UIO: add automata sercos3 pci card support

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>

UIO: add automata sercos3 pci card support
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>
John Ogness · Greg Kroah-Hartman
1 parent a6fcc3a196
Showing 3 changed files with 257 additions and 0 deletions Side-by-side Diff
drivers/uio/Kconfig
drivers/uio/Makefile
drivers/uio/uio_sercos3.c
@@ -58,5 +58,18 @@
  
 	  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
@@ -3,4 +3,5 @@
 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
+/* 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");
...	...	@@ -58,5 +58,18 @@
58	58
59	59	If you compile this as a module, it will be called uio_smx.
60	60
	61	+config UIO_SERCOS3
	62	+ tristate "Automata Sercos III PCI card driver"
	63	+ default n
	64	+ help
	65	+ Userspace I/O interface for the Sercos III PCI card from
	66	+ Automata GmbH. The userspace part of this driver will be
	67	+ available for download from the Automata GmbH web site.
	68	+
	69	+ Automata GmbH: http://www.automataweb.com
	70	+ Sercos III interface: http://www.sercos.com
	71	+
	72	+ If you compile this as a module, it will be called uio_sercos3.
	73	+
61	74	endif
...	...	@@ -3,4 +3,5 @@
3	3	obj-$(CONFIG_UIO_PDRV) += uio_pdrv.o
4	4	obj-$(CONFIG_UIO_PDRV_GENIRQ) += uio_pdrv_genirq.o
5	5	obj-$(CONFIG_UIO_SMX) += uio_smx.o
	6	+obj-$(CONFIG_UIO_SERCOS3) += uio_sercos3.o
	1	+/* sercos3: UIO driver for the Automata Sercos III PCI card
	2	+
	3	+ Copyright (C) 2008 Linutronix GmbH
	4	+ Author: John Ogness <john.ogness@linutronix.de>
	5	+
	6	+ This is a straight-forward UIO driver, where interrupts are disabled
	7	+ by the interrupt handler and re-enabled via a write to the UIO device
	8	+ by the userspace-part.
	9	+
	10	+ The only part that may seem odd is the use of a logical OR when
	11	+ storing and restoring enabled interrupts. This is done because the
	12	+ userspace-part could directly modify the Interrupt Enable Register
	13	+ at any time. To reduce possible conflicts, the kernel driver uses
	14	+ a logical OR to make more controlled changes (rather than blindly
	15	+ overwriting previous values).
	16	+
	17	+ Race conditions exist if the userspace-part directly modifies the
	18	+ Interrupt Enable Register while in operation. The consequences are
	19	+ that certain interrupts would fail to be enabled or disabled. For
	20	+ this reason, the userspace-part should only directly modify the
	21	+ Interrupt Enable Register at the beginning (to get things going).
	22	+ The userspace-part can safely disable interrupts at any time using
	23	+ a write to the UIO device.
	24	+*/
	25	+
	26	+#include <linux/device.h>
	27	+#include <linux/module.h>
	28	+#include <linux/pci.h>
	29	+#include <linux/uio_driver.h>
	30	+#include <linux/io.h>
	31	+
	32	+/* ID's for SERCOS III PCI card (PLX 9030) */
	33	+#define SERCOS_SUB_VENDOR_ID 0x1971
	34	+#define SERCOS_SUB_SYSID_3530 0x3530
	35	+#define SERCOS_SUB_SYSID_3535 0x3535
	36	+#define SERCOS_SUB_SYSID_3780 0x3780
	37	+
	38	+/* Interrupt Enable Register */
	39	+#define IER0_OFFSET 0x08
	40	+
	41	+/* Interrupt Status Register */
	42	+#define ISR0_OFFSET 0x18
	43	+
	44	+struct sercos3_priv {
	45	+ u32 ier0_cache;
	46	+ spinlock_t ier0_cache_lock;
	47	+};
	48	+
	49	+/* this function assumes ier0_cache_lock is locked! */
	50	+static void sercos3_disable_interrupts(struct uio_info *info,
	51	+ struct sercos3_priv *priv)
	52	+{
	53	+ void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
	54	+
	55	+ /* add enabled interrupts to cache */
	56	+ priv->ier0_cache \|= ioread32(ier0);
	57	+
	58	+ /* disable interrupts */
	59	+ iowrite32(0, ier0);
	60	+}
	61	+
	62	+/* this function assumes ier0_cache_lock is locked! */
	63	+static void sercos3_enable_interrupts(struct uio_info *info,
	64	+ struct sercos3_priv *priv)
	65	+{
	66	+ void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
	67	+
	68	+ /* restore previously enabled interrupts */
	69	+ iowrite32(ioread32(ier0) \| priv->ier0_cache, ier0);
	70	+ priv->ier0_cache = 0;
	71	+}
	72	+
	73	+static irqreturn_t sercos3_handler(int irq, struct uio_info *info)
	74	+{
	75	+ struct sercos3_priv *priv = info->priv;
	76	+ void __iomem *isr0 = info->mem[3].internal_addr + ISR0_OFFSET;
	77	+ void __iomem *ier0 = info->mem[3].internal_addr + IER0_OFFSET;
	78	+
	79	+ if (!(ioread32(isr0) & ioread32(ier0)))
	80	+ return IRQ_NONE;
	81	+
	82	+ spin_lock(&priv->ier0_cache_lock);
	83	+ sercos3_disable_interrupts(info, priv);
	84	+ spin_unlock(&priv->ier0_cache_lock);
	85	+
	86	+ return IRQ_HANDLED;
	87	+}
	88	+
	89	+static int sercos3_irqcontrol(struct uio_info *info, s32 irq_on)
	90	+{
	91	+ struct sercos3_priv *priv = info->priv;
	92	+
	93	+ spin_lock_irq(&priv->ier0_cache_lock);
	94	+ if (irq_on)
	95	+ sercos3_enable_interrupts(info, priv);
	96	+ else
	97	+ sercos3_disable_interrupts(info, priv);
	98	+ spin_unlock_irq(&priv->ier0_cache_lock);
	99	+
	100	+ return 0;
	101	+}
	102	+
	103	+static int sercos3_setup_iomem(struct pci_dev dev, struct uio_info info,
	104	+ int n, int pci_bar)
	105	+{
	106	+ info->mem[n].addr = pci_resource_start(dev, pci_bar);
	107	+ if (!info->mem[n].addr)
	108	+ return -1;
	109	+ info->mem[n].internal_addr = ioremap(pci_resource_start(dev, pci_bar),
	110	+ pci_resource_len(dev, pci_bar));
	111	+ if (!info->mem[n].internal_addr)
	112	+ return -1;
	113	+ info->mem[n].size = pci_resource_len(dev, pci_bar);
	114	+ info->mem[n].memtype = UIO_MEM_PHYS;
	115	+ return 0;
	116	+}
	117	+
	118	+static int __devinit sercos3_pci_probe(struct pci_dev *dev,
	119	+ const struct pci_device_id *id)
	120	+{
	121	+ struct uio_info *info;
	122	+ struct sercos3_priv *priv;
	123	+ int i;
	124	+
	125	+ info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
	126	+ if (!info)
	127	+ return -ENOMEM;
	128	+
	129	+ priv = kzalloc(sizeof(struct sercos3_priv), GFP_KERNEL);
	130	+ if (!priv)
	131	+ goto out_free;
	132	+
	133	+ if (pci_enable_device(dev))
	134	+ goto out_free_priv;
	135	+
	136	+ if (pci_request_regions(dev, "sercos3"))
	137	+ goto out_disable;
	138	+
	139	+ /* we only need PCI BAR's 0, 2, 3, 4, 5 */
	140	+ if (sercos3_setup_iomem(dev, info, 0, 0))
	141	+ goto out_unmap;
	142	+ if (sercos3_setup_iomem(dev, info, 1, 2))
	143	+ goto out_unmap;
	144	+ if (sercos3_setup_iomem(dev, info, 2, 3))
	145	+ goto out_unmap;
	146	+ if (sercos3_setup_iomem(dev, info, 3, 4))
	147	+ goto out_unmap;
	148	+ if (sercos3_setup_iomem(dev, info, 4, 5))
	149	+ goto out_unmap;
	150	+
	151	+ spin_lock_init(&priv->ier0_cache_lock);
	152	+ info->priv = priv;
	153	+ info->name = "Sercos_III_PCI";
	154	+ info->version = "0.0.1";
	155	+ info->irq = dev->irq;
	156	+ info->irq_flags = IRQF_DISABLED \| IRQF_SHARED;
	157	+ info->handler = sercos3_handler;
	158	+ info->irqcontrol = sercos3_irqcontrol;
	159	+
	160	+ pci_set_drvdata(dev, info);
	161	+
	162	+ if (uio_register_device(&dev->dev, info))
	163	+ goto out_unmap;
	164	+
	165	+ return 0;
	166	+
	167	+out_unmap:
	168	+ for (i = 0; i < 5; i++) {
	169	+ if (info->mem[i].internal_addr)
	170	+ iounmap(info->mem[i].internal_addr);
	171	+ }
	172	+ pci_release_regions(dev);
	173	+out_disable:
	174	+ pci_disable_device(dev);
	175	+out_free_priv:
	176	+ kfree(priv);
	177	+out_free:
	178	+ kfree(info);
	179	+ return -ENODEV;
	180	+}
	181	+
	182	+static void sercos3_pci_remove(struct pci_dev *dev)
	183	+{
	184	+ struct uio_info *info = pci_get_drvdata(dev);
	185	+ int i;
	186	+
	187	+ uio_unregister_device(info);
	188	+ pci_release_regions(dev);
	189	+ pci_disable_device(dev);
	190	+ pci_set_drvdata(dev, NULL);
	191	+ for (i = 0; i < 5; i++) {
	192	+ if (info->mem[i].internal_addr)
	193	+ iounmap(info->mem[i].internal_addr);
	194	+ }
	195	+ kfree(info->priv);
	196	+ kfree(info);
	197	+}
	198	+
	199	+static struct pci_device_id sercos3_pci_ids[] __devinitdata = {
	200	+ {
	201	+ .vendor = PCI_VENDOR_ID_PLX,
	202	+ .device = PCI_DEVICE_ID_PLX_9030,
	203	+ .subvendor = SERCOS_SUB_VENDOR_ID,
	204	+ .subdevice = SERCOS_SUB_SYSID_3530,
	205	+ },
	206	+ {
	207	+ .vendor = PCI_VENDOR_ID_PLX,
	208	+ .device = PCI_DEVICE_ID_PLX_9030,
	209	+ .subvendor = SERCOS_SUB_VENDOR_ID,
	210	+ .subdevice = SERCOS_SUB_SYSID_3535,
	211	+ },
	212	+ {
	213	+ .vendor = PCI_VENDOR_ID_PLX,
	214	+ .device = PCI_DEVICE_ID_PLX_9030,
	215	+ .subvendor = SERCOS_SUB_VENDOR_ID,
	216	+ .subdevice = SERCOS_SUB_SYSID_3780,
	217	+ },
	218	+ { 0, }
	219	+};
	220	+
	221	+static struct pci_driver sercos3_pci_driver = {
	222	+ .name = "sercos3",
	223	+ .id_table = sercos3_pci_ids,
	224	+ .probe = sercos3_pci_probe,
	225	+ .remove = sercos3_pci_remove,
	226	+};
	227	+
	228	+static int __init sercos3_init_module(void)
	229	+{
	230	+ return pci_register_driver(&sercos3_pci_driver);
	231	+}
	232	+
	233	+static void __exit sercos3_exit_module(void)
	234	+{
	235	+ pci_unregister_driver(&sercos3_pci_driver);
	236	+}
	237	+
	238	+module_init(sercos3_init_module);
	239	+module_exit(sercos3_exit_module);
	240	+
	241	+MODULE_DESCRIPTION("UIO driver for the Automata Sercos III PCI card");
	242	+MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>");
	243	+MODULE_LICENSE("GPL v2");