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7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/fs.h>
10#include <linux/errno.h>
11#include <linux/major.h>
12#include <linux/init.h>
13#include <linux/miscdevice.h>
14#include <linux/ioport.h>
15#include <linux/slab.h>
16#include <linux/mutex.h>
17#include <linux/of.h>
18#include <linux/of_device.h>
19#include <linux/atomic.h>
20#include <asm/uaccess.h>
21#include <asm/io.h>
22
23#include <asm/display7seg.h>
24
25#define D7S_MINOR 193
26#define DRIVER_NAME "d7s"
27#define PFX DRIVER_NAME ": "
28
29static DEFINE_MUTEX(d7s_mutex);
30static int sol_compat = 0;
31
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43
44
45
46module_param(sol_compat, int, 0);
47MODULE_PARM_DESC(sol_compat,
48 "Disables documented functionality omitted from Solaris driver");
49
50MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
51MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500");
52MODULE_LICENSE("GPL");
53MODULE_SUPPORTED_DEVICE("d7s");
54
55struct d7s {
56 void __iomem *regs;
57 bool flipped;
58};
59struct d7s *d7s_device;
60
61
62
63
64
65
66
67
68
69
70
71
72static atomic_t d7s_users = ATOMIC_INIT(0);
73
74static int d7s_open(struct inode *inode, struct file *f)
75{
76 if (D7S_MINOR != iminor(inode))
77 return -ENODEV;
78 atomic_inc(&d7s_users);
79 return 0;
80}
81
82static int d7s_release(struct inode *inode, struct file *f)
83{
84
85
86
87
88 if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
89 struct d7s *p = d7s_device;
90 u8 regval = 0;
91
92 regval = readb(p->regs);
93 if (p->flipped)
94 regval |= D7S_FLIP;
95 else
96 regval &= ~D7S_FLIP;
97 writeb(regval, p->regs);
98 }
99
100 return 0;
101}
102
103static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
104{
105 struct d7s *p = d7s_device;
106 u8 regs = readb(p->regs);
107 int error = 0;
108 u8 ireg = 0;
109
110 if (D7S_MINOR != iminor(file_inode(file)))
111 return -ENODEV;
112
113 mutex_lock(&d7s_mutex);
114 switch (cmd) {
115 case D7SIOCWR:
116
117
118
119 if (get_user(ireg, (int __user *) arg)) {
120 error = -EFAULT;
121 break;
122 }
123 if (sol_compat) {
124 if (regs & D7S_FLIP)
125 ireg |= D7S_FLIP;
126 else
127 ireg &= ~D7S_FLIP;
128 }
129 writeb(ireg, p->regs);
130 break;
131
132 case D7SIOCRD:
133
134
135
136
137
138
139 if (put_user(regs, (int __user *) arg)) {
140 error = -EFAULT;
141 break;
142 }
143 break;
144
145 case D7SIOCTM:
146
147 if (regs & D7S_FLIP)
148 regs &= ~D7S_FLIP;
149 else
150 regs |= D7S_FLIP;
151 writeb(regs, p->regs);
152 break;
153 }
154 mutex_unlock(&d7s_mutex);
155
156 return error;
157}
158
159static const struct file_operations d7s_fops = {
160 .owner = THIS_MODULE,
161 .unlocked_ioctl = d7s_ioctl,
162 .compat_ioctl = d7s_ioctl,
163 .open = d7s_open,
164 .release = d7s_release,
165 .llseek = noop_llseek,
166};
167
168static struct miscdevice d7s_miscdev = {
169 .minor = D7S_MINOR,
170 .name = DRIVER_NAME,
171 .fops = &d7s_fops
172};
173
174static int d7s_probe(struct platform_device *op)
175{
176 struct device_node *opts;
177 int err = -EINVAL;
178 struct d7s *p;
179 u8 regs;
180
181 if (d7s_device)
182 goto out;
183
184 p = kzalloc(sizeof(*p), GFP_KERNEL);
185 err = -ENOMEM;
186 if (!p)
187 goto out;
188
189 p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s");
190 if (!p->regs) {
191 printk(KERN_ERR PFX "Cannot map chip registers\n");
192 goto out_free;
193 }
194
195 err = misc_register(&d7s_miscdev);
196 if (err) {
197 printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n",
198 D7S_MINOR);
199 goto out_iounmap;
200 }
201
202
203
204
205 regs = readb(p->regs);
206 opts = of_find_node_by_path("/options");
207 if (opts &&
208 of_get_property(opts, "d7s-flipped?", NULL))
209 p->flipped = true;
210
211 if (p->flipped)
212 regs |= D7S_FLIP;
213 else
214 regs &= ~D7S_FLIP;
215
216 writeb(regs, p->regs);
217
218 printk(KERN_INFO PFX "7-Segment Display%s at [%s:0x%llx] %s\n",
219 op->dev.of_node->full_name,
220 (regs & D7S_FLIP) ? " (FLIPPED)" : "",
221 op->resource[0].start,
222 sol_compat ? "in sol_compat mode" : "");
223
224 dev_set_drvdata(&op->dev, p);
225 d7s_device = p;
226 err = 0;
227
228out:
229 return err;
230
231out_iounmap:
232 of_iounmap(&op->resource[0], p->regs, sizeof(u8));
233
234out_free:
235 kfree(p);
236 goto out;
237}
238
239static int d7s_remove(struct platform_device *op)
240{
241 struct d7s *p = dev_get_drvdata(&op->dev);
242 u8 regs = readb(p->regs);
243
244
245 if (sol_compat) {
246 if (p->flipped)
247 regs |= D7S_FLIP;
248 else
249 regs &= ~D7S_FLIP;
250 writeb(regs, p->regs);
251 }
252
253 misc_deregister(&d7s_miscdev);
254 of_iounmap(&op->resource[0], p->regs, sizeof(u8));
255 kfree(p);
256
257 return 0;
258}
259
260static const struct of_device_id d7s_match[] = {
261 {
262 .name = "display7seg",
263 },
264 {},
265};
266MODULE_DEVICE_TABLE(of, d7s_match);
267
268static struct platform_driver d7s_driver = {
269 .driver = {
270 .name = DRIVER_NAME,
271 .owner = THIS_MODULE,
272 .of_match_table = d7s_match,
273 },
274 .probe = d7s_probe,
275 .remove = d7s_remove,
276};
277
278module_platform_driver(d7s_driver);
279