Merge branch 'xgene_txrx_delay'

Iyappan Subramanian says:

====================
drivers: xgene: Add support RGMII TX/RX delay configuration

X-Gene RGMII ethernet controller has a RGMII bridge that performs the
task of converting the RGMII signal {RX_CLK,RX_CTL, RX_DATA[3:0]} from
PHY to GMII signal {RX_DV,RX_ER,RX_DATA[7:0]} and vice versa.  This
RGMII bridge has a provision to internally delay the input RX_CLK and
the output TX_CLK using configuration registers. This will help in
maintain the CLK-CTL delay relationship in various operating
conditions.

This patch adds support RGMII TX/RX delay configuration.
====================

Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/apm-xgene-enet.txt

@@ -37,6 +37,14 @@ Required properties for ethernet interfaces that have external PHY:
 
 Optional properties:
 - status: Should be "ok" or "disabled" for enabled/disabled. Default is "ok".
+- tx-delay: Delay value for RGMII bridge TX clock.
+	    Valid values are between 0 to 7, that maps to
+	    417, 717, 1020, 1321, 1611, 1913, 2215, 2514 ps
+	    Default value is 4, which corresponds to 1611 ps
+- rx-delay: Delay value for RGMII bridge RX clock.
+	    Valid values are between 0 to 7, that maps to
+	    273, 589, 899, 1222, 1480, 1806, 2147, 2464 ps
+	    Default value is 2, which corresponds to 899 ps
 
 Example:
 	menetclk: menetclk {
@@ -72,5 +80,7 @@ Example:
 
 /* Board-specific peripheral configurations */
 &menet {
+	tx-delay = <4>;
+	rx-delay = <2>;
         status = "ok";
 };

drivers/net/ethernet/apm/xgene/xgene_enet_hw.c

@@ -461,6 +461,7 @@ static void xgene_gmac_reset(struct xgene_enet_pdata *pdata)
 
 static void xgene_gmac_init(struct xgene_enet_pdata *pdata)
 {
+	struct device *dev = &pdata->pdev->dev;
 	u32 value, mc2;
 	u32 intf_ctl, rgmii;
 	u32 icm0, icm2;
@@ -490,7 +491,12 @@ static void xgene_gmac_init(struct xgene_enet_pdata *pdata)
 	default:
 		ENET_INTERFACE_MODE2_SET(&mc2, 2);
 		intf_ctl |= ENET_GHD_MODE;
-		CFG_TXCLK_MUXSEL0_SET(&rgmii, 4);
+
+		if (dev->of_node) {
+			CFG_TXCLK_MUXSEL0_SET(&rgmii, pdata->tx_delay);
+			CFG_RXCLK_MUXSEL0_SET(&rgmii, pdata->rx_delay);
+		}
+
 		xgene_enet_rd_csr(pdata, DEBUG_REG_ADDR, &value);
 		value |= CFG_BYPASS_UNISEC_TX | CFG_BYPASS_UNISEC_RX;
 		xgene_enet_wr_csr(pdata, DEBUG_REG_ADDR, value);

drivers/net/ethernet/apm/xgene/xgene_enet_hw.h

@@ -144,6 +144,7 @@ enum xgene_enet_rm {
 #define CFG_BYPASS_UNISEC_RX		BIT(1)
 #define CFG_CLE_BYPASS_EN0		BIT(31)
 #define CFG_TXCLK_MUXSEL0_SET(dst, val)	xgene_set_bits(dst, val, 29, 3)
+#define CFG_RXCLK_MUXSEL0_SET(dst, val)	xgene_set_bits(dst, val, 26, 3)
 
 #define CFG_CLE_IP_PROTOCOL0_SET(dst, val)	xgene_set_bits(dst, val, 16, 2)
 #define CFG_CLE_DSTQID0_SET(dst, val)		xgene_set_bits(dst, val, 0, 12)

drivers/net/ethernet/apm/xgene/xgene_enet_main.c

@@ -1118,6 +1118,47 @@ static int xgene_get_port_id_dt(struct device *dev, struct xgene_enet_pdata *pda
 	return ret;
 }
 
+static int xgene_get_tx_delay(struct xgene_enet_pdata *pdata)
+{
+	struct device *dev = &pdata->pdev->dev;
+	int delay, ret;
+
+	ret = of_property_read_u32(dev->of_node, "tx-delay", &delay);
+	if (ret) {
+		pdata->tx_delay = 4;
+		return 0;
+	}
+
+	if (delay < 0 || delay > 7) {
+		dev_err(dev, "Invalid tx-delay specified\n");
+		return -EINVAL;
+	}
+
+	pdata->tx_delay = delay;
+
+	return 0;
+}
+
+static int xgene_get_rx_delay(struct xgene_enet_pdata *pdata)
+{
+	struct device *dev = &pdata->pdev->dev;
+	int delay, ret;
+
+	ret = of_property_read_u32(dev->of_node, "rx-delay", &delay);
+	if (ret) {
+		pdata->rx_delay = 2;
+		return 0;
+	}
+
+	if (delay < 0 || delay > 7) {
+		dev_err(dev, "Invalid rx-delay specified\n");
+		return -EINVAL;
+	}
+
+	pdata->rx_delay = delay;
+
+	return 0;
+}
 
 static int xgene_enet_get_resources(struct xgene_enet_pdata *pdata)
 {
@@ -1194,6 +1235,14 @@ static int xgene_enet_get_resources(struct xgene_enet_pdata *pdata)
 		return -ENODEV;
 	}
 
+	ret = xgene_get_tx_delay(pdata);
+	if (ret)
+		return ret;
+
+	ret = xgene_get_rx_delay(pdata);
+	if (ret)
+		return ret;
+
 	ret = platform_get_irq(pdev, 0);
 	if (ret <= 0) {
 		dev_err(dev, "Unable to get ENET Rx IRQ\n");

drivers/net/ethernet/apm/xgene/xgene_enet_main.h

@@ -184,6 +184,8 @@ struct xgene_enet_pdata {
 	u8 bp_bufnum;
 	u16 ring_num;
 	u32 mss;
+	u8 tx_delay;
+	u8 rx_delay;
 };
 
 struct xgene_indirect_ctl {