[PATCH net-next v3 4/9] net: stmmac: qcom-ethqos: fix RGMII_ID mode to use DLL bypass

@@ -67,6 +67,9 @@
 /* SDC4_STATUS bits */
 #define SDC4_STATUS_DLL_LOCK			BIT(7)
 
+/* SDCC_USR_CTL bits */
+#define SDCC_USR_CTL_DDR_BYPASS			BIT(30)
+
 /* RGMII_IO_MACRO_CONFIG2 fields */
 #define RGMII_CONFIG2_RSVD_CONFIG15		GENMASK(31, 17)
 #define RGMII_CONFIG2_RGMII_CLK_SEL_CFG		BIT(16)

@@ -183,7 +186,15 @@ static int ethqos_set_clk_tx_rate(void *bsp_priv, struct clk *clk_tx_i,
 	if (rate < 0)
 		return rate;
 
-	return clk_set_rate(ethqos->link_clk, rate * 2);
+	/* Clock Rate Requirements:
+	 * MAC added delay: 250/50/5 Mhz for 1G/100M/10M
+	 * No MAC delay (DLL bypass): 250/25/2.5 Mhz for 1G/100M/10M
+	 */
+	if (ethqos->phy_mode != PHY_INTERFACE_MODE_RGMII_ID ||
+	    speed == SPEED_1000)
+		rate *= 2;
+
+	return clk_set_rate(ethqos->link_clk, rate);
 }
 
 static void

@@ -405,8 +416,7 @@ static void ethqos_rgmii_macro_init(struct qcom_ethqos *ethqos, int speed)
 		      RGMII_IO_MACRO_CONFIG2);
 
 	/* Determine if the PHY adds a 2 ns TX delay or the MAC handles it */
-	if (ethqos->phy_mode == PHY_INTERFACE_MODE_RGMII_ID ||
-	    ethqos->phy_mode == PHY_INTERFACE_MODE_RGMII_TXID)
+	if (ethqos->phy_mode == PHY_INTERFACE_MODE_RGMII_TXID)
 		phase_shift = 0;
 	else
 		phase_shift = RGMII_CONFIG2_TX_CLK_PHASE_SHIFT_EN;

@@ -475,6 +485,42 @@ static void ethqos_rgmii_macro_init(struct qcom_ethqos *ethqos, int speed)
 		      RGMII_IO_MACRO_CONFIG);
 }
 
+static void ethqos_rgmii_id_macro_init(struct qcom_ethqos *ethqos, int speed)
+{
+	rgmii_clrmask(ethqos, RGMII_CONFIG2_TX_TO_RX_LOOPBACK_EN,
+		      RGMII_IO_MACRO_CONFIG2);
+
+	if (speed == SPEED_1000)
+		rgmii_setmask(ethqos, RGMII_CONFIG_DDR_MODE, RGMII_IO_MACRO_CONFIG);
+	else
+		rgmii_clrmask(ethqos, RGMII_CONFIG_DDR_MODE, RGMII_IO_MACRO_CONFIG);
+	rgmii_setmask(ethqos, RGMII_CONFIG_BYPASS_TX_ID_EN, RGMII_IO_MACRO_CONFIG);
+	rgmii_clrmask(ethqos, RGMII_CONFIG_POS_NEG_DATA_SEL, RGMII_IO_MACRO_CONFIG);
+	rgmii_clrmask(ethqos, RGMII_CONFIG_PROG_SWAP, RGMII_IO_MACRO_CONFIG);
+
+	if (ethqos->has_emac_ge_3)
+		rgmii_clrmask(ethqos, RGMII_CONFIG2_DATA_DIVIDE_CLK_SEL,
+			      RGMII_IO_MACRO_CONFIG2);
+	else
+		rgmii_setmask(ethqos, RGMII_CONFIG2_DATA_DIVIDE_CLK_SEL,
+			      RGMII_IO_MACRO_CONFIG2);
+
+	rgmii_clrmask(ethqos, RGMII_CONFIG2_TX_CLK_PHASE_SHIFT_EN,
+		      RGMII_IO_MACRO_CONFIG2);
+
+	if (speed == SPEED_1000)
+		rgmii_clrmask(ethqos, RGMII_CONFIG2_RSVD_CONFIG15, RGMII_IO_MACRO_CONFIG2);
+	else
+		rgmii_setmask(ethqos, RGMII_CONFIG2_RSVD_CONFIG15, RGMII_IO_MACRO_CONFIG2);
+
+	if (ethqos->rgmii_config_loopback_en)
+		rgmii_setmask(ethqos, RGMII_CONFIG_LOOPBACK_EN, RGMII_IO_MACRO_CONFIG);
+	else
+		rgmii_clrmask(ethqos, RGMII_CONFIG_LOOPBACK_EN, RGMII_IO_MACRO_CONFIG);
+
+	rgmii_setmask(ethqos, RGMII_CONFIG2_RX_PROG_SWAP, RGMII_IO_MACRO_CONFIG2);
+}
+
 static void ethqos_fix_mac_speed_rgmii(void *bsp_priv,
 				       phy_interface_t interface, int speed,
 				       unsigned int mode)

@@ -493,6 +539,21 @@ static void ethqos_fix_mac_speed_rgmii(void *bsp_priv,
 
 	ethqos_set_func_clk_en(ethqos);
 
+	/* For rgmii-id mode, the PHY should add the required delays.
+	 * Therefore, power down the DLL and program it in bypass mode.
+	 * Program the IO_MACRO as per the settings recommended by the
+	 * programming guide for bypass mode. This will ensure that the
+	 * MAC core doesn't add any additional delays.
+	 */
+	if (ethqos->phy_mode == PHY_INTERFACE_MODE_RGMII_ID) {
+		rgmii_setmask(ethqos, SDCC_DLL_CONFIG_PDN, SDCC_HC_REG_DLL_CONFIG);
+		rgmii_setmask(ethqos, SDCC_USR_CTL_DDR_BYPASS, SDCC_USR_CTL);
+
+		ethqos_rgmii_id_macro_init(ethqos, speed);
+
+		return;
+	}
+
 	/* Initialize the DLL first */
 
 	/* Set DLL_RST */