diff mbox

[v5,2/2] Ethernet driver for the WIZnet W5100 chip

Message ID 1333090806-27988-2-git-send-email-msink@permonline.ru
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Mike Sinkovsky March 30, 2012, 7 a.m. UTC
Tested and used in production with Blackfin BF531 embedded processor.

Signed-off-by: Mike Sinkovsky <msink@permonline.ru>
---
v5:
 - added driver for WIZnet W5100

---
 drivers/net/ethernet/wiznet/Kconfig  |   13 +
 drivers/net/ethernet/wiznet/Makefile |    1 +
 drivers/net/ethernet/wiznet/w5100.c  |  799 ++++++++++++++++++++++++++++++++++
 3 files changed, 814 insertions(+), 1 deletions(-)
 create mode 100644 drivers/net/ethernet/wiznet/w5100.c

Comments

Eric Dumazet March 30, 2012, 9:23 a.m. UTC | #1
Le vendredi 30 mars 2012 à 13:00 +0600, Mike Sinkovsky a écrit :
> Tested and used in production with Blackfin BF531 embedded processor.
> 
> Signed-off-by: Mike Sinkovsky <msink@permonline.ru>
> ---

> +
> +static int w5100_start_tx(struct sk_buff *skb, struct net_device *ndev)
> +{
> +	struct w5100_priv *priv = netdev_priv(ndev);
> +	u16 offset;
> +
> +	if (w5100_read16(priv, W5100_S0_TX_FSR) < skb->len) {

There is a race here.

Interrupt came come right here before you set the stop_queue()


> +		netif_stop_queue(ndev);

So Here I suggest adding a test again
	
	if (w5100_read16(priv, W5100_S0_TX_FSR) >= skb->len)
		netif_wake_queue(ndev);
	else
		return NETDEV_TX_BUSY;

> +		return NETDEV_TX_BUSY;
> +	}
> +
> +	offset = w5100_read16(priv, W5100_S0_TX_WR);
> +	w5100_writebuf(priv, offset, skb->data, skb->len);
> +	w5100_write16(priv, W5100_S0_TX_WR, offset + skb->len);
> +	w5100_command(priv, S0_CR_SEND);
> +	ndev->stats.tx_bytes += skb->len;
> +	ndev->stats.tx_packets++;
> +	dev_kfree_skb(skb);
> +
> +	return NETDEV_TX_OK;
> +}
> +



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Francois Romieu March 31, 2012, 9:40 a.m. UTC | #2
Eric Dumazet <eric.dumazet@gmail.com> :
> Le vendredi 30 mars 2012 ?? 13:00 +0600, Mike Sinkovsky a ??crit :
> > Tested and used in production with Blackfin BF531 embedded processor.
[...]
> > +static int w5100_start_tx(struct sk_buff *skb, struct net_device *ndev)
> > +{
> > +	struct w5100_priv *priv = netdev_priv(ndev);
> > +	u16 offset;
> > +
> > +	if (w5100_read16(priv, W5100_S0_TX_FSR) < skb->len) {
> 
> There is a race here.
> 
> Interrupt came come right here before you set the stop_queue()
> 
> 
> > +		netif_stop_queue(ndev);
> 
> So Here I suggest adding a test again
> 	
> 	if (w5100_read16(priv, W5100_S0_TX_FSR) >= skb->len)
> 		netif_wake_queue(ndev);
> 	else
> 		return NETDEV_TX_BUSY;

The start_tx logic seems broken anyway: it claims it always can take
packets until it is given one it can't process. The driver should rather
do the opposite and stop queueing as soon as there is no guarantee for
the next packet.
Francois Romieu March 31, 2012, 9:46 a.m. UTC | #3
Francois Romieu <romieu@fr.zoreil.com> :
[...]
> The start_tx logic seems broken anyway: it claims it always can take
> packets until it is given one it can't process. The driver should rather
> do the opposite and stop queueing as soon as there is no guarantee for
> the next packet.

Forget it: the driver stops queuing in this path anyway.
Mike Sinkovsky March 31, 2012, 9:52 a.m. UTC | #4
30.03.2012 15:23, Eric Dumazet написал:

>> +static int w5100_start_tx(struct sk_buff *skb, struct net_device *ndev)
>> +{
>> +	struct w5100_priv *priv = netdev_priv(ndev);
>> +	u16 offset;
>> +
>> +	if (w5100_read16(priv, W5100_S0_TX_FSR)<  skb->len) {
>
> There is a race here.
> Interrupt came come right here before you set the stop_queue()
>
>> +		netif_stop_queue(ndev);
>
> So Here I suggest adding a test again
> 	
> 	if (w5100_read16(priv, W5100_S0_TX_FSR)>= skb->len)
> 		netif_wake_queue(ndev);
> 	else
> 		return NETDEV_TX_BUSY;
>
>> +		return NETDEV_TX_BUSY;

Maybe, but I cannot test this, sorry - when I set breakpoint on this 
branch - it never triggered, on all my tests on all boards.
Appears that my processor is too slow and cannot feed packets fast enough.

But will do, maybe it triggers for someone on fastest processors.
Eric Dumazet March 31, 2012, 10:24 a.m. UTC | #5
On Sat, 2012-03-31 at 15:52 +0600, Mike Sinkovsky wrote:


> Maybe, but I cannot test this, sorry - when I set breakpoint on this 
> branch - it never triggered, on all my tests on all boards.
> Appears that my processor is too slow and cannot feed packets fast enough.

Really ?

A pktgen script should certainly hit your NIC limit, unless this is a
100Gbit link ...



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Mark Brown March 31, 2012, 9:23 p.m. UTC | #6
On Fri, Mar 30, 2012 at 01:00:06PM +0600, Mike Sinkovsky wrote:

> +config WIZNET_W5100
> +	tristate "WIZnet W5100 Ethernet support"
> +	depends on ARM || BLACKFIN

What are the architecture dependencies here?

> +static irqreturn_t w5100_interrupt(int irq, void *ndev_instance)
> +{
> +	struct net_device *ndev = ndev_instance;
> +	struct w5100_priv *priv = netdev_priv(ndev);
> +
> +	int ir = w5100_read(priv, W5100_S0_IR);
> +	w5100_write(priv, W5100_S0_IR, ir);
> +
> +	if (ir & S0_IR_RECV) {
> +		if (napi_schedule_prep(&priv->napi)) {
> +			w5100_write(priv, W5100_IMR, 0);
> +			mmiowb();
> +			__napi_schedule(&priv->napi);
> +		}
> +	}
> +
> +	if (ir & S0_IR_SENDOK) {
> +		if (unlikely(netif_queue_stopped(ndev)))
> +			netif_wake_queue(ndev);
> +	}
> +
> +	return IRQ_HANDLED;

This unconditionally acknowledges the interrupt even if one wasn't
reported by the device.

> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
> +	ret = devm_request_irq(&pdev->dev, irq, w5100_interrupt,
> +			       IRQ_TYPE_LEVEL_LOW, name, ndev);
> +	if (ret < 0)
> +		return ret;
> +	priv->irq = irq;
> +
> +	link = platform_get_resource(pdev, IORESOURCE_IO, 0);
> +	if (!link) {
> +		priv->link_gpio = -1;

This is rather an abuse of the resource API and will run into trouble on
device tree based systems.  You should use platform data for non-DT
systems.

> +		if (request_irq(priv->link_irq, w5100_detect_link,
> +				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> +				link_name, priv->ndev) < 0)

Suggest using request_any_context_irq() to increase the range of
supported interrupt controllers.

> +err_register:
> +	free_netdev(ndev);
> +	platform_set_drvdata(pdev, NULL);
> +	dev_info(&pdev->dev, "probe failed (%d)\n", err);

This will be done for you by the driver core.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Mike Sinkovsky April 2, 2012, 9:40 a.m. UTC | #7
01.04.2012 3:23, Mark Brown wrote:
> On Fri, Mar 30, 2012 at 01:00:06PM +0600, Mike Sinkovsky wrote:
>
>> +config WIZNET_W5100
>> +	tristate "WIZnet W5100 Ethernet support"
>> +	depends on ARM || BLACKFIN
>
> What are the architecture dependencies here?

Original driver from chip manufacturer was written for ARM, and now we 
use it on Blackfin.
Completely untested on other arch's, but should work. Maybe.


>> +static irqreturn_t w5100_interrupt(int irq, void *ndev_instance)
>> +{
>> +	struct net_device *ndev = ndev_instance;
>> +	struct w5100_priv *priv = netdev_priv(ndev);
>> +
>> +	int ir = w5100_read(priv, W5100_S0_IR);
>> +	w5100_write(priv, W5100_S0_IR, ir);
>> +
>> +	if (ir&  S0_IR_RECV) {
>> +		if (napi_schedule_prep(&priv->napi)) {
>> +			w5100_write(priv, W5100_IMR, 0);
>> +			mmiowb();
>> +			__napi_schedule(&priv->napi);
>> +		}
>> +	}
>> +
>> +	if (ir&  S0_IR_SENDOK) {
>> +		if (unlikely(netif_queue_stopped(ndev)))
>> +			netif_wake_queue(ndev);
>> +	}
>> +
>> +	return IRQ_HANDLED;
>
> This unconditionally acknowledges the interrupt even if one wasn't
> reported by the device.

Hm? Don't get you.
W5100_S0_IR register is R/W1C - writing back clears it.
Or what do you mean?


>> +	irq = platform_get_irq(pdev, 0);
>> +	if (irq<  0)
>> +		return irq;
>> +	ret = devm_request_irq(&pdev->dev, irq, w5100_interrupt,
>> +			       IRQ_TYPE_LEVEL_LOW, name, ndev);
>> +	if (ret<  0)
>> +		return ret;
>> +	priv->irq = irq;
>> +
>> +	link = platform_get_resource(pdev, IORESOURCE_IO, 0);
>> +	if (!link) {
>> +		priv->link_gpio = -1;
>
> This is rather an abuse of the resource API and will run into trouble on
> device tree based systems.  You should use platform data for non-DT
> systems.

Ok, will move it to struct wiznet_platform_data.
But here is downside - this gpio is optional, and if board doesn't have 
it - it must be initialized as negative value, not just omitted.


>> +		if (request_irq(priv->link_irq, w5100_detect_link,
>> +				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
>> +				link_name, priv->ndev)<  0)
>
> Suggest using request_any_context_irq() to increase the range of
> supported interrupt controllers.

Could it be anything but hard irq?
But there is another bug - it should be devm_request_irq...
:)


>> +err_register:
>> +	free_netdev(ndev);
>> +	platform_set_drvdata(pdev, NULL);
>> +	dev_info(&pdev->dev, "probe failed (%d)\n", err);
>
> This will be done for you by the driver core.

You mean platform_set_drvdata() and dev_info()? Maybe.
I'm sure platform_driver will not do free_netdev() for me.
Mark Brown April 2, 2012, 11:21 a.m. UTC | #8
On Mon, Apr 02, 2012 at 03:40:18PM +0600, Mike Sinkovsky wrote:
> 01.04.2012 3:23, Mark Brown wrote:
> >On Fri, Mar 30, 2012 at 01:00:06PM +0600, Mike Sinkovsky wrote:

> >>+config WIZNET_W5100
> >>+	tristate "WIZnet W5100 Ethernet support"
> >>+	depends on ARM || BLACKFIN

> >What are the architecture dependencies here?

> Original driver from chip manufacturer was written for ARM, and now
> we use it on Blackfin.
> Completely untested on other arch's, but should work. Maybe.

Remove the dependency then.  If there's an issue people can fix it.

> >>+static irqreturn_t w5100_interrupt(int irq, void *ndev_instance)
> >>+{
> >>+	struct net_device *ndev = ndev_instance;
> >>+	struct w5100_priv *priv = netdev_priv(ndev);
> >>+
> >>+	int ir = w5100_read(priv, W5100_S0_IR);
> >>+	w5100_write(priv, W5100_S0_IR, ir);
> >>+
> >>+	if (ir&  S0_IR_RECV) {
> >>+		if (napi_schedule_prep(&priv->napi)) {
> >>+			w5100_write(priv, W5100_IMR, 0);
> >>+			mmiowb();
> >>+			__napi_schedule(&priv->napi);
> >>+		}
> >>+	}
> >>+
> >>+	if (ir&  S0_IR_SENDOK) {
> >>+		if (unlikely(netif_queue_stopped(ndev)))
> >>+			netif_wake_queue(ndev);
> >>+	}
> >>+
> >>+	return IRQ_HANDLED;

> >This unconditionally acknowledges the interrupt even if one wasn't
> >reported by the device.

> Hm? Don't get you.
> W5100_S0_IR register is R/W1C - writing back clears it.
> Or what do you mean?

If you read back and no interrupts are flagged (all bits in the IRQ
status register clear) you'll still return IRQ_HANDLED.

> >This is rather an abuse of the resource API and will run into trouble on
> >device tree based systems.  You should use platform data for non-DT
> >systems.

> Ok, will move it to struct wiznet_platform_data.
> But here is downside - this gpio is optional, and if board doesn't
> have it - it must be initialized as negative value, not just
> omitted.

Sure, this is all totally standard to the Linux GPIO framework.
Realistically treating 0 as an invalid GPIO should be fine.

> >>+		if (request_irq(priv->link_irq, w5100_detect_link,
> >>+				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> >>+				link_name, priv->ndev)<  0)

> >Suggest using request_any_context_irq() to increase the range of
> >supported interrupt controllers.

> Could it be anything but hard irq?

It could be a threaded IRQ (if the interrupt controller can't be
accessed from hard IRQ context).

> >>+	platform_set_drvdata(pdev, NULL);
> >>+	dev_info(&pdev->dev, "probe failed (%d)\n", err);

> >This will be done for you by the driver core.

> You mean platform_set_drvdata() and dev_info()? Maybe.
> I'm sure platform_driver will not do free_netdev() for me.

The error logging.
diff mbox

Patch

diff --git a/drivers/net/ethernet/wiznet/Kconfig b/drivers/net/ethernet/wiznet/Kconfig
index 7ca5c95..8ad5bfa 100644
--- a/drivers/net/ethernet/wiznet/Kconfig
+++ b/drivers/net/ethernet/wiznet/Kconfig
@@ -17,6 +17,19 @@  config NET_VENDOR_WIZNET
 
 if NET_VENDOR_WIZNET
 
+config WIZNET_W5100
+	tristate "WIZnet W5100 Ethernet support"
+	depends on ARM || BLACKFIN
+	---help---
+	  Support for WIZnet W5100 chips.
+
+	  W5100 is a single chip with integrated 10/100 Ethernet MAC,
+	  PHY and hardware TCP/IP stack, but this driver is limited to
+	  the MAC and PHY functions only, onchip TCP/IP is unused.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called w5100.
+
 config WIZNET_W5300
 	tristate "WIZnet W5300 Ethernet support"
 	depends on ARM || BLACKFIN
diff --git a/drivers/net/ethernet/wiznet/Makefile b/drivers/net/ethernet/wiznet/Makefile
index 88e0a3e..c614535 100644
--- a/drivers/net/ethernet/wiznet/Makefile
+++ b/drivers/net/ethernet/wiznet/Makefile
@@ -1 +1,2 @@ 
+obj-$(CONFIG_WIZNET_W5100) += w5100.o
 obj-$(CONFIG_WIZNET_W5300) += w5300.o
diff --git a/drivers/net/ethernet/wiznet/w5100.c b/drivers/net/ethernet/wiznet/w5100.c
new file mode 100644
index 0000000..ce7dfba
--- /dev/null
+++ b/drivers/net/ethernet/wiznet/w5100.c
@@ -0,0 +1,799 @@ 
+/*
+ * Ethernet driver for the WIZnet W5100 chip.
+ *
+ * Copyright (C) 2006-2008 WIZnet Co.,Ltd.
+ * Copyright (C) 2012 Mike Sinkovsky <msink@permonline.ru>
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/wiznet.h>
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+
+#define DRV_NAME	"WIZnet W5100"
+#define DRV_VERSION	"2012-03-28"
+
+MODULE_DESCRIPTION(DRV_NAME" Ethernet driver v"DRV_VERSION);
+MODULE_AUTHOR("Mike Sinkovsky <msink@permonline.ru>");
+MODULE_ALIAS("platform:"KBUILD_MODNAME);
+MODULE_LICENSE("GPL");
+
+/*
+ * Registers
+ */
+#define W5100_COMM_REGS		0x0000
+#define W5100_MR		0x0000 /* Mode Register */
+#define   MR_RST		  0x80 /* S/W reset */
+#define   MR_PB			  0x10 /* Ping block */
+#define   MR_AI			  0x02 /* Address Auto-Increment */
+#define   MR_IND		  0x01 /* Indirect mode */
+#define W5100_SHAR		0x0009 /* Source MAC address */
+#define W5100_IR		0x0015 /* Interrupt */
+#define W5100_IMR		0x0016 /* Interrupt Mask */
+#define   IR_S0			  0x01 /* S0 interrupt */
+#define W5100_RTR		0x0017 /* Retry Time-value Register */
+#define   RTR_DEFAULT		  2000 /* =0x07d0 (2000) */
+#define W5100_RMSR		0x001a /* Receive memory size */
+#define W5100_TMSR		0x001b /* Transmit memory size */
+#define W5100_COMM_REGS_LEN	0x0040
+
+#define W5100_S0_REGS		0x0400
+#define W5100_S0_MR		0x0400 /* Socket Mode */
+#define   S0_MR_MACRAW		  0x04 /* MAC RAW mode (promiscous) */
+#define   S0_MR_MACRAW_MF	  0x44 /* MAC RAW mode (filtered) */
+#define W5100_S0_CR		0x0401 /* Socket Command */
+#define   S0_CR_OPEN		  0x01 /* OPEN command */
+#define   S0_CR_CLOSE		  0x10 /* CLOSE command */
+#define   S0_CR_SEND		  0x21 /* SEND command */
+#define   S0_CR_RECV		  0x40 /* RECV command */
+#define W5100_S0_IR		0x0402 /* Socket Interrupt */
+#define   S0_IR_SENDOK		  0x10 /* complete sending */
+#define   S0_IR_RECV		  0x04 /* receiving data */
+#define W5100_S0_SR		0x0403 /* Socket Status */
+#define   S0_SR_MACRAW		  0x42 /* mac raw mode socket */
+#define W5100_S0_TX_FSR		0x0420 /* Transmit free memory size */
+#define W5100_S0_TX_RD		0x0422 /* Transmit memory read pointer */
+#define W5100_S0_TX_WR		0x0424 /* Transmit memory write pointer */
+#define W5100_S0_RX_RSR		0x0426 /* Receive free memory size */
+#define W5100_S0_RX_RD		0x0428 /* Receive memory read pointer */
+#define W5100_S0_REGS_LEN	0x0040
+
+#define W5100_TX_MEM_START	0x4000
+#define W5100_TX_MEM_END	0x5fff
+#define W5100_TX_MEM_MASK	0x1fff
+#define W5100_RX_MEM_START	0x6000
+#define W5100_RX_MEM_END	0x7fff
+#define W5100_RX_MEM_MASK	0x1fff
+
+/*
+ * Device driver private data structure
+ */
+struct w5100_priv {
+	void __iomem *base;
+	bool indirect;
+	spinlock_t reg_lock;
+	u8   (*read)(struct w5100_priv *priv, u16 addr);
+	void (*write)(struct w5100_priv *priv, u16 addr, u8 data);
+	u16  (*read16)(struct w5100_priv *priv, u16 addr);
+	void (*write16)(struct w5100_priv *priv, u16 addr, u16 data);
+	void (*readbuf)(struct w5100_priv *priv, u16 addr, u8 *buf, int len);
+	void (*writebuf)(struct w5100_priv *priv, u16 addr, u8 *buf, int len);
+	int irq;
+	int link_irq;
+	int link_gpio;
+
+	struct napi_struct napi;
+	struct net_device *ndev;
+	bool promisc;
+	u32 msg_enable;
+};
+
+/************************************************************************
+ *
+ *  Lowlevel I/O functions
+ *
+ ***********************************************************************/
+
+/*
+ * In direct address mode host system can directly access W5100 registers
+ * after mapping to Memory-Mapped I/O space.
+ *
+ * 0x8000 bytes are required for memory space.
+ */
+static inline u8 w5100_read_direct(struct w5100_priv *priv, u16 addr)
+{
+	return ioread8(priv->base + (addr << CONFIG_WIZNET_BUS_SHIFT));
+}
+
+static inline void w5100_write_direct(struct w5100_priv *priv,
+				      u16 addr, u8 data)
+{
+	iowrite8(data, priv->base + (addr << CONFIG_WIZNET_BUS_SHIFT));
+}
+
+static u16 w5100_read16_direct(struct w5100_priv *priv, u16 addr)
+{
+	u16 ret;
+	ret  = w5100_read_direct(priv, addr) << 8;
+	ret |= w5100_read_direct(priv, addr + 1);
+	return ret;
+}
+
+static void w5100_write16_direct(struct w5100_priv *priv, u16 addr, u16 data)
+{
+	w5100_write_direct(priv, addr, data >> 8);
+	w5100_write_direct(priv, addr + 1, data);
+}
+
+static void w5100_readbuf_direct(struct w5100_priv *priv,
+				 u16 offset, u8 *buf, int len)
+{
+	u16 addr = W5100_RX_MEM_START + (offset & W5100_RX_MEM_MASK);
+	int i;
+
+	for (i = 0; i < len; i++, addr++) {
+		if (unlikely(addr > W5100_RX_MEM_END))
+			addr = W5100_RX_MEM_START;
+		*buf++ = w5100_read_direct(priv, addr);
+	}
+}
+
+static void w5100_writebuf_direct(struct w5100_priv *priv,
+				  u16 offset, u8 *buf, int len)
+{
+	u16 addr = W5100_TX_MEM_START + (offset & W5100_TX_MEM_MASK);
+	int i;
+
+	for (i = 0; i < len; i++, addr++) {
+		if (unlikely(addr > W5100_TX_MEM_END))
+			addr = W5100_TX_MEM_START;
+		w5100_write_direct(priv, addr, *buf++);
+	}
+}
+
+/*
+ * In indirect address mode host system indirectly accesses registers by
+ * using Indirect Mode Address Register (IDM_AR) and Indirect Mode Data
+ * Register (IDM_DR), which are directly mapped to Memory-Mapped I/O space.
+ * Mode Register (MR) is directly accessible.
+ *
+ * Only 0x04 bytes are required for memory space.
+ */
+#define W5100_IDM_AR		0x01   /* Indirect Mode Address Register */
+#define W5100_IDM_DR		0x03   /* Indirect Mode Data Register */
+
+static u8 w5100_read_indirect(struct w5100_priv *priv, u16 addr)
+{
+	unsigned long flags;
+	u8 data;
+
+	spin_lock_irqsave(&priv->reg_lock, flags);
+	w5100_write16_direct(priv, W5100_IDM_AR, addr);
+	mmiowb();
+	data = w5100_read_direct(priv, W5100_IDM_DR);
+	spin_unlock_irqrestore(&priv->reg_lock, flags);
+
+	return data;
+}
+
+static void w5100_write_indirect(struct w5100_priv *priv, u16 addr, u8 data)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->reg_lock, flags);
+	w5100_write16_direct(priv, W5100_IDM_AR, addr);
+	mmiowb();
+	w5100_write_direct(priv, W5100_IDM_DR, data);
+	mmiowb();
+	spin_unlock_irqrestore(&priv->reg_lock, flags);
+}
+
+static u16 w5100_read16_indirect(struct w5100_priv *priv, u16 addr)
+{
+	unsigned long flags;
+	u16 data;
+
+	spin_lock_irqsave(&priv->reg_lock, flags);
+	w5100_write16_direct(priv, W5100_IDM_AR, addr);
+	mmiowb();
+	data  = w5100_read_direct(priv, W5100_IDM_DR) << 8;
+	data |= w5100_read_direct(priv, W5100_IDM_DR);
+	spin_unlock_irqrestore(&priv->reg_lock, flags);
+
+	return data;
+}
+
+static void w5100_write16_indirect(struct w5100_priv *priv, u16 addr, u16 data)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->reg_lock, flags);
+	w5100_write16_direct(priv, W5100_IDM_AR, addr);
+	mmiowb();
+	w5100_write_direct(priv, W5100_IDM_DR, data >> 8);
+	w5100_write_direct(priv, W5100_IDM_DR, data);
+	mmiowb();
+	spin_unlock_irqrestore(&priv->reg_lock, flags);
+}
+
+static void w5100_readbuf_indirect(struct w5100_priv *priv,
+				   u16 offset, u8 *buf, int len)
+{
+	u16 addr = (offset & W5100_RX_MEM_MASK) + W5100_RX_MEM_START;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&priv->reg_lock, flags);
+	w5100_write16_direct(priv, W5100_IDM_AR, addr);
+	mmiowb();
+
+	for (i = 0; i < len; i++, addr++) {
+		if (unlikely(addr > W5100_RX_MEM_END)) {
+			addr = W5100_RX_MEM_START;
+			w5100_write16_direct(priv, W5100_IDM_AR, addr);
+			mmiowb();
+		}
+		*buf++ = w5100_read_direct(priv, W5100_IDM_DR);
+	}
+	mmiowb();
+	spin_unlock_irqrestore(&priv->reg_lock, flags);
+}
+
+static void w5100_writebuf_indirect(struct w5100_priv *priv,
+				    u16 offset, u8 *buf, int len)
+{
+	u16 addr = (offset & W5100_TX_MEM_MASK) + W5100_TX_MEM_START;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&priv->reg_lock, flags);
+	w5100_write16_direct(priv, W5100_IDM_AR, addr);
+	mmiowb();
+
+	for (i = 0; i < len; i++, addr++) {
+		if (unlikely(addr > W5100_TX_MEM_END)) {
+			addr = W5100_TX_MEM_START;
+			w5100_write16_direct(priv, W5100_IDM_AR, addr);
+			mmiowb();
+		}
+		w5100_write_direct(priv, W5100_IDM_DR, *buf++);
+	}
+	mmiowb();
+	spin_unlock_irqrestore(&priv->reg_lock, flags);
+}
+
+#if defined(CONFIG_WIZNET_BUS_DIRECT)
+#define w5100_read	w5100_read_direct
+#define w5100_write	w5100_write_direct
+#define w5100_read16	w5100_read16_direct
+#define w5100_write16	w5100_write16_direct
+#define w5100_readbuf	w5100_readbuf_direct
+#define w5100_writebuf	w5100_writebuf_direct
+
+#elif defined(CONFIG_WIZNET_BUS_INDIRECT)
+#define w5100_read	w5100_read_indirect
+#define w5100_write	w5100_write_indirect
+#define w5100_read16	w5100_read16_indirect
+#define w5100_write16	w5100_write16_indirect
+#define w5100_readbuf	w5100_readbuf_indirect
+#define w5100_writebuf	w5100_writebuf_indirect
+
+#else /* CONFIG_WIZNET_BUS_ANY */
+#define w5100_read	priv->read
+#define w5100_write	priv->write
+#define w5100_read16	priv->read16
+#define w5100_write16	priv->write16
+#define w5100_readbuf	priv->readbuf
+#define w5100_writebuf	priv->writebuf
+#endif
+
+static int w5100_command(struct w5100_priv *priv, u16 cmd)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(100);
+
+	w5100_write(priv, W5100_S0_CR, cmd);
+	mmiowb();
+
+	while (w5100_read(priv, W5100_S0_CR) != 0) {
+		if (time_after(jiffies, timeout))
+			return -EIO;
+		cpu_relax();
+	}
+
+	return 0;
+}
+
+static void w5100_write_macaddr(struct w5100_priv *priv)
+{
+	struct net_device *ndev = priv->ndev;
+	int i;
+
+	for (i = 0; i < ETH_ALEN; i++)
+		w5100_write(priv, W5100_SHAR + i, ndev->dev_addr[i]);
+	mmiowb();
+}
+
+static void w5100_hw_reset(struct w5100_priv *priv)
+{
+	w5100_write_direct(priv, W5100_MR, MR_RST);
+	mmiowb();
+	mdelay(5);
+	w5100_write_direct(priv, W5100_MR, priv->indirect ?
+				  MR_PB | MR_AI | MR_IND :
+				  MR_PB);
+	mmiowb();
+	w5100_write(priv, W5100_IMR, 0);
+	w5100_write_macaddr(priv);
+
+	/*
+	 * Configure 16K of internal memory
+	 * as 8K RX buffer and 8K TX buffer
+	 */
+	w5100_write(priv, W5100_RMSR, 0x03);
+	w5100_write(priv, W5100_TMSR, 0x03);
+	mmiowb();
+}
+
+static void w5100_hw_start(struct w5100_priv *priv)
+{
+	w5100_write(priv, W5100_S0_MR, priv->promisc ?
+			  S0_MR_MACRAW : S0_MR_MACRAW_MF);
+	w5100_command(priv, S0_CR_OPEN);
+	w5100_write(priv, W5100_IMR, IR_S0);
+	mmiowb();
+}
+
+static void w5100_hw_close(struct w5100_priv *priv)
+{
+	w5100_write(priv, W5100_IMR, 0);
+	mmiowb();
+	w5100_command(priv, S0_CR_CLOSE);
+}
+
+/***********************************************************************
+ *
+ *   Device driver functions / callbacks
+ *
+ ***********************************************************************/
+
+static void w5100_get_drvinfo(struct net_device *ndev,
+			      struct ethtool_drvinfo *info)
+{
+	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
+	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
+	strlcpy(info->bus_info, dev_name(ndev->dev.parent),
+		sizeof(info->bus_info));
+}
+
+static u32 w5100_get_link(struct net_device *ndev)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	if (priv->link_gpio < 0)
+		return 1;
+
+	return !!gpio_get_value(priv->link_gpio);
+}
+
+static u32 w5100_get_msglevel(struct net_device *ndev)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	return priv->msg_enable;
+}
+
+static void w5100_set_msglevel(struct net_device *ndev, u32 value)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	priv->msg_enable = value;
+}
+
+static int w5100_get_regs_len(struct net_device *ndev)
+{
+	return W5100_COMM_REGS_LEN + W5100_S0_REGS_LEN;
+}
+
+static void w5100_get_regs(struct net_device *ndev,
+			   struct ethtool_regs *regs, void *_buf)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+	u8 *buf = _buf;
+	u16 i;
+
+	regs->version = 1;
+	for (i = 0; i < W5100_COMM_REGS_LEN; i++)
+		*buf++ = w5100_read(priv, W5100_COMM_REGS + i);
+	for (i = 0; i < W5100_S0_REGS_LEN; i++)
+		*buf++ = w5100_read(priv, W5100_S0_REGS + i);
+}
+
+static void w5100_tx_timeout(struct net_device *ndev)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	netif_stop_queue(ndev);
+	w5100_hw_reset(priv);
+	w5100_hw_start(priv);
+	ndev->stats.tx_errors++;
+	ndev->trans_start = jiffies;
+	netif_wake_queue(ndev);
+}
+
+static int w5100_start_tx(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+	u16 offset;
+
+	if (w5100_read16(priv, W5100_S0_TX_FSR) < skb->len) {
+		netif_stop_queue(ndev);
+		return NETDEV_TX_BUSY;
+	}
+
+	offset = w5100_read16(priv, W5100_S0_TX_WR);
+	w5100_writebuf(priv, offset, skb->data, skb->len);
+	w5100_write16(priv, W5100_S0_TX_WR, offset + skb->len);
+	w5100_command(priv, S0_CR_SEND);
+	ndev->stats.tx_bytes += skb->len;
+	ndev->stats.tx_packets++;
+	dev_kfree_skb(skb);
+
+	return NETDEV_TX_OK;
+}
+
+static int w5100_napi_poll(struct napi_struct *napi, int budget)
+{
+	struct w5100_priv *priv = container_of(napi, struct w5100_priv, napi);
+	struct net_device *ndev = priv->ndev;
+	struct sk_buff *skb;
+	int rx_count;
+	u16 rx_len;
+	u16 offset;
+	u8 header[2];
+
+	for (rx_count = 0; rx_count < budget; rx_count++) {
+		u16 rx_buf_len = w5100_read16(priv, W5100_S0_RX_RSR);
+		if (rx_buf_len == 0)
+			break;
+
+		offset = w5100_read16(priv, W5100_S0_RX_RD);
+		w5100_readbuf(priv, offset, header, 2);
+		rx_len = get_unaligned_be16(header) - 2;
+
+		skb = netdev_alloc_skb_ip_align(ndev, rx_len);
+		if (unlikely(!skb)) {
+			w5100_write16(priv, W5100_S0_RX_RD,
+					    offset + rx_buf_len);
+			w5100_command(priv, S0_CR_RECV);
+			ndev->stats.rx_dropped++;
+			return -ENOMEM;
+		}
+
+		skb_put(skb, rx_len);
+		w5100_readbuf(priv, offset + 2, skb->data, rx_len);
+		w5100_write16(priv, W5100_S0_RX_RD, offset + 2 + rx_len);
+		mmiowb();
+		w5100_command(priv, S0_CR_RECV);
+		skb->protocol = eth_type_trans(skb, ndev);
+
+		netif_receive_skb(skb);
+		ndev->stats.rx_packets++;
+		ndev->stats.rx_bytes += rx_len;
+	}
+
+	if (rx_count < budget) {
+		w5100_write(priv, W5100_IMR, IR_S0);
+		mmiowb();
+		napi_complete(napi);
+	}
+
+	return rx_count;
+}
+
+static irqreturn_t w5100_interrupt(int irq, void *ndev_instance)
+{
+	struct net_device *ndev = ndev_instance;
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	int ir = w5100_read(priv, W5100_S0_IR);
+	w5100_write(priv, W5100_S0_IR, ir);
+
+	if (ir & S0_IR_RECV) {
+		if (napi_schedule_prep(&priv->napi)) {
+			w5100_write(priv, W5100_IMR, 0);
+			mmiowb();
+			__napi_schedule(&priv->napi);
+		}
+	}
+
+	if (ir & S0_IR_SENDOK) {
+		if (unlikely(netif_queue_stopped(ndev)))
+			netif_wake_queue(ndev);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t w5100_detect_link(int irq, void *ndev_instance)
+{
+	struct net_device *ndev = ndev_instance;
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	if (netif_running(ndev)) {
+		if (gpio_get_value(priv->link_gpio) != 0) {
+			netif_info(priv, link, ndev, "link is up\n");
+			netif_carrier_on(ndev);
+		} else {
+			netif_info(priv, link, ndev, "link is down\n");
+			netif_carrier_off(ndev);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void w5100_set_rx_mode(struct net_device *ndev)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+	bool set_promisc = (ndev->flags & IFF_PROMISC) != 0;
+
+	if (priv->promisc != set_promisc) {
+		priv->promisc = set_promisc;
+		w5100_hw_start(priv);
+	}
+}
+
+static int w5100_set_macaddr(struct net_device *ndev, void *addr)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+	struct sockaddr *sock_addr = addr;
+
+	if (!is_valid_ether_addr(sock_addr->sa_data))
+		return -EADDRNOTAVAIL;
+	memcpy(ndev->dev_addr, sock_addr->sa_data, ETH_ALEN);
+	ndev->addr_assign_type &= ~NET_ADDR_RANDOM;
+	w5100_write_macaddr(priv);
+	return 0;
+}
+
+static int w5100_open(struct net_device *ndev)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	netif_info(priv, ifup, ndev, "enabling\n");
+	if (!is_valid_ether_addr(ndev->dev_addr))
+		return -EINVAL;
+	w5100_hw_start(priv);
+	napi_enable(&priv->napi);
+	netif_start_queue(ndev);
+	if (priv->link_gpio < 0 || gpio_get_value(priv->link_gpio))
+		netif_carrier_on(ndev);
+	return 0;
+}
+
+static int w5100_stop(struct net_device *ndev)
+{
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	netif_info(priv, ifdown, ndev, "shutting down\n");
+	w5100_hw_close(priv);
+	netif_carrier_off(ndev);
+	netif_stop_queue(ndev);
+	napi_disable(&priv->napi);
+	return 0;
+}
+
+static const struct ethtool_ops w5100_ethtool_ops = {
+	.get_drvinfo		= w5100_get_drvinfo,
+	.get_msglevel		= w5100_get_msglevel,
+	.set_msglevel		= w5100_set_msglevel,
+	.get_link		= w5100_get_link,
+	.get_regs_len		= w5100_get_regs_len,
+	.get_regs		= w5100_get_regs,
+};
+
+static const struct net_device_ops w5100_netdev_ops = {
+	.ndo_open		= w5100_open,
+	.ndo_stop		= w5100_stop,
+	.ndo_start_xmit		= w5100_start_tx,
+	.ndo_tx_timeout		= w5100_tx_timeout,
+	.ndo_set_rx_mode	= w5100_set_rx_mode,
+	.ndo_set_mac_address	= w5100_set_macaddr,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_change_mtu		= eth_change_mtu,
+};
+
+static int __devinit w5100_hw_probe(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct w5100_priv *priv = netdev_priv(ndev);
+	const char *name = netdev_name(ndev);
+	struct resource *link;
+	struct resource *mem;
+	int mem_size;
+	int irq;
+	int ret;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem)
+		return -ENXIO;
+	mem_size = resource_size(mem);
+	if (!devm_request_mem_region(&pdev->dev, mem->start, mem_size, name))
+		return -EBUSY;
+	priv->base = devm_ioremap(&pdev->dev, mem->start, mem_size);
+	if (!priv->base)
+		return -EBUSY;
+
+	spin_lock_init(&priv->reg_lock);
+	priv->indirect = mem_size < W5100_BUS_DIRECT_SIZE;
+	if (priv->indirect) {
+		priv->read     = w5100_read_indirect;
+		priv->write    = w5100_write_indirect;
+		priv->read16   = w5100_read16_indirect;
+		priv->write16  = w5100_write16_indirect;
+		priv->readbuf  = w5100_readbuf_indirect;
+		priv->writebuf = w5100_writebuf_indirect;
+	} else {
+		priv->read     = w5100_read_direct;
+		priv->write    = w5100_write_direct;
+		priv->read16   = w5100_read16_direct;
+		priv->write16  = w5100_write16_direct;
+		priv->readbuf  = w5100_readbuf_direct;
+		priv->writebuf = w5100_writebuf_direct;
+	}
+	w5100_hw_reset(priv);
+	if (w5100_read16(priv, W5100_RTR) != RTR_DEFAULT)
+		return -ENODEV;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	ret = devm_request_irq(&pdev->dev, irq, w5100_interrupt,
+			       IRQ_TYPE_LEVEL_LOW, name, ndev);
+	if (ret < 0)
+		return ret;
+	priv->irq = irq;
+
+	link = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (!link) {
+		priv->link_gpio = -1;
+	} else {
+		char *link_name = devm_kzalloc(&pdev->dev, 16, GFP_KERNEL);
+		if (!link_name)
+			return -ENOMEM;
+		snprintf(link_name, 16, "%s-link", name);
+		priv->link_gpio = link->start;
+		priv->link_irq = gpio_to_irq(priv->link_gpio);
+		if (request_irq(priv->link_irq, w5100_detect_link,
+				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+				link_name, priv->ndev) < 0)
+			priv->link_gpio = -1;
+	}
+
+	netdev_info(ndev, "at 0x%llx irq %d\n", (u64)mem->start, irq);
+	return 0;
+}
+
+static int __devinit w5100_probe(struct platform_device *pdev)
+{
+	struct wiznet_platform_data *data = pdev->dev.platform_data;
+	struct w5100_priv *priv;
+	struct net_device *ndev;
+	int err;
+
+	ndev = alloc_etherdev(sizeof(*priv));
+	if (!ndev)
+		return -ENOMEM;
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+	platform_set_drvdata(pdev, ndev);
+	priv = netdev_priv(ndev);
+	priv->ndev = ndev;
+
+	ether_setup(ndev);
+	ndev->netdev_ops = &w5100_netdev_ops;
+	ndev->ethtool_ops = &w5100_ethtool_ops;
+	ndev->watchdog_timeo = 2 * HZ;
+	netif_napi_add(ndev, &priv->napi, w5100_napi_poll, 16);
+
+	/* This chip doesn't support VLAN packets with normal MTU,
+	 * so disable VLAN for this device.
+	 */
+	ndev->features |= NETIF_F_VLAN_CHALLENGED;
+
+	err = register_netdev(ndev);
+	if (err < 0)
+		goto err_register;
+
+	if (data && is_valid_ether_addr(data->mac_addr)) {
+		memcpy(ndev->dev_addr, data->mac_addr, ETH_ALEN);
+	} else {
+		random_ether_addr(ndev->dev_addr);
+		ndev->addr_assign_type |= NET_ADDR_RANDOM;
+	}
+	err = w5100_hw_probe(pdev);
+	if (err < 0)
+		goto err_hw_probe;
+
+	return 0;
+
+err_hw_probe:
+	unregister_netdev(ndev);
+err_register:
+	free_netdev(ndev);
+	platform_set_drvdata(pdev, NULL);
+	dev_info(&pdev->dev, "probe failed (%d)\n", err);
+	return err;
+}
+
+static int __devexit w5100_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+
+	unregister_netdev(ndev);
+	free_netdev(ndev);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int w5100_suspend(struct platform_device *pdev, pm_message_t mesg)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	if (netif_running(ndev)) {
+		netif_carrier_off(ndev);
+		netif_device_detach(ndev);
+
+		w5100_hw_close(priv);
+	}
+	return 0;
+}
+
+static int w5100_resume(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct w5100_priv *priv = netdev_priv(ndev);
+
+	if (netif_running(ndev)) {
+		w5100_hw_reset(priv);
+		w5100_hw_start(priv);
+
+		netif_device_attach(ndev);
+		if (priv->link_gpio < 0 || gpio_get_value(priv->link_gpio))
+			netif_carrier_on(ndev);
+	}
+	return 0;
+}
+#endif /* CONFIG_PM */
+
+static SIMPLE_DEV_PM_OPS(w5100_pm_ops, w5100_suspend, w5100_resume);
+
+static struct platform_driver w5100_driver = {
+	.driver		= {
+		.name	= KBUILD_MODNAME,
+		.owner	= THIS_MODULE,
+		.pm	= &w5100_pm_ops,
+	},
+	.probe		= w5100_probe,
+	.remove		= __devexit_p(w5100_remove),
+};
+
+module_platform_driver(w5100_driver);