[PATCHv2 1/1] uio: add automata sercos3 pci card support

[PATCHv2 1/1] uio: add automata sercos3 pci card support

[John Ogness]

This patch adds kernel-side support for the Sercos III PCI card from
Automata GmbH. An example of such a card can be found here:

http://www.automataweb.com/en/kat/uid_kategorien/0000119/id_matchcode/PCI_SERC_III/bop/0/print/false/chksum/9b334826704320c91437abc5c8ff48d1/beetools.html

Automata is currently working on getting the userspace-part organized
for easy download access and use. At the time of this writing, the
userspace-part is not yet available for download.

I wish to be personally CC'ed on answers/comments posted to the list
in response to this posting.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
 drivers/uio/Kconfig       |   13 ++
 drivers/uio/Makefile      |    1 
 drivers/uio/uio_sercos3.c |  229 ++++++++++++++++++++++++++++++++++++
 3 files changed, 243 insertions(+)
diff -uprN a/drivers/uio/Kconfig b/drivers/uio/Kconfig
--- a/drivers/uio/Kconfig	2008-09-15 15:39:32.000000000 +0200
+++ b/drivers/uio/Kconfig	2008-09-16 12:13:24.000000000 +0200
@@ -58,4 +58,17 @@ config UIO_SMX
 
 	  If you compile this as a module, it will be called uio_smx.
 
+config UIO_SERCOS3
+	tristate "Automata Sercos III PCI card driver"
+	default n
+	help
+	  Userspace I/O interface for the Sercos III PCI card from
+	  Automata GmbH. The userspace part of this driver will be
+	  available for download from the Automata GmbH web site.
+
+	  Automata GmbH:        http://www.automataweb.com
+	  Sercos III interface: http://www.sercos.com
+
+	  If you compile this as a module, it will be called uio_sercos3.
+
 endif
diff -uprN a/drivers/uio/Makefile b/drivers/uio/Makefile
--- a/drivers/uio/Makefile	2008-09-15 15:39:32.000000000 +0200
+++ b/drivers/uio/Makefile	2008-09-15 15:20:21.000000000 +0200
@@ -3,3 +3,4 @@ obj-$(CONFIG_UIO_CIF)	+= uio_cif.o
 obj-$(CONFIG_UIO_PDRV)	+= uio_pdrv.o
 obj-$(CONFIG_UIO_PDRV_GENIRQ)	+= uio_pdrv_genirq.o
 obj-$(CONFIG_UIO_SMX)	+= uio_smx.o
+obj-$(CONFIG_UIO_SERCOS3)	+= uio_sercos3.o
diff -uprN a/drivers/uio/uio_sercos3.c b/drivers/uio/uio_sercos3.c
--- a/drivers/uio/uio_sercos3.c	1970-01-01 01:00:00.000000000 +0100
+++ b/drivers/uio/uio_sercos3.c	2008-09-17 09:54:54.000000000 +0200
@@ -0,0 +1,229 @@
+/* sercos3: UIO driver for the Automata Sercos III PCI card
+
+   Copyright (C) 2008 Linutronix GmbH
+     Author: John Ogness <john.ogness@linutronix.de>
+*/
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/uio_driver.h>
+#include <linux/io.h>
+
+/* ID's for SERCOS III PCI card (PLX 9030) */
+#define SERCOS_SUB_VENDOR_ID  0x1971
+#define SERCOS_SUB_SYSID_3530 0x3530
+#define SERCOS_SUB_SYSID_3535 0x3535
+#define SERCOS_SUB_SYSID_3780 0x3780
+
+/* Interrupt Enable Register */
+#define IER0_OFFSET 0x08
+
+/* Interrupt Status Register */
+#define ISR0_OFFSET 0x18
+
+struct sercos3_priv {
+	u32 ier0_cache;
+	spinlock_t ier0_cache_lock;
+};
+
+/* this function assumes ier0_cache_lock is locked! */
+static void sercos3_disable_interrupts(struct uio_info *info,
+				       struct sercos3_priv *priv)
+{
+	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
+	u32 tmp = ioread32(ier0);
+
+	if (tmp) {
+		/* store previously enabled interrupts */
+		priv->ier0_cache |= tmp;
+
+		/* disable interrupts */
+		iowrite32(0, ier0);
+	}
+}
+
+/* this function assumes ier0_cache_lock is locked! */
+static void sercos3_enable_interrupts(struct uio_info *info,
+				      struct sercos3_priv *priv)
+{
+	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
+
+	if (priv->ier0_cache) {
+		/* restore previously enabled interrupts */
+		iowrite32(priv->ier0_cache, ier0);
+		priv->ier0_cache = 0;
+	}
+
+}
+
+static irqreturn_t sercos3_handler(int irq, struct uio_info *info)
+{
+	struct sercos3_priv *priv = info->priv;
+	void __iomem *isr0 = info->mem[3].internal_addr + ISR0_OFFSET;
+
+	if (!ioread32(isr0))
+		return IRQ_NONE;
+
+	spin_lock(&priv->ier0_cache_lock);
+	sercos3_disable_interrupts(info, priv);
+	spin_unlock(&priv->ier0_cache_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int sercos3_irqcontrol(struct uio_info *info, s32 irq_on)
+{
+	struct sercos3_priv *priv = info->priv;
+
+	spin_lock_irq(&priv->ier0_cache_lock);
+	if (irq_on)
+		sercos3_enable_interrupts(info, priv);
+	else
+		sercos3_disable_interrupts(info, priv);
+	spin_unlock_irq(&priv->ier0_cache_lock);
+
+	return 0;
+}
+
+static int sercos3_setup_iomem(struct pci_dev *dev, struct uio_info *info,
+			       int n, int pci_bar)
+{
+	info->mem[n].addr = pci_resource_start(dev, pci_bar);
+	if (!info->mem[n].addr)
+		return -1;
+	info->mem[n].internal_addr = ioremap(pci_resource_start(dev, pci_bar),
+					     pci_resource_len(dev, pci_bar));
+	if (!info->mem[n].internal_addr)
+		return -1;
+	info->mem[n].size = pci_resource_len(dev, pci_bar);
+	info->mem[n].memtype = UIO_MEM_PHYS;
+	return 0;
+}
+
+static int __devinit sercos3_pci_probe(struct pci_dev *dev,
+				       const struct pci_device_id *id)
+{
+	struct uio_info *info;
+	struct sercos3_priv *priv;
+	int i;
+
+	info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	priv = kzalloc(sizeof(struct sercos3_priv), GFP_KERNEL);
+	if (!priv)
+		goto out_free;
+
+	if (pci_enable_device(dev))
+		goto out_free_priv;
+
+	if (pci_request_regions(dev, "sercos3"))
+		goto out_disable;
+
+	/* we only need PCI BAR's 0, 2, 3, 4, 5 */
+	if (sercos3_setup_iomem(dev, info, 0, 0))
+		goto out_unmap;
+	if (sercos3_setup_iomem(dev, info, 1, 2))
+		goto out_unmap;
+	if (sercos3_setup_iomem(dev, info, 2, 3))
+		goto out_unmap;
+	if (sercos3_setup_iomem(dev, info, 3, 4))
+		goto out_unmap;
+	if (sercos3_setup_iomem(dev, info, 4, 5))
+		goto out_unmap;
+
+	spin_lock_init(&priv->ier0_cache_lock);
+	info->priv = priv;
+	info->name = "Sercos_III_PCI";
+	info->version = "0.0.1";
+	info->irq = dev->irq;
+	info->irq_flags = IRQF_DISABLED | IRQF_SHARED;
+	info->handler = sercos3_handler;
+	info->irqcontrol = sercos3_irqcontrol;
+
+	pci_set_drvdata(dev, info);
+
+	if (uio_register_device(&dev->dev, info))
+		goto out_unmap;
+
+	return 0;
+
+out_unmap:
+	for (i = 0; i < 5; i++) {
+		if (info->mem[i].internal_addr)
+			iounmap(info->mem[i].internal_addr);
+	}
+	pci_release_regions(dev);
+out_disable:
+	pci_disable_device(dev);
+out_free_priv:
+	kfree(priv);
+out_free:
+	kfree(info);
+	return -ENODEV;
+}
+
+static void sercos3_pci_remove(struct pci_dev *dev)
+{
+	struct uio_info *info = pci_get_drvdata(dev);
+	int i;
+
+	uio_unregister_device(info);
+	pci_release_regions(dev);
+	pci_disable_device(dev);
+	pci_set_drvdata(dev, NULL);
+	for (i = 0; i < 5; i++) {
+		if (info->mem[i].internal_addr)
+			iounmap(info->mem[i].internal_addr);
+	}
+	kfree(info->priv);
+	kfree(info);
+}
+
+static struct pci_device_id sercos3_pci_ids[] __devinitdata = {
+	{
+		.vendor =       PCI_VENDOR_ID_PLX,
+		.device =       PCI_DEVICE_ID_PLX_9030,
+		.subvendor =    SERCOS_SUB_VENDOR_ID,
+		.subdevice =    SERCOS_SUB_SYSID_3530,
+	},
+	{
+		.vendor =       PCI_VENDOR_ID_PLX,
+		.device =       PCI_DEVICE_ID_PLX_9030,
+		.subvendor =    SERCOS_SUB_VENDOR_ID,
+		.subdevice =    SERCOS_SUB_SYSID_3535,
+	},
+	{
+		.vendor =       PCI_VENDOR_ID_PLX,
+		.device =       PCI_DEVICE_ID_PLX_9030,
+		.subvendor =    SERCOS_SUB_VENDOR_ID,
+		.subdevice =    SERCOS_SUB_SYSID_3780,
+	},
+	{ 0, }
+};
+
+static struct pci_driver sercos3_pci_driver = {
+	.name = "sercos3",
+	.id_table = sercos3_pci_ids,
+	.probe = sercos3_pci_probe,
+	.remove = sercos3_pci_remove,
+};
+
+static int __init sercos3_init_module(void)
+{
+	return pci_register_driver(&sercos3_pci_driver);
+}
+
+static void __exit sercos3_exit_module(void)
+{
+	pci_unregister_driver(&sercos3_pci_driver);
+}
+
+module_init(sercos3_init_module);
+module_exit(sercos3_exit_module);
+
+MODULE_DESCRIPTION("UIO driver for the Automata Sercos III PCI card");
+MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>");
+MODULE_LICENSE("GPL v2");

Re: [PATCHv2 1/1] uio: add automata sercos3 pci card support

[Hans J. Koch]

On Wed, Sep 17, 2008 at 10:35:03AM +0200, John Ogness wrote:
> This patch adds kernel-side support for the Sercos III PCI card from
> Automata GmbH. An example of such a card can be found here:
> 
> http://www.automataweb.com/en/kat/uid_kategorien/0000119/id_matchcode/PCI_SERC_III/bop/0/print/false/chksum/9b334826704320c91437abc5c8ff48d1/beetools.html
> 
> Automata is currently working on getting the userspace-part organized
> for easy download access and use. At the time of this writing, the
> userspace-part is not yet available for download.

Hi John,
looks quite good. However, there seems to be a problem with shared
interrupts, see below. Could you please check?

Thanks,
Hans

> 
> I wish to be personally CC'ed on answers/comments posted to the list
> in response to this posting.
> 
> Signed-off-by: John Ogness <john.ogness@linutronix.de>
> ---
>  drivers/uio/Kconfig       |   13 ++
>  drivers/uio/Makefile      |    1 
>  drivers/uio/uio_sercos3.c |  229 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 243 insertions(+)
> diff -uprN a/drivers/uio/Kconfig b/drivers/uio/Kconfig
> --- a/drivers/uio/Kconfig	2008-09-15 15:39:32.000000000 +0200
> +++ b/drivers/uio/Kconfig	2008-09-16 12:13:24.000000000 +0200
> @@ -58,4 +58,17 @@ config UIO_SMX
>  
>  	  If you compile this as a module, it will be called uio_smx.
>  
> +config UIO_SERCOS3
> +	tristate "Automata Sercos III PCI card driver"
> +	default n
> +	help
> +	  Userspace I/O interface for the Sercos III PCI card from
> +	  Automata GmbH. The userspace part of this driver will be
> +	  available for download from the Automata GmbH web site.
> +
> +	  Automata GmbH:        http://www.automataweb.com
> +	  Sercos III interface: http://www.sercos.com
> +
> +	  If you compile this as a module, it will be called uio_sercos3.
> +
>  endif
> diff -uprN a/drivers/uio/Makefile b/drivers/uio/Makefile
> --- a/drivers/uio/Makefile	2008-09-15 15:39:32.000000000 +0200
> +++ b/drivers/uio/Makefile	2008-09-15 15:20:21.000000000 +0200
> @@ -3,3 +3,4 @@ obj-$(CONFIG_UIO_CIF)	+= uio_cif.o
>  obj-$(CONFIG_UIO_PDRV)	+= uio_pdrv.o
>  obj-$(CONFIG_UIO_PDRV_GENIRQ)	+= uio_pdrv_genirq.o
>  obj-$(CONFIG_UIO_SMX)	+= uio_smx.o
> +obj-$(CONFIG_UIO_SERCOS3)	+= uio_sercos3.o
> diff -uprN a/drivers/uio/uio_sercos3.c b/drivers/uio/uio_sercos3.c
> --- a/drivers/uio/uio_sercos3.c	1970-01-01 01:00:00.000000000 +0100
> +++ b/drivers/uio/uio_sercos3.c	2008-09-17 09:54:54.000000000 +0200
> @@ -0,0 +1,229 @@
> +/* sercos3: UIO driver for the Automata Sercos III PCI card
> +
> +   Copyright (C) 2008 Linutronix GmbH
> +     Author: John Ogness <john.ogness@linutronix.de>
> +*/
> +
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/uio_driver.h>
> +#include <linux/io.h>
> +
> +/* ID's for SERCOS III PCI card (PLX 9030) */
> +#define SERCOS_SUB_VENDOR_ID  0x1971
> +#define SERCOS_SUB_SYSID_3530 0x3530
> +#define SERCOS_SUB_SYSID_3535 0x3535
> +#define SERCOS_SUB_SYSID_3780 0x3780
> +
> +/* Interrupt Enable Register */
> +#define IER0_OFFSET 0x08
> +
> +/* Interrupt Status Register */
> +#define ISR0_OFFSET 0x18
> +
> +struct sercos3_priv {
> +	u32 ier0_cache;
> +	spinlock_t ier0_cache_lock;
> +};
> +
> +/* this function assumes ier0_cache_lock is locked! */
> +static void sercos3_disable_interrupts(struct uio_info *info,
> +				       struct sercos3_priv *priv)
> +{
> +	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
> +	u32 tmp = ioread32(ier0);
> +
> +	if (tmp) {

Is that needed?

> +		/* store previously enabled interrupts */
> +		priv->ier0_cache |= tmp;

This doesn't match the comment. Why |= and not a simple assignment?

> +
> +		/* disable interrupts */
> +		iowrite32(0, ier0);
> +	}
> +}
> +
> +/* this function assumes ier0_cache_lock is locked! */
> +static void sercos3_enable_interrupts(struct uio_info *info,
> +				      struct sercos3_priv *priv)
> +{
> +	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
> +
> +	if (priv->ier0_cache) {
> +		/* restore previously enabled interrupts */
> +		iowrite32(priv->ier0_cache, ier0);
> +		priv->ier0_cache = 0;
> +	}
> +
> +}
> +
> +static irqreturn_t sercos3_handler(int irq, struct uio_info *info)
> +{
> +	struct sercos3_priv *priv = info->priv;
> +	void __iomem *isr0 = info->mem[3].internal_addr + ISR0_OFFSET;
> +
> +	if (!ioread32(isr0))
> +		return IRQ_NONE;

If that card has an irq status and an irq enable register, you have to
check both. The status bit could be set, but the irq is not enabled, in
which case you have to return IRQ_NONE. Should look something like this:

	if (!(ier & isr))
		return IRQ_NONE;

This assumes the enable and corresponding status bits are in the same
bit position in the registers.

> +
> +	spin_lock(&priv->ier0_cache_lock);
> +	sercos3_disable_interrupts(info, priv);
> +	spin_unlock(&priv->ier0_cache_lock);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int sercos3_irqcontrol(struct uio_info *info, s32 irq_on)
> +{
> +	struct sercos3_priv *priv = info->priv;
> +
> +	spin_lock_irq(&priv->ier0_cache_lock);
> +	if (irq_on)
> +		sercos3_enable_interrupts(info, priv);
> +	else
> +		sercos3_disable_interrupts(info, priv);
> +	spin_unlock_irq(&priv->ier0_cache_lock);
> +
> +	return 0;
> +}
> +
> +static int sercos3_setup_iomem(struct pci_dev *dev, struct uio_info *info,
> +			       int n, int pci_bar)
> +{
> +	info->mem[n].addr = pci_resource_start(dev, pci_bar);
> +	if (!info->mem[n].addr)
> +		return -1;
> +	info->mem[n].internal_addr = ioremap(pci_resource_start(dev, pci_bar),
> +					     pci_resource_len(dev, pci_bar));
> +	if (!info->mem[n].internal_addr)
> +		return -1;
> +	info->mem[n].size = pci_resource_len(dev, pci_bar);
> +	info->mem[n].memtype = UIO_MEM_PHYS;
> +	return 0;
> +}
> +
> +static int __devinit sercos3_pci_probe(struct pci_dev *dev,
> +				       const struct pci_device_id *id)
> +{
> +	struct uio_info *info;
> +	struct sercos3_priv *priv;
> +	int i;
> +
> +	info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	priv = kzalloc(sizeof(struct sercos3_priv), GFP_KERNEL);
> +	if (!priv)
> +		goto out_free;
> +
> +	if (pci_enable_device(dev))
> +		goto out_free_priv;
> +
> +	if (pci_request_regions(dev, "sercos3"))
> +		goto out_disable;
> +
> +	/* we only need PCI BAR's 0, 2, 3, 4, 5 */
> +	if (sercos3_setup_iomem(dev, info, 0, 0))
> +		goto out_unmap;
> +	if (sercos3_setup_iomem(dev, info, 1, 2))
> +		goto out_unmap;
> +	if (sercos3_setup_iomem(dev, info, 2, 3))
> +		goto out_unmap;
> +	if (sercos3_setup_iomem(dev, info, 3, 4))
> +		goto out_unmap;
> +	if (sercos3_setup_iomem(dev, info, 4, 5))
> +		goto out_unmap;
> +
> +	spin_lock_init(&priv->ier0_cache_lock);
> +	info->priv = priv;
> +	info->name = "Sercos_III_PCI";
> +	info->version = "0.0.1";
> +	info->irq = dev->irq;
> +	info->irq_flags = IRQF_DISABLED | IRQF_SHARED;
> +	info->handler = sercos3_handler;
> +	info->irqcontrol = sercos3_irqcontrol;
> +
> +	pci_set_drvdata(dev, info);
> +
> +	if (uio_register_device(&dev->dev, info))
> +		goto out_unmap;
> +
> +	return 0;
> +
> +out_unmap:
> +	for (i = 0; i < 5; i++) {
> +		if (info->mem[i].internal_addr)
> +			iounmap(info->mem[i].internal_addr);
> +	}
> +	pci_release_regions(dev);
> +out_disable:
> +	pci_disable_device(dev);
> +out_free_priv:
> +	kfree(priv);
> +out_free:
> +	kfree(info);
> +	return -ENODEV;
> +}
> +
> +static void sercos3_pci_remove(struct pci_dev *dev)
> +{
> +	struct uio_info *info = pci_get_drvdata(dev);
> +	int i;
> +
> +	uio_unregister_device(info);
> +	pci_release_regions(dev);
> +	pci_disable_device(dev);
> +	pci_set_drvdata(dev, NULL);
> +	for (i = 0; i < 5; i++) {
> +		if (info->mem[i].internal_addr)
> +			iounmap(info->mem[i].internal_addr);
> +	}
> +	kfree(info->priv);
> +	kfree(info);
> +}
> +
> +static struct pci_device_id sercos3_pci_ids[] __devinitdata = {
> +	{
> +		.vendor =       PCI_VENDOR_ID_PLX,
> +		.device =       PCI_DEVICE_ID_PLX_9030,
> +		.subvendor =    SERCOS_SUB_VENDOR_ID,
> +		.subdevice =    SERCOS_SUB_SYSID_3530,
> +	},
> +	{
> +		.vendor =       PCI_VENDOR_ID_PLX,
> +		.device =       PCI_DEVICE_ID_PLX_9030,
> +		.subvendor =    SERCOS_SUB_VENDOR_ID,
> +		.subdevice =    SERCOS_SUB_SYSID_3535,
> +	},
> +	{
> +		.vendor =       PCI_VENDOR_ID_PLX,
> +		.device =       PCI_DEVICE_ID_PLX_9030,
> +		.subvendor =    SERCOS_SUB_VENDOR_ID,
> +		.subdevice =    SERCOS_SUB_SYSID_3780,
> +	},
> +	{ 0, }
> +};
> +
> +static struct pci_driver sercos3_pci_driver = {
> +	.name = "sercos3",
> +	.id_table = sercos3_pci_ids,
> +	.probe = sercos3_pci_probe,
> +	.remove = sercos3_pci_remove,
> +};
> +
> +static int __init sercos3_init_module(void)
> +{
> +	return pci_register_driver(&sercos3_pci_driver);
> +}
> +
> +static void __exit sercos3_exit_module(void)
> +{
> +	pci_unregister_driver(&sercos3_pci_driver);
> +}
> +
> +module_init(sercos3_init_module);
> +module_exit(sercos3_exit_module);
> +
> +MODULE_DESCRIPTION("UIO driver for the Automata Sercos III PCI card");
> +MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>");
> +MODULE_LICENSE("GPL v2");

Re: [PATCHv2 1/1] uio: add automata sercos3 pci card support

[John Ogness]

On 2008-09-17, Hans J. Koch <hjk@linutronix.de> wrote:
>> +/* this function assumes ier0_cache_lock is locked! */
>> +static void sercos3_disable_interrupts(struct uio_info *info,
>> +				       struct sercos3_priv *priv)
>> +{
>> +	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
>> +	u32 tmp = ioread32(ier0);
>> +
>> +	if (tmp) {
>
> Is that needed?

I check the value here for 2 reasons:

1. If the interrupts are already disabled, there is no need to perform
   an iowrite32().

2. If the interrupts are already disabled, we do not want to overwrite
   the ier0_cache with a 0.

Be aware that sercos3_disable_interrupts() can also be called via
sercos3_irqcontrol(). The official driver would never do this, but
maybe someone else would? (Your review of PATCHv1 insisted that
sercos3_irqcontrol() supports disabling the interrupt.) I don't want
to risk enabled interrupts getting lost (i.e. not being re-enabled
later).

>> +		/* store previously enabled interrupts */
>> +		priv->ier0_cache |= tmp;
>
> This doesn't match the comment. Why |= and not a simple assignment?

Here I was concerned that interrupts are being disabled but the
ier0_cache isn't empty. This situation would occur if the
userspace-driver manually enabled some interrupts before handling
pending interrupts.

Normally this would not happen, but since UIO-drivers deal with
context switches to userspace, I decided that it could be possible. So
I decided to |= the bitmask instead of overwriting it to prevent
enabled interrupts from getting lost.

I can change the comment to read:
        /* add enabled interrupts to cache */

>> +
>> +		/* disable interrupts */
>> +		iowrite32(0, ier0);
>> +	}
>> +}

[...]

>> +static irqreturn_t sercos3_handler(int irq, struct uio_info *info)
>> +{
>> +	struct sercos3_priv *priv = info->priv;
>> +	void __iomem *isr0 = info->mem[3].internal_addr + ISR0_OFFSET;
>> +
>> +	if (!ioread32(isr0))
>> +		return IRQ_NONE;
>
> If that card has an irq status and an irq enable register, you have
> to check both. The status bit could be set, but the irq is not
> enabled, in which case you have to return IRQ_NONE. Should look
> something like this:
>
> 	if (!(ier & isr))
> 		return IRQ_NONE;
>
> This assumes the enable and corresponding status bits are in the
> same bit position in the registers.

They are in the same bit position. For PATCHv3 I will change to code
to be:

        if (!(ioread32(isr0) & ioread32(ier0)))
                return IRQ_NONE;

>> +	spin_lock(&priv->ier0_cache_lock);
>> +	sercos3_disable_interrupts(info, priv);
>> +	spin_unlock(&priv->ier0_cache_lock);
>> +
>> +	return IRQ_HANDLED;
>> +}

[PATCHv3 1/1] uio: add automata sercos3 pci card support

[John Ogness]

Here is a new version of the patch to support the Automata Sercos III
PCI card driver. I now check that the IRQ is enabled before accepting
the interrupt.

I still use a logical OR to store the enabled interrupts and I've
added a second use of a logical OR when restoring the enabled
interrupts. I added an explanation of why I do this in comments at the
top of the source file.

Since I use a logical OR, I also removed the extra checks if the
Interrupt Enable Register and ier0_cache are 0.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
 drivers/uio/Kconfig       |   13 +
 drivers/uio/Makefile      |    1 
 drivers/uio/uio_sercos3.c |  243 ++++++++++++++++++++++++++++++++++++
 3 files changed, 257 insertions(+)
diff -uprN a/drivers/uio/Kconfig b/drivers/uio/Kconfig
--- a/drivers/uio/Kconfig	2008-09-17 10:25:40.000000000 +0200
+++ b/drivers/uio/Kconfig	2008-09-16 12:13:24.000000000 +0200
@@ -58,4 +58,17 @@ config UIO_SMX
 
 	  If you compile this as a module, it will be called uio_smx.
 
+config UIO_SERCOS3
+	tristate "Automata Sercos III PCI card driver"
+	default n
+	help
+	  Userspace I/O interface for the Sercos III PCI card from
+	  Automata GmbH. The userspace part of this driver will be
+	  available for download from the Automata GmbH web site.
+
+	  Automata GmbH:        http://www.automataweb.com
+	  Sercos III interface: http://www.sercos.com
+
+	  If you compile this as a module, it will be called uio_sercos3.
+
 endif
diff -uprN a/drivers/uio/Makefile b/drivers/uio/Makefile
--- a/drivers/uio/Makefile	2008-09-17 10:25:40.000000000 +0200
+++ b/drivers/uio/Makefile	2008-09-15 15:20:21.000000000 +0200
@@ -3,3 +3,4 @@ obj-$(CONFIG_UIO_CIF)	+= uio_cif.o
 obj-$(CONFIG_UIO_PDRV)	+= uio_pdrv.o
 obj-$(CONFIG_UIO_PDRV_GENIRQ)	+= uio_pdrv_genirq.o
 obj-$(CONFIG_UIO_SMX)	+= uio_smx.o
+obj-$(CONFIG_UIO_SERCOS3)	+= uio_sercos3.o
diff -uprN a/drivers/uio/uio_sercos3.c b/drivers/uio/uio_sercos3.c
--- a/drivers/uio/uio_sercos3.c	1970-01-01 01:00:00.000000000 +0100
+++ b/drivers/uio/uio_sercos3.c	2008-09-18 11:49:34.000000000 +0200
@@ -0,0 +1,243 @@
+/* sercos3: UIO driver for the Automata Sercos III PCI card
+
+   Copyright (C) 2008 Linutronix GmbH
+     Author: John Ogness <john.ogness@linutronix.de>
+
+   This is a straight-forward UIO driver, where interrupts are disabled
+   by the interrupt handler and re-enabled via a write to the UIO device
+   by the userspace-part.
+
+   The only part that may seem odd is the use of a logical OR when
+   storing and restoring enabled interrupts. This is done because the
+   userspace-part could directly modify the Interrupt Enable Register
+   at any time. To reduce possible conflicts, the kernel driver uses
+   a logical OR to make more controlled changes (rather than blindly
+   overwriting previous values).
+
+   Race conditions exist if the userspace-part directly modifies the
+   Interrupt Enable Register while in operation. The consequences are
+   that certain interrupts would fail to be enabled or disabled. For
+   this reason, the userspace-part should only directly modify the
+   Interrupt Enable Register at the beginning (to get things going).
+   The userspace-part can safely disable interrupts at any time using
+   a write to the UIO device.
+*/
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/uio_driver.h>
+#include <linux/io.h>
+
+/* ID's for SERCOS III PCI card (PLX 9030) */
+#define SERCOS_SUB_VENDOR_ID  0x1971
+#define SERCOS_SUB_SYSID_3530 0x3530
+#define SERCOS_SUB_SYSID_3535 0x3535
+#define SERCOS_SUB_SYSID_3780 0x3780
+
+/* Interrupt Enable Register */
+#define IER0_OFFSET 0x08
+
+/* Interrupt Status Register */
+#define ISR0_OFFSET 0x18
+
+struct sercos3_priv {
+	u32 ier0_cache;
+	spinlock_t ier0_cache_lock;
+};
+
+/* this function assumes ier0_cache_lock is locked! */
+static void sercos3_disable_interrupts(struct uio_info *info,
+				       struct sercos3_priv *priv)
+{
+	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
+
+	/* add enabled interrupts to cache */
+	priv->ier0_cache |= ioread32(ier0);
+
+	/* disable interrupts */
+	iowrite32(0, ier0);
+}
+
+/* this function assumes ier0_cache_lock is locked! */
+static void sercos3_enable_interrupts(struct uio_info *info,
+				      struct sercos3_priv *priv)
+{
+	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
+
+	/* restore previously enabled interrupts */
+	iowrite32(ioread32(ier0) | priv->ier0_cache, ier0);
+	priv->ier0_cache = 0;
+}
+
+static irqreturn_t sercos3_handler(int irq, struct uio_info *info)
+{
+	struct sercos3_priv *priv = info->priv;
+	void __iomem *isr0 = info->mem[3].internal_addr + ISR0_OFFSET;
+	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
+
+	if (!(ioread32(isr0) & ioread32(ier0)))
+		return IRQ_NONE;
+
+	spin_lock(&priv->ier0_cache_lock);
+	sercos3_disable_interrupts(info, priv);
+	spin_unlock(&priv->ier0_cache_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int sercos3_irqcontrol(struct uio_info *info, s32 irq_on)
+{
+	struct sercos3_priv *priv = info->priv;
+
+	spin_lock_irq(&priv->ier0_cache_lock);
+	if (irq_on)
+		sercos3_enable_interrupts(info, priv);
+	else
+		sercos3_disable_interrupts(info, priv);
+	spin_unlock_irq(&priv->ier0_cache_lock);
+
+	return 0;
+}
+
+static int sercos3_setup_iomem(struct pci_dev *dev, struct uio_info *info,
+			       int n, int pci_bar)
+{
+	info->mem[n].addr = pci_resource_start(dev, pci_bar);
+	if (!info->mem[n].addr)
+		return -1;
+	info->mem[n].internal_addr = ioremap(pci_resource_start(dev, pci_bar),
+					     pci_resource_len(dev, pci_bar));
+	if (!info->mem[n].internal_addr)
+		return -1;
+	info->mem[n].size = pci_resource_len(dev, pci_bar);
+	info->mem[n].memtype = UIO_MEM_PHYS;
+	return 0;
+}
+
+static int __devinit sercos3_pci_probe(struct pci_dev *dev,
+				       const struct pci_device_id *id)
+{
+	struct uio_info *info;
+	struct sercos3_priv *priv;
+	int i;
+
+	info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	priv = kzalloc(sizeof(struct sercos3_priv), GFP_KERNEL);
+	if (!priv)
+		goto out_free;
+
+	if (pci_enable_device(dev))
+		goto out_free_priv;
+
+	if (pci_request_regions(dev, "sercos3"))
+		goto out_disable;
+
+	/* we only need PCI BAR's 0, 2, 3, 4, 5 */
+	if (sercos3_setup_iomem(dev, info, 0, 0))
+		goto out_unmap;
+	if (sercos3_setup_iomem(dev, info, 1, 2))
+		goto out_unmap;
+	if (sercos3_setup_iomem(dev, info, 2, 3))
+		goto out_unmap;
+	if (sercos3_setup_iomem(dev, info, 3, 4))
+		goto out_unmap;
+	if (sercos3_setup_iomem(dev, info, 4, 5))
+		goto out_unmap;
+
+	spin_lock_init(&priv->ier0_cache_lock);
+	info->priv = priv;
+	info->name = "Sercos_III_PCI";
+	info->version = "0.0.1";
+	info->irq = dev->irq;
+	info->irq_flags = IRQF_DISABLED | IRQF_SHARED;
+	info->handler = sercos3_handler;
+	info->irqcontrol = sercos3_irqcontrol;
+
+	pci_set_drvdata(dev, info);
+
+	if (uio_register_device(&dev->dev, info))
+		goto out_unmap;
+
+	return 0;
+
+out_unmap:
+	for (i = 0; i < 5; i++) {
+		if (info->mem[i].internal_addr)
+			iounmap(info->mem[i].internal_addr);
+	}
+	pci_release_regions(dev);
+out_disable:
+	pci_disable_device(dev);
+out_free_priv:
+	kfree(priv);
+out_free:
+	kfree(info);
+	return -ENODEV;
+}
+
+static void sercos3_pci_remove(struct pci_dev *dev)
+{
+	struct uio_info *info = pci_get_drvdata(dev);
+	int i;
+
+	uio_unregister_device(info);
+	pci_release_regions(dev);
+	pci_disable_device(dev);
+	pci_set_drvdata(dev, NULL);
+	for (i = 0; i < 5; i++) {
+		if (info->mem[i].internal_addr)
+			iounmap(info->mem[i].internal_addr);
+	}
+	kfree(info->priv);
+	kfree(info);
+}
+
+static struct pci_device_id sercos3_pci_ids[] __devinitdata = {
+	{
+		.vendor =       PCI_VENDOR_ID_PLX,
+		.device =       PCI_DEVICE_ID_PLX_9030,
+		.subvendor =    SERCOS_SUB_VENDOR_ID,
+		.subdevice =    SERCOS_SUB_SYSID_3530,
+	},
+	{
+		.vendor =       PCI_VENDOR_ID_PLX,
+		.device =       PCI_DEVICE_ID_PLX_9030,
+		.subvendor =    SERCOS_SUB_VENDOR_ID,
+		.subdevice =    SERCOS_SUB_SYSID_3535,
+	},
+	{
+		.vendor =       PCI_VENDOR_ID_PLX,
+		.device =       PCI_DEVICE_ID_PLX_9030,
+		.subvendor =    SERCOS_SUB_VENDOR_ID,
+		.subdevice =    SERCOS_SUB_SYSID_3780,
+	},
+	{ 0, }
+};
+
+static struct pci_driver sercos3_pci_driver = {
+	.name = "sercos3",
+	.id_table = sercos3_pci_ids,
+	.probe = sercos3_pci_probe,
+	.remove = sercos3_pci_remove,
+};
+
+static int __init sercos3_init_module(void)
+{
+	return pci_register_driver(&sercos3_pci_driver);
+}
+
+static void __exit sercos3_exit_module(void)
+{
+	pci_unregister_driver(&sercos3_pci_driver);
+}
+
+module_init(sercos3_init_module);
+module_exit(sercos3_exit_module);
+
+MODULE_DESCRIPTION("UIO driver for the Automata Sercos III PCI card");
+MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>");
+MODULE_LICENSE("GPL v2");

Re: [PATCHv3 1/1] uio: add automata sercos3 pci card support

[Hans J. Koch]

On Thu, Sep 18, 2008 at 11:57:15AM +0200, John Ogness wrote:
> Here is a new version of the patch to support the Automata Sercos III
> PCI card driver. I now check that the IRQ is enabled before accepting
> the interrupt.

Fine ;-)

> 
> I still use a logical OR to store the enabled interrupts and I've
> added a second use of a logical OR when restoring the enabled
> interrupts. I added an explanation of why I do this in comments at the
> top of the source file.

Good, thanks.

> 
> Since I use a logical OR, I also removed the extra checks if the
> Interrupt Enable Register and ier0_cache are 0.

Greg, could you please add this v3 of the patch to your tree?

John tested this on a VIA C3 with a test program causing 4000 irqs per
second, it works fine.

> 
> Signed-off-by: John Ogness <john.ogness@linutronix.de>

Signed-off-by: Hans J. Koch <hjk@linutronix.de>

> ---
>  drivers/uio/Kconfig       |   13 +
>  drivers/uio/Makefile      |    1 
>  drivers/uio/uio_sercos3.c |  243 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 257 insertions(+)
> diff -uprN a/drivers/uio/Kconfig b/drivers/uio/Kconfig
> --- a/drivers/uio/Kconfig	2008-09-17 10:25:40.000000000 +0200
> +++ b/drivers/uio/Kconfig	2008-09-16 12:13:24.000000000 +0200
> @@ -58,4 +58,17 @@ config UIO_SMX
>  
>  	  If you compile this as a module, it will be called uio_smx.
>  
> +config UIO_SERCOS3
> +	tristate "Automata Sercos III PCI card driver"
> +	default n
> +	help
> +	  Userspace I/O interface for the Sercos III PCI card from
> +	  Automata GmbH. The userspace part of this driver will be
> +	  available for download from the Automata GmbH web site.
> +
> +	  Automata GmbH:        http://www.automataweb.com
> +	  Sercos III interface: http://www.sercos.com
> +
> +	  If you compile this as a module, it will be called uio_sercos3.
> +
>  endif
> diff -uprN a/drivers/uio/Makefile b/drivers/uio/Makefile
> --- a/drivers/uio/Makefile	2008-09-17 10:25:40.000000000 +0200
> +++ b/drivers/uio/Makefile	2008-09-15 15:20:21.000000000 +0200
> @@ -3,3 +3,4 @@ obj-$(CONFIG_UIO_CIF)	+= uio_cif.o
>  obj-$(CONFIG_UIO_PDRV)	+= uio_pdrv.o
>  obj-$(CONFIG_UIO_PDRV_GENIRQ)	+= uio_pdrv_genirq.o
>  obj-$(CONFIG_UIO_SMX)	+= uio_smx.o
> +obj-$(CONFIG_UIO_SERCOS3)	+= uio_sercos3.o
> diff -uprN a/drivers/uio/uio_sercos3.c b/drivers/uio/uio_sercos3.c
> --- a/drivers/uio/uio_sercos3.c	1970-01-01 01:00:00.000000000 +0100
> +++ b/drivers/uio/uio_sercos3.c	2008-09-18 11:49:34.000000000 +0200
> @@ -0,0 +1,243 @@
> +/* sercos3: UIO driver for the Automata Sercos III PCI card
> +
> +   Copyright (C) 2008 Linutronix GmbH
> +     Author: John Ogness <john.ogness@linutronix.de>
> +
> +   This is a straight-forward UIO driver, where interrupts are disabled
> +   by the interrupt handler and re-enabled via a write to the UIO device
> +   by the userspace-part.
> +
> +   The only part that may seem odd is the use of a logical OR when
> +   storing and restoring enabled interrupts. This is done because the
> +   userspace-part could directly modify the Interrupt Enable Register
> +   at any time. To reduce possible conflicts, the kernel driver uses
> +   a logical OR to make more controlled changes (rather than blindly
> +   overwriting previous values).
> +
> +   Race conditions exist if the userspace-part directly modifies the
> +   Interrupt Enable Register while in operation. The consequences are
> +   that certain interrupts would fail to be enabled or disabled. For
> +   this reason, the userspace-part should only directly modify the
> +   Interrupt Enable Register at the beginning (to get things going).
> +   The userspace-part can safely disable interrupts at any time using
> +   a write to the UIO device.
> +*/
> +
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/uio_driver.h>
> +#include <linux/io.h>
> +
> +/* ID's for SERCOS III PCI card (PLX 9030) */
> +#define SERCOS_SUB_VENDOR_ID  0x1971
> +#define SERCOS_SUB_SYSID_3530 0x3530
> +#define SERCOS_SUB_SYSID_3535 0x3535
> +#define SERCOS_SUB_SYSID_3780 0x3780
> +
> +/* Interrupt Enable Register */
> +#define IER0_OFFSET 0x08
> +
> +/* Interrupt Status Register */
> +#define ISR0_OFFSET 0x18
> +
> +struct sercos3_priv {
> +	u32 ier0_cache;
> +	spinlock_t ier0_cache_lock;
> +};
> +
> +/* this function assumes ier0_cache_lock is locked! */
> +static void sercos3_disable_interrupts(struct uio_info *info,
> +				       struct sercos3_priv *priv)
> +{
> +	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
> +
> +	/* add enabled interrupts to cache */
> +	priv->ier0_cache |= ioread32(ier0);
> +
> +	/* disable interrupts */
> +	iowrite32(0, ier0);
> +}
> +
> +/* this function assumes ier0_cache_lock is locked! */
> +static void sercos3_enable_interrupts(struct uio_info *info,
> +				      struct sercos3_priv *priv)
> +{
> +	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
> +
> +	/* restore previously enabled interrupts */
> +	iowrite32(ioread32(ier0) | priv->ier0_cache, ier0);
> +	priv->ier0_cache = 0;
> +}
> +
> +static irqreturn_t sercos3_handler(int irq, struct uio_info *info)
> +{
> +	struct sercos3_priv *priv = info->priv;
> +	void __iomem *isr0 = info->mem[3].internal_addr + ISR0_OFFSET;
> +	void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
> +
> +	if (!(ioread32(isr0) & ioread32(ier0)))
> +		return IRQ_NONE;
> +
> +	spin_lock(&priv->ier0_cache_lock);
> +	sercos3_disable_interrupts(info, priv);
> +	spin_unlock(&priv->ier0_cache_lock);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int sercos3_irqcontrol(struct uio_info *info, s32 irq_on)
> +{
> +	struct sercos3_priv *priv = info->priv;
> +
> +	spin_lock_irq(&priv->ier0_cache_lock);
> +	if (irq_on)
> +		sercos3_enable_interrupts(info, priv);
> +	else
> +		sercos3_disable_interrupts(info, priv);
> +	spin_unlock_irq(&priv->ier0_cache_lock);
> +
> +	return 0;
> +}
> +
> +static int sercos3_setup_iomem(struct pci_dev *dev, struct uio_info *info,
> +			       int n, int pci_bar)
> +{
> +	info->mem[n].addr = pci_resource_start(dev, pci_bar);
> +	if (!info->mem[n].addr)
> +		return -1;
> +	info->mem[n].internal_addr = ioremap(pci_resource_start(dev, pci_bar),
> +					     pci_resource_len(dev, pci_bar));
> +	if (!info->mem[n].internal_addr)
> +		return -1;
> +	info->mem[n].size = pci_resource_len(dev, pci_bar);
> +	info->mem[n].memtype = UIO_MEM_PHYS;
> +	return 0;
> +}
> +
> +static int __devinit sercos3_pci_probe(struct pci_dev *dev,
> +				       const struct pci_device_id *id)
> +{
> +	struct uio_info *info;
> +	struct sercos3_priv *priv;
> +	int i;
> +
> +	info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	priv = kzalloc(sizeof(struct sercos3_priv), GFP_KERNEL);
> +	if (!priv)
> +		goto out_free;
> +
> +	if (pci_enable_device(dev))
> +		goto out_free_priv;
> +
> +	if (pci_request_regions(dev, "sercos3"))
> +		goto out_disable;
> +
> +	/* we only need PCI BAR's 0, 2, 3, 4, 5 */
> +	if (sercos3_setup_iomem(dev, info, 0, 0))
> +		goto out_unmap;
> +	if (sercos3_setup_iomem(dev, info, 1, 2))
> +		goto out_unmap;
> +	if (sercos3_setup_iomem(dev, info, 2, 3))
> +		goto out_unmap;
> +	if (sercos3_setup_iomem(dev, info, 3, 4))
> +		goto out_unmap;
> +	if (sercos3_setup_iomem(dev, info, 4, 5))
> +		goto out_unmap;
> +
> +	spin_lock_init(&priv->ier0_cache_lock);
> +	info->priv = priv;
> +	info->name = "Sercos_III_PCI";
> +	info->version = "0.0.1";
> +	info->irq = dev->irq;
> +	info->irq_flags = IRQF_DISABLED | IRQF_SHARED;
> +	info->handler = sercos3_handler;
> +	info->irqcontrol = sercos3_irqcontrol;
> +
> +	pci_set_drvdata(dev, info);
> +
> +	if (uio_register_device(&dev->dev, info))
> +		goto out_unmap;
> +
> +	return 0;
> +
> +out_unmap:
> +	for (i = 0; i < 5; i++) {
> +		if (info->mem[i].internal_addr)
> +			iounmap(info->mem[i].internal_addr);
> +	}
> +	pci_release_regions(dev);
> +out_disable:
> +	pci_disable_device(dev);
> +out_free_priv:
> +	kfree(priv);
> +out_free:
> +	kfree(info);
> +	return -ENODEV;
> +}
> +
> +static void sercos3_pci_remove(struct pci_dev *dev)
> +{
> +	struct uio_info *info = pci_get_drvdata(dev);
> +	int i;
> +
> +	uio_unregister_device(info);
> +	pci_release_regions(dev);
> +	pci_disable_device(dev);
> +	pci_set_drvdata(dev, NULL);
> +	for (i = 0; i < 5; i++) {
> +		if (info->mem[i].internal_addr)
> +			iounmap(info->mem[i].internal_addr);
> +	}
> +	kfree(info->priv);
> +	kfree(info);
> +}
> +
> +static struct pci_device_id sercos3_pci_ids[] __devinitdata = {
> +	{
> +		.vendor =       PCI_VENDOR_ID_PLX,
> +		.device =       PCI_DEVICE_ID_PLX_9030,
> +		.subvendor =    SERCOS_SUB_VENDOR_ID,
> +		.subdevice =    SERCOS_SUB_SYSID_3530,
> +	},
> +	{
> +		.vendor =       PCI_VENDOR_ID_PLX,
> +		.device =       PCI_DEVICE_ID_PLX_9030,
> +		.subvendor =    SERCOS_SUB_VENDOR_ID,
> +		.subdevice =    SERCOS_SUB_SYSID_3535,
> +	},
> +	{
> +		.vendor =       PCI_VENDOR_ID_PLX,
> +		.device =       PCI_DEVICE_ID_PLX_9030,
> +		.subvendor =    SERCOS_SUB_VENDOR_ID,
> +		.subdevice =    SERCOS_SUB_SYSID_3780,
> +	},
> +	{ 0, }
> +};
> +
> +static struct pci_driver sercos3_pci_driver = {
> +	.name = "sercos3",
> +	.id_table = sercos3_pci_ids,
> +	.probe = sercos3_pci_probe,
> +	.remove = sercos3_pci_remove,
> +};
> +
> +static int __init sercos3_init_module(void)
> +{
> +	return pci_register_driver(&sercos3_pci_driver);
> +}
> +
> +static void __exit sercos3_exit_module(void)
> +{
> +	pci_unregister_driver(&sercos3_pci_driver);
> +}
> +
> +module_init(sercos3_init_module);
> +module_exit(sercos3_exit_module);
> +
> +MODULE_DESCRIPTION("UIO driver for the Automata Sercos III PCI card");
> +MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>");
> +MODULE_LICENSE("GPL v2");