net: fec_mxc: add support for i.MX8X

Add compatible property and enable the FEC ipg clock when probing
on i.MX8X. Add specific function for reading FEC clock rate via
clock driver when configuring MII speed register. Allow FEC_MXC
selection for i.MX8.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/net/Kconfig

@@ -176,7 +176,7 @@ config FEC_MXC_MDIO_BASE
 
 config FEC_MXC
 	bool "FEC Ethernet controller"
-	depends on MX5 || MX6 || MX7
+	depends on MX5 || MX6 || MX7 || IMX8
 	help
 	  This driver supports the 10/100 Fast Ethernet controller for
 	  NXP i.MX processors.

drivers/net/fec_mxc.c

@@ -123,6 +123,32 @@ static int fec_mdio_read(struct ethernet_regs *eth, uint8_t phyaddr,
 	return val;
 }
 
+static int fec_get_clk_rate(void *udev, int idx)
+{
+#if IS_ENABLED(CONFIG_IMX8)
+	struct fec_priv *fec;
+	struct udevice *dev;
+	int ret;
+
+	dev = udev;
+	if (!dev) {
+		ret = uclass_get_device(UCLASS_ETH, idx, &dev);
+		if (ret < 0) {
+			debug("Can't get FEC udev: %d\n", ret);
+			return ret;
+		}
+	}
+
+	fec = dev_get_priv(dev);
+	if (fec)
+		return fec->clk_rate;
+
+	return -EINVAL;
+#else
+	return imx_get_fecclk();
+#endif
+}
+
 static void fec_mii_setspeed(struct ethernet_regs *eth)
 {
 	/*
@@ -140,9 +166,20 @@ static void fec_mii_setspeed(struct ethernet_regs *eth)
 	 * Given that ceil(clkrate / 5000000) <= 64, the calculation for
 	 * holdtime cannot result in a value greater than 3.
 	 */
-	u32 pclk = imx_get_fecclk();
-	u32 speed = DIV_ROUND_UP(pclk, 5000000);
-	u32 hold = DIV_ROUND_UP(pclk, 100000000) - 1;
+	u32 pclk;
+	u32 speed;
+	u32 hold;
+	int ret;
+
+	ret = fec_get_clk_rate(NULL, 0);
+	if (ret < 0) {
+		printf("Can't find FEC0 clk rate: %d\n", ret);
+		return;
+	}
+	pclk = ret;
+	speed = DIV_ROUND_UP(pclk, 5000000);
+	hold = DIV_ROUND_UP(pclk, 100000000) - 1;
+
 #ifdef FEC_QUIRK_ENET_MAC
 	speed--;
 #endif
@@ -1269,6 +1306,21 @@ static int fecmxc_probe(struct udevice *dev)
 	uint32_t start;
 	int ret;
 
+	if (IS_ENABLED(CONFIG_IMX8)) {
+		ret = clk_get_by_name(dev, "ipg", &priv->ipg_clk);
+		if (ret < 0) {
+			debug("Can't get FEC ipg clk: %d\n", ret);
+			return ret;
+		}
+		ret = clk_enable(&priv->ipg_clk);
+		if (ret < 0) {
+			debug("Can't enable FEC ipg clk: %d\n", ret);
+			return ret;
+		}
+
+		priv->clk_rate = clk_get_rate(&priv->ipg_clk);
+	}
+
 	ret = fec_alloc_descs(priv);
 	if (ret)
 		return ret;
@@ -1412,6 +1464,7 @@ static const struct udevice_id fecmxc_ids[] = {
 	{ .compatible = "fsl,imx6sx-fec" },
 	{ .compatible = "fsl,imx6ul-fec" },
 	{ .compatible = "fsl,imx53-fec" },
+	{ .compatible = "fsl,imx7d-fec" },
 	{ }
 };
 

drivers/net/fec_mxc.h

@@ -16,6 +16,8 @@
 #ifndef __FEC_MXC_H
 #define __FEC_MXC_H
 
+#include <clk.h>
+
 /* Layout description of the FEC */
 struct ethernet_regs {
 	/* [10:2]addr = 00 */
@@ -260,6 +262,8 @@ struct fec_priv {
 #ifdef CONFIG_DM_ETH
 	u32 interface;
 #endif
+	struct clk ipg_clk;
+	u32 clk_rate;
 };
 
 void imx_get_mac_from_fuse(int dev_id, unsigned char *mac);