w5300.c

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/*
 * Ethernet driver for the WIZnet W5300 chip.
 *
 * Copyright (C) 2008-2009 WIZnet Co.,Ltd.
 * Copyright (C) 2011 Taehun Kim <kth3321 <at> gmail.com>
 * Copyright (C) 2012 Mike Sinkovsky <[email protected]>
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kconfig.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/platform_device.h>
#include <linux/platform_data/wiznet.h>
#include <linux/ethtool.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/gpio.h>

#define DRV_NAME    "w5300"
#define DRV_VERSION "2012-04-04"

MODULE_DESCRIPTION("WIZnet W5300 Ethernet driver v"DRV_VERSION);
MODULE_AUTHOR("Mike Sinkovsky <[email protected]>");
MODULE_ALIAS("platform:"DRV_NAME);
MODULE_LICENSE("GPL");

/*
 * Registers
 */
#define W5300_MR        0x0000  /* Mode Register */
#define   MR_DBW          (1 << 15) /* Data bus width */
#define   MR_MPF          (1 << 14) /* Mac layer pause frame */
#define   MR_WDF(n)       (((n)&7)<<11) /* Write data fetch time */
#define   MR_RDH          (1 << 10) /* Read data hold time */
#define   MR_FS           (1 << 8)  /* FIFO swap */
#define   MR_RST          (1 << 7)  /* S/W reset */
#define   MR_PB           (1 << 4)  /* Ping block */
#define   MR_DBS          (1 << 2)  /* Data bus swap */
#define   MR_IND          (1 << 0)  /* Indirect mode */
#define W5300_IR        0x0002  /* Interrupt Register */
#define W5300_IMR       0x0004  /* Interrupt Mask Register */
#define   IR_S0           0x0001  /* S0 interrupt */
#define W5300_SHARL     0x0008  /* Source MAC address (0123) */
#define W5300_SHARH     0x000c  /* Source MAC address (45) */
#define W5300_TMSRL     0x0020  /* Transmit Memory Size (0123) */
#define W5300_TMSRH     0x0024  /* Transmit Memory Size (4567) */
#define W5300_RMSRL     0x0028  /* Receive Memory Size (0123) */
#define W5300_RMSRH     0x002c  /* Receive Memory Size (4567) */
#define W5300_MTYPE     0x0030  /* Memory Type */
#define W5300_IDR       0x00fe  /* Chip ID register */
#define   IDR_W5300       0x5300  /* =0x5300 for WIZnet W5300 */
#define W5300_S0_MR     0x0200  /* S0 Mode Register */
#define   S0_MR_CLOSED        0x0000  /* Close mode */
#define   S0_MR_MACRAW        0x0004  /* MAC RAW mode (promiscous) */
#define   S0_MR_MACRAW_MF     0x0044  /* MAC RAW mode (filtered) */
#define W5300_S0_CR     0x0202  /* S0 Command Register */
#define   S0_CR_OPEN          0x0001  /* OPEN command */
#define   S0_CR_CLOSE         0x0010  /* CLOSE command */
#define   S0_CR_SEND          0x0020  /* SEND command */
#define   S0_CR_RECV          0x0040  /* RECV command */
#define W5300_S0_IMR        0x0204  /* S0 Interrupt Mask Register */
#define W5300_S0_IR     0x0206  /* S0 Interrupt Register */
#define   S0_IR_RECV          0x0004  /* Receive interrupt */
#define   S0_IR_SENDOK        0x0010  /* Send OK interrupt */
#define W5300_S0_SSR        0x0208  /* S0 Socket Status Register */
#define W5300_S0_TX_WRSR    0x0220  /* S0 TX Write Size Register */
#define W5300_S0_TX_FSR     0x0224  /* S0 TX Free Size Register */
#define W5300_S0_RX_RSR     0x0228  /* S0 Received data Size */
#define W5300_S0_TX_FIFO    0x022e  /* S0 Transmit FIFO */
#define W5300_S0_RX_FIFO    0x0230  /* S0 Receive FIFO */
#define W5300_REGS_LEN      0x0400

/*
 * Device driver private data structure
 */
struct w5300_priv {
    void __iomem *base;
    spinlock_t reg_lock;
    bool indirect;
    u16  (*read) (struct w5300_priv *priv, u16 addr);
    void (*write)(struct w5300_priv *priv, u16 addr, u16 data);
    int irq;
    int link_irq;
    int link_gpio;

    struct napi_struct napi;
    struct net_device *ndev;
    bool promisc;
    u32 msg_enable;
};

/************************************************************************
 *
 *  Lowlevel I/O functions
 *
 ***********************************************************************/

/*
 * In direct address mode host system can directly access W5300 registers
 * after mapping to Memory-Mapped I/O space.
 *
 * 0x400 bytes are required for memory space.
 */
static inline u16 w5300_read_direct(struct w5300_priv *priv, u16 addr)
{
    return ioread16(priv->base + (addr << CONFIG_WIZNET_BUS_SHIFT));
}

static inline void w5300_write_direct(struct w5300_priv *priv,
                      u16 addr, u16 data)
{
    iowrite16(data, priv->base + (addr << CONFIG_WIZNET_BUS_SHIFT));
}

/*
 * In indirect address mode host system indirectly accesses registers by
 * using Indirect Mode Address Register (IDM_AR) and Indirect Mode Data
 * Register (IDM_DR), which are directly mapped to Memory-Mapped I/O space.
 * Mode Register (MR) is directly accessible.
 *
 * Only 0x06 bytes are required for memory space.
 */
#define W5300_IDM_AR        0x0002   /* Indirect Mode Address */
#define W5300_IDM_DR        0x0004   /* Indirect Mode Data */

static u16 w5300_read_indirect(struct w5300_priv *priv, u16 addr)
{
    unsigned long flags;
    u16 data;

    spin_lock_irqsave(&priv->reg_lock, flags);
    w5300_write_direct(priv, W5300_IDM_AR, addr);
    mmiowb();
    data = w5300_read_direct(priv, W5300_IDM_DR);
    spin_unlock_irqrestore(&priv->reg_lock, flags);

    return data;
}

static void w5300_write_indirect(struct w5300_priv *priv, u16 addr, u16 data)
{
    unsigned long flags;

    spin_lock_irqsave(&priv->reg_lock, flags);
    w5300_write_direct(priv, W5300_IDM_AR, addr);
    mmiowb();
    w5300_write_direct(priv, W5300_IDM_DR, data);
    mmiowb();
    spin_unlock_irqrestore(&priv->reg_lock, flags);
}

#if defined(CONFIG_WIZNET_BUS_DIRECT)
#define w5300_read  w5300_read_direct
#define w5300_write w5300_write_direct

#elif defined(CONFIG_WIZNET_BUS_INDIRECT)
#define w5300_read  w5300_read_indirect
#define w5300_write w5300_write_indirect

#else /* CONFIG_WIZNET_BUS_ANY */
#define w5300_read  priv->read
#define w5300_write priv->write
#endif

static u32 w5300_read32(struct w5300_priv *priv, u16 addr)
{
    u32 data;
    data  = w5300_read(priv, addr) << 16;
    data |= w5300_read(priv, addr + 2);
    return data;
}

static void w5300_write32(struct w5300_priv *priv, u16 addr, u32 data)
{
    w5300_write(priv, addr, data >> 16);
    w5300_write(priv, addr + 2, data);
}

static int w5300_command(struct w5300_priv *priv, u16 cmd)
{
    unsigned long timeout = jiffies + msecs_to_jiffies(100);

    w5300_write(priv, W5300_S0_CR, cmd);
    mmiowb();

    while (w5300_read(priv, W5300_S0_CR) != 0) {
        if (time_after(jiffies, timeout))
            return -EIO;
        cpu_relax();
    }

    return 0;
}

static void w5300_read_frame(struct w5300_priv *priv, u8 *buf, int len)
{
    u16 fifo;
    int i;

    for (i = 0; i < len; i += 2) {
        fifo = w5300_read(priv, W5300_S0_RX_FIFO);
        *buf++ = fifo >> 8;
        *buf++ = fifo;
    }
    fifo = w5300_read(priv, W5300_S0_RX_FIFO);
    fifo = w5300_read(priv, W5300_S0_RX_FIFO);
}

static void w5300_write_frame(struct w5300_priv *priv, u8 *buf, int len)
{
    u16 fifo;
    int i;

    for (i = 0; i < len; i += 2) {
        fifo  = *buf++ << 8;
        fifo |= *buf++;
        w5300_write(priv, W5300_S0_TX_FIFO, fifo);
    }
    w5300_write32(priv, W5300_S0_TX_WRSR, len);
}

static void w5300_write_macaddr(struct w5300_priv *priv)
{
    struct net_device *ndev = priv->ndev;
    w5300_write32(priv, W5300_SHARL,
              ndev->dev_addr[0] << 24 |
              ndev->dev_addr[1] << 16 |
              ndev->dev_addr[2] << 8 |
              ndev->dev_addr[3]);
    w5300_write(priv, W5300_SHARH,
              ndev->dev_addr[4] << 8 |
              ndev->dev_addr[5]);
    mmiowb();
}

static void w5300_hw_reset(struct w5300_priv *priv)
{
    w5300_write_direct(priv, W5300_MR, MR_RST);
    mmiowb();
    mdelay(5);
    w5300_write_direct(priv, W5300_MR, priv->indirect ?
                 MR_WDF(7) | MR_PB | MR_IND :
                 MR_WDF(7) | MR_PB);
    mmiowb();
    w5300_write(priv, W5300_IMR, 0);
    w5300_write_macaddr(priv);

    /* Configure 128K of internal memory
     * as 64K RX fifo and 64K TX fifo
     */
    w5300_write32(priv, W5300_RMSRL, 64 << 24);
    w5300_write32(priv, W5300_RMSRH, 0);
    w5300_write32(priv, W5300_TMSRL, 64 << 24);
    w5300_write32(priv, W5300_TMSRH, 0);
    w5300_write(priv, W5300_MTYPE, 0x00ff);
    mmiowb();
}

static void w5300_hw_start(struct w5300_priv *priv)
{
    w5300_write(priv, W5300_S0_MR, priv->promisc ?
              S0_MR_MACRAW : S0_MR_MACRAW_MF);
    mmiowb();
    w5300_command(priv, S0_CR_OPEN);
    w5300_write(priv, W5300_S0_IMR, S0_IR_RECV | S0_IR_SENDOK);
    w5300_write(priv, W5300_IMR, IR_S0);
    mmiowb();
}

static void w5300_hw_close(struct w5300_priv *priv)
{
    w5300_write(priv, W5300_IMR, 0);
    mmiowb();
    w5300_command(priv, S0_CR_CLOSE);
}

/***********************************************************************
 *
 *   Device driver functions / callbacks
 *
 ***********************************************************************/

static void w5300_get_drvinfo(struct net_device *ndev,
                  struct ethtool_drvinfo *info)
{
    strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
    strlcpy(info->version, DRV_VERSION, sizeof(info->version));
    strlcpy(info->bus_info, dev_name(ndev->dev.parent),
        sizeof(info->bus_info));
}

static u32 w5300_get_link(struct net_device *ndev)
{
    struct w5300_priv *priv = netdev_priv(ndev);

    if (gpio_is_valid(priv->link_gpio))
        return !!gpio_get_value(priv->link_gpio);

    return 1;
}

static u32 w5300_get_msglevel(struct net_device *ndev)
{
    struct w5300_priv *priv = netdev_priv(ndev);

    return priv->msg_enable;
}

static void w5300_set_msglevel(struct net_device *ndev, u32 value)
{
    struct w5300_priv *priv = netdev_priv(ndev);

    priv->msg_enable = value;
}

static int w5300_get_regs_len(struct net_device *ndev)
{
    return W5300_REGS_LEN;
}

static void w5300_get_regs(struct net_device *ndev,
               struct ethtool_regs *regs, void *_buf)
{
    struct w5300_priv *priv = netdev_priv(ndev);
    u8 *buf = _buf;
    u16 addr;
    u16 data;

    regs->version = 1;
    for (addr = 0; addr < W5300_REGS_LEN; addr += 2) {
        switch (addr & 0x23f) {
        case W5300_S0_TX_FIFO: /* cannot read TX_FIFO */
        case W5300_S0_RX_FIFO: /* cannot read RX_FIFO */
            data = 0xffff;
            break;
        default:
            data = w5300_read(priv, addr);
            break;
        }
        *buf++ = data >> 8;
        *buf++ = data;
    }
}

static void w5300_tx_timeout(struct net_device *ndev)
{
    struct w5300_priv *priv = netdev_priv(ndev);

    netif_stop_queue(ndev);
    w5300_hw_reset(priv);
    w5300_hw_start(priv);
    ndev->stats.tx_errors++;
    ndev->trans_start = jiffies;
    netif_wake_queue(ndev);
}

static int w5300_start_tx(struct sk_buff *skb, struct net_device *ndev)
{
    struct w5300_priv *priv = netdev_priv(ndev);

    netif_stop_queue(ndev);

    w5300_write_frame(priv, skb->data, skb->len);
    mmiowb();
    ndev->stats.tx_packets++;
    ndev->stats.tx_bytes += skb->len;
    dev_kfree_skb(skb);
    netif_dbg(priv, tx_queued, ndev, "tx queued\n");

    w5300_command(priv, S0_CR_SEND);

    return NETDEV_TX_OK;
}

static int w5300_napi_poll(struct napi_struct *napi, int budget)
{
    struct w5300_priv *priv = container_of(napi, struct w5300_priv, napi);
    struct net_device *ndev = priv->ndev;
    struct sk_buff *skb;
    int rx_count;
    u16 rx_len;

    for (rx_count = 0; rx_count < budget; rx_count++) {
        u32 rx_fifo_len = w5300_read32(priv, W5300_S0_RX_RSR);
        if (rx_fifo_len == 0)
            break;

        rx_len = w5300_read(priv, W5300_S0_RX_FIFO);

        skb = netdev_alloc_skb_ip_align(ndev, roundup(rx_len, 2));
        if (unlikely(!skb)) {
            u32 i;
            for (i = 0; i < rx_fifo_len; i += 2)
                w5300_read(priv, W5300_S0_RX_FIFO);
            ndev->stats.rx_dropped++;
            return -ENOMEM;
        }

        skb_put(skb, rx_len);
        w5300_read_frame(priv, skb->data, rx_len);
        skb->protocol = eth_type_trans(skb, ndev);

        netif_receive_skb(skb);
        ndev->stats.rx_packets++;
        ndev->stats.rx_bytes += rx_len;
    }

    if (rx_count < budget) {
        w5300_write(priv, W5300_IMR, IR_S0);
        mmiowb();
        napi_complete(napi);
    }

    return rx_count;
}

static irqreturn_t w5300_interrupt(int irq, void *ndev_instance)
{
    struct net_device *ndev = ndev_instance;
    struct w5300_priv *priv = netdev_priv(ndev);

    int ir = w5300_read(priv, W5300_S0_IR);
    if (!ir)
        return IRQ_NONE;
    w5300_write(priv, W5300_S0_IR, ir);
    mmiowb();

    if (ir & S0_IR_SENDOK) {
        netif_dbg(priv, tx_done, ndev, "tx done\n");
        netif_wake_queue(ndev);
    }

    if (ir & S0_IR_RECV) {
        if (napi_schedule_prep(&priv->napi)) {
            w5300_write(priv, W5300_IMR, 0);
            mmiowb();
            __napi_schedule(&priv->napi);
        }
    }

    return IRQ_HANDLED;
}

static irqreturn_t w5300_detect_link(int irq, void *ndev_instance)
{
    struct net_device *ndev = ndev_instance;
    struct w5300_priv *priv = netdev_priv(ndev);

    if (netif_running(ndev)) {
        if (gpio_get_value(priv->link_gpio) != 0) {
            netif_info(priv, link, ndev, "link is up\n");
            netif_carrier_on(ndev);
        } else {
            netif_info(priv, link, ndev, "link is down\n");
            netif_carrier_off(ndev);
        }
    }

    return IRQ_HANDLED;
}

static void w5300_set_rx_mode(struct net_device *ndev)
{
    struct w5300_priv *priv = netdev_priv(ndev);
    bool set_promisc = (ndev->flags & IFF_PROMISC) != 0;

    if (priv->promisc != set_promisc) {
        priv->promisc = set_promisc;
        w5300_hw_start(priv);
    }
}

static int w5300_set_macaddr(struct net_device *ndev, void *addr)
{
    struct w5300_priv *priv = netdev_priv(ndev);
    struct sockaddr *sock_addr = addr;

    if (!is_valid_ether_addr(sock_addr->sa_data))
        return -EADDRNOTAVAIL;
    memcpy(ndev->dev_addr, sock_addr->sa_data, ETH_ALEN);
    ndev->addr_assign_type &= ~NET_ADDR_RANDOM;
    w5300_write_macaddr(priv);
    return 0;
}

static int w5300_open(struct net_device *ndev)
{
    struct w5300_priv *priv = netdev_priv(ndev);

    netif_info(priv, ifup, ndev, "enabling\n");
    if (!is_valid_ether_addr(ndev->dev_addr))
        return -EINVAL;
    w5300_hw_start(priv);
    napi_enable(&priv->napi);
    netif_start_queue(ndev);
    if (!gpio_is_valid(priv->link_gpio) ||
        gpio_get_value(priv->link_gpio) != 0)
        netif_carrier_on(ndev);
    return 0;
}

static int w5300_stop(struct net_device *ndev)
{
    struct w5300_priv *priv = netdev_priv(ndev);

    netif_info(priv, ifdown, ndev, "shutting down\n");
    w5300_hw_close(priv);
    netif_carrier_off(ndev);
    netif_stop_queue(ndev);
    napi_disable(&priv->napi);
    return 0;
}

static const struct ethtool_ops w5300_ethtool_ops = {
    .get_drvinfo        = w5300_get_drvinfo,
    .get_msglevel       = w5300_get_msglevel,
    .set_msglevel       = w5300_set_msglevel,
    .get_link       = w5300_get_link,
    .get_regs_len       = w5300_get_regs_len,
    .get_regs       = w5300_get_regs,
};

static const struct net_device_ops w5300_netdev_ops = {
    .ndo_open       = w5300_open,
    .ndo_stop       = w5300_stop,
    .ndo_start_xmit     = w5300_start_tx,
    .ndo_tx_timeout     = w5300_tx_timeout,
    .ndo_set_rx_mode    = w5300_set_rx_mode,
    .ndo_set_mac_address    = w5300_set_macaddr,
    .ndo_validate_addr  = eth_validate_addr,
    .ndo_change_mtu     = eth_change_mtu,
};

static int __devinit w5300_hw_probe(struct platform_device *pdev)
{
    struct wiznet_platform_data *data = pdev->dev.platform_data;
    struct net_device *ndev = platform_get_drvdata(pdev);
    struct w5300_priv *priv = netdev_priv(ndev);
    const char *name = netdev_name(ndev);
    struct resource *mem;
    int mem_size;
    int irq;
    int ret;

    if (data && is_valid_ether_addr(data->mac_addr)) {
        memcpy(ndev->dev_addr, data->mac_addr, ETH_ALEN);
    } else {
        eth_hw_addr_random(ndev);
    }

    mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!mem)
        return -ENXIO;
    mem_size = resource_size(mem);
    if (!devm_request_mem_region(&pdev->dev, mem->start, mem_size, name))
        return -EBUSY;
    priv->base = devm_ioremap(&pdev->dev, mem->start, mem_size);
    if (!priv->base)
        return -EBUSY;

    spin_lock_init(&priv->reg_lock);
    priv->indirect = mem_size < W5300_BUS_DIRECT_SIZE;
    if (priv->indirect) {
        priv->read  = w5300_read_indirect;
        priv->write = w5300_write_indirect;
    } else {
        priv->read  = w5300_read_direct;
        priv->write = w5300_write_direct;
    }

    w5300_hw_reset(priv);
    if (w5300_read(priv, W5300_IDR) != IDR_W5300)
        return -ENODEV;

    irq = platform_get_irq(pdev, 0);
    if (irq < 0)
        return irq;
    ret = request_irq(irq, w5300_interrupt,
              IRQ_TYPE_LEVEL_LOW, name, ndev);
    if (ret < 0)
        return ret;
    priv->irq = irq;

    priv->link_gpio = data ? data->link_gpio : -EINVAL;
    if (gpio_is_valid(priv->link_gpio)) {
        char *link_name = devm_kzalloc(&pdev->dev, 16, GFP_KERNEL);
        if (!link_name)
            return -ENOMEM;
        snprintf(link_name, 16, "%s-link", name);
        priv->link_irq = gpio_to_irq(priv->link_gpio);
        if (request_any_context_irq(priv->link_irq, w5300_detect_link,
                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
                link_name, priv->ndev) < 0)
            priv->link_gpio = -EINVAL;
    }

    netdev_info(ndev, "at 0x%llx irq %d\n", (u64)mem->start, irq);
    return 0;
}

static int __devinit w5300_probe(struct platform_device *pdev)
{
    struct w5300_priv *priv;
    struct net_device *ndev;
    int err;

    ndev = alloc_etherdev(sizeof(*priv));
    if (!ndev)
        return -ENOMEM;
    SET_NETDEV_DEV(ndev, &pdev->dev);
    platform_set_drvdata(pdev, ndev);
    priv = netdev_priv(ndev);
    priv->ndev = ndev;

    ether_setup(ndev);
    ndev->netdev_ops = &w5300_netdev_ops;
    ndev->ethtool_ops = &w5300_ethtool_ops;
    ndev->watchdog_timeo = HZ;
    netif_napi_add(ndev, &priv->napi, w5300_napi_poll, 16);

    /* This chip doesn't support VLAN packets with normal MTU,
     * so disable VLAN for this device.
     */
    ndev->features |= NETIF_F_VLAN_CHALLENGED;

    err = register_netdev(ndev);
    if (err < 0)
        goto err_register;

    err = w5300_hw_probe(pdev);
    if (err < 0)
        goto err_hw_probe;

    return 0;

err_hw_probe:
    unregister_netdev(ndev);
err_register:
    free_netdev(ndev);
    platform_set_drvdata(pdev, NULL);
    return err;
}

static int __devexit w5300_remove(struct platform_device *pdev)
{
    struct net_device *ndev = platform_get_drvdata(pdev);
    struct w5300_priv *priv = netdev_priv(ndev);

    w5300_hw_reset(priv);
    free_irq(priv->irq, ndev);
    if (gpio_is_valid(priv->link_gpio))
        free_irq(priv->link_irq, ndev);

    unregister_netdev(ndev);
    free_netdev(ndev);
    platform_set_drvdata(pdev, NULL);
    return 0;
}

#ifdef CONFIG_PM
static int w5300_suspend(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct net_device *ndev = platform_get_drvdata(pdev);
    struct w5300_priv *priv = netdev_priv(ndev);

    if (netif_running(ndev)) {
        netif_carrier_off(ndev);
        netif_device_detach(ndev);

        w5300_hw_close(priv);
    }
    return 0;
}

static int w5300_resume(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct net_device *ndev = platform_get_drvdata(pdev);
    struct w5300_priv *priv = netdev_priv(ndev);

    if (!netif_running(ndev)) {
        w5300_hw_reset(priv);
        w5300_hw_start(priv);

        netif_device_attach(ndev);
        if (!gpio_is_valid(priv->link_gpio) ||
            gpio_get_value(priv->link_gpio) != 0)
            netif_carrier_on(ndev);
    }
    return 0;
}
#endif /* CONFIG_PM */

static SIMPLE_DEV_PM_OPS(w5300_pm_ops, w5300_suspend, w5300_resume);

static struct platform_driver w5300_driver = {
    .driver     = {
        .name   = DRV_NAME,
        .owner  = THIS_MODULE,
        .pm = &w5300_pm_ops,
    },
    .probe      = w5300_probe,
    .remove     = __devexit_p(w5300_remove),
};

module_platform_driver(w5300_driver);