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SubjectRe: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller
From
On Tue, Nov 10, 2015 at 6:14 PM, Mans Rullgard <mans@mansr.com> 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.

Few nitpicks below.

>
> Signed-off-by: Mans Rullgard <mans@mansr.com>
> ---
> Changes:
> - Refactored mdio access functions
> - Refactored register access helpers
> - Improved error handling in rx buffer allocation
> - Optimised some fifo parameters
> - Overhauled tx dma. Multiple packets are now chained in a single dma
> operation if xmit_more is set, improving performance.
> - Improved rx irq handling. It's not possible to disable interrupts
> entirely for napi poll, but they can be slowed down a little.
> - Use readx_poll_timeout in various places
> - Improved error detection
> - Improved statistics
> - Report hardware statistics counters through ethtool
> - Improved tangox-specific setup
> - Support for flow control using pause frames
> - Explanatory comments added
> - Various minor stylistic changes
> ---
> drivers/net/ethernet/Kconfig | 1 +
> drivers/net/ethernet/Makefile | 1 +
> drivers/net/ethernet/aurora/Kconfig | 20 +
> drivers/net/ethernet/aurora/Makefile | 1 +
> drivers/net/ethernet/aurora/nb8800.c | 1530 ++++++++++++++++++++++++++++++++++
> drivers/net/ethernet/aurora/nb8800.h | 314 +++++++
> 6 files changed, 1867 insertions(+)
> create mode 100644 drivers/net/ethernet/aurora/Kconfig
> create mode 100644 drivers/net/ethernet/aurora/Makefile
> create mode 100644 drivers/net/ethernet/aurora/nb8800.c
> create mode 100644 drivers/net/ethernet/aurora/nb8800.h
>
> diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
> index 05aa759..8310163 100644
> --- a/drivers/net/ethernet/Kconfig
> +++ b/drivers/net/ethernet/Kconfig
> @@ -29,6 +29,7 @@ source "drivers/net/ethernet/apm/Kconfig"
> source "drivers/net/ethernet/apple/Kconfig"
> source "drivers/net/ethernet/arc/Kconfig"
> source "drivers/net/ethernet/atheros/Kconfig"
> +source "drivers/net/ethernet/aurora/Kconfig"
> source "drivers/net/ethernet/cadence/Kconfig"
> source "drivers/net/ethernet/adi/Kconfig"
> source "drivers/net/ethernet/broadcom/Kconfig"
> diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
> index ddfc808..b435fb0 100644
> --- a/drivers/net/ethernet/Makefile
> +++ b/drivers/net/ethernet/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_NET_XGENE) += apm/
> obj-$(CONFIG_NET_VENDOR_APPLE) += apple/
> obj-$(CONFIG_NET_VENDOR_ARC) += arc/
> obj-$(CONFIG_NET_VENDOR_ATHEROS) += atheros/
> +obj-$(CONFIG_NET_VENDOR_AURORA) += aurora/
> obj-$(CONFIG_NET_CADENCE) += cadence/
> obj-$(CONFIG_NET_BFIN) += adi/
> obj-$(CONFIG_NET_VENDOR_BROADCOM) += broadcom/
> diff --git a/drivers/net/ethernet/aurora/Kconfig b/drivers/net/ethernet/aurora/Kconfig
> new file mode 100644
> index 0000000..a3c7106
> --- /dev/null
> +++ b/drivers/net/ethernet/aurora/Kconfig
> @@ -0,0 +1,20 @@
> +config NET_VENDOR_AURORA
> + bool "Aurora VLSI devices"
> + help
> + If you have a network (Ethernet) device belonging to this class,
> + say Y.
> +
> + Note that the answer to this question doesn't directly affect the
> + kernel: saying N will just cause the configurator to skip all
> + questions about Aurora devices. If you say Y, you will be asked
> + for your specific device in the following questions.
> +
> +if NET_VENDOR_AURORA
> +
> +config AURORA_NB8800
> + tristate "Aurora AU-NB8800 support"
> + select PHYLIB
> + help
> + Support for the AU-NB8800 gigabit Ethernet controller.
> +
> +endif
> diff --git a/drivers/net/ethernet/aurora/Makefile b/drivers/net/ethernet/aurora/Makefile
> new file mode 100644
> index 0000000..6cb528a
> --- /dev/null
> +++ b/drivers/net/ethernet/aurora/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_AURORA_NB8800) += nb8800.o
> diff --git a/drivers/net/ethernet/aurora/nb8800.c b/drivers/net/ethernet/aurora/nb8800.c
> new file mode 100644
> index 0000000..11cd389
> --- /dev/null
> +++ b/drivers/net/ethernet/aurora/nb8800.c
> @@ -0,0 +1,1530 @@
> +/*
> + * Copyright (C) 2015 Mans Rullgard <mans@mansr.com>
> + *
> + * Mostly rewritten, based on driver from Sigma Designs. Original
> + * copyright notice below.
> + *
> + *
> + * Driver for tangox SMP864x/SMP865x/SMP867x/SMP868x builtin Ethernet Mac.
> + *
> + * Copyright (C) 2005 Maxime Bizon <mbizon@freebox.fr>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/etherdevice.h>
> +#include <linux/delay.h>
> +#include <linux/ethtool.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/of_device.h>
> +#include <linux/of_mdio.h>
> +#include <linux/of_net.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/phy.h>
> +#include <linux/cache.h>
> +#include <linux/jiffies.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <asm/barrier.h>
> +
> +#include "nb8800.h"
> +
> +static int nb8800_dma_stop(struct net_device *dev);
> +
> +static inline u8 nb8800_readb(struct nb8800_priv *priv, int reg)
> +{
> + return readb(priv->base + reg);
> +}
> +
> +static inline u32 nb8800_readl(struct nb8800_priv *priv, int reg)
> +{
> + return readl(priv->base + reg);
> +}
> +
> +static inline void nb8800_writeb(struct nb8800_priv *priv, int reg, u8 val)
> +{
> + writeb(val, priv->base + reg);
> +}
> +
> +static inline void nb8800_writew(struct nb8800_priv *priv, int reg, u16 val)
> +{
> + writew(val, priv->base + reg);
> +}
> +
> +static inline void nb8800_writel(struct nb8800_priv *priv, int reg, u32 val)
> +{
> + writel(val, priv->base + reg);
> +}
> +
> +static inline void nb8800_maskb(struct nb8800_priv *priv, int reg,
> + u32 mask, u32 val)
> +{
> + u32 old = nb8800_readb(priv, reg);
> + u32 new = (old & ~mask) | val;

Shoudn't be "… | (val & mask);" ?

+ empty line?

> + if (new != old)
> + nb8800_writeb(priv, reg, new);
> +}
> +
> +static inline void nb8800_maskl(struct nb8800_priv *priv, int reg,
> + u32 mask, u32 val)
> +{
> + u32 old = nb8800_readl(priv, reg);
> + u32 new = (old & ~mask) | val;

Ditto.

> + if (new != old)
> + nb8800_writel(priv, reg, new);
> +}
> +
> +static inline void nb8800_modb(struct nb8800_priv *priv, int reg, u8 bits,
> + bool set)
> +{
> + nb8800_maskb(priv, reg, bits, set ? bits : 0);
> +}
> +
> +static inline void nb8800_setb(struct nb8800_priv *priv, int reg, u8 bits)
> +{
> + nb8800_maskb(priv, reg, bits, bits);
> +}
> +
> +static inline void nb8800_clearb(struct nb8800_priv *priv, int reg, u8 bits)
> +{
> + nb8800_maskb(priv, reg, bits, 0);
> +}
> +
> +static inline void nb8800_modl(struct nb8800_priv *priv, int reg, u32 bits,
> + bool set)
> +{
> + nb8800_maskl(priv, reg, bits, set ? bits : 0);
> +}
> +
> +static inline void nb8800_setl(struct nb8800_priv *priv, int reg, u32 bits)
> +{
> + nb8800_maskl(priv, reg, bits, bits);
> +}
> +
> +static inline void nb8800_clearl(struct nb8800_priv *priv, int reg, u32 bits)
> +{
> + nb8800_maskl(priv, reg, bits, 0);
> +}
> +
> +static int nb8800_mdio_wait(struct mii_bus *bus)
> +{
> + struct nb8800_priv *priv = bus->priv;
> + u32 val;
> +
> + return readl_poll_timeout_atomic(priv->base + NB8800_MDIO_CMD,
> + val, !(val & MDIO_CMD_GO), 1, 1000);
> +}
> +
> +static int nb8800_mdio_cmd(struct mii_bus *bus, u32 cmd)
> +{
> + struct nb8800_priv *priv = bus->priv;
> + int err;
> +
> + err = nb8800_mdio_wait(bus);
> + if (err)
> + return err;
> +
> + nb8800_writel(priv, NB8800_MDIO_CMD, cmd);
> + udelay(10);
> + nb8800_writel(priv, NB8800_MDIO_CMD, cmd | MDIO_CMD_GO);
> +
> + return nb8800_mdio_wait(bus);
> +}
> +
> +static int nb8800_mdio_read(struct mii_bus *bus, int phy_id, int reg)
> +{
> + struct nb8800_priv *priv = bus->priv;
> + u32 val;
> + int err;
> +
> + err = nb8800_mdio_cmd(bus, MIIAR_ADDR(phy_id) | MIIAR_REG(reg));
> + if (err)
> + return err;
> +
> + val = nb8800_readl(priv, NB8800_MDIO_STS);
> + if (val & MDIO_STS_ERR)
> + return 0xffff;
> +
> + return val & 0xffff;
> +}
> +
> +static int nb8800_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
> +{
> + u32 cmd = MIIAR_DATA(val) | MIIAR_ADDR(phy_id) | MIIAR_REG(reg) |
> + MDIO_CMD_WR;
> +
> + return nb8800_mdio_cmd(bus, cmd);
> +}
> +
> +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();
> +
> + nb8800_modb(priv, NB8800_TX_CTL1, TX_EN, enable);
> +}
> +
> +static void nb8800_mac_rx(struct net_device *dev, bool enable)
> +{
> + nb8800_modb(netdev_priv(dev), NB8800_RX_CTL, RX_EN, enable);
> +}
> +
> +static void nb8800_mac_af(struct net_device *dev, bool enable)
> +{
> + nb8800_modb(netdev_priv(dev), NB8800_RX_CTL, RX_AF_EN, enable);
> +}
> +
> +static void nb8800_start_rx(struct net_device *dev)
> +{
> + nb8800_setl(netdev_priv(dev), 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_rx_desc *rxd = &priv->rx_descs[i];
> + struct nb8800_rx_buf *rxb = &priv->rx_bufs[i];
> + int size = L1_CACHE_ALIGN(RX_BUF_SIZE);
> + dma_addr_t dma_addr;
> + struct page *page;
> + unsigned long offset;
> + void *data;
> +
> + data = napi ? napi_alloc_frag(size) : netdev_alloc_frag(size);
> + if (!data)
> + return -ENOMEM;
> +
> + page = virt_to_head_page(data);
> + offset = data - page_address(page);
> +
> + dma_addr = dma_map_page(&dev->dev, page, offset, RX_BUF_SIZE,
> + DMA_FROM_DEVICE);
> +
> + if (dma_mapping_error(&dev->dev, dma_addr)) {
> + skb_free_frag(data);
> + return -ENOMEM;
> + }
> +
> + rxb->page = page;
> + rxb->offset = offset;
> + rxd->desc.s_addr = dma_addr;
> +
> + return 0;
> +}
> +
> +static void nb8800_receive(struct net_device *dev, int i, int len)

unsigned int i ?
len as well?

> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_rx_desc *rxd = &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 = rxd->desc.s_addr;

dma -> addr ?

> + struct sk_buff *skb;
> + int size;
> + int err;
> +
> + size = len <= RX_COPYBREAK ? len : RX_COPYHDR;
> +
> + skb = napi_alloc_skb(&priv->napi, size);
> + if (!skb) {
> + netdev_err(dev, "rx skb allocation failed\n");
> + dev->stats.rx_dropped++;
> + 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 {
> + err = nb8800_alloc_rx(dev, i, true);
> + if (err) {
> + netdev_err(dev, "rx buffer allocation failed\n");
> + dev->stats.rx_dropped++;
> + return;
> + }
> +
> + dma_unmap_page(&dev->dev, dma, RX_BUF_SIZE, DMA_FROM_DEVICE);
> + memcpy(skb_put(skb, RX_COPYHDR), data, RX_COPYHDR);
> + skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
> + offset + RX_COPYHDR, len - RX_COPYHDR,
> + RX_BUF_SIZE);
> + }
> +
> + skb->protocol = eth_type_trans(skb, dev);
> + netif_receive_skb(skb);
> +}
> +
> +static void nb8800_rx_error(struct net_device *dev, u32 report)
> +{
> + if (report & RX_LENGTH_ERR)
> + dev->stats.rx_length_errors++;
> +
> + if (report & RX_FCS_ERR)
> + dev->stats.rx_crc_errors++;
> +
> + if (report & RX_FIFO_OVERRUN)
> + dev->stats.rx_fifo_errors++;
> +
> + if (report & RX_ALIGNMENT_ERROR)
> + dev->stats.rx_frame_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_rx_desc *rxd;
> + int work = 0;
> + int last = priv->rx_eoc;
> + int next;
> +
> +again:
> + while (work < budget) {
> + struct nb8800_rx_buf *rxb;
> + int len;
> +
> + next = (last + 1) % RX_DESC_COUNT;
> +
> + rxb = &priv->rx_bufs[next];
> + rxd = &priv->rx_descs[next];
> +
> + if (!rxd->report)
> + break;
> +
> + len = RX_BYTES_TRANSFERRED(rxd->report);
> +
> + if (IS_RX_ERROR(rxd->report))
> + nb8800_rx_error(dev, rxd->report);
> + else
> + nb8800_receive(dev, next, len);
> +
> + dev->stats.rx_packets++;
> + dev->stats.rx_bytes += len;
> +
> + if (rxd->report & RX_MULTICAST_PKT)
> + dev->stats.multicast++;
> +
> + rxd->report = 0;
> + last = next;
> + work++;
> + }
> +
> + if (work) {
> + priv->rx_descs[last].desc.config |= DESC_EOC;
> + wmb(); /* ensure new EOC is written before clearing old */
> + priv->rx_descs[priv->rx_eoc].desc.config &= ~DESC_EOC;
> + priv->rx_eoc = last;
> + nb8800_start_rx(dev);
> + }
> +
> + if (work < budget) {
> + nb8800_writel(priv, NB8800_RX_ITR, priv->rx_itr_irq);
> +
> + /* If a packet arrived after we last checked but
> + * before writing RX_ITR, the interrupt will be
> + * delayed, so we retrieve it now. */

Block comments usually
/*
* text
*/

Can be longer lines?

> + if (priv->rx_descs[next].report)
> + goto again;
> +
> + napi_complete_done(napi, work);
> + }
> +
> + return work;
> +}
> +
> +static void nb8800_tx_dma_start(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_tx_buf *txb;
> + u32 txc_cr;
> +
> + txb = &priv->tx_bufs[priv->tx_queue];
> + if (!txb->ready)
> + return;
> +
> + txc_cr = nb8800_readl(priv, NB8800_TXC_CR);
> + if (txc_cr & TCR_EN)
> + return;
> +
> + nb8800_writel(priv, NB8800_TX_DESC_ADDR, txb->dma_desc);
> + wmb(); /* ensure desc addr is written before starting DMA */

Hm… Have I missed corresponding rmb() ? If it's about MMIO, perhaps mmiowb() ?

> + nb8800_writel(priv, NB8800_TXC_CR, txc_cr | TCR_EN);
> +
> + priv->tx_queue = (priv->tx_queue + txb->chain_len) % TX_DESC_COUNT;
> +}
> +
> +static void nb8800_tx_dma_start_irq(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + spin_lock(&priv->tx_lock);
> + nb8800_tx_dma_start(dev);
> + spin_unlock(&priv->tx_lock);
> +}
> +
> +static int nb8800_xmit(struct sk_buff *skb, struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_tx_desc *txd;
> + struct nb8800_tx_buf *txb;
> + struct nb8800_dma_desc *dma;

dma -> desc ?

> + dma_addr_t dma_addr;
> + unsigned int dma_len;
> + unsigned long flags;
> + int align;
> + int next;
> +
> + if (atomic_read(&priv->tx_free) <= NB8800_DESC_LOW) {
> + netif_stop_queue(dev);
> + return NETDEV_TX_BUSY;
> + }
> +
> + align = (8 - (uintptr_t)skb->data) & 7;
> +
> + dma_len = skb->len - align;
> + dma_addr = dma_map_single(&dev->dev, skb->data + align,
> + dma_len, DMA_TO_DEVICE);
> +
> + if (dma_mapping_error(&dev->dev, dma_addr)) {
> + netdev_err(dev, "tx dma mapping error\n");
> + kfree_skb(skb);
> + dev->stats.tx_dropped++;
> + return NETDEV_TX_OK;
> + }
> +
> + if (atomic_dec_return(&priv->tx_free) <= NB8800_DESC_LOW)
> + netif_stop_queue(dev);
> +
> + next = priv->tx_next;
> + txb = &priv->tx_bufs[next];
> + txd = &priv->tx_descs[next];
> + dma = &txd->desc[0];
> +
> + next = (next + 1) % TX_DESC_COUNT;
> +
> + if (align) {
> + memcpy(txd->buf, skb->data, align);
> +
> + dma->s_addr =
> + txb->dma_desc + offsetof(struct nb8800_tx_desc, buf);
> + dma->n_addr = txb->dma_desc + sizeof(txd->desc[0]);
> + dma->config = DESC_BTS(2) | DESC_DS | align;
> +
> + dma++;
> + }
> +
> + dma->s_addr = dma_addr;
> + dma->n_addr = priv->tx_bufs[next].dma_desc;
> + dma->config = DESC_BTS(2) | DESC_DS | DESC_EOF | dma_len;
> +
> + if (!skb->xmit_more)
> + dma->config |= DESC_EOC;
> +
> + txb->skb = skb;
> + txb->dma_addr = dma_addr;
> + txb->dma_len = dma_len;
> +
> + if (!priv->tx_chain) {
> + txb->chain_len = 1;
> + priv->tx_chain = txb;
> + } else {
> + priv->tx_chain->chain_len++;
> + }
> +
> + netdev_sent_queue(dev, skb->len);
> +
> + smp_mb__before_spinlock();
> + spin_lock_irqsave(&priv->tx_lock, flags);
> +
> + if (!skb->xmit_more) {
> + priv->tx_chain->ready = true;
> + priv->tx_chain = NULL;
> + nb8800_tx_dma_start(dev);
> + }
> +
> + spin_unlock_irqrestore(&priv->tx_lock, flags);
> +
> + priv->tx_next = next;
> +
> + return NETDEV_TX_OK;
> +}
> +
> +static void nb8800_tx_error(struct net_device *dev, u32 report)
> +{
> + if (report & TX_LATE_COLLISION)
> + dev->stats.collisions++;
> +
> + if (report & TX_PACKET_DROPPED)
> + dev->stats.tx_dropped++;
> +
> + if (report & TX_FIFO_UNDERRUN)
> + dev->stats.tx_fifo_errors++;
> +
> + dev->stats.tx_errors++;
> +}
> +
> +static void nb8800_tx_done(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int limit = priv->tx_next;
> + int done = priv->tx_done;
> + unsigned int packets = 0;
> + unsigned int len = 0;
> +
> + while (done != limit) {
> + struct nb8800_tx_desc *txd = &priv->tx_descs[done];
> + struct nb8800_tx_buf *txb = &priv->tx_bufs[done];
> + struct sk_buff *skb;
> +
> + if (!txd->report)
> + break;
> +
> + skb = txb->skb;
> + len += skb->len;
> +
> + dma_unmap_single(&dev->dev, txb->dma_addr, txb->dma_len,
> + DMA_TO_DEVICE);
> +
> + if (IS_TX_ERROR(txd->report)) {
> + nb8800_tx_error(dev, txd->report);
> + dev_kfree_skb_irq(skb);
> + } else {
> + dev_consume_skb_irq(skb);
> + }
> +
> + dev->stats.tx_packets++;
> + dev->stats.tx_bytes += TX_BYTES_TRANSFERRED(txd->report);
> + dev->stats.collisions += TX_EARLY_COLLISIONS(txd->report);
> +
> + txb->skb = NULL;
> + txb->ready = false;
> + txd->report = 0;
> +
> + done = (done + 1) % TX_DESC_COUNT;
> + packets++;
> + }
> +
> + if (packets) {
> + smp_mb__before_atomic();
> + atomic_add(packets, &priv->tx_free);
> + netdev_completed_queue(dev, packets, len);
> + netif_wake_queue(dev);
> + priv->tx_done = done;
> + }
> +}
> +
> +static irqreturn_t nb8800_irq(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 (val & TSR_DI)
> + nb8800_tx_dma_start_irq(dev);
> +
> + if (val & TSR_TI)
> + nb8800_tx_done(dev);
> +
> + if (unlikely(val & TSR_DE))
> + netdev_err(dev, "TX DMA error\n");
> +
> + /* should never happen with automatic status retrieval */
> + 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_itr_poll);
> + napi_schedule_irqoff(&priv->napi);
> + }
> +
> + if (unlikely(val & RSR_DE))
> + netdev_err(dev, "RX DMA error\n");
> +
> + /* should never happen with automatic status retrieval */
> + if (unlikely(val & RSR_RO))
> + netdev_err(dev, "RX Status FIFO overflow\n");
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void nb8800_mac_config(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + bool gigabit = priv->speed == SPEED_1000;
> + u32 mac_mode_mask = RGMII_MODE | HALF_DUPLEX | GMAC_MODE;
> + u32 mac_mode = 0;
> + u32 slot_time;
> + u32 phy_clk;
> + u32 ict;
> +
> + if (!priv->duplex)
> + mac_mode |= HALF_DUPLEX;
> +
> + if (gigabit) {
> + if (priv->phy_mode == PHY_INTERFACE_MODE_RGMII)
> + mac_mode |= RGMII_MODE;
> +
> + mac_mode |= GMAC_MODE;
> + phy_clk = 125000000;
> +
> + /* Should be 512 but register is only 8 bits */
> + slot_time = 255;
> + } else {
> + phy_clk = 25000000;
> + slot_time = 128;
> + }
> +
> + ict = DIV_ROUND_UP(phy_clk, clk_get_rate(priv->clk));
> +
> + nb8800_writeb(priv, NB8800_IC_THRESHOLD, ict);
> + nb8800_writeb(priv, NB8800_SLOT_TIME, slot_time);
> + nb8800_maskb(priv, NB8800_MAC_MODE, mac_mode_mask, mac_mode);
> +}
> +
> +static void nb8800_pause_config(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct phy_device *phydev = priv->phydev;
> + u32 rxcr;
> +
> + if (priv->pause_aneg) {
> + if (!phydev || !phydev->link)
> + return;
> +
> + priv->pause_rx = phydev->pause;
> + priv->pause_tx = phydev->pause ^ phydev->asym_pause;
> + }
> +
> + nb8800_modb(priv, NB8800_RX_CTL, RX_PAUSE_EN, priv->pause_rx);
> +
> + rxcr = nb8800_readl(priv, NB8800_RXC_CR);
> + if (!!(rxcr & RCR_FL) == priv->pause_tx)
> + return;
> +
> + if (netif_running(dev)) {
> + napi_disable(&priv->napi);
> + netif_tx_lock_bh(dev);
> + nb8800_dma_stop(dev);
> + nb8800_modl(priv, NB8800_RXC_CR, RCR_FL, priv->pause_tx);
> + nb8800_start_rx(dev);
> + netif_tx_unlock_bh(dev);
> + napi_enable(&priv->napi);
> + } else {
> + nb8800_modl(priv, NB8800_RXC_CR, RCR_FL, priv->pause_tx);
> + }
> +}
> +
> +static void nb8800_link_reconfigure(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct phy_device *phydev = priv->phydev;
> + int change = 0;
> +
> + if (phydev->link) {
> + if (phydev->speed != priv->speed) {
> + priv->speed = phydev->speed;
> + change = 1;
> + }
> +
> + if (phydev->duplex != priv->duplex) {
> + priv->duplex = phydev->duplex;
> + change = 1;
> + }
> +
> + if (change)
> + nb8800_mac_config(dev);
> +
> + nb8800_pause_config(dev);
> + }
> +
> + if (phydev->link != priv->link) {
> + priv->link = phydev->link;
> + change = 1;
> + }
> +
> + if (change)
> + phy_print_status(priv->phydev);
> +}
> +
> +static void nb8800_update_mac_addr(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int i;
> +
> + for (i = 0; i < ETH_ALEN; i++)
> + nb8800_writeb(priv, NB8800_SRC_ADDR(i), dev->dev_addr[i]);
> +
> + for (i = 0; i < ETH_ALEN; i++)
> + 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);
> + readb_poll_timeout_atomic(priv->base + NB8800_MC_INIT, val, !val,
> + 1, 1000);
> +}
> +
> +static void nb8800_set_rx_mode(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct netdev_hw_addr *ha;
> + int i;
> +
> + 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) {
> + for (i = 0; i < ETH_ALEN; i++)
> + nb8800_writeb(priv, NB8800_MC_ADDR(i), ha->addr[i]);
> +
> + nb8800_mc_init(dev, 0xff);
> + }
> +}
> +
> +#define RX_DESC_SIZE (RX_DESC_COUNT * sizeof(struct nb8800_rx_desc))
> +#define TX_DESC_SIZE (TX_DESC_COUNT * sizeof(struct nb8800_tx_desc))
> +
> +static void nb8800_dma_free(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int i;

looks like unsigned 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 void nb8800_dma_reset(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_rx_desc *rxd;
> + struct nb8800_tx_desc *txd;
> + int i;

Ditto.

> +
> + for (i = 0; i < RX_DESC_COUNT; i++) {
> + dma_addr_t rx_dma = priv->rx_desc_dma + i * sizeof(*rxd);
> +
> + rxd = &priv->rx_descs[i];
> + rxd->desc.n_addr = rx_dma + sizeof(*rxd);
> + rxd->desc.r_addr =
> + rx_dma + offsetof(struct nb8800_rx_desc, report);
> + rxd->desc.config = priv->rx_dma_config;
> + rxd->report = 0;
> + }
> +
> + rxd->desc.n_addr = priv->rx_desc_dma;
> + rxd->desc.config |= DESC_EOC;
> +
> + priv->rx_eoc = RX_DESC_COUNT - 1;
> +
> + for (i = 0; i < TX_DESC_COUNT; i++) {
> + struct nb8800_tx_buf *txb = &priv->tx_bufs[i];
> + dma_addr_t r_dma = txb->dma_desc +
> + offsetof(struct nb8800_tx_desc, report);
> +
> + txd = &priv->tx_descs[i];
> + txd->desc[0].r_addr = r_dma;
> + txd->desc[1].r_addr = r_dma;
> + txd->report = 0;
> + }
> +
> + priv->tx_next = 0;
> + priv->tx_queue = 0;
> + priv->tx_done = 0;
> + atomic_set(&priv->tx_free, TX_DESC_COUNT);
> +
> + nb8800_writel(priv, NB8800_RX_DESC_ADDR, priv->rx_desc_dma);
> +
> + wmb(); /* ensure all setup is written before starting */
> +}
> +
> +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 err;
> + int i;

Ditto.

> +
> + 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++) {
> + err = nb8800_alloc_rx(dev, i, false);
> + if (err)
> + goto err_out;
> + }
> +
> + 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++)
> + priv->tx_bufs[i].dma_desc =
> + priv->tx_desc_dma + i * sizeof(struct nb8800_tx_desc);
> +
> + nb8800_dma_reset(dev);
> +
> + return 0;
> +
> +err_out:
> + nb8800_dma_free(dev);
> +
> + return -ENOMEM;
> +}
> +
> +static int nb8800_dma_stop(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + struct nb8800_tx_buf *txb = &priv->tx_bufs[0];
> + struct nb8800_tx_desc *txd = &priv->tx_descs[0];
> + int retry = 5;
> + u32 txcr;
> + u32 rxcr;
> + int err;
> + int i;

Ditto.

> +
> + /* wait for tx to finish */
> + err = readl_poll_timeout_atomic(priv->base + NB8800_TXC_CR, txcr,
> + !(txcr & TCR_EN) &&
> + priv->tx_done == priv->tx_next,
> + 1000, 1000000);
> + if (err)
> + return err;
> +
> + /* The rx DMA only stops if it reaches the end of chain.
> + * To make this happen, we set the EOC flag on all rx
> + * descriptors, put the device in loopback mode, and send
> + * a few dummy frames. The interrupt handler will ignore
> + * these since NAPI is disabled and no real frames are in
> + * the tx queue. */

Block comment
/*
* text
*/

> +
> + for (i = 0; i < RX_DESC_COUNT; i++)
> + priv->rx_descs[i].desc.config |= DESC_EOC;
> +
> + txd->desc[0].s_addr =
> + txb->dma_desc + offsetof(struct nb8800_tx_desc, buf);
> + txd->desc[0].config = DESC_BTS(2) | DESC_DS | DESC_EOF | DESC_EOC | 8;
> + memset(txd->buf, 0, sizeof(txd->buf));
> +
> + nb8800_mac_af(dev, false);
> + nb8800_setb(priv, NB8800_MAC_MODE, LOOPBACK_EN);
> +
> + do {
> + nb8800_writel(priv, NB8800_TX_DESC_ADDR, txb->dma_desc);
> + wmb();
> + nb8800_writel(priv, NB8800_TXC_CR, txcr | TCR_EN);
> +
> + err = readl_poll_timeout_atomic(priv->base + NB8800_RXC_CR,
> + rxcr, !(rxcr & RCR_EN),
> + 1000, 100000);
> + } while (err && --retry);
> +
> + nb8800_mac_af(dev, true);
> + nb8800_clearb(priv, NB8800_MAC_MODE, LOOPBACK_EN);
> + nb8800_dma_reset(dev);
> +
> + return retry ? 0 : -ETIMEDOUT;
> +}
> +
> +static void nb8800_pause_adv(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + u32 adv = 0;
> +
> + if (!priv->phydev)
> + return;
> +
> + if (priv->pause_rx)
> + adv |= ADVERTISED_Pause | ADVERTISED_Asym_Pause;
> + if (priv->pause_tx)
> + adv ^= ADVERTISED_Asym_Pause;
> +
> + priv->phydev->supported |= adv;
> + priv->phydev->advertising |= adv;
> +
> +}
> +
> +static int nb8800_open(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int err;
> +
> + /* clear any pending interrupts */
> + 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_irq, 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;
> +
> + nb8800_pause_adv(dev);
> +
> + netdev_reset_queue(dev);
> + 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);
> +
> + phy_stop(priv->phydev);
> +
> + netif_stop_queue(dev);
> + napi_disable(&priv->napi);
> +
> + nb8800_dma_stop(dev);
> + nb8800_mac_rx(dev, false);
> + nb8800_mac_tx(dev, false);
> +
> + phy_disconnect(priv->phydev);
> + priv->phydev = NULL;
> +
> + free_irq(dev->irq, dev);
> +
> + nb8800_dma_free(dev);
> +
> + return 0;
> +}
> +
> +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_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);
> +
> + if (!priv->phydev)
> + return -ENODEV;
> +
> + 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);
> +
> + if (!priv->phydev)
> + return -ENODEV;
> +
> + return phy_ethtool_sset(priv->phydev, cmd);
> +}
> +
> +static int nb8800_nway_reset(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + if (!priv->phydev)
> + return -ENODEV;
> +
> + return genphy_restart_aneg(priv->phydev);
> +}
> +
> +static void nb8800_get_pauseparam(struct net_device *dev,
> + struct ethtool_pauseparam *pp)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + pp->autoneg = priv->pause_aneg;
> + pp->rx_pause = priv->pause_rx;
> + pp->tx_pause = priv->pause_tx;
> +}
> +
> +static int nb8800_set_pauseparam(struct net_device *dev,
> + struct ethtool_pauseparam *pp)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> +
> + priv->pause_aneg = pp->autoneg;
> + priv->pause_rx = pp->rx_pause;
> + priv->pause_tx = pp->tx_pause;
> +
> + nb8800_pause_adv(dev);
> +
> + if (!priv->pause_aneg)
> + nb8800_pause_config(dev);
> + else if (priv->phydev)
> + phy_start_aneg(priv->phydev);
> +
> + return 0;
> +}
> +
> +static const char nb8800_stats_names[][ETH_GSTRING_LEN] = {
> + "rx_bytes_ok",
> + "rx_frames_ok",
> + "rx_undersize_frames",
> + "rx_fragment_frames",
> + "rx_64_byte_frames",
> + "rx_127_byte_frames",
> + "rx_255_byte_frames",
> + "rx_511_byte_frames",
> + "rx_1023_byte_frames",
> + "rx_max_size_frames",
> + "rx_oversize_frames",
> + "rx_bad_fcs_frames",
> + "rx_broadcast_frames",
> + "rx_multicast_frames",
> + "rx_control_frames",
> + "rx_pause_frames",
> + "rx_unsup_control_frames",
> + "rx_align_error_frames",
> + "rx_overrun_frames",
> + "rx_jabber_frames",
> + "rx_bytes",
> + "rx_frames",
> +
> + "tx_bytes_ok",
> + "tx_frames_ok",
> + "tx_64_byte_frames",
> + "tx_127_byte_frames",
> + "tx_255_byte_frames",
> + "tx_511_byte_frames",
> + "tx_1023_byte_frames",
> + "tx_max_size_frames",
> + "tx_oversize_frames",
> + "tx_broadcast_frames",
> + "tx_multicast_frames",
> + "tx_control_frames",
> + "tx_pause_frames",
> + "tx_underrun_frames",
> + "tx_single_collision_frames",
> + "tx_multi_collision_frames",
> + "tx_deferred_collision_frames",
> + "tx_late_collision_frames",
> + "tx_excessive_collision_frames",
> + "tx_bytes",
> + "tx_frames",
> + "tx_collisions",
> +};
> +
> +#define NB8800_NUM_STATS ARRAY_SIZE(nb8800_stats_names)
> +
> +static int nb8800_get_sset_count(struct net_device *dev, int sset)
> +{
> + if (sset == ETH_SS_STATS)
> + return NB8800_NUM_STATS;
> +
> + return -EOPNOTSUPP;
> +}
> +
> +static void nb8800_get_strings(struct net_device *dev, u32 sset, u8 *buf)
> +{
> + if (sset == ETH_SS_STATS)
> + memcpy(buf, &nb8800_stats_names, sizeof(nb8800_stats_names));
> +}
> +
> +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 void nb8800_get_ethtool_stats(struct net_device *dev,
> + struct ethtool_stats *estats, u64 *st)
> +{
> + u32 rx, tx;
> + int i;

unsigned int i;

> +
> + for (i = 0; i < NB8800_NUM_STATS / 2; i++) {
> + rx = nb8800_read_stat(dev, i);
> + tx = nb8800_read_stat(dev, i | 0x80);
> + st[i] = rx;
> + st[i + NB8800_NUM_STATS / 2] = tx;
> + }
> +}
> +
> +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,
> + .get_pauseparam = nb8800_get_pauseparam,
> + .set_pauseparam = nb8800_set_pauseparam,
> + .get_sset_count = nb8800_get_sset_count,
> + .get_strings = nb8800_get_strings,
> + .get_ethtool_stats = nb8800_get_ethtool_stats,
> +};
> +
> +static int nb8800_hw_init(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + u32 val;
> +
> + 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_AF_EN;
> + nb8800_writeb(priv, NB8800_RX_CTL, val);
> +
> + /* Chosen by fair dice roll */
> + nb8800_writeb(priv, NB8800_RANDOM_SEED, 4);
> +
> + /* TX cycles per deferral period */
> + nb8800_writeb(priv, NB8800_TX_SDP, 12);
> +
> + /* The following three threshold values have been
> + * experimentally determined for good results. */
> +
> + /* RX/TX FIFO threshold for partial empty (64-bit entries) */
> + nb8800_writeb(priv, NB8800_PE_THRESHOLD, 0);
> +
> + /* RX/TX FIFO threshold for partial full (64-bit entries) */
> + nb8800_writeb(priv, NB8800_PF_THRESHOLD, 255);
> +
> + /* Buffer size for transmit (64-bit entries) */
> + nb8800_writeb(priv, NB8800_TX_BUFSIZE, 64);
> +
> + /* Configure tx DMA */
> +
> + val = nb8800_readl(priv, NB8800_TXC_CR);
> + val &= TCR_LE; /* keep endian setting */
> + val |= TCR_DM; /* DMA descriptor mode */
> + val |= TCR_RS; /* automatically store tx status */
> + val |= TCR_DIE; /* interrupt on DMA chain completion */
> + val |= TCR_TFI(7); /* interrupt after 7 frames transmitted */
> + val |= TCR_BTS(2); /* 32-byte bus transaction size */
> + nb8800_writel(priv, NB8800_TXC_CR, val);
> +
> + /* TX complete interrupt after 10 ms or 7 frames (see above) */
> + val = clk_get_rate(priv->clk) / 100;
> + nb8800_writel(priv, NB8800_TX_ITR, val);
> +
> + /* Configure rx DMA */
> +
> + val = nb8800_readl(priv, NB8800_RXC_CR);
> + val &= RCR_LE; /* keep endian setting */
> + val |= RCR_DM; /* DMA descriptor mode */
> + val |= RCR_RS; /* automatically store rx status */
> + val |= RCR_DIE; /* interrupt at end of DMA chain */
> + val |= RCR_RFI(7); /* interrupt after 7 frames received */
> + val |= RCR_BTS(2); /* 32-byte bus transaction size */
> + nb8800_writel(priv, NB8800_RXC_CR, val);
> +
> + /* The rx interrupt can fire before the DMA has completed
> + * unless a small delay is added. 50 us is hopefully enough. */
> + priv->rx_itr_irq = clk_get_rate(priv->clk) / 20000;
> +
> + /* In NAPI poll mode we want to disable interrupts, but the
> + * hardware does not permit this. Delay 10 ms instead. */
> + priv->rx_itr_poll = clk_get_rate(priv->clk) / 100;
> +
> + nb8800_writel(priv, NB8800_RX_ITR, priv->rx_itr_irq);
> +
> + priv->rx_dma_config = RX_BUF_SIZE | DESC_BTS(2) | DESC_DS | DESC_EOF;
> +
> + /* Flow control settings */
> +
> + /* Pause time of 0.1 ms */
> + val = 100000 / 512;
> + nb8800_writeb(priv, NB8800_PQ1, val >> 8);
> + nb8800_writeb(priv, NB8800_PQ2, val & 0xff);
> +
> + /* Auto-negotiate by default */
> + priv->pause_aneg = true;
> + priv->pause_rx = true;
> + priv->pause_tx = true;
> +
> + nb8800_mc_init(dev, 0);
> +
> + return 0;
> +}
> +
> +static int nb8800_tangox_init(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + u32 pad_mode = PAD_MODE_MII;
> +
> + switch (priv->phy_mode) {
> + case PHY_INTERFACE_MODE_MII:
> + case PHY_INTERFACE_MODE_GMII:
> + pad_mode = PAD_MODE_MII;
> + break;
> +
> + case PHY_INTERFACE_MODE_RGMII:
> + pad_mode = PAD_MODE_RGMII;
> + break;
> +
> + case PHY_INTERFACE_MODE_RGMII_TXID:
> + pad_mode = PAD_MODE_RGMII | PAD_MODE_GTX_CLK_DELAY;
> + break;
> +
> + default:
> + dev_err(dev->dev.parent, "unsupported phy mode %s\n",
> + phy_modes(priv->phy_mode));
> + return -EINVAL;
> + }
> +
> + nb8800_writeb(priv, NB8800_TANGOX_PAD_MODE, pad_mode);
> +
> + return 0;
> +}
> +
> +static int 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);
> +
> + return 0;
> +}
> +
> +static const struct nb8800_ops nb8800_tangox_ops = {
> + .init = nb8800_tangox_init,
> + .reset = nb8800_tangox_reset,
> +};
> +
> +static int nb8800_tango4_init(struct net_device *dev)
> +{
> + struct nb8800_priv *priv = netdev_priv(dev);
> + int err;
> +
> + err = nb8800_tangox_init(dev);
> + if (err)
> + return err;
> +
> + /* On tango4 interrupt on DMA completion per frame works and gives
> + * better performance despite generating more rx interrupts. */
> +
> + /* Disable unnecessary interrupt on rx completion */
> + nb8800_clearl(priv, NB8800_RXC_CR, RCR_RFI(7));
> +
> + /* Request interrupt on descriptor DMA completion */
> + priv->rx_dma_config |= DESC_ID;
> +
> + return 0;
> +}
> +
> +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;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq <= 0) {
> + dev_err(&pdev->dev, "No IRQ\n");
> + return -EINVAL;
> + }
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
> +
> + dev_dbg(&pdev->dev, "AU-NB8800 Ethernet at %pa\n", &res->start);
> +
> + 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;
> +
> + spin_lock_init(&priv->tx_lock);
> +
> + if (ops && ops->reset) {
> + ret = ops->reset(dev);
> + if (ret)
> + goto err_free_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, "%lx.nb8800-mii",
> + (unsigned long)res->start);
> + 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) {
> + ret = ops->init(dev);
> + if (ret)
> + goto err_free_bus;
> + }
> +
> + 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_DESCRIPTION("Aurora AU-NB8800 Ethernet driver");
> +MODULE_AUTHOR("Mans Rullgard <mans@mansr.com>");
> +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..e108d01
> --- /dev/null
> +++ b/drivers/net/ethernet/aurora/nb8800.h
> @@ -0,0 +1,314 @@
> +#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 RX_COPYBREAK 256
> +#define RX_COPYHDR 128
> +
> +#define MAX_MDC_CLOCK 2500000
> +
> +/* Stargate Solutions SSN8800 core registers */
> +#define NB8800_TX_CTL1 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 0x001
> +
> +#define NB8800_RX_CTL 0x004
> +#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 0x008
> +#define NB8800_TX_SDP 0x14
> +#define NB8800_TX_TPDP1 0x18
> +#define NB8800_TX_TPDP2 0x19
> +#define NB8800_SLOT_TIME 0x1c
> +
> +#define NB8800_MDIO_CMD 0x020
> +#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)

Perhaps sort them by bits used?

> +
> +#define NB8800_MDIO_STS 0x024
> +#define MDIO_STS_ERR BIT(31)
> +
> +#define NB8800_MC_ADDR(i) (0x028 + (i))
> +#define NB8800_MC_INIT 0x02e
> +#define NB8800_UC_ADDR(i) (0x03c + (i))
> +
> +#define NB8800_MAC_MODE 0x044
> +#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 0x050
> +#define NB8800_PE_THRESHOLD 0x051
> +#define NB8800_PF_THRESHOLD 0x052
> +#define NB8800_TX_BUFSIZE 0x054
> +#define NB8800_FIFO_CTL 0x056
> +#define NB8800_PQ1 0x060
> +#define NB8800_PQ2 0x061
> +#define NB8800_SRC_ADDR(i) (0x06a + (i))
> +#define NB8800_STAT_DATA 0x078
> +#define NB8800_STAT_INDEX 0x07c
> +#define NB8800_STAT_CLEAR 0x07d
> +
> +#define NB8800_SLEEP_MODE 0x07e
> +#define SLEEP_MODE BIT(0)
> +
> +#define NB8800_WAKEUP 0x07f
> +#define WAKEUP BIT(0)
> +
> +/* Aurora NB8800 host interface registers */
> +#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_TRANSFERRED(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) & 0x07)
> +
> +#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_ALIGNMENT_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 PAD_MODE_MASK 0x7
> +#define PAD_MODE_MII 0x0
> +#define PAD_MODE_RGMII 0x1
> +#define PAD_MODE_GTX_CLK_INV BIT(3)
> +#define PAD_MODE_GTX_CLK_DELAY BIT(4)
> +
> +#define NB8800_TANGOX_MDIO_CLKDIV 0x420
> +#define NB8800_TANGOX_RESET 0x424
> +
> +/* Hardware DMA descriptor */
> +struct nb8800_dma_desc {
> + u32 s_addr; /* start address */
> + u32 n_addr; /* next descriptor address */
> + u32 r_addr; /* report address */
> + u32 config;
> +} __aligned(8);
> +
> +#define DESC_ID BIT(23)
> +#define DESC_EOC BIT(22)
> +#define DESC_EOF BIT(21)
> +#define DESC_LK BIT(20)
> +#define DESC_DS BIT(19)
> +#define DESC_BTS(x) (((x) & 0x7) << 16)
> +
> +/* DMA descriptor and associated data for rx.
> + * Allocated from coherent memory.
> + */
> +struct nb8800_rx_desc {
> + /* DMA descriptor */
> + struct nb8800_dma_desc desc;
> +
> + /* Status report filled in by hardware */
> + u32 report;
> +};
> +
> +/* Address of buffer on rx ring */
> +struct nb8800_rx_buf {
> + struct page *page;
> + unsigned long offset;
> +};
> +
> +/* DMA descriptors and associated data for tx.
> + * Allocated from coherent memory.
> + */

Convert to kernel doc?

> +struct nb8800_tx_desc {
> + /* DMA descriptor. The second descriptor is used if packet
> + * data is unaligned. *


> + struct nb8800_dma_desc desc[2];
> +
> + /* Status report filled in by hardware */
> + u32 report;
> +
> + /* Bounce buffer for initial unaligned part of packet */

> + u8 buf[8] __aligned(8);
> +};
> +
> +/* Packet in tx queue */
> +struct nb8800_tx_buf {


> + /* Currently queued skb */
> + struct sk_buff *skb;
> +
> + /* DMA address of the first descriptor */
> + dma_addr_t dma_desc;
> +
> + /* DMA address of packet data */
> + dma_addr_t dma_addr;
> +
> + /* Length of DMA mapping, less than skb->len if alignment
> + * buffer is used. */
> + unsigned int dma_len;
> +
> + /* Number of packets in chain starting here */
> + unsigned int chain_len;
> +
> + /* Packet chain ready to be submitted to hardware */
> + bool ready;
> +};
> +
> +struct nb8800_priv {

> + struct napi_struct napi;
> +
> + void __iomem *base;
> +
> + /* RX DMA descriptors */
> + struct nb8800_rx_desc *rx_descs;
> +
> + /* RX buffers referenced by DMA descriptors */
> + struct nb8800_rx_buf *rx_bufs;
> +
> + /* Current end of chain */
> + u32 rx_eoc;
> +
> + /* Value for rx interrupt time register in NAPI interrupt mode */
> + u32 rx_itr_irq;
> +
> + /* Value for rx interrupt time register in NAPI poll mode */
> + u32 rx_itr_poll;
> +
> + /* Value for config field of rx DMA descriptors */
> + u32 rx_dma_config;
> +
> + /* TX DMA descriptors */
> + struct nb8800_tx_desc *tx_descs;
> +
> + /* TX packet queue */
> + struct nb8800_tx_buf *tx_bufs;
> +
> + /* Number of free tx queue entries */
> + atomic_t tx_free;
> +
> + /* First free tx queue entry */
> + u32 tx_next;
> +
> + /* Next buffer to transmit */
> + u32 tx_queue;
> +
> + /* Start of current packet chain */
> + struct nb8800_tx_buf *tx_chain;
> +
> + /* Next buffer to reclaim */
> + u32 tx_done;
> +
> + /* Lock for DMA activation */
> + spinlock_t tx_lock;
> +
> + struct mii_bus *mii_bus;
> + struct device_node *phy_node;
> + struct phy_device *phydev;
> +
> + /* PHY connection type from DT */
> + int phy_mode;
> +
> + /* Current link status */
> + int speed;
> + int duplex;
> + int link;
> +
> + /* Pause settings */
> + bool pause_aneg;
> + bool pause_rx;
> + bool pause_tx;
> +
> + /* DMA base address of rx descriptors, see rx_descs above */
> + dma_addr_t rx_desc_dma;
> +
> + /* DMA base address of tx descriptors, see tx_descs above */
> + dma_addr_t tx_desc_dma;
> +
> + struct clk *clk;
> +};
> +
> +struct nb8800_ops {
> + int (*init)(struct net_device *dev);
> + int (*reset)(struct net_device *dev);
> +};
> +
> +#endif /* _NB8800_H_ */
> --
> 2.6.3
>
> --
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--
With Best Regards,
Andy Shevchenko


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