ethernet/arc/arc_emac - Add new driver

Driver for non-standard on-chip ethernet device ARC EMAC 10/100,
instantiated in some legacy ARC (Synopsys) FPGA Boards such as
ARCAngel4/ML50x.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Francois Romieu <romieu@fr.zoreil.com>
Cc: Joe Perches <joe@perches.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Mischa Jonker <mjonker@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-kernel@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Florian Fainelli <florian@openwrt.org>
Cc: David Laight <david.laight@aculab.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 214 insertions, 0 deletions

diff --git a/drivers/net/ethernet/arc/emac.h b/drivers/net/ethernet/arc/emac.h
new file mode 100644
index 00000000000..dc08678bf9a
--- /dev/null
+++ b/drivers/net/ethernet/arc/emac.h
@@ -0,0 +1,214 @@
+/*
+ * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * Registers and bits definitions of ARC EMAC
+ */
+
+#ifndef ARC_EMAC_H
+#define ARC_EMAC_H
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/netdevice.h>
+#include <linux/phy.h>
+
+/* STATUS and ENABLE Register bit masks */
+#define TXINT_MASK	(1<<0)	/* Transmit interrupt */
+#define RXINT_MASK	(1<<1)	/* Receive interrupt */
+#define ERR_MASK	(1<<2)	/* Error interrupt */
+#define TXCH_MASK	(1<<3)	/* Transmit chaining error interrupt */
+#define MSER_MASK	(1<<4)	/* Missed packet counter error */
+#define RXCR_MASK	(1<<8)	/* RXCRCERR counter rolled over  */
+#define RXFR_MASK	(1<<9)	/* RXFRAMEERR counter rolled over */
+#define RXFL_MASK	(1<<10)	/* RXOFLOWERR counter rolled over */
+#define MDIO_MASK	(1<<12)	/* MDIO complete interrupt */
+#define TXPL_MASK	(1<<31)	/* Force polling of BD by EMAC */
+
+/* CONTROL Register bit masks */
+#define EN_MASK		(1<<0)	/* VMAC enable */
+#define TXRN_MASK	(1<<3)	/* TX enable */
+#define RXRN_MASK	(1<<4)	/* RX enable */
+#define DSBC_MASK	(1<<8)	/* Disable receive broadcast */
+#define ENFL_MASK	(1<<10)	/* Enable Full-duplex */
+#define PROM_MASK	(1<<11)	/* Promiscuous mode */
+
+/* Buffer descriptor INFO bit masks */
+#define OWN_MASK	(1<<31)	/* 0-CPU owns buffer, 1-EMAC owns buffer */
+#define FIRST_MASK	(1<<16)	/* First buffer in chain */
+#define LAST_MASK	(1<<17)	/* Last buffer in chain */
+#define LEN_MASK	0x000007FF	/* last 11 bits */
+#define CRLS		(1<<21)
+#define DEFR		(1<<22)
+#define DROP		(1<<23)
+#define RTRY		(1<<24)
+#define LTCL		(1<<28)
+#define UFLO		(1<<29)
+
+#define FOR_EMAC	OWN_MASK
+#define FOR_CPU		0
+
+/* ARC EMAC register set combines entries for MAC and MDIO */
+enum {
+	R_ID = 0,
+	R_STATUS,
+	R_ENABLE,
+	R_CTRL,
+	R_POLLRATE,
+	R_RXERR,
+	R_MISS,
+	R_TX_RING,
+	R_RX_RING,
+	R_ADDRL,
+	R_ADDRH,
+	R_LAFL,
+	R_LAFH,
+	R_MDIO,
+};
+
+#define TX_TIMEOUT		(400*HZ/1000)	/* Transmission timeout */
+
+#define ARC_EMAC_NAPI_WEIGHT	40		/* Workload for NAPI */
+
+#define EMAC_BUFFER_SIZE	1536		/* EMAC buffer size */
+
+/**
+ * struct arc_emac_bd - EMAC buffer descriptor (BD).
+ *
+ * @info:	Contains status information on the buffer itself.
+ * @data:	32-bit byte addressable pointer to the packet data.
+ */
+struct arc_emac_bd {
+	__le32 info;
+	dma_addr_t data;
+};
+
+/* Number of Rx/Tx BD's */
+#define RX_BD_NUM	128
+#define TX_BD_NUM	128
+
+#define RX_RING_SZ	(RX_BD_NUM * sizeof(struct arc_emac_bd))
+#define TX_RING_SZ	(TX_BD_NUM * sizeof(struct arc_emac_bd))
+
+/**
+ * struct buffer_state - Stores Rx/Tx buffer state.
+ * @sk_buff:	Pointer to socket buffer.
+ * @addr:	Start address of DMA-mapped memory region.
+ * @len:	Length of DMA-mapped memory region.
+ */
+struct buffer_state {
+	struct sk_buff *skb;
+	DEFINE_DMA_UNMAP_ADDR(addr);
+	DEFINE_DMA_UNMAP_LEN(len);
+};
+
+/**
+ * struct arc_emac_priv - Storage of EMAC's private information.
+ * @dev:	Pointer to the current device.
+ * @ndev:	Pointer to the current network device.
+ * @phy_dev:	Pointer to attached PHY device.
+ * @bus:	Pointer to the current MII bus.
+ * @regs:	Base address of EMAC memory-mapped control registers.
+ * @napi:	Structure for NAPI.
+ * @stats:	Network device statistics.
+ * @rxbd:	Pointer to Rx BD ring.
+ * @txbd:	Pointer to Tx BD ring.
+ * @rxbd_dma:	DMA handle for Rx BD ring.
+ * @txbd_dma:	DMA handle for Tx BD ring.
+ * @rx_buff:	Storage for Rx buffers states.
+ * @tx_buff:	Storage for Tx buffers states.
+ * @txbd_curr:	Index of Tx BD to use on the next "ndo_start_xmit".
+ * @txbd_dirty:	Index of Tx BD to free on the next Tx interrupt.
+ * @last_rx_bd:	Index of the last Rx BD we've got from EMAC.
+ * @link:	PHY's last seen link state.
+ * @duplex:	PHY's last set duplex mode.
+ * @speed:	PHY's last set speed.
+ * @max_speed:	Maximum supported by current system network data-rate.
+ */
+struct arc_emac_priv {
+	/* Devices */
+	struct device *dev;
+	struct net_device *ndev;
+	struct phy_device *phy_dev;
+	struct mii_bus *bus;
+
+	void __iomem *regs;
+
+	struct napi_struct napi;
+	struct net_device_stats stats;
+
+	struct arc_emac_bd *rxbd;
+	struct arc_emac_bd *txbd;
+
+	dma_addr_t rxbd_dma;
+	dma_addr_t txbd_dma;
+
+	struct buffer_state rx_buff[RX_BD_NUM];
+	struct buffer_state tx_buff[TX_BD_NUM];
+	unsigned int txbd_curr;
+	unsigned int txbd_dirty;
+
+	unsigned int last_rx_bd;
+
+	unsigned int link;
+	unsigned int duplex;
+	unsigned int speed;
+	unsigned int max_speed;
+};
+
+/**
+ * arc_reg_set - Sets EMAC register with provided value.
+ * @priv:	Pointer to ARC EMAC private data structure.
+ * @reg:	Register offset from base address.
+ * @value:	Value to set in register.
+ */
+static inline void arc_reg_set(struct arc_emac_priv *priv, int reg, int value)
+{
+	iowrite32(value, priv->regs + reg * sizeof(int));
+}
+
+/**
+ * arc_reg_get - Gets value of specified EMAC register.
+ * @priv:	Pointer to ARC EMAC private data structure.
+ * @reg:	Register offset from base address.
+ *
+ * returns:	Value of requested register.
+ */
+static inline unsigned int arc_reg_get(struct arc_emac_priv *priv, int reg)
+{
+	return ioread32(priv->regs + reg * sizeof(int));
+}
+
+/**
+ * arc_reg_or - Applies mask to specified EMAC register - ("reg" | "mask").
+ * @priv:	Pointer to ARC EMAC private data structure.
+ * @reg:	Register offset from base address.
+ * @mask:	Mask to apply to specified register.
+ *
+ * This function reads initial register value, then applies provided mask
+ * to it and then writes register back.
+ */
+static inline void arc_reg_or(struct arc_emac_priv *priv, int reg, int mask)
+{
+	unsigned int value = arc_reg_get(priv, reg);
+	arc_reg_set(priv, reg, value | mask);
+}
+
+/**
+ * arc_reg_clr - Applies mask to specified EMAC register - ("reg" & ~"mask").
+ * @priv:	Pointer to ARC EMAC private data structure.
+ * @reg:	Register offset from base address.
+ * @mask:	Mask to apply to specified register.
+ *
+ * This function reads initial register value, then applies provided mask
+ * to it and then writes register back.
+ */
+static inline void arc_reg_clr(struct arc_emac_priv *priv, int reg, int mask)
+{
+	unsigned int value = arc_reg_get(priv, reg);
+	arc_reg_set(priv, reg, value & ~mask);
+}
+
+int arc_mdio_probe(struct platform_device *pdev, struct arc_emac_priv *priv);
+int arc_mdio_remove(struct arc_emac_priv *priv);
+
+#endif /* ARC_EMAC_H */