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John Ognessa6030fcc2008-09-18 11:57:15 +02001/* 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
44struct sercos3_priv {
45 u32 ier0_cache;
46 spinlock_t ier0_cache_lock;
47};
48
49/* this function assumes ier0_cache_lock is locked! */
50static 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! */
63static 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
73static 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
89static 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
103static 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
118static 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
167out_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);
173out_disable:
174 pci_disable_device(dev);
175out_free_priv:
176 kfree(priv);
177out_free:
178 kfree(info);
179 return -ENODEV;
180}
181
182static 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
199static 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
221static 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
228static int __init sercos3_init_module(void)
229{
230 return pci_register_driver(&sercos3_pci_driver);
231}
232
233static void __exit sercos3_exit_module(void)
234{
235 pci_unregister_driver(&sercos3_pci_driver);
236}
237
238module_init(sercos3_init_module);
239module_exit(sercos3_exit_module);
240
241MODULE_DESCRIPTION("UIO driver for the Automata Sercos III PCI card");
242MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>");
243MODULE_LICENSE("GPL v2");