path: root/drivers/net/ethernet/allwinner/sun4i-emac.c

/*
 * Allwinner EMAC Fast Ethernet driver for Linux.
 *
 * Copyright 2012-2013 Stefan Roese <sr@denx.de>
 * Copyright 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
 *
 * Based on the Linux driver provided by Allwinner:
 * Copyright (C) 1997  Sten Wang
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/clk.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/mii.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/phy.h>

#include "sun4i-emac.h"

#define DRV_NAME		"sun4i-emac"
#define DRV_VERSION		"1.02"

#define EMAC_MAX_FRAME_LEN	0x0600

/* Transmit timeout, default 5 seconds. */
static int watchdog = 5000;
module_param(watchdog, int, 0400);
MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");

/* EMAC register address locking.
 *
 * The EMAC uses an address register to control where data written
 * to the data register goes. This means that the address register
 * must be preserved over interrupts or similar calls.
 *
 * During interrupt and other critical calls, a spinlock is used to
 * protect the system, but the calls themselves save the address
 * in the address register in case they are interrupting another
 * access to the device.
 *
 * For general accesses a lock is provided so that calls which are
 * allowed to sleep are serialised so that the address register does
 * not need to be saved. This lock also serves to serialise access
 * to the EEPROM and PHY access registers which are shared between
 * these two devices.
 */

/* The driver supports the original EMACE, and now the two newer
 * devices, EMACA and EMACB.
 */

struct emac_board_info {
	struct clk		*clk;
	struct device		*dev;
	struct platform_device	*pdev;
	spinlock_t		lock;
	void __iomem		*membase;
	u32			msg_enable;
	struct net_device	*ndev;
	struct sk_buff		*skb_last;
	u16			tx_fifo_stat;

	int			emacrx_completed_flag;

	struct phy_device	*phy_dev;
	struct device_node	*phy_node;
	unsigned int		link;
	unsigned int		speed;
	unsigned int		duplex;

	phy_interface_t		phy_interface;
};

static void emac_update_speed(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	unsigned int reg_val;

	/* set EMAC SPEED, depend on PHY  */
	reg_val = readl(db->membase + EMAC_MAC_SUPP_REG);
	reg_val &= ~(0x1 << 8);
	if (db->speed == SPEED_100)
		reg_val |= 1 << 8;
	writel(reg_val, db->membase + EMAC_MAC_SUPP_REG);
}

static void emac_update_duplex(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	unsigned int reg_val;

	/* set duplex depend on phy */
	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
	reg_val &= ~EMAC_MAC_CTL1_DUPLEX_EN;
	if (db->duplex)
		reg_val |= EMAC_MAC_CTL1_DUPLEX_EN;
	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
}

static void emac_handle_link_change(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	struct phy_device *phydev = db->phy_dev;
	unsigned long flags;
	int status_change = 0;

	if (phydev->link) {
		if (db->speed != phydev->speed) {
			spin_lock_irqsave(&db->lock, flags);
			db->speed = phydev->speed;
			emac_update_speed(dev);
			spin_unlock_irqrestore(&db->lock, flags);
			status_change = 1;
		}

		if (db->duplex != phydev->duplex) {
			spin_lock_irqsave(&db->lock, flags);
			db->duplex = phydev->duplex;
			emac_update_duplex(dev);
			spin_unlock_irqrestore(&db->lock, flags);
			status_change = 1;
		}
	}

	if (phydev->link != db->link) {
		if (!phydev->link) {
			db->speed = 0;
			db->duplex = -1;
		}
		db->link = phydev->link;

		status_change = 1;
	}

	if (status_change)
		phy_print_status(phydev);
}

static int emac_mdio_probe(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);

	/* to-do: PHY interrupts are currently not supported */

	/* attach the mac to the phy */
	db->phy_dev = of_phy_connect(db->ndev, db->phy_node,
				     &emac_handle_link_change, 0,
				     db->phy_interface);
	if (!db->phy_dev) {
		netdev_err(db->ndev, "could not find the PHY\n");
		return -ENODEV;
	}

	/* mask with MAC supported features */
	db->phy_dev->supported &= PHY_BASIC_FEATURES;
	db->phy_dev->advertising = db->phy_dev->supported;

	db->link = 0;
	db->speed = 0;
	db->duplex = -1;

	return 0;
}

static void emac_mdio_remove(struct