1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
/* 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>
#include <linux/slab.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 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_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[] = {
{
.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,
};
module_pci_driver(sercos3_pci_driver);
MODULE_DESCRIPTION("UIO driver for the Automata Sercos III PCI card");
MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>");
MODULE_LICENSE("GPL v2");
|
