Re: [PATCH v4] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

From: Andy Shevchenko
Date: Sat Oct 31 2015 - 13:22:29 EST


On Thu, Oct 29, 2015 at 6:48 PM, Mans Rullgard <mans@xxxxxxxxx> wrote:
> This adds a driver for the Aurora VLSI NB8800 Ethernet controller.
> It is an almost complete rewrite of a driver originally found in
> a Sigma Designs 2.6.22 tree.
>
> Signed-off-by: Mans Rullgard <mans@xxxxxxxxx>


> +++ b/drivers/net/ethernet/aurora/nb8800.c
> @@ -0,0 +1,1146 @@

> +#define nb8800_set_bits(sz, priv, reg, bits) do { \
> + u32 __o = nb8800_read##sz(priv, reg); \
> + u32 __n = __o | (bits); \
> + if (__n != __o) \
> + nb8800_write##sz(priv, reg, __n); \
> + } while (0)
> +
> +#define nb8800_clear_bits(sz, priv, reg, bits) do { \
> + u32 __o = nb8800_read##sz(priv, reg); \
> + u32 __n = __o & ~(bits); \
> + if (__n != __o) \
> + nb8800_write##sz(priv, reg, __n); \
> + } while (0)
> +
> +#define MDIO_TIMEOUT 1000
> +
> +static int nb8800_mdio_wait(struct mii_bus *bus)
> +{
> + struct nb8800_priv *priv = bus->priv;
> + int tmo = MDIO_TIMEOUT;
> +
> + while (--tmo) {
> + if (!(nb8800_readl(priv, NB8800_MDIO_CMD) & MDIO_CMD_GO))
> + break;
> + udelay(1);

Can you use cpu_relax() or readx_poll_timeout() ?

> + }
> +
> + return tmo;
> +}
> +
> +static int nb8800_mdio_read(struct mii_bus *bus, int phy_id, int reg)
> +{
> + struct nb8800_priv *priv = bus->priv;
> + int val;
> +
> + if (!nb8800_mdio_wait(bus))
> + return -ETIMEDOUT;
> +
> + val = MIIAR_ADDR(phy_id) | MIIAR_REG(reg);
> +
> + nb8800_writel(priv, NB8800_MDIO_CMD, val);
> + udelay(10);

Why 10? Perhaps add a comment line.

> + nb8800_writel(priv, NB8800_MDIO_CMD, val | MDIO_CMD_GO);
> +
> + if (!nb8800_mdio_wait(bus))
> + return -ETIMEDOUT;
> +
> + val = nb8800_readl(priv, NB8800_MDIO_STS);
> + if (val & MDIO_STS_ERR)
> + return 0xffff;

Can we return an error here?

> +
> + return val & 0xffff;
> +}
> +
> +static int nb8800_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
> +{
> + struct nb8800_priv *priv = bus->priv;
> + int tmp;
> +
> + if (!nb8800_mdio_wait(bus))
> + return -ETIMEDOUT;
> +
> + tmp = MIIAR_DATA(val) | MIIAR_ADDR(phy_id) | MIIAR_REG(reg) |
> + MDIO_CMD_WR;
> +
> + nb8800_writel(priv, NB8800_MDIO_CMD, tmp);
> + udelay(10);
> + nb8800_writel(priv, NB8800_MDIO_CMD, tmp | MDIO_CMD_GO);
> +
> + if (!nb8800_mdio_wait(bus))
> + return -ETIMEDOUT;
> +
> + return 0;
> +}
> +
> +static void nb8800_mac_tx(struct net_device *dev, bool enable)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + while (nb8800_readl(priv, NB8800_TXC_CR) & TCR_EN)
> + cpu_relax();
> +
> + if (enable)
> + nb8800_set_bits(b, priv, NB8800_TX_CTL1, TX_EN);
> + else
> + nb8800_clear_bits(b, priv, NB8800_TX_CTL1, TX_EN);
> +}
> +
> +static void nb8800_mac_rx(struct net_device *dev, bool enable)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + if (enable)
> + nb8800_set_bits(b, priv, NB8800_RX_CTL, RX_EN);
> + else
> + nb8800_clear_bits(b, priv, NB8800_RX_CTL, RX_EN);
> +}
> +
> +static void nb8800_mac_af(struct net_device *dev, bool enable)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + if (enable)
> + nb8800_set_bits(b, priv, NB8800_RX_CTL, RX_AF_EN);
> + else
> + nb8800_clear_bits(b, priv, NB8800_RX_CTL, RX_AF_EN);
> +}
> +
> +static void nb8800_stop_rx(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int i;
> +
> + for (i = 0; i < RX_DESC_COUNT; i++)
> + priv->rx_descs[i].config |= DESC_EOC;
> +
> + while (nb8800_readl(priv, NB8800_RXC_CR) & RCR_EN)
> + usleep_range(1000, 10000);

Here is a busy loop without timeout limitation.

> +}
> +
> +static void nb8800_start_rx(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + nb8800_set_bits(l, priv, NB8800_RXC_CR, RCR_EN);
> +}
> +
> +static int nb8800_alloc_rx(struct net_device *dev, int i, bool napi)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_dma_desc *rx = &priv->rx_descs[i];
> + struct rx_buf *buf = &priv->rx_bufs[i];
> + int size = L1_CACHE_ALIGN(RX_BUF_SIZE);
> + void *data;
> +
> + data = napi ? napi_alloc_frag(size) : netdev_alloc_frag(size);
> + if (!data) {
> + buf->page = NULL;
> + rx->config = DESC_EOF;
> + return -ENOMEM;
> + }
> +
> + buf->page = virt_to_head_page(data);
> + buf->offset = data - page_address(buf->page);
> +
> + rx->config = priv->rx_dma_config;
> + rx->s_addr = dma_map_page(&dev->dev, buf->page, buf->offset,
> + RX_BUF_SIZE, DMA_FROM_DEVICE);
> +
> + if (dma_mapping_error(&dev->dev, rx->s_addr)) {
> + skb_free_frag(data);
> + buf->page = NULL;
> + rx->config = DESC_EOF;
> + return -ENOMEM;
> + }
> +
> + return 0;
> +}
> +
> +static void nb8800_receive(struct net_device *dev, int i, int len)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_dma_desc *rx = &priv->rx_descs[i];
> + struct page *page = priv->rx_bufs[i].page;
> + int offset = priv->rx_bufs[i].offset;
> + void *data = page_address(page) + offset;
> + dma_addr_t dma = rx->s_addr;
> + struct sk_buff *skb;
> +
> + skb = napi_alloc_skb(&priv->napi, RX_COPYBREAK);
> + if (!skb) {
> + netdev_err(dev, "rx skb allocation failed\n");
> + return;
> + }
> +
> + if (len <= RX_COPYBREAK) {
> + dma_sync_single_for_cpu(&dev->dev, dma, len, DMA_FROM_DEVICE);
> + memcpy(skb_put(skb, len), data, len);
> + dma_sync_single_for_device(&dev->dev, dma, len,
> + DMA_FROM_DEVICE);
> + } else {
> + dma_unmap_page(&dev->dev, dma, RX_BUF_SIZE, DMA_FROM_DEVICE);
> + memcpy(skb_put(skb, 128), data, 128);

Magic number.

> + skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
> + offset + 128, len - 128, RX_BUF_SIZE);


> + priv->rx_bufs[i].page = NULL;
> + }
> +
> + skb->protocol = eth_type_trans(skb, dev);
> + netif_receive_skb(skb);
> +}
> +
> +static void nb8800_rx_error(struct net_device *dev, u32 report)
> +{
> + int len = RX_BYTES_TRANSFERRED(report);
> +
> + if (report & RX_FCS_ERR)
> + dev->stats.rx_crc_errors++;
> +
> + if ((report & (RX_FRAME_LEN_ERROR | RX_LENGTH_ERR)) ||
> + (len > RX_BUF_SIZE))
> + dev->stats.rx_length_errors++;
> +
> + dev->stats.rx_errors++;
> +}
> +
> +static int nb8800_poll(struct napi_struct *napi, int budget)
> +{
> + struct net_device *dev = napi->dev;
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_dma_desc *rx;
> + int work = 0;
> + int last = priv->rx_eoc;
> + int next;
> +
> + while (work < budget) {
> + struct rx_buf *rx_buf;
> + u32 report;
> + int len;
> +
> + next = (last + 1) & (RX_DESC_COUNT - 1);

Maybe (last + 1) % RX_DESC_COUNT ? It will not prevent to use
non-power-of-two numbers.

> +
> + rx_buf = &priv->rx_bufs[next];
> + rx = &priv->rx_descs[next];

> + report = rx->report;

Maybe you can use rx->report directly below.

> +
> + if (!report)
> + break;
> +
> + if (IS_RX_ERROR(report)) {
> + nb8800_rx_error(dev, report);
> + } else if (likely(rx_buf->page)) {
> + len = RX_BYTES_TRANSFERRED(report);
> + nb8800_receive(dev, next, len);
> + }
> +
> + rx->report = 0;
> + if (!rx_buf->page)
> + nb8800_alloc_rx(dev, next, true);
> +
> + last = next;
> + work++;
> + }
> +
> + if (work) {
> + priv->rx_descs[last].config |= DESC_EOC;
> + wmb(); /* ensure new EOC is written before clearing old */
> + priv->rx_descs[priv->rx_eoc].config &= ~DESC_EOC;
> + priv->rx_eoc = last;
> + nb8800_start_rx(dev);
> + }
> +
> + if (work < budget) {
> + nb8800_writel(priv, NB8800_RX_ITR, 1);
> + napi_complete_done(napi, work);
> + }
> +
> + return work;
> +}
> +
> +static void nb8800_tx_dma_queue(struct net_device *dev, dma_addr_t data,
> + int len, int flags)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int next = priv->tx_next;
> + struct nb8800_dma_desc *tx = &priv->tx_descs[next];
> +
> + tx->s_addr = data;
> + tx->config = DESC_BTS(2) | DESC_DS | flags | len;
> + tx->report = 0;
> +
> + priv->tx_next = (next + 1) & (TX_DESC_COUNT - 1);
> +}
> +
> +static void nb8800_tx_dma_start(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct tx_buf *tx_buf;
> + u32 txc_cr;
> +
> + if (xchg(&priv->tx_lock, 1))
> + return;
> +
> + txc_cr = nb8800_readl(priv, NB8800_TXC_CR) & 0xffff;
> + if (txc_cr & TCR_EN)
> + goto end;
> +
> + tx_buf = &priv->tx_bufs[priv->tx_done];
> + if (!tx_buf->frags)
> + goto end;
> +
> + nb8800_writel(priv, NB8800_TX_DESC_ADDR, tx_buf->desc_dma);
> + wmb(); /* ensure desc addr is written before starting DMA */
> + nb8800_writel(priv, NB8800_TXC_CR, txc_cr | TCR_EN);
> +
> +end:
> + priv->tx_lock = 0;
> +}
> +
> +static int nb8800_xmit(struct sk_buff *skb, struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct tx_skb_data *skb_data;
> + struct tx_buf *tx_buf;
> + dma_addr_t dma_addr;
> + unsigned int dma_len;
> + int cpsz, next;
> + int frags;
> +
> + if (atomic_read(&priv->tx_free) <= NB8800_DESC_LOW) {
> + netif_stop_queue(dev);
> + return NETDEV_TX_BUSY;
> + }
> +
> + cpsz = (8 - (uintptr_t)skb->data) & 7;

So, cast to uintptr_t looks strange in this driver, since used only
twice in such expression, why not to use plain unsigned int * ?

> +
> + dma_len = skb->len - cpsz;
> + dma_addr = dma_map_single(&dev->dev, skb->data + cpsz,
> + dma_len, DMA_TO_DEVICE);
> +
> + if (dma_mapping_error(&dev->dev, dma_addr)) {
> + kfree_skb(skb);
> + return NETDEV_TX_OK;
> + }
> +
> + frags = cpsz ? 2 : 1;
> +
> + if (atomic_sub_return(frags, &priv->tx_free) <= NB8800_DESC_LOW)
> + netif_stop_queue(dev);
> +
> + next = priv->tx_next;
> + tx_buf = &priv->tx_bufs[next];
> +
> + if (cpsz) {
> + dma_addr_t dma = tx_buf->desc_dma +
> + offsetof(struct nb8800_dma_desc, buf);
> + memcpy(priv->tx_descs[next].buf, skb->data, cpsz);
> + nb8800_tx_dma_queue(dev, dma, cpsz, 0);
> + }
> +
> + nb8800_tx_dma_queue(dev, dma_addr, dma_len, priv->tx_dma_config);
> +
> + skb_data = (struct tx_skb_data *)skb->cb;
> + skb_data->dma_addr = dma_addr;
> + skb_data->dma_len = dma_len;
> +
> + tx_buf->skb = skb;
> +
> + smp_wmb();
> + tx_buf->frags = frags;
> +
> + netdev_sent_queue(dev, skb->len);
> +
> + if (!skb->xmit_more)
> + nb8800_tx_dma_start(dev);
> +
> + return NETDEV_TX_OK;
> +}
> +
> +static void nb8800_tx_done(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct tx_buf *tx_buf = &priv->tx_bufs[priv->tx_done];
> + struct sk_buff *skb = tx_buf->skb;
> + struct tx_skb_data *skb_data = (struct tx_skb_data *)skb->cb;
> + int frags = tx_buf->frags;
> +
> + netdev_completed_queue(dev, 1, skb->len);
> + dma_unmap_single(&dev->dev, skb_data->dma_addr, skb_data->dma_len,
> + DMA_TO_DEVICE);
> + dev_consume_skb_irq(tx_buf->skb);
> +
> + atomic_add(frags, &priv->tx_free);
> +
> + tx_buf->skb = NULL;
> + tx_buf->frags = 0;
> +
> + smp_wmb();
> +
> + priv->tx_done = (priv->tx_done + frags) & (TX_DESC_COUNT - 1);
> +
> + nb8800_tx_dma_start(dev);
> + netif_wake_queue(dev);
> +}
> +
> +static irqreturn_t nb8800_isr(int irq, void *dev_id)
> +{
> + struct net_device *dev = dev_id;
> + struct nb8800_priv *priv = netdev_priv(dev);
> + u32 val;
> +
> + /* tx interrupt */
> + val = nb8800_readl(priv, NB8800_TXC_SR);
> + if (val) {
> + nb8800_writel(priv, NB8800_TXC_SR, val);
> +
> + if (likely(val & (TSR_TI | TSR_DI)))
> + nb8800_tx_done(dev);
> +
> + if (unlikely(val & TSR_DE))
> + netdev_err(dev, "TX DMA error\n");
> +
> + if (unlikely(val & TSR_TO))
> + netdev_err(dev, "TX Status FIFO overflow\n");
> + }
> +
> + /* rx interrupt */
> + val = nb8800_readl(priv, NB8800_RXC_SR);
> + if (val) {
> + nb8800_writel(priv, NB8800_RXC_SR, val);
> +
> + if (likely(val & (RSR_RI | RSR_DI))) {
> + nb8800_writel(priv, NB8800_RX_ITR, priv->rx_poll_itr);
> + napi_schedule_irqoff(&priv->napi);
> + }
> +
> + if (unlikely(val & RSR_DE))
> + netdev_err(dev, "RX DMA error\n");
> +
> + if (unlikely(val & RSR_RO)) {
> + int i;
> +
> + netdev_err(dev, "RX Status FIFO overflow\n");
> +
> + for (i = 0; i < 4; i++)
> + nb8800_readl(priv, NB8800_RX_FIFO_SR);
> + }
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void nb8800_mac_config(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + unsigned phy_clk;
> + unsigned ict;
> +
> + if (priv->duplex)
> + nb8800_clear_bits(b, priv, NB8800_MAC_MODE, HALF_DUPLEX);
> + else
> + nb8800_set_bits(b, priv, NB8800_MAC_MODE, HALF_DUPLEX);

Like in other review you asked to refactor pieces like above.

> +
> + if (priv->speed == SPEED_1000) {
> + nb8800_set_bits(b, priv, NB8800_MAC_MODE,
> + RGMII_MODE | GMAC_MODE);
> + nb8800_writeb(priv, NB8800_SLOT_TIME, 255);
> + phy_clk = 125000000;
> + } else {
> + nb8800_clear_bits(b, priv, NB8800_MAC_MODE,
> + RGMII_MODE | GMAC_MODE);
> + nb8800_writeb(priv, NB8800_SLOT_TIME, 127);
> + phy_clk = 25000000;
> + }
> +
> + ict = DIV_ROUND_UP(phy_clk, clk_get_rate(priv->clk));
> + nb8800_writeb(priv, NB8800_IC_THRESHOLD, ict);
> +}
> +
> +static void nb8800_link_reconfigure(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct phy_device *phydev = priv->phydev;
> +
> + if (phydev->speed == priv->speed && phydev->duplex == priv->duplex &&
> + phydev->link == priv->link)
> + return;
> +
> + if (phydev->link != priv->link || phydev->link)
> + phy_print_status(priv->phydev);
> +
> + priv->speed = phydev->speed;
> + priv->duplex = phydev->duplex;
> + priv->link = phydev->link;
> +
> + if (priv->link)
> + nb8800_mac_config(dev);
> +}
> +
> +static void nb8800_update_mac_addr(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int i;
> +
> + for (i = 0; i < 6; i++)

ETH_ALEN ?

> + nb8800_writeb(priv, NB8800_SRC_ADDR(i), dev->dev_addr[i]);
> +
> + for (i = 0; i < 6; i++)

Ditto.

> + nb8800_writeb(priv, NB8800_UC_ADDR(i), dev->dev_addr[i]);
> +}
> +
> +static int nb8800_set_mac_address(struct net_device *dev, void *addr)
> +{
> + struct sockaddr *sock = addr;
> +
> + if (netif_running(dev))
> + return -EBUSY;
> +
> + ether_addr_copy(dev->dev_addr, sock->sa_data);
> + nb8800_update_mac_addr(dev);
> +
> + return 0;
> +}
> +
> +static void nb8800_mc_init(struct net_device *dev, int val)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + nb8800_writeb(priv, NB8800_MC_INIT, val);
> + while (nb8800_readb(priv, NB8800_MC_INIT))
> + cpu_relax();

Busy loop with possible infinite number of steps.

> +}
> +
> +static void nb8800_set_rx_mode(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct netdev_hw_addr *ha;
> + bool af_en;
> + int i;
> +
> + if (dev->flags & (IFF_PROMISC | IFF_ALLMULTI))
> + af_en = false;
> + else
> + af_en = true;
> +
> + nb8800_mac_af(dev, af_en);
> +
> + if (!af_en)
> + return;

Would it be

if (dev->flags & (IFF_PROMISC | IFF_ALLMULTI)) {
nb8800_mac_af(dev, false);
return;
}

nb8800_mac_af(dev, true);

?

> +
> + nb8800_mc_init(dev, 0);
> +
> + netdev_for_each_mc_addr(ha, dev) {
> + char *addr = ha->addr;
> +
> + for (i = 0; i < 6; i++)

ETH_ALEN ?

> + nb8800_writeb(priv, NB8800_MC_ADDR(i), addr[i]);
> +
> + nb8800_mc_init(dev, 0xff);
> + }
> +}
> +
> +#define RX_DESC_SIZE (RX_DESC_COUNT * sizeof(struct nb8800_dma_desc))
> +#define TX_DESC_SIZE (TX_DESC_COUNT * sizeof(struct nb8800_dma_desc))
> +
> +static void nb8800_dma_free(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int i;
> +
> + if (priv->rx_bufs) {
> + for (i = 0; i < RX_DESC_COUNT; i++)
> + if (priv->rx_bufs[i].page)
> + put_page(priv->rx_bufs[i].page);
> +
> + kfree(priv->rx_bufs);
> + priv->rx_bufs = NULL;
> + }
> +
> + if (priv->tx_bufs) {
> + for (i = 0; i < TX_DESC_COUNT; i++)
> + kfree_skb(priv->tx_bufs[i].skb);
> +
> + kfree(priv->tx_bufs);
> + priv->tx_bufs = NULL;
> + }
> +
> + if (priv->rx_descs) {
> + dma_free_coherent(dev->dev.parent, RX_DESC_SIZE, priv->rx_descs,
> + priv->rx_desc_dma);
> + priv->rx_descs = NULL;
> + }
> +
> + if (priv->tx_descs) {
> + dma_free_coherent(dev->dev.parent, TX_DESC_SIZE, priv->tx_descs,
> + priv->tx_desc_dma);
> + priv->tx_descs = NULL;
> + }
> +}
> +
> +static int nb8800_dma_init(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int n_rx = RX_DESC_COUNT;
> + int n_tx = TX_DESC_COUNT;
> + int i;
> +
> + priv->rx_descs = dma_alloc_coherent(dev->dev.parent, RX_DESC_SIZE,
> + &priv->rx_desc_dma, GFP_KERNEL);
> + if (!priv->rx_descs)
> + goto err_out;
> +
> + priv->rx_bufs = kcalloc(n_rx, sizeof(*priv->rx_bufs), GFP_KERNEL);
> + if (!priv->rx_bufs)
> + goto err_out;
> +
> + for (i = 0; i < n_rx; i++) {
> + struct nb8800_dma_desc *rx = &priv->rx_descs[i];
> + dma_addr_t rx_dma;
> + int err;
> +
> + rx_dma = priv->rx_desc_dma + i * sizeof(struct nb8800_dma_desc);
> + rx->n_addr = rx_dma + sizeof(struct nb8800_dma_desc);
> + rx->r_addr = rx_dma + offsetof(struct nb8800_dma_desc, report);
> + rx->report = 0;
> +
> + err = nb8800_alloc_rx(dev, i, false);
> + if (err)
> + goto err_out;
> + }
> +
> + priv->rx_descs[n_rx - 1].n_addr = priv->rx_desc_dma;
> + priv->rx_descs[n_rx - 1].config |= DESC_EOC;
> +
> + priv->rx_eoc = RX_DESC_COUNT - 1;
> +
> + priv->tx_descs = dma_alloc_coherent(dev->dev.parent, TX_DESC_SIZE,
> + &priv->tx_desc_dma, GFP_KERNEL);
> + if (!priv->tx_descs)
> + goto err_out;
> +
> + priv->tx_bufs = kcalloc(n_tx, sizeof(*priv->tx_bufs), GFP_KERNEL);
> + if (!priv->tx_bufs)
> + goto err_out;
> +
> + for (i = 0; i < n_tx; i++) {
> + struct nb8800_dma_desc *tx = &priv->tx_descs[i];
> + dma_addr_t tx_dma;
> +
> + tx_dma = priv->tx_desc_dma + i * sizeof(struct nb8800_dma_desc);
> + tx->n_addr = tx_dma + sizeof(struct nb8800_dma_desc);
> + tx->r_addr = tx_dma + offsetof(struct nb8800_dma_desc, report);
> +
> + priv->tx_bufs[i].desc_dma = tx_dma;
> + }
> +
> + priv->tx_descs[n_tx - 1].n_addr = priv->tx_desc_dma;
> +
> + priv->tx_next = 0;
> + priv->tx_done = 0;
> + atomic_set(&priv->tx_free, TX_DESC_COUNT);
> +
> + nb8800_writel(priv, NB8800_TX_DESC_ADDR, priv->tx_desc_dma);
> + nb8800_writel(priv, NB8800_RX_DESC_ADDR, priv->rx_desc_dma);
> +
> + wmb(); /* ensure all setup is written before starting */
> +
> + return 0;
> +
> +err_out:
> + nb8800_dma_free(dev);
> +
> + return -ENOMEM;
> +}
> +
> +static int nb8800_open(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int err;
> +
> + nb8800_writel(priv, NB8800_RXC_SR, 0xf);
> + nb8800_writel(priv, NB8800_TXC_SR, 0xf);
> +
> + err = nb8800_dma_init(dev);
> + if (err)
> + return err;
> +
> + err = request_irq(dev->irq, nb8800_isr, 0, dev_name(&dev->dev), dev);
> + if (err)
> + goto err_free_dma;
> +
> + nb8800_mac_rx(dev, true);
> + nb8800_mac_tx(dev, true);
> +
> + priv->phydev = of_phy_connect(dev, priv->phy_node,
> + nb8800_link_reconfigure, 0,
> + priv->phy_mode);
> + if (!priv->phydev)
> + goto err_free_irq;
> +
> + napi_enable(&priv->napi);
> + netif_start_queue(dev);
> +
> + nb8800_start_rx(dev);
> + phy_start(priv->phydev);
> +
> + return 0;
> +
> +err_free_irq:
> + free_irq(dev->irq, dev);
> +err_free_dma:
> + nb8800_dma_free(dev);
> +
> + return err;
> +}
> +
> +static int nb8800_stop(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + netif_stop_queue(dev);
> + napi_disable(&priv->napi);
> +
> + nb8800_stop_rx(dev);
> +
> + nb8800_mac_rx(dev, false);
> + nb8800_mac_tx(dev, false);
> +
> + free_irq(dev->irq, dev);
> +
> + phy_stop(priv->phydev);
> + phy_disconnect(priv->phydev);
> +
> + nb8800_dma_free(dev);
> +
> + return 0;
> +}
> +
> +static u32 nb8800_read_stat(struct net_device *dev, int index)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + nb8800_writeb(priv, NB8800_STAT_INDEX, index);
> +
> + return nb8800_readl(priv, NB8800_STAT_DATA);
> +}
> +
> +static struct net_device_stats *nb8800_get_stats(struct net_device *dev)
> +{
> + dev->stats.rx_bytes = nb8800_read_stat(dev, 0x00);
> + dev->stats.rx_packets = nb8800_read_stat(dev, 0x01);
> + dev->stats.multicast = nb8800_read_stat(dev, 0x0d);
> + dev->stats.tx_bytes = nb8800_read_stat(dev, 0x80);
> + dev->stats.tx_packets = nb8800_read_stat(dev, 0x81);
> +
> + return &dev->stats;
> +}
> +
> +static int nb8800_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + return phy_mii_ioctl(priv->phydev, rq, cmd);
> +}
> +
> +static const struct net_device_ops nb8800_netdev_ops = {
> + .ndo_open = nb8800_open,
> + .ndo_stop = nb8800_stop,
> + .ndo_start_xmit = nb8800_xmit,
> + .ndo_set_mac_address = nb8800_set_mac_address,
> + .ndo_set_rx_mode = nb8800_set_rx_mode,
> + .ndo_do_ioctl = nb8800_ioctl,
> + .ndo_get_stats = nb8800_get_stats,
> + .ndo_change_mtu = eth_change_mtu,
> + .ndo_validate_addr = eth_validate_addr,
> +};
> +
> +static int nb8800_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + return phy_ethtool_gset(priv->phydev, cmd);
> +}
> +
> +static int nb8800_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + return phy_ethtool_sset(priv->phydev, cmd);
> +}
> +
> +static int nb8800_nway_reset(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + return genphy_restart_aneg(priv->phydev);
> +}
> +
> +static const struct ethtool_ops nb8800_ethtool_ops = {
> + .get_settings = nb8800_get_settings,
> + .set_settings = nb8800_set_settings,
> + .nway_reset = nb8800_nway_reset,
> + .get_link = ethtool_op_get_link,
> +};
> +
> +static int nb8800_hw_init(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);

> + unsigned int val = 0;

Useless assignment.

> +
> + nb8800_writeb(priv, NB8800_RANDOM_SEED, 0x08);
> +
> + /* TX single deferral params */
> + nb8800_writeb(priv, NB8800_TX_SDP, 0xc);
> +
> + /* Threshold for partial full */
> + nb8800_writeb(priv, NB8800_PF_THRESHOLD, 0xff);
> +
> + /* Pause Quanta */
> + nb8800_writeb(priv, NB8800_PQ1, 0xff);
> + nb8800_writeb(priv, NB8800_PQ2, 0xff);

Lot of magic numbers above and below.

> +
> + /* configure TX DMA Channels */
> + val = nb8800_readl(priv, NB8800_TXC_CR);
> + val &= TCR_LE;
> + val |= TCR_DM | TCR_RS | TCR_TFI(1) | TCR_BTS(2);
> + nb8800_writel(priv, NB8800_TXC_CR, val);
> +
> + /* TX Interrupt Time Register */
> + nb8800_writel(priv, NB8800_TX_ITR, 1);
> +
> + /* configure RX DMA Channels */
> + val = nb8800_readl(priv, NB8800_RXC_CR);
> + val &= RCR_LE;
> + val |= RCR_DM | RCR_RS | RCR_RFI(7) | RCR_BTS(2) | RCR_FL;
> + nb8800_writel(priv, NB8800_RXC_CR, val);
> +
> + /* RX Interrupt Time Register */
> + nb8800_writel(priv, NB8800_RX_ITR, 1);
> +
> + val = TX_RETRY_EN | TX_PAD_EN | TX_APPEND_FCS;
> + nb8800_writeb(priv, NB8800_TX_CTL1, val);
> +
> + /* collision retry count */
> + nb8800_writeb(priv, NB8800_TX_CTL2, 5);
> +
> + val = RX_PAD_STRIP | RX_PAUSE_EN | RX_AF_EN | RX_RUNT;
> + nb8800_writeb(priv, NB8800_RX_CTL, val);
> +
> + nb8800_mc_init(dev, 0);
> +
> + nb8800_writeb(priv, NB8800_TX_BUFSIZE, 0xff);
> +
> + return 0;
> +}
> +
> +static void nb8800_tangox_init(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + u32 val;
> +
> + val = nb8800_readb(priv, NB8800_TANGOX_PAD_MODE) & 0x78;

Magic 0x78.

> + if (priv->phy_mode == PHY_INTERFACE_MODE_RGMII)
> + val |= 1;
> + nb8800_writeb(priv, NB8800_TANGOX_PAD_MODE, val);
> +}
> +
> +static void nb8800_tangox_reset(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int clk_div;
> +
> + nb8800_writeb(priv, NB8800_TANGOX_RESET, 0);
> + usleep_range(1000, 10000);
> + nb8800_writeb(priv, NB8800_TANGOX_RESET, 1);
> +
> + wmb(); /* ensure reset is cleared before proceeding */
> +
> + clk_div = DIV_ROUND_UP(clk_get_rate(priv->clk), 2 * MAX_MDC_CLOCK);
> + nb8800_writew(priv, NB8800_TANGOX_MDIO_CLKDIV, clk_div);
> +}
> +
> +static const struct nb8800_ops nb8800_tangox_ops = {
> + .init = nb8800_tangox_init,
> + .reset = nb8800_tangox_reset,
> +};
> +
> +static void nb8800_tango4_init(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + u32 val;
> +
> + nb8800_tangox_init(dev);
> +
> + val = nb8800_readl(priv, NB8800_RXC_CR);
> + val &= ~RCR_RFI(7);
> + val |= RCR_DIE;
> + nb8800_writel(priv, NB8800_RXC_CR, val);
> +
> + val = nb8800_readl(priv, NB8800_TXC_CR);
> + val &= ~TCR_TFI(7);
> + val |= TCR_DIE;
> + nb8800_writel(priv, NB8800_TXC_CR, val);
> +
> + priv->rx_dma_config |= DESC_ID;
> + priv->tx_dma_config |= DESC_ID;
> +}
> +
> +static const struct nb8800_ops nb8800_tango4_ops = {
> + .init = nb8800_tango4_init,
> + .reset = nb8800_tangox_reset,
> +};
> +
> +static const struct of_device_id nb8800_dt_ids[] = {
> + {
> + .compatible = "aurora,nb8800",
> + },
> + {
> + .compatible = "sigma,smp8642-ethernet",
> + .data = &nb8800_tangox_ops,
> + },
> + {
> + .compatible = "sigma,smp8734-ethernet",
> + .data = &nb8800_tango4_ops,
> + },
> + { }
> +};
> +
> +static int nb8800_probe(struct platform_device *pdev)
> +{
> + const struct of_device_id *match;
> + const struct nb8800_ops *ops = NULL;
> + struct nb8800_priv *priv;
> + struct resource *res;
> + struct net_device *dev;
> + struct mii_bus *bus;
> + const unsigned char *mac;
> + void __iomem *base;
> + int irq;
> + int ret;
> +
> + match = of_match_device(nb8800_dt_ids, &pdev->dev);
> + if (match)
> + ops = match->data;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "No MMIO base\n");
> + return -EINVAL;
> + }

Move platform_get_resource() just before devm_ioremap_resource() and
remove redundant condition with the message.

> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq <= 0) {
> + dev_err(&pdev->dev, "No IRQ\n");
> + return -EINVAL;
> + }
> +
> + base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
> +
> + dev_info(&pdev->dev, "AU-NB8800 Ethernet at %pa\n", &res->start);

Probe still might fail, -> dev_dbg().

> +
> + dev = alloc_etherdev(sizeof(*priv));
> + if (!dev)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, dev);
> + SET_NETDEV_DEV(dev, &pdev->dev);
> +
> + priv = netdev_priv(dev);
> + priv->base = base;
> +
> + priv->phy_mode = of_get_phy_mode(pdev->dev.of_node);
> + if (priv->phy_mode < 0)
> + priv->phy_mode = PHY_INTERFACE_MODE_RGMII;
> +
> + priv->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(priv->clk)) {
> + dev_err(&pdev->dev, "failed to get clock\n");
> + ret = PTR_ERR(priv->clk);
> + goto err_free_dev;
> + }
> +
> + ret = clk_prepare_enable(priv->clk);
> + if (ret)
> + goto err_free_dev;
> +
> + priv->rx_poll_itr = clk_get_rate(priv->clk) / 1000;
> + priv->rx_dma_config = RX_BUF_SIZE | DESC_BTS(2) | DESC_DS | DESC_EOF;
> + priv->tx_dma_config = DESC_EOF | DESC_EOC;
> +
> + if (ops && ops->reset)
> + ops->reset(dev);
> +
> + bus = devm_mdiobus_alloc(&pdev->dev);
> + if (!bus) {
> + ret = -ENOMEM;
> + goto err_disable_clk;
> + }
> +
> + bus->name = "nb8800-mii";
> + bus->read = nb8800_mdio_read;
> + bus->write = nb8800_mdio_write;
> + bus->parent = &pdev->dev;
> + snprintf(bus->id, MII_BUS_ID_SIZE, "%.*s-mii", MII_BUS_ID_SIZE - 5,
> + pdev->name);

You are not using any IDs here, why not just to strscpy(bus->id,
bus->name, MII_BUS_ID_SIZE); for now?

> + bus->priv = priv;
> +
> + ret = of_mdiobus_register(bus, pdev->dev.of_node);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to register MII bus\n");
> + goto err_disable_clk;
> + }
> +
> + priv->phy_node = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
> + if (!priv->phy_node) {
> + dev_err(&pdev->dev, "no PHY specified\n");
> + ret = -ENODEV;
> + goto err_free_bus;
> + }
> +
> + priv->mii_bus = bus;
> +
> + ret = nb8800_hw_init(dev);
> + if (ret)
> + goto err_free_bus;
> +
> + if (ops && ops->init)
> + ops->init(dev);
> +
> + dev->netdev_ops = &nb8800_netdev_ops;
> + dev->ethtool_ops = &nb8800_ethtool_ops;
> + dev->flags |= IFF_MULTICAST;
> + dev->irq = irq;
> +
> + mac = of_get_mac_address(pdev->dev.of_node);
> + if (mac)
> + ether_addr_copy(dev->dev_addr, mac);
> +
> + if (!is_valid_ether_addr(dev->dev_addr))
> + eth_hw_addr_random(dev);
> +
> + nb8800_update_mac_addr(dev);
> +
> + netif_carrier_off(dev);
> +
> + ret = register_netdev(dev);
> + if (ret) {
> + netdev_err(dev, "failed to register netdev\n");
> + goto err_free_dma;
> + }
> +
> + netif_napi_add(dev, &priv->napi, nb8800_poll, NAPI_POLL_WEIGHT);
> +
> + netdev_info(dev, "MAC address %pM\n", dev->dev_addr);
> +
> + return 0;
> +
> +err_free_dma:
> + nb8800_dma_free(dev);
> +err_free_bus:
> + mdiobus_unregister(bus);
> +err_disable_clk:
> + clk_disable_unprepare(priv->clk);
> +err_free_dev:
> + free_netdev(dev);
> +
> + return ret;
> +}
> +
> +static int nb8800_remove(struct platform_device *pdev)
> +{
> + struct net_device *ndev = platform_get_drvdata(pdev);
> + struct nb8800_priv *priv = netdev_priv(ndev);
> +
> + unregister_netdev(ndev);
> +
> + mdiobus_unregister(priv->mii_bus);
> +
> + clk_disable_unprepare(priv->clk);
> +
> + nb8800_dma_free(ndev);
> + free_netdev(ndev);
> +
> + return 0;
> +}
> +
> +static struct platform_driver nb8800_driver = {
> + .driver = {
> + .name = "nb8800",
> + .of_match_table = nb8800_dt_ids,
> + },
> + .probe = nb8800_probe,
> + .remove = nb8800_remove,
> +};
> +
> +module_platform_driver(nb8800_driver);
> +

MODULE_AUTHOR?

> +MODULE_DESCRIPTION("Aurora AU-NB8800 Ethernet driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/net/ethernet/aurora/nb8800.h b/drivers/net/ethernet/aurora/nb8800.h
> new file mode 100644
> index 0000000..d99236e
> --- /dev/null
> +++ b/drivers/net/ethernet/aurora/nb8800.h
> @@ -0,0 +1,230 @@
> +#ifndef _NB8800_H_
> +#define _NB8800_H_
> +
> +#include <linux/types.h>
> +#include <linux/skbuff.h>
> +#include <linux/phy.h>
> +#include <linux/clk.h>
> +#include <linux/bitops.h>
> +
> +#define RX_DESC_COUNT 256
> +#define TX_DESC_COUNT 256
> +
> +#define NB8800_DESC_LOW 4
> +
> +#define RX_BUF_SIZE 1552
> +#define TX_BUF_SIZE 1552
> +
> +#define RX_COPYBREAK 256
> +
> +#define MAX_MDC_CLOCK 2500000
> +
> +/* register offsets */
> +#define NB8800_TX_CTL1 0x00

Since offsets are going to be 3 digits below, maybe use 3 digits here
as well? 0x000

> +#define TX_TPD BIT(5)
> +#define TX_APPEND_FCS BIT(4)
> +#define TX_PAD_EN BIT(3)
> +#define TX_RETRY_EN BIT(2)
> +#define TX_EN BIT(0)
> +
> +#define NB8800_TX_CTL2 0x01
> +
> +#define NB8800_RX_CTL 0x04
> +#define RX_BC_DISABLE BIT(7)
> +#define RX_RUNT BIT(6)
> +#define RX_AF_EN BIT(5)
> +#define RX_PAUSE_EN BIT(3)
> +#define RX_SEND_CRC BIT(2)
> +#define RX_PAD_STRIP BIT(1)
> +#define RX_EN BIT(0)
> +
> +#define NB8800_RANDOM_SEED 0x8
> +#define NB8800_TX_SDP 0x14
> +#define NB8800_TX_TPDP1 0x18
> +#define NB8800_TX_TPDP2 0x19
> +#define NB8800_SLOT_TIME 0x1c
> +
> +#define NB8800_MDIO_CMD 0x20
> +#define MIIAR_ADDR(x) ((x) << 21)
> +#define MIIAR_REG(x) ((x) << 16)
> +#define MIIAR_DATA(x) ((x) << 0)
> +#define MDIO_CMD_GO BIT(31)
> +#define MDIO_CMD_WR BIT(26)
> +
> +#define NB8800_MDIO_STS 0x24
> +#define MDIO_STS_ERR BIT(31)
> +
> +#define NB8800_MC_ADDR(i) (0x28 + (i))
> +#define NB8800_MC_INIT 0x2e
> +#define NB8800_UC_ADDR(i) (0x3c + (i))
> +
> +#define NB8800_MAC_MODE 0x44
> +#define RGMII_MODE BIT(7)
> +#define HALF_DUPLEX BIT(4)
> +#define BURST_EN BIT(3)
> +#define LOOPBACK_EN BIT(2)
> +#define GMAC_MODE BIT(0)
> +
> +#define NB8800_IC_THRESHOLD 0x50
> +#define NB8800_PE_THRESHOLD 0x51
> +#define NB8800_PF_THRESHOLD 0x52
> +#define NB8800_TX_BUFSIZE 0x54
> +#define NB8800_FIFO_CTL 0x56
> +#define NB8800_PQ1 0x60
> +#define NB8800_PQ2 0x61
> +#define NB8800_SRC_ADDR(i) (0x6a + (i))
> +#define NB8800_STAT_DATA 0x78
> +#define NB8800_STAT_INDEX 0x7c
> +#define NB8800_STAT_CLEAR 0x7d
> +
> +#define NB8800_SLEEP_MODE 0x7e
> +#define SLEEP_MODE BIT(0)
> +
> +#define NB8800_WAKEUP 0x7f
> +#define WAKEUP BIT(0)
> +
> +#define NB8800_TXC_CR 0x100
> +#define TCR_LK BIT(12)
> +#define TCR_DS BIT(11)
> +#define TCR_BTS(x) (((x) & 0x7) << 8)
> +#define TCR_DIE BIT(7)
> +#define TCR_TFI(x) (((x) & 0x7) << 4)
> +#define TCR_LE BIT(3)
> +#define TCR_RS BIT(2)
> +#define TCR_DM BIT(1)
> +#define TCR_EN BIT(0)
> +
> +#define NB8800_TXC_SR 0x104
> +#define TSR_DE BIT(3)
> +#define TSR_DI BIT(2)
> +#define TSR_TO BIT(1)
> +#define TSR_TI BIT(0)
> +
> +#define NB8800_TX_SAR 0x108
> +#define NB8800_TX_DESC_ADDR 0x10c
> +
> +#define NB8800_TX_REPORT_ADDR 0x110
> +#define TX_BYTES_TRASFERRED(x) (((x) >> 16) & 0xffff)
> +#define TX_FIRST_DEFERRAL BIT(7)
> +#define TX_EARLY_COLLISIONS(x) (((x) >> 3) & 0xf)
> +#define TX_LATE_COLLISION BIT(2)
> +#define TX_PACKET_DROPPED BIT(1)
> +#define TX_FIFO_UNDERRUN BIT(0)
> +#define IS_TX_ERROR(r) ((r) & 0x87)
> +
> +#define NB8800_TX_FIFO_SR 0x114
> +#define NB8800_TX_ITR 0x118
> +
> +#define NB8800_RXC_CR 0x200
> +#define RCR_FL BIT(13)
> +#define RCR_LK BIT(12)
> +#define RCR_DS BIT(11)
> +#define RCR_BTS(x) (((x) & 7) << 8)
> +#define RCR_DIE BIT(7)
> +#define RCR_RFI(x) (((x) & 7) << 4)
> +#define RCR_LE BIT(3)
> +#define RCR_RS BIT(2)
> +#define RCR_DM BIT(1)
> +#define RCR_EN BIT(0)
> +
> +#define NB8800_RXC_SR 0x204
> +#define RSR_DE BIT(3)
> +#define RSR_DI BIT(2)
> +#define RSR_RO BIT(1)
> +#define RSR_RI BIT(0)
> +
> +#define NB8800_RX_SAR 0x208
> +#define NB8800_RX_DESC_ADDR 0x20c
> +
> +#define NB8800_RX_REPORT_ADDR 0x210
> +#define RX_BYTES_TRANSFERRED(x) (((x) >> 16) & 0xFFFF)
> +#define RX_MULTICAST_PKT BIT(9)
> +#define RX_BROADCAST_PKT BIT(8)
> +#define RX_LENGTH_ERR BIT(7)
> +#define RX_FCS_ERR BIT(6)
> +#define RX_RUNT_PKT BIT(5)
> +#define RX_FIFO_OVERRUN BIT(4)
> +#define RX_LATE_COLLISION BIT(3)
> +#define RX_FRAME_LEN_ERROR BIT(2)
> +#define RX_ERROR_MASK 0xfc
> +#define IS_RX_ERROR(r) ((r) & RX_ERROR_MASK)
> +
> +#define NB8800_RX_FIFO_SR 0x214
> +#define NB8800_RX_ITR 0x218
> +
> +/* Sigma Designs SMP86xx additional registers */
> +#define NB8800_TANGOX_PAD_MODE 0x400
> +#define NB8800_TANGOX_MDIO_CLKDIV 0x420
> +#define NB8800_TANGOX_RESET 0x424
> +


--
With Best Regards,
Andy Shevchenko
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/