[PATCH v13 2/2] phy: rockchip: naneng-combphy: add SGMII MAC selection for RK3568

[Coia Prant <coiaprant@gmail.com>]

On RK3568, the SGMII interface can be routed to either GMAC0 or
GMAC1 via the GRF register pipe_sgmii_mac_sel.

Add support for this selection by introducing the
"rockchip,sgmii-mac-sel" DT property.

From the RK3568 TRM (Part1, Page 229), the PIPE_GRF_XPCS_CON0
bit 1 (pipe_sgmii_mac_sel) is defined as:

    0: SGMII routed to GMAC0
    1: SGMII routed to GMAC1

The hardware reset value is 1 (GMAC1). If the property is set to 0,
the driver routes SGMII to GMAC0; if set to 1, it routes to GMAC1.
If the property is absent, the driver leaves the routing unchanged,
so the effective value is whatever the bootloader or hardware reset
left.

The driver validates the value and rejects anything other than 0 or 1.

This is necessary for boards such as the Ariaboard Photonicat, which
uses the SGMII interface connected to GMAC0.

Link: https://dl.radxa.com/rock3/docs/hw/datasheet/Rockchip%20RK3568%20TRM%20Part1%20V1.1-20210301.pdf (Page 229)
Signed-off-by: Coia Prant <coiaprant@gmail.com>
---
 .../rockchip/phy-rockchip-naneng-combphy.c    | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c b/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c
index 7843356a4dd47..f76b48009673d 100644
--- a/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c
+++ b/drivers/phy/rockchip/phy-rockchip-naneng-combphy.c
@@ -186,6 +186,7 @@ struct rockchip_combphy_grfcfg {
 	struct combphy_reg pipe_xpcs_phy_ready;
 	struct combphy_reg pipe_pcie1l0_sel;
 	struct combphy_reg pipe_pcie1l1_sel;
+	struct combphy_reg pipe_sgmii_mac_sel;
 	struct combphy_reg u3otg0_port_en;
 	struct combphy_reg u3otg1_port_en;
 };
@@ -212,6 +213,8 @@ struct rockchip_combphy_priv {
 	bool enable_ssc;
 	bool ext_refclk;
 	struct clk *refclk;
+	bool sgmii_mac_sel_present;
+	u32 sgmii_mac_sel;
 };
 
 static void rockchip_combphy_updatel(struct rockchip_combphy_priv *priv,
@@ -341,6 +344,7 @@ static struct phy *rockchip_combphy_xlate(struct device *dev, const struct of_ph
 static int rockchip_combphy_parse_dt(struct device *dev, struct rockchip_combphy_priv *priv)
 {
 	int i;
+	int ret;
 
 	priv->num_clks = devm_clk_bulk_get_all(dev, &priv->clks);
 	if (priv->num_clks < 1)
@@ -375,6 +379,16 @@ static int rockchip_combphy_parse_dt(struct device *dev, struct rockchip_combphy
 
 	priv->ext_refclk = device_property_present(dev, "rockchip,ext-refclk");
 
+	if (device_property_present(dev, "rockchip,sgmii-mac-sel")) {
+		ret = device_property_read_u32(dev, "rockchip,sgmii-mac-sel", &priv->sgmii_mac_sel);
+		if (ret) {
+			dev_err(dev, "failed to read sgmii-mac-sel property\n");
+			return ret;
+		}
+
+		priv->sgmii_mac_sel_present = true;
+	}
+
 	priv->phy_rst = devm_reset_control_get_exclusive(dev, "phy");
 	/* fallback to old behaviour */
 	if (PTR_ERR(priv->phy_rst) == -ENOENT)
@@ -803,11 +817,34 @@ static const struct rockchip_combphy_cfg rk3562_combphy_cfgs = {
 	.combphy_cfg	= rk3562_combphy_cfg,
 };
 
+static int rk3568_combphy_select_sgmii_mac(struct rockchip_combphy_priv *priv)
+{
+	const struct rockchip_combphy_grfcfg *cfg = priv->cfg->grfcfg;
+
+	if (!priv->sgmii_mac_sel_present)
+		return 0;
+
+	switch (priv->sgmii_mac_sel) {
+	case 0:
+		rockchip_combphy_param_write(priv->pipe_grf, &cfg->pipe_sgmii_mac_sel, false);
+		break;
+	case 1:
+		rockchip_combphy_param_write(priv->pipe_grf, &cfg->pipe_sgmii_mac_sel, true);
+		break;
+	default:
+		dev_err(priv->dev, "invalid sgmii-mac-sel value %u\n", priv->sgmii_mac_sel);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int rk3568_combphy_cfg(struct rockchip_combphy_priv *priv)
 {
 	const struct rockchip_combphy_grfcfg *cfg = priv->cfg->grfcfg;
 	unsigned long rate;
 	u32 val;
+	int ret;
 
 	switch (priv->type) {
 	case PHY_TYPE_PCIE:
@@ -873,6 +910,10 @@ static int rk3568_combphy_cfg(struct rockchip_combphy_priv *priv)
 		break;
 
 	case PHY_TYPE_SGMII:
+		ret = rk3568_combphy_select_sgmii_mac(priv);
+		if (ret)
+			return ret;
+
 		rockchip_combphy_param_write(priv->pipe_grf, &cfg->pipe_xpcs_phy_ready, true);
 		rockchip_combphy_param_write(priv->phy_grf, &cfg->pipe_phymode_sel, true);
 		rockchip_combphy_param_write(priv->phy_grf, &cfg->pipe_sel_qsgmii, true);
@@ -984,6 +1025,7 @@ static const struct rockchip_combphy_grfcfg rk3568_combphy_grfcfgs = {
 	.con3_for_sata		= { 0x000c, 15, 0, 0x00, 0x4407 },
 	/* pipe-grf */
 	.pipe_con0_for_sata	= { 0x0000, 15, 0, 0x00, 0x2220 },
+	.pipe_sgmii_mac_sel	= { 0x0040, 1, 1, 0x00, 0x01 },
 	.pipe_xpcs_phy_ready	= { 0x0040, 2, 2, 0x00, 0x01 },
 	.u3otg0_port_en		= { 0x0104, 15, 0, 0x0181, 0x1100 },
 	.u3otg1_port_en		= { 0x0144, 15, 0, 0x0181, 0x1100 },
-- 
2.47.3