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
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
|
// SPDX-License-Identifier: GPL-2.0-only
/* display7seg.c - Driver implementation for the 7-segment display
* present on Sun Microsystems CP1400 and CP1500
*
* Copyright (c) 2000 Eric Brower (ebrower@usa.net)
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/major.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h> /* request_region */
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/atomic.h>
#include <linux/uaccess.h> /* put_/get_user */
#include <asm/io.h>
#include <asm/display7seg.h>
#define DRIVER_NAME "d7s"
#define PFX DRIVER_NAME ": "
static DEFINE_MUTEX(d7s_mutex);
static int sol_compat = 0; /* Solaris compatibility mode */
/* Solaris compatibility flag -
* The Solaris implementation omits support for several
* documented driver features (ref Sun doc 806-0180-03).
* By default, this module supports the documented driver
* abilities, rather than the Solaris implementation:
*
* 1) Device ALWAYS reverts to OBP-specified FLIPPED mode
* upon closure of device or module unload.
* 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
* FLIP bit
*
* If you wish the device to operate as under Solaris,
* omitting above features, set this parameter to non-zero.
*/
module_param(sol_compat, int, 0);
MODULE_PARM_DESC(sol_compat,
"Disables documented functionality omitted from Solaris driver");
MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("d7s");
struct d7s {
void __iomem *regs;
bool flipped;
};
struct d7s *d7s_device;
/*
* Register block address- see header for details
* -----------------------------------------
* | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 |
* -----------------------------------------
*
* DP - Toggles decimal point on/off
* ALARM - Toggles "Alarm" LED green/red
* FLIP - Inverts display for upside-down mounted board
* bits 0-4 - 7-segment display contents
*/
static atomic_t d7s_users = ATOMIC_INIT(0);
static int d7s_open(struct inode *inode, struct file *f)
{
if (D7S_MINOR != iminor(inode))
return -ENODEV;
atomic_inc(&d7s_users);
return 0;
}
static int d7s_release(struct inode *inode, struct file *f)
{
/* Reset flipped state to OBP default only if
* no other users have the device open and we
* are not operating in solaris-compat mode
*/
if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
struct d7s *p = d7s_device;
u8 regval = 0;
regval = readb(p->regs);
if (p->flipped)
regval |= D7S_FLIP;
else
regval &= ~D7S_FLIP;
writeb(regval, p->regs);
}
return 0;
}
static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct d7s *p = d7s_device;
u8 regs = readb(p->regs);
int error = 0;
u8 ireg = 0;
if (D7S_MINOR != iminor(file_inode(file)))
return -ENODEV;
mutex_lock(&d7s_mutex);
switch (cmd) {
case D7SIOCWR:
/* assign device register values we mask-out D7S_FLIP
* if in sol_compat mode
*/
if (get_user(ireg, (int __user *) arg)) {
error = -EFAULT;
break;
}
if (sol_compat) {
if (regs & D7S_FLIP)
ireg |= D7S_FLIP;
else
ireg &= ~D7S_FLIP;
}
writeb(ireg, p->regs);
break;
case D7SIOCRD:
/* retrieve device register values
* NOTE: Solaris implementation returns D7S_FLIP bit
* as toggled by user, even though it does not honor it.
* This driver will not misinform you about the state
* of your hardware while in sol_compat mode
*/
if (put_user(regs, (int __user *) arg)) {
error = -EFAULT;
break;
}
break;
case D7SIOCTM:
/* toggle device mode-- flip display orientation */
regs ^= D7S_FLIP;
writeb(regs, p->regs);
break;
}
mutex_unlock(&d7s_mutex);
return error;
}
static const struct file_operations d7s_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = d7s_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = d7s_open,
.release = d7s_release,
.llseek = noop_llseek,
};
static struct miscdevice d7s_miscdev = {
.minor = D7S_MINOR,
.name = DRIVER_NAME,
.fops = &d7s_fops
};
static int d7s_probe(struct platform_device *op)
{
struct device_node *opts;
int err = -EINVAL;
struct d7s *p;
u8 regs;
if (d7s_device)
goto out;
p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);
err = -ENOMEM;
if (!p)
goto out;
p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s");
if (!p->regs) {
printk(KERN_ERR PFX "Cannot map chip registers\n");
goto out_free;
}
err = misc_register(&d7s_miscdev);
if (err) {
printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n",
D7S_MINOR);
goto out_iounmap;
}
/* OBP option "d7s-flipped?" is honored as default for the
* device, and reset default when detached
*/
regs = readb(p->regs);
opts = of_find_node_by_path("/options");
if (opts &&
of_get_property(opts, "d7s-flipped?", NULL))
p->flipped = true;
if (p->flipped)
regs |= D7S_FLIP;
else
regs &= ~D7S_FLIP;
writeb(regs, p->regs);
printk(KERN_INFO PFX "7-Segment Display%pOF at [%s:0x%llx] %s\n",
op->dev.of_node,
(regs & D7S_FLIP) ? " (FLIPPED)" : "",
op->resource[0].start,
sol_compat ? "in sol_compat mode" : "");
dev_set_drvdata(&op->dev, p);
d7s_device = p;
err = 0;
of_node_put(opts);
out:
return err;
out_iounmap:
of_iounmap(&op->resource[0], p->regs, sizeof(u8));
out_free:
goto out;
}
static int d7s_remove(struct platform_device *op)
{
struct d7s *p = dev_get_drvdata(&op->dev);
u8 regs = readb(p->regs);
/* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
if (sol_compat) {
if (p->flipped)
regs |= D7S_FLIP;
else
regs &= ~D7S_FLIP;
writeb(regs, p->regs);
}
misc_deregister(&d7s_miscdev);
of_iounmap(&op->resource[0], p->regs, sizeof(u8));
return 0;
}
static const struct of_device_id d7s_match[] = {
{
.name = "display7seg",
},
{},
};
MODULE_DEVICE_TABLE(of, d7s_match);
static struct platform_driver d7s_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = d7s_match,
},
.probe = d7s_probe,
.remove = d7s_remove,
};
module_platform_driver(d7s_driver);
|
