drivers: net: add NXP ENETC ethernet driver

Adds a driver for NXP ENETC ethernet controller currently integrated in
LS1028A.  ENETC is a fairly straight-forward BD ring device and interfaces
are presented as PCI EPs on the SoC ECAM.

Signed-off-by: Catalin Horghidan <catalin.horghidan@nxp.com>
Signed-off-by: Alex Marginean <alexm.osslist@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/fsl_enetc.h b/drivers/net/fsl_enetc.h
new file mode 100644
index 0000000..155ecc8
--- /dev/null
+++ b/drivers/net/fsl_enetc.h
@@ -0,0 +1,168 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * ENETC ethernet controller driver
+ * Copyright 2017-2019 NXP
+ */
+
+#ifndef _ENETC_H
+#define _ENETC_H
+
+#define enetc_dbg(dev, fmt, args...)	debug("%s:" fmt, dev->name, ##args)
+
+/* PCI function IDs */
+#define PCI_DEVICE_ID_ENETC_ETH		0xE100
+
+/* ENETC Ethernet controller registers */
+/* Station interface register offsets */
+#define ENETC_SIMR		0x000
+#define  ENETC_SIMR_EN		BIT(31)
+#define ENETC_SICAR0		0x040
+/* write cache cfg: snoop, no allocate, data & BD coherent */
+#define  ENETC_SICAR_WR_CFG	0x6767
+/* read cache cfg: coherent copy, look up, don't alloc in cache */
+#define  ENETC_SICAR_RD_CFG	0x27270000
+#define ENETC_SIROCT		0x300
+#define ENETC_SIRFRM		0x308
+#define ENETC_SITOCT		0x320
+#define ENETC_SITFRM		0x328
+
+/* Rx/Tx Buffer Descriptor Ring registers */
+enum enetc_bdr_type {TX, RX};
+#define ENETC_BDR(type, n, off)	(0x8000 + (type) * 0x100 + (n) * 0x200 + (off))
+#define ENETC_BDR_IDX_MASK	0xffff
+
+/* Rx BDR reg offsets */
+#define ENETC_RBMR		0x00
+#define  ENETC_RBMR_EN		BIT(31)
+#define ENETC_RBBSR		0x08
+/* initial consumer index for Rx BDR */
+#define ENETC_RBCIR		0x0c
+#define ENETC_RBBAR0		0x10
+#define ENETC_RBBAR1		0x14
+#define ENETC_RBPIR		0x18
+#define ENETC_RBLENR		0x20
+
+/* Tx BDR reg offsets */
+#define ENETC_TBMR		0x00
+#define  ENETC_TBMR_EN		BIT(31)
+#define ENETC_TBBAR0		0x10
+#define ENETC_TBBAR1		0x14
+#define ENETC_TBPIR		0x18
+#define ENETC_TBCIR		0x1c
+#define ENETC_TBLENR		0x20
+
+/* Port registers offset */
+#define ENETC_PORT_REGS_OFF		0x10000
+
+/* Port registers */
+#define ENETC_PMR			0x0000
+#define  ENETC_PMR_SI0_EN		BIT(16)
+#define ENETC_PSIPMMR			0x0018
+#define ENETC_PSIPMAR0			0x0100
+#define ENETC_PSIPMAR1			0x0104
+#define ENETC_PSICFGR(n)		(0x0940 + (n) * 0x10)
+#define  ENETC_PSICFGR_SET_TXBDR(val)	((val) & 0xff)
+#define  ENETC_PSICFGR_SET_RXBDR(val)	(((val) & 0xff) << 16)
+/* MAC configuration */
+#define ENETC_PM_CC			0x8008
+#define  ENETC_PM_CC_DEFAULT		0x0810
+#define  ENETC_PM_CC_RX_TX_EN		0x8813
+#define ENETC_PM_MAXFRM			0x8014
+#define  ENETC_RX_MAXFRM_SIZE		PKTSIZE_ALIGN
+
+/* buffer descriptors count must be multiple of 8 and aligned to 128 bytes */
+#define ENETC_BD_CNT		CONFIG_SYS_RX_ETH_BUFFER
+#define ENETC_BD_ALIGN		128
+
+/* single pair of Rx/Tx rings */
+#define ENETC_RX_BDR_CNT	1
+#define ENETC_TX_BDR_CNT	1
+#define ENETC_RX_BDR_ID		0
+#define ENETC_TX_BDR_ID		0
+
+/* Tx buffer descriptor */
+struct enetc_tx_bd {
+	__le64 addr;
+	__le16 buf_len;
+	__le16 frm_len;
+	__le16 err_csum;
+	__le16 flags;
+};
+
+#define ENETC_TXBD_FLAGS_F	BIT(15)
+#define ENETC_POLL_TRIES	32000
+
+/* Rx buffer descriptor */
+union enetc_rx_bd {
+	/* SW provided BD format */
+	struct {
+		__le64 addr;
+		u8 reserved[8];
+	} w;
+
+	/* ENETC returned BD format */
+	struct {
+		__le16 inet_csum;
+		__le16 parse_summary;
+		__le32 rss_hash;
+		__le16 buf_len;
+		__le16 vlan_opt;
+		union {
+			struct {
+				__le16 flags;
+				__le16 error;
+			};
+			__le32 lstatus;
+		};
+	} r;
+};
+
+#define ENETC_RXBD_STATUS_R(status)		(((status) >> 30) & 0x1)
+#define ENETC_RXBD_STATUS_F(status)		(((status) >> 31) & 0x1)
+#define ENETC_RXBD_STATUS_ERRORS(status)	(((status) >> 16) & 0xff)
+#define ENETC_RXBD_STATUS(flags)		((flags) << 16)
+
+/* Tx/Rx ring info */
+struct bd_ring {
+	void *cons_idx;
+	void *prod_idx;
+	/* next BD index to use */
+	int next_prod_idx;
+	int next_cons_idx;
+	int bd_count;
+};
+
+/* ENETC private structure */
+struct enetc_priv {
+	struct enetc_tx_bd *enetc_txbd;
+	union enetc_rx_bd *enetc_rxbd;
+
+	void *regs_base; /* base ENETC registers */
+	void *port_regs; /* base ENETC port registers */
+
+	/* Rx/Tx buffer descriptor rings info */
+	struct bd_ring tx_bdr;
+	struct bd_ring rx_bdr;
+};
+
+/* register accessors */
+#define enetc_read_reg(x)	readl((x))
+#define enetc_write_reg(x, val)	writel((val), (x))
+#define enetc_read(priv, off)	enetc_read_reg((priv)->regs_base + (off))
+#define enetc_write(priv, off, v) \
+			enetc_write_reg((priv)->regs_base + (off), v)
+
+/* port register accessors */
+#define enetc_port_regs(priv, off) ((priv)->port_regs + (off))
+#define enetc_read_port(priv, off) \
+			enetc_read_reg(enetc_port_regs((priv), (off)))
+#define enetc_write_port(priv, off, v) \
+			enetc_write_reg(enetc_port_regs((priv), (off)), v)
+
+/* BDR register accessors, see ENETC_BDR() */
+#define enetc_bdr_read(priv, t, n, off) \
+			enetc_read(priv, ENETC_BDR(t, n, off))
+#define enetc_bdr_write(priv, t, n, off, val) \
+			enetc_write(priv, ENETC_BDR(t, n, off), val)
+
+#endif /* _ENETC_H */