diff mbox series

[v2,2/2] net: Add driver for LiteX's LiteEth network interface

Message ID 20210820074726.2860425-3-joel@jms.id.au
State Superseded
Headers show
Series net: Add LiteETH network driver | expand

Commit Message

Joel Stanley Aug. 20, 2021, 7:47 a.m. UTC
LiteX is a soft system-on-chip that targets FPGAs. LiteEth is a basic
network device that is commonly used in LiteX designs.

The driver was first written in 2017 and has been maintained by the
LiteX community in various trees. Thank you to all who have contributed.

Co-developed-by: Gabriel Somlo <gsomlo@gmail.com>
Co-developed-by: David Shah <dave@ds0.me>
Co-developed-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v2:
 - check for bad len in liteeth_rx before getting skb
 - use netdev_alloc_skb_ip_align
 - remove unused duplex/speed and mii_bus variables
 - set carrier off when stopping device
 - increment packet count in the same place as bytes
 - fix error return code when irq could not be found
 - remove request of mdio base address until it is used
 - fix of_property_read line wrapping/alignment
 - only check that reader isn't busy, and then send off next packet
 - drop phy reset, it was incorrect (wrong address)
 - Add an description to the kconfig text
 - stop tx queue when busy and re-start after tx complete irq fires
 - use litex accessors to support big endian socs
 - clean up unused includes
 - use standard fifo-depth properties, which are in bytes

 drivers/net/ethernet/Kconfig               |   1 +
 drivers/net/ethernet/Makefile              |   1 +
 drivers/net/ethernet/litex/Kconfig         |  27 ++
 drivers/net/ethernet/litex/Makefile        |   5 +
 drivers/net/ethernet/litex/litex_liteeth.c | 327 +++++++++++++++++++++
 5 files changed, 361 insertions(+)
 create mode 100644 drivers/net/ethernet/litex/Kconfig
 create mode 100644 drivers/net/ethernet/litex/Makefile
 create mode 100644 drivers/net/ethernet/litex/litex_liteeth.c

Comments

kernel test robot Aug. 20, 2021, 11:50 a.m. UTC | #1
Hi Joel,

I love your patch! Perhaps something to improve:

[auto build test WARNING on robh/for-next]
[also build test WARNING on net-next/master net/master linus/master v5.14-rc6 next-20210819]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Joel-Stanley/net-Add-LiteETH-network-driver/20210820-154958
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/3355b2a96c6d9881128ebac1d3801171b988dbeb
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Joel-Stanley/net-Add-LiteETH-network-driver/20210820-154958
        git checkout 3355b2a96c6d9881128ebac1d3801171b988dbeb
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=sh 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/net/ethernet/litex/litex_liteeth.c:204:5: warning: no previous prototype for 'liteeth_setup_slots' [-Wmissing-prototypes]
     204 | int liteeth_setup_slots(struct liteeth *priv)
         |     ^~~~~~~~~~~~~~~~~~~

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for SND_ATMEL_SOC_PDC
   Depends on SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && HAS_DMA
   Selected by
   - SND_ATMEL_SOC_SSC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC
   - SND_ATMEL_SOC_SSC_PDC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && ATMEL_SSC


vim +/liteeth_setup_slots +204 drivers/net/ethernet/litex/litex_liteeth.c

   203	
 > 204	int liteeth_setup_slots(struct liteeth *priv)
   205	{
   206		struct device_node *np = priv->dev->of_node;
   207		int err, depth;
   208	
   209		err = of_property_read_u32(np, "rx-fifo-depth", &depth);
   210		if (err) {
   211			dev_err(priv->dev, "unable to get rx-fifo-depth\n");
   212			return err;
   213		}
   214		if (depth < LITEETH_BUFFER_SIZE) {
   215			dev_err(priv->dev, "invalid tx-fifo-depth: %d\n", depth);
   216			return -EINVAL;
   217		}
   218		priv->num_rx_slots = depth / LITEETH_BUFFER_SIZE;
   219	
   220		err = of_property_read_u32(np, "tx-fifo-depth", &depth);
   221		if (err) {
   222			dev_err(priv->dev, "unable to get tx-fifo-depth\n");
   223			return err;
   224		}
   225		if (depth < LITEETH_BUFFER_SIZE) {
   226			dev_err(priv->dev, "invalid rx-fifo-depth: %d\n", depth);
   227			return -EINVAL;
   228		}
   229		priv->num_tx_slots = depth / LITEETH_BUFFER_SIZE;
   230	
   231		return 0;
   232	}
   233	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Gabriel L. Somlo Aug. 25, 2021, noon UTC | #2
On Wed, Aug 25, 2021 at 06:35:17AM +0000, Joel Stanley wrote:
> > > +
> > > +     netdev = devm_alloc_etherdev(&pdev->dev, sizeof(*priv));
> > > +     if (!netdev)
> > > +             return -ENOMEM;
> > > +
> > > +     SET_NETDEV_DEV(netdev, &pdev->dev);
> > > +     platform_set_drvdata(pdev, netdev);
> > > +
> > > +     priv = netdev_priv(netdev);
> > > +     priv->netdev = netdev;
> > > +     priv->dev = &pdev->dev;
> > > +
> > > +     irq = platform_get_irq(pdev, 0);
> > > +     if (irq < 0) {
> > > +             dev_err(&pdev->dev, "Failed to get IRQ %d\n", irq);
> > > +             return irq;
> >
> > At this point, netdev has been dynamically allocated, and should
> > probably be free'd before liteeth_probe() is allowed to fail,
> > to avoid any potential leaks...
> 
> We use the managed variant of alloc_etherdev, which means the
> structure is freed by the driver core when the driver is removed. This
> saves having to open code the cleanup/free code.
> 
> Have a read of Documentation/driver-api/driver-model/devres.rst for
> more information.

That makes sense, thanks for the link!

Cheers,
--Gabriel
Andrew Lunn Aug. 27, 2021, 2:11 a.m. UTC | #3
On Wed, Aug 25, 2021 at 06:35:17AM +0000, Joel Stanley wrote:
> On Tue, 24 Aug 2021 at 19:43, Gabriel L. Somlo <gsomlo@gmail.com> wrote:
> >
> > Hi Joel,
> >
> > Couple of comments below:
> >
> > On Fri, Aug 20, 2021 at 05:17:26PM +0930, Joel Stanley wrote:
> 
> > > diff --git a/drivers/net/ethernet/litex/Kconfig b/drivers/net/ethernet/litex/Kconfig
> > > new file mode 100644
> > > index 000000000000..265dba414b41
> > > --- /dev/null
> > > +++ b/drivers/net/ethernet/litex/Kconfig
> 
> > > +
> > > +config LITEX_LITEETH
> > > +     tristate "LiteX Ethernet support"
> >
> > Mostly cosmetic, but should there be a "depends on LITEX" statement in here?
> 
> No, there's as there is no dependency on the litex soc driver.

Which is good, you will get more build coverage that way, it will be
built of x86, arm, mips, etc...

> 
> > Maybe also "select MII" and "select PHYLIB"?
> 
> Again, there is no mii or phy code so the driver doesn't need these.

Yet.

At some point i expect you will need these, but you don't need them
now.

	Andrew
diff mbox series

Patch

diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
index 1cdff1dca790..d796684ec9ca 100644
--- a/drivers/net/ethernet/Kconfig
+++ b/drivers/net/ethernet/Kconfig
@@ -118,6 +118,7 @@  config LANTIQ_XRX200
 	  Support for the PMAC of the Gigabit switch (GSWIP) inside the
 	  Lantiq / Intel VRX200 VDSL SoC
 
+source "drivers/net/ethernet/litex/Kconfig"
 source "drivers/net/ethernet/marvell/Kconfig"
 source "drivers/net/ethernet/mediatek/Kconfig"
 source "drivers/net/ethernet/mellanox/Kconfig"
diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
index cb3f9084a21b..aaa5078cd7d1 100644
--- a/drivers/net/ethernet/Makefile
+++ b/drivers/net/ethernet/Makefile
@@ -51,6 +51,7 @@  obj-$(CONFIG_JME) += jme.o
 obj-$(CONFIG_KORINA) += korina.o
 obj-$(CONFIG_LANTIQ_ETOP) += lantiq_etop.o
 obj-$(CONFIG_LANTIQ_XRX200) += lantiq_xrx200.o
+obj-$(CONFIG_NET_VENDOR_LITEX) += litex/
 obj-$(CONFIG_NET_VENDOR_MARVELL) += marvell/
 obj-$(CONFIG_NET_VENDOR_MEDIATEK) += mediatek/
 obj-$(CONFIG_NET_VENDOR_MELLANOX) += mellanox/
diff --git a/drivers/net/ethernet/litex/Kconfig b/drivers/net/ethernet/litex/Kconfig
new file mode 100644
index 000000000000..265dba414b41
--- /dev/null
+++ b/drivers/net/ethernet/litex/Kconfig
@@ -0,0 +1,27 @@ 
+#
+# LiteX device configuration
+#
+
+config NET_VENDOR_LITEX
+	bool "LiteX devices"
+	default y
+	help
+	  If you have a network (Ethernet) card 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
+	  the questions about LiteX devices. If you say Y, you will be asked
+	  for your specific card in the following questions.
+
+if NET_VENDOR_LITEX
+
+config LITEX_LITEETH
+	tristate "LiteX Ethernet support"
+	help
+	  If you wish to compile a kernel for hardware with a LiteX LiteEth
+	  device then you should answer Y to this.
+
+	  LiteX is a soft system-on-chip that targets FPGAs. LiteETH is a basic
+	  network device that is commonly used in LiteX designs.
+
+endif # NET_VENDOR_LITEX
diff --git a/drivers/net/ethernet/litex/Makefile b/drivers/net/ethernet/litex/Makefile
new file mode 100644
index 000000000000..9343b73b8e49
--- /dev/null
+++ b/drivers/net/ethernet/litex/Makefile
@@ -0,0 +1,5 @@ 
+#
+# Makefile for the LiteX network device drivers.
+#
+
+obj-$(CONFIG_LITEX_LITEETH) += litex_liteeth.o
diff --git a/drivers/net/ethernet/litex/litex_liteeth.c b/drivers/net/ethernet/litex/litex_liteeth.c
new file mode 100644
index 000000000000..e9c5d817e1f9
--- /dev/null
+++ b/drivers/net/ethernet/litex/litex_liteeth.c
@@ -0,0 +1,327 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * LiteX Liteeth Ethernet
+ *
+ * Copyright 2017 Joel Stanley <joel@jms.id.au>
+ *
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/interrupt.h>
+#include <linux/litex.h>
+#include <linux/module.h>
+#include <linux/of_net.h>
+#include <linux/platform_device.h>
+
+#define LITEETH_WRITER_SLOT       0x00
+#define LITEETH_WRITER_LENGTH     0x04
+#define LITEETH_WRITER_ERRORS     0x08
+#define LITEETH_WRITER_EV_STATUS  0x0C
+#define LITEETH_WRITER_EV_PENDING 0x10
+#define LITEETH_WRITER_EV_ENABLE  0x14
+#define LITEETH_READER_START      0x18
+#define LITEETH_READER_READY      0x1C
+#define LITEETH_READER_LEVEL      0x20
+#define LITEETH_READER_SLOT       0x24
+#define LITEETH_READER_LENGTH     0x28
+#define LITEETH_READER_EV_STATUS  0x2C
+#define LITEETH_READER_EV_PENDING 0x30
+#define LITEETH_READER_EV_ENABLE  0x34
+#define LITEETH_PREAMBLE_CRC      0x38
+#define LITEETH_PREAMBLE_ERRORS   0x3C
+#define LITEETH_CRC_ERRORS        0x40
+
+#define LITEETH_PHY_CRG_RESET     0x00
+#define LITEETH_MDIO_W            0x04
+#define LITEETH_MDIO_R            0x0C
+
+#define DRV_NAME	"liteeth"
+
+#define LITEETH_BUFFER_SIZE		0x800
+#define MAX_PKT_SIZE			LITEETH_BUFFER_SIZE
+
+struct liteeth {
+	void __iomem *base;
+	struct net_device *netdev;
+	struct device *dev;
+
+	/* Tx */
+	int tx_slot;
+	int num_tx_slots;
+	void __iomem *tx_base;
+
+	/* Rx */
+	int rx_slot;
+	int num_rx_slots;
+	void __iomem *rx_base;
+};
+
+static int liteeth_rx(struct net_device *netdev)
+{
+	struct liteeth *priv = netdev_priv(netdev);
+	struct sk_buff *skb;
+	unsigned char *data;
+	u8 rx_slot;
+	int len;
+
+	rx_slot = litex_read8(priv->base + LITEETH_WRITER_SLOT);
+	len = litex_read32(priv->base + LITEETH_WRITER_LENGTH);
+
+	if (len == 0 || len > 2048)
+		goto rx_drop;
+
+	skb = netdev_alloc_skb_ip_align(netdev, len);
+	if (!skb) {
+		netdev_err(netdev, "couldn't get memory\n");
+		goto rx_drop;
+	}
+
+	data = skb_put(skb, len);
+	memcpy_fromio(data, priv->rx_base + rx_slot * LITEETH_BUFFER_SIZE, len);
+	skb->protocol = eth_type_trans(skb, netdev);
+
+	netdev->stats.rx_packets++;
+	netdev->stats.rx_bytes += len;
+
+	return netif_rx(skb);
+
+rx_drop:
+	netdev->stats.rx_dropped++;
+	netdev->stats.rx_errors++;
+
+	return NET_RX_DROP;
+}
+
+static irqreturn_t liteeth_interrupt(int irq, void *dev_id)
+{
+	struct net_device *netdev = dev_id;
+	struct liteeth *priv = netdev_priv(netdev);
+	u8 reg;
+
+	reg = litex_read8(priv->base + LITEETH_READER_EV_PENDING);
+	if (reg) {
+		if (netif_queue_stopped(netdev))
+			netif_wake_queue(netdev);
+		litex_write8(priv->base + LITEETH_READER_EV_PENDING, reg);
+	}
+
+	reg = litex_read8(priv->base + LITEETH_WRITER_EV_PENDING);
+	if (reg) {
+		liteeth_rx(netdev);
+		litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, reg);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int liteeth_open(struct net_device *netdev)
+{
+	struct liteeth *priv = netdev_priv(netdev);
+	int err;
+
+	/* Clear pending events */
+	litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, 1);
+	litex_write8(priv->base + LITEETH_READER_EV_PENDING, 1);
+
+	err = request_irq(netdev->irq, liteeth_interrupt, 0, netdev->name, netdev);
+	if (err) {
+		netdev_err(netdev, "failed to request irq %d\n", netdev->irq);
+		return err;
+	}
+
+	/* Enable IRQs */
+	litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 1);
+	litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 1);
+
+	netif_carrier_on(netdev);
+	netif_start_queue(netdev);
+
+	return 0;
+}
+
+static int liteeth_stop(struct net_device *netdev)
+{
+	struct liteeth *priv = netdev_priv(netdev);
+
+	netif_stop_queue(netdev);
+	netif_carrier_off(netdev);
+
+	litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 0);
+	litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 0);
+
+	free_irq(netdev->irq, netdev);
+
+	return 0;
+}
+
+static int liteeth_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+	struct liteeth *priv = netdev_priv(netdev);
+	void __iomem *txbuffer;
+
+	if (!litex_read8(priv->base + LITEETH_READER_READY)) {
+		if (net_ratelimit())
+			netdev_err(netdev, "LITEETH_READER_READY not ready\n");
+
+		netif_stop_queue(netdev);
+
+		return NETDEV_TX_BUSY;
+	}
+
+	/* Reject oversize packets */
+	if (unlikely(skb->len > MAX_PKT_SIZE)) {
+		if (net_ratelimit())
+			netdev_err(netdev, "tx packet too big\n");
+
+		dev_kfree_skb_any(skb);
+		netdev->stats.tx_dropped++;
+		netdev->stats.tx_errors++;
+
+		return NETDEV_TX_OK;
+	}
+
+	txbuffer = priv->tx_base + priv->tx_slot * LITEETH_BUFFER_SIZE;
+	memcpy_toio(txbuffer, skb->data, skb->len);
+	litex_write8(priv->base + LITEETH_READER_SLOT, priv->tx_slot);
+	litex_write16(priv->base + LITEETH_READER_LENGTH, skb->len);
+	litex_write8(priv->base + LITEETH_READER_START, 1);
+
+	netdev->stats.tx_bytes += skb->len;
+	netdev->stats.tx_packets++;
+
+	priv->tx_slot = (priv->tx_slot + 1) % priv->num_tx_slots;
+	dev_kfree_skb_any(skb);
+
+	return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops liteeth_netdev_ops = {
+	.ndo_open		= liteeth_open,
+	.ndo_stop		= liteeth_stop,
+	.ndo_start_xmit         = liteeth_start_xmit,
+};
+
+int liteeth_setup_slots(struct liteeth *priv)
+{
+	struct device_node *np = priv->dev->of_node;
+	int err, depth;
+
+	err = of_property_read_u32(np, "rx-fifo-depth", &depth);
+	if (err) {
+		dev_err(priv->dev, "unable to get rx-fifo-depth\n");
+		return err;
+	}
+	if (depth < LITEETH_BUFFER_SIZE) {
+		dev_err(priv->dev, "invalid tx-fifo-depth: %d\n", depth);
+		return -EINVAL;
+	}
+	priv->num_rx_slots = depth / LITEETH_BUFFER_SIZE;
+
+	err = of_property_read_u32(np, "tx-fifo-depth", &depth);
+	if (err) {
+		dev_err(priv->dev, "unable to get tx-fifo-depth\n");
+		return err;
+	}
+	if (depth < LITEETH_BUFFER_SIZE) {
+		dev_err(priv->dev, "invalid rx-fifo-depth: %d\n", depth);
+		return -EINVAL;
+	}
+	priv->num_tx_slots = depth / LITEETH_BUFFER_SIZE;
+
+	return 0;
+}
+
+static int liteeth_probe(struct platform_device *pdev)
+{
+	struct net_device *netdev;
+	void __iomem *buf_base;
+	struct resource *res;
+	struct liteeth *priv;
+	int irq, err;
+
+	netdev = devm_alloc_etherdev(&pdev->dev, sizeof(*priv));
+	if (!netdev)
+		return -ENOMEM;
+
+	SET_NETDEV_DEV(netdev, &pdev->dev);
+	platform_set_drvdata(pdev, netdev);
+
+	priv = netdev_priv(netdev);
+	priv->netdev = netdev;
+	priv->dev = &pdev->dev;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "Failed to get IRQ %d\n", irq);
+		return irq;
+	}
+	netdev->irq = irq;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mac");
+	priv->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "buffer");
+	buf_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(buf_base))
+		return PTR_ERR(buf_base);
+
+	err = liteeth_setup_slots(priv);
+	if (err)
+		return err;
+
+	/* Rx slots */
+	priv->rx_base = buf_base;
+	priv->rx_slot = 0;
+
+	/* Tx slots come after Rx slots */
+	priv->tx_base = buf_base + priv->num_rx_slots * LITEETH_BUFFER_SIZE;
+	priv->tx_slot = 0;
+
+	err = of_get_mac_address(pdev->dev.of_node, netdev->dev_addr);
+	if (err)
+		eth_hw_addr_random(netdev);
+
+	netdev->netdev_ops = &liteeth_netdev_ops;
+
+	err = register_netdev(netdev);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to register netdev %d\n", err);
+		return err;
+	}
+
+	netdev_info(netdev, "irq %d tx slots %d rx slots %d",
+		    netdev->irq, priv->num_tx_slots, priv->num_rx_slots);
+
+	return 0;
+}
+
+static int liteeth_remove(struct platform_device *pdev)
+{
+	struct net_device *netdev = platform_get_drvdata(pdev);
+
+	unregister_netdev(netdev);
+	free_netdev(netdev);
+
+	return 0;
+}
+
+static const struct of_device_id liteeth_of_match[] = {
+	{ .compatible = "litex,liteeth" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, liteeth_of_match);
+
+static struct platform_driver liteeth_driver = {
+	.probe = liteeth_probe,
+	.remove = liteeth_remove,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = liteeth_of_match,
+	},
+};
+module_platform_driver(liteeth_driver);
+
+MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");
+MODULE_LICENSE("GPL");