a6030fcc60
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> Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
243 lines
6.4 KiB
C
243 lines
6.4 KiB
C
/* 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");
|