internally. Out-of-band mode does not work because the MAC would need to change the clock rate to 125/12.5/1.25 MHz for 1000/100/10 Mbps respectively, and the clock is fixed. Enable default_an_inband for SGMII and disable the generic stmmac set_clk_tx_rate callback. This forces phylink to use in-band mode, where the PCS is responsible for speed/duplex negotiation. Note that default_an_inband can be overridden by a fixed-link node, and phylink may also fall back to out-of-band if the PHY does not support in-band signalling. Out-of-band SGMII is not supported by this driver: the MAC clock would stay at 125 MHz for 10/100 Mbps, giving working TX but failing RX. Boards must use in-band mode (managed = "in-band-status" or an in-band capable PHY). Link: https://dl.radxa.com/rock3/docs/hw/datasheet/Rockchip%20RK3568%20TRM%20Part1%20V1.1-20210301.pdf (Page 386) Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Signed-off-by: Coia Prant <redacted> --- drivers/net/ethernet/stmicro/stmmac/Kconfig | 1 + .../net/ethernet/stmicro/stmmac/dwmac-rk.c | 134 +++++++++++++++--- 2 files changed, 115 insertions(+), 20 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index e3dd5adda5aca..5088acc06982e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig@@ -170,6 +170,7 @@ config DWMAC_ROCKCHIP default ARCH_ROCKCHIP depends on OF && (ARCH_ROCKCHIP || COMPILE_TEST) select MFD_SYSCON + select PCS_XPCS_ROCKCHIP help Support for Ethernet controller on Rockchip RK3288 SoC.
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
index 8d7042e689261..5d501ed8d1429 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c@@ -20,6 +20,7 @@ #include <linux/delay.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> +#include <linux/pcs/pcs-xpcs-rk.h> #include <linux/pm_runtime.h> #include "stmmac_platform.h"
@@ -47,6 +48,7 @@ struct rk_gmac_ops { void (*set_to_rgmii)(struct rk_priv_data *bsp_priv, int tx_delay, int rx_delay); void (*set_to_rmii)(struct rk_priv_data *bsp_priv); + void (*set_to_sgmii)(struct rk_priv_data *bsp_priv); int (*set_speed)(struct rk_priv_data *bsp_priv, phy_interface_t interface, int speed); void (*integrated_phy_powerup)(struct rk_priv_data *bsp_priv);
@@ -63,6 +65,7 @@ struct rk_gmac_ops { bool clock_grf_reg_in_php; bool supports_rgmii; bool supports_rmii; + bool supports_sgmii; bool php_grf_required; bool regs_valid; u32 regs[];
@@ -98,6 +101,7 @@ struct rk_priv_data { bool integrated_phy; bool supports_rgmii; bool supports_rmii; + bool supports_sgmii; struct clk_bulk_data *clks; int num_clks;
@@ -809,6 +813,8 @@ static const struct rk_gmac_ops rk3528_ops = { #define RK3568_GRF_GMAC1_CON1 0x038c /* RK3568_GRF_GMAC0_CON1 && RK3568_GRF_GMAC1_CON1 */ +#define RK3568_GMAC_MODE_RMII_RGMII GRF_CLR_BIT(7) +#define RK3568_GMAC_MODE_SGMII_QSGMII GRF_BIT(7) #define RK3568_GMAC_FLOW_CTRL GRF_BIT(3) #define RK3568_GMAC_FLOW_CTRL_CLR GRF_CLR_BIT(3) #define RK3568_GMAC_RXCLK_DLY_ENABLE GRF_BIT(1)
@@ -836,6 +842,17 @@ static int rk3568_init(struct rk_priv_data *bsp_priv) } } +static void rk3568_set_to_rmii(struct rk_priv_data *bsp_priv) +{ + u32 con1; + + con1 = (bsp_priv->id == 1) ? RK3568_GRF_GMAC1_CON1 : + RK3568_GRF_GMAC0_CON1; + + regmap_write(bsp_priv->grf, con1, + RK3568_GMAC_MODE_RMII_RGMII); +} + static void rk3568_set_to_rgmii(struct rk_priv_data *bsp_priv, int tx_delay, int rx_delay) {
@@ -851,19 +868,31 @@ static void rk3568_set_to_rgmii(struct rk_priv_data *bsp_priv, RK3568_GMAC_CLK_TX_DL_CFG(tx_delay)); regmap_write(bsp_priv->grf, con1, + RK3568_GMAC_MODE_RMII_RGMII | RK3568_GMAC_RXCLK_DLY_ENABLE | RK3568_GMAC_TXCLK_DLY_ENABLE); } +static void rk3568_set_to_sgmii(struct rk_priv_data *bsp_priv) +{ + u32 con1; + + con1 = (bsp_priv->id == 1) ? RK3568_GRF_GMAC1_CON1 : + RK3568_GRF_GMAC0_CON1; + + regmap_write(bsp_priv->grf, con1, RK3568_GMAC_MODE_SGMII_QSGMII); +} + static const struct rk_gmac_ops rk3568_ops = { .init = rk3568_init, + .set_to_rmii = rk3568_set_to_rmii, .set_to_rgmii = rk3568_set_to_rgmii, + .set_to_sgmii = rk3568_set_to_sgmii, + .set_speed = rk_set_clk_mac_speed, .gmac_phy_intf_sel_mask = GENMASK_U16(6, 4), - .supports_rmii = true, - .regs_valid = true, .regs = { 0xfe2a0000, /* gmac0 */
@@ -1208,6 +1237,43 @@ static void rk_phy_powerdown(struct rk_priv_data *bsp_priv) dev_err(bsp_priv->dev, "fail to disable phy-supply\n"); } +static int rk_pcs_init(struct stmmac_priv *priv) +{ + struct device_node *np = priv->device->of_node; + struct device_node *pcs_node; + struct dw_xpcs *xpcs; + + pcs_node = of_parse_phandle(np, "pcs-handle", 0); + if (!pcs_node) + return -ENODEV; + + xpcs = xpcs_rk_create(priv->device, pcs_node); + of_node_put(pcs_node); + if (IS_ERR(xpcs)) + return PTR_ERR(xpcs); + + priv->hw->xpcs = xpcs; + return 0; +} + +static void rk_pcs_exit(struct stmmac_priv *priv) +{ + if (!priv->hw->xpcs) + return; + + xpcs_destroy(priv->hw->xpcs); + priv->hw->xpcs = NULL; +} + +static struct phylink_pcs *rk_select_pcs(struct stmmac_priv *priv, + phy_interface_t interface) +{ + if (!priv->hw->xpcs) + return NULL; + + return xpcs_to_phylink_pcs(priv->hw->xpcs); +} + static struct rk_priv_data *rk_gmac_setup(struct platform_device *pdev, struct plat_stmmacenet_data *plat, const struct rk_gmac_ops *ops)
@@ -1330,6 +1396,7 @@ static struct rk_priv_data *rk_gmac_setup(struct platform_device *pdev, bsp_priv->supports_rgmii = ops->supports_rgmii || !!ops->set_to_rgmii; bsp_priv->supports_rmii = ops->supports_rmii || !!ops->set_to_rmii; + bsp_priv->supports_sgmii = ops->supports_sgmii || !!ops->set_to_sgmii; if (ops->init) { ret = ops->init(bsp_priv);
@@ -1361,6 +1428,10 @@ static int rk_gmac_check_ops(struct rk_priv_data *bsp_priv) if (!bsp_priv->supports_rmii) return -EINVAL; break; + case PHY_INTERFACE_MODE_SGMII: + if (!bsp_priv->supports_sgmii) + return -EINVAL; + break; default: dev_err(bsp_priv->dev, "unsupported interface %d", bsp_priv->phy_iface);
@@ -1379,16 +1450,19 @@ static int rk_gmac_powerup(struct rk_priv_data *bsp_priv) if (ret) return ret; + ret = gmac_clk_enable(bsp_priv, true); + if (ret) + return ret; + + if (bsp_priv->phy_iface == PHY_INTERFACE_MODE_SGMII) + goto set_mode; + ret = rk_get_phy_intf_sel(bsp_priv->phy_iface); if (ret < 0) - return ret; + goto clk_disable; intf = ret; - ret = gmac_clk_enable(bsp_priv, true); - if (ret) - return ret; - if (bsp_priv->gmac_phy_intf_sel_mask || bsp_priv->gmac_rmii_mode_mask) { /* If defined, encode the phy_intf_sel value */
@@ -1399,10 +1473,8 @@ static int rk_gmac_powerup(struct rk_priv_data *bsp_priv) bsp_priv->gmac_rmii_mode_mask); ret = rk_write_gmac_grf_reg(bsp_priv, val); - if (ret < 0) { - gmac_clk_enable(bsp_priv, false); - return ret; - } + if (ret < 0) + goto clk_disable; } if (bsp_priv->clock.rmii_mode_mask) {
@@ -1410,13 +1482,12 @@ static int rk_gmac_powerup(struct rk_priv_data *bsp_priv) bsp_priv->clock.rmii_mode_mask); ret = rk_write_clock_grf_reg(bsp_priv, val); - if (ret < 0) { - gmac_clk_enable(bsp_priv, false); - return ret; - } + if (ret < 0) + goto clk_disable; } - /*rmii or rgmii*/ +set_mode: + /* rmii, rgmii, sgmii */ switch (bsp_priv->phy_iface) { case PHY_INTERFACE_MODE_RGMII: dev_info(dev, "init for RGMII\n");
@@ -1447,15 +1518,20 @@ static int rk_gmac_powerup(struct rk_priv_data *bsp_priv) if (bsp_priv->ops->set_to_rmii) bsp_priv->ops->set_to_rmii(bsp_priv); break; + case PHY_INTERFACE_MODE_SGMII: + dev_info(dev, "init for SGMII\n"); + if (bsp_priv->ops->set_to_sgmii) + bsp_priv->ops->set_to_sgmii(bsp_priv); + break; default: dev_err(dev, "NO interface defined!\n"); + ret = -EINVAL; + goto clk_disable; } ret = rk_phy_powerup(bsp_priv); - if (ret) { - gmac_clk_enable(bsp_priv, false); - return ret; - } + if (ret) + goto clk_disable; pm_runtime_get_sync(dev);
@@ -1463,6 +1539,10 @@ static int rk_gmac_powerup(struct rk_priv_data *bsp_priv) bsp_priv->ops->integrated_phy_powerup(bsp_priv); return 0; + +clk_disable: + gmac_clk_enable(bsp_priv, false); + return ret; } static void rk_gmac_powerdown(struct rk_priv_data *gmac)
@@ -1486,6 +1566,9 @@ static void rk_get_interfaces(struct stmmac_priv *priv, void *bsp_priv, if (rk->supports_rmii) __set_bit(PHY_INTERFACE_MODE_RMII, interfaces); + + if (rk->supports_sgmii) + __set_bit(PHY_INTERFACE_MODE_SGMII, interfaces); } static int rk_set_clk_tx_rate(void *bsp_priv_, struct clk *clk_tx_i,
@@ -1602,6 +1685,17 @@ static int rk_gmac_probe(struct platform_device *pdev) plat_dat->suspend = rk_gmac_suspend; plat_dat->resume = rk_gmac_resume; + if (plat_dat->phy_interface == PHY_INTERFACE_MODE_SGMII) { + /* SGMII clock always runs at 125 MHz */ + plat_dat->set_clk_tx_rate = NULL; + + /* SGMII requires a PCS */ + plat_dat->default_an_inband = true; + plat_dat->pcs_init = rk_pcs_init; + plat_dat->pcs_exit = rk_pcs_exit; + plat_dat->select_pcs = rk_select_pcs; + } + plat_dat->bsp_priv = rk_gmac_setup(pdev, plat_dat, data); if (IS_ERR(plat_dat->bsp_priv)) return PTR_ERR(plat_dat->bsp_priv);
--
2.47.3