Commit | Line | Data |
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95d43905 DM |
1 | /* display7seg.c - Driver implementation for the 7-segment display |
2 | * present on Sun Microsystems CP1400 and CP1500 | |
1da177e4 LT |
3 | * |
4 | * Copyright (c) 2000 Eric Brower (ebrower@usa.net) | |
1da177e4 LT |
5 | */ |
6 | ||
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> | |
fb911ee8 | 14 | #include <linux/ioport.h> /* request_region */ |
1d5d00bd | 15 | #include <linux/smp_lock.h> |
95d43905 DM |
16 | #include <linux/of.h> |
17 | #include <linux/of_device.h> | |
1da177e4 | 18 | #include <asm/atomic.h> |
1da177e4 | 19 | #include <asm/uaccess.h> /* put_/get_user */ |
3049f89d | 20 | #include <asm/io.h> |
1da177e4 LT |
21 | |
22 | #include <asm/display7seg.h> | |
23 | ||
24 | #define D7S_MINOR 193 | |
95d43905 DM |
25 | #define DRIVER_NAME "d7s" |
26 | #define PFX DRIVER_NAME ": " | |
1da177e4 LT |
27 | |
28 | static int sol_compat = 0; /* Solaris compatibility mode */ | |
29 | ||
1da177e4 LT |
30 | /* Solaris compatibility flag - |
31 | * The Solaris implementation omits support for several | |
32 | * documented driver features (ref Sun doc 806-0180-03). | |
33 | * By default, this module supports the documented driver | |
34 | * abilities, rather than the Solaris implementation: | |
35 | * | |
36 | * 1) Device ALWAYS reverts to OBP-specified FLIPPED mode | |
37 | * upon closure of device or module unload. | |
38 | * 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of | |
39 | * FLIP bit | |
40 | * | |
41 | * If you wish the device to operate as under Solaris, | |
42 | * omitting above features, set this parameter to non-zero. | |
43 | */ | |
95d43905 DM |
44 | module_param(sol_compat, int, 0); |
45 | MODULE_PARM_DESC(sol_compat, | |
46 | "Disables documented functionality omitted from Solaris driver"); | |
47 | ||
48 | MODULE_AUTHOR("Eric Brower <ebrower@usa.net>"); | |
49 | MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500"); | |
1da177e4 | 50 | MODULE_LICENSE("GPL"); |
95d43905 DM |
51 | MODULE_SUPPORTED_DEVICE("d7s"); |
52 | ||
53 | struct d7s { | |
54 | void __iomem *regs; | |
55 | bool flipped; | |
56 | }; | |
57 | struct d7s *d7s_device; | |
1da177e4 LT |
58 | |
59 | /* | |
60 | * Register block address- see header for details | |
61 | * ----------------------------------------- | |
62 | * | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 | | |
63 | * ----------------------------------------- | |
64 | * | |
65 | * DP - Toggles decimal point on/off | |
66 | * ALARM - Toggles "Alarm" LED green/red | |
67 | * FLIP - Inverts display for upside-down mounted board | |
68 | * bits 0-4 - 7-segment display contents | |
69 | */ | |
1da177e4 LT |
70 | static atomic_t d7s_users = ATOMIC_INIT(0); |
71 | ||
72 | static int d7s_open(struct inode *inode, struct file *f) | |
73 | { | |
74 | if (D7S_MINOR != iminor(inode)) | |
75 | return -ENODEV; | |
009228df | 76 | cycle_kernel_lock(); |
1da177e4 LT |
77 | atomic_inc(&d7s_users); |
78 | return 0; | |
79 | } | |
80 | ||
81 | static int d7s_release(struct inode *inode, struct file *f) | |
82 | { | |
83 | /* Reset flipped state to OBP default only if | |
84 | * no other users have the device open and we | |
85 | * are not operating in solaris-compat mode | |
86 | */ | |
87 | if (atomic_dec_and_test(&d7s_users) && !sol_compat) { | |
95d43905 DM |
88 | struct d7s *p = d7s_device; |
89 | u8 regval = 0; | |
90 | ||
91 | regval = readb(p->regs); | |
92 | if (p->flipped) | |
93 | regval |= D7S_FLIP; | |
94 | else | |
95 | regval &= ~D7S_FLIP; | |
96 | writeb(regval, p->regs); | |
1da177e4 LT |
97 | } |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
1d5d00bd | 102 | static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 103 | { |
95d43905 DM |
104 | struct d7s *p = d7s_device; |
105 | u8 regs = readb(p->regs); | |
a5aac37f | 106 | int error = 0; |
95d43905 | 107 | u8 ireg = 0; |
1da177e4 | 108 | |
7fa95f72 | 109 | if (D7S_MINOR != iminor(file->f_path.dentry->d_inode)) |
1da177e4 LT |
110 | return -ENODEV; |
111 | ||
1d5d00bd | 112 | lock_kernel(); |
1da177e4 LT |
113 | switch (cmd) { |
114 | case D7SIOCWR: | |
95d43905 DM |
115 | /* assign device register values we mask-out D7S_FLIP |
116 | * if in sol_compat mode | |
1da177e4 | 117 | */ |
1d5d00bd CH |
118 | if (get_user(ireg, (int __user *) arg)) { |
119 | error = -EFAULT; | |
120 | break; | |
121 | } | |
95d43905 DM |
122 | if (sol_compat) { |
123 | if (regs & D7S_FLIP) | |
124 | ireg |= D7S_FLIP; | |
125 | else | |
126 | ireg &= ~D7S_FLIP; | |
1da177e4 | 127 | } |
95d43905 | 128 | writeb(ireg, p->regs); |
1da177e4 LT |
129 | break; |
130 | ||
131 | case D7SIOCRD: | |
132 | /* retrieve device register values | |
133 | * NOTE: Solaris implementation returns D7S_FLIP bit | |
134 | * as toggled by user, even though it does not honor it. | |
135 | * This driver will not misinform you about the state | |
136 | * of your hardware while in sol_compat mode | |
137 | */ | |
1d5d00bd CH |
138 | if (put_user(regs, (int __user *) arg)) { |
139 | error = -EFAULT; | |
140 | break; | |
141 | } | |
1da177e4 LT |
142 | break; |
143 | ||
144 | case D7SIOCTM: | |
145 | /* toggle device mode-- flip display orientation */ | |
95d43905 DM |
146 | if (regs & D7S_FLIP) |
147 | regs &= ~D7S_FLIP; | |
148 | else | |
149 | regs |= D7S_FLIP; | |
150 | writeb(regs, p->regs); | |
1da177e4 LT |
151 | break; |
152 | }; | |
feee207e | 153 | unlock_kernel(); |
1da177e4 | 154 | |
1d5d00bd | 155 | return error; |
1da177e4 LT |
156 | } |
157 | ||
00977a59 | 158 | static const struct file_operations d7s_fops = { |
1d5d00bd CH |
159 | .owner = THIS_MODULE, |
160 | .unlocked_ioctl = d7s_ioctl, | |
161 | .compat_ioctl = d7s_ioctl, | |
162 | .open = d7s_open, | |
163 | .release = d7s_release, | |
1da177e4 LT |
164 | }; |
165 | ||
95d43905 DM |
166 | static struct miscdevice d7s_miscdev = { |
167 | .minor = D7S_MINOR, | |
168 | .name = DRIVER_NAME, | |
169 | .fops = &d7s_fops | |
170 | }; | |
1da177e4 | 171 | |
95d43905 DM |
172 | static int __devinit d7s_probe(struct of_device *op, |
173 | const struct of_device_id *match) | |
1da177e4 | 174 | { |
95d43905 DM |
175 | struct device_node *opts; |
176 | int err = -EINVAL; | |
177 | struct d7s *p; | |
178 | u8 regs; | |
179 | ||
180 | if (d7s_device) | |
181 | goto out; | |
182 | ||
183 | p = kzalloc(sizeof(*p), GFP_KERNEL); | |
184 | err = -ENOMEM; | |
185 | if (!p) | |
186 | goto out; | |
187 | ||
188 | p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s"); | |
189 | if (!p->regs) { | |
190 | printk(KERN_ERR PFX "Cannot map chip registers\n"); | |
191 | goto out_free; | |
1da177e4 LT |
192 | } |
193 | ||
95d43905 DM |
194 | err = misc_register(&d7s_miscdev); |
195 | if (err) { | |
196 | printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n", | |
197 | D7S_MINOR); | |
198 | goto out_iounmap; | |
1da177e4 LT |
199 | } |
200 | ||
95d43905 DM |
201 | /* OBP option "d7s-flipped?" is honored as default for the |
202 | * device, and reset default when detached | |
1da177e4 | 203 | */ |
95d43905 DM |
204 | regs = readb(p->regs); |
205 | opts = of_find_node_by_path("/options"); | |
206 | if (opts && | |
207 | of_get_property(opts, "d7s-flipped?", NULL)) | |
208 | p->flipped = true; | |
209 | ||
210 | if (p->flipped) | |
211 | regs |= D7S_FLIP; | |
212 | else | |
213 | regs &= ~D7S_FLIP; | |
214 | ||
215 | writeb(regs, p->regs); | |
216 | ||
3f4528d6 | 217 | printk(KERN_INFO PFX "7-Segment Display%s at [%s:0x%llx] %s\n", |
95d43905 DM |
218 | op->node->full_name, |
219 | (regs & D7S_FLIP) ? " (FLIPPED)" : "", | |
220 | op->resource[0].start, | |
221 | sol_compat ? "in sol_compat mode" : ""); | |
222 | ||
223 | dev_set_drvdata(&op->dev, p); | |
224 | d7s_device = p; | |
225 | err = 0; | |
226 | ||
227 | out: | |
228 | return err; | |
229 | ||
230 | out_iounmap: | |
231 | of_iounmap(&op->resource[0], p->regs, sizeof(u8)); | |
232 | ||
233 | out_free: | |
234 | kfree(p); | |
235 | goto out; | |
1da177e4 LT |
236 | } |
237 | ||
95d43905 | 238 | static int __devexit d7s_remove(struct of_device *op) |
1da177e4 | 239 | { |
95d43905 DM |
240 | struct d7s *p = dev_get_drvdata(&op->dev); |
241 | u8 regs = readb(p->regs); | |
1da177e4 LT |
242 | |
243 | /* Honor OBP d7s-flipped? unless operating in solaris-compat mode */ | |
95d43905 DM |
244 | if (sol_compat) { |
245 | if (p->flipped) | |
246 | regs |= D7S_FLIP; | |
247 | else | |
248 | regs &= ~D7S_FLIP; | |
249 | writeb(regs, p->regs); | |
1da177e4 LT |
250 | } |
251 | ||
252 | misc_deregister(&d7s_miscdev); | |
95d43905 DM |
253 | of_iounmap(&op->resource[0], p->regs, sizeof(u8)); |
254 | kfree(p); | |
255 | ||
256 | return 0; | |
257 | } | |
258 | ||
fd098316 | 259 | static const struct of_device_id d7s_match[] = { |
95d43905 DM |
260 | { |
261 | .name = "display7seg", | |
262 | }, | |
263 | {}, | |
264 | }; | |
265 | MODULE_DEVICE_TABLE(of, d7s_match); | |
266 | ||
267 | static struct of_platform_driver d7s_driver = { | |
268 | .name = DRIVER_NAME, | |
269 | .match_table = d7s_match, | |
270 | .probe = d7s_probe, | |
271 | .remove = __devexit_p(d7s_remove), | |
272 | }; | |
273 | ||
274 | static int __init d7s_init(void) | |
275 | { | |
276 | return of_register_driver(&d7s_driver, &of_bus_type); | |
277 | } | |
278 | ||
279 | static void __exit d7s_exit(void) | |
280 | { | |
281 | of_unregister_driver(&d7s_driver); | |
1da177e4 LT |
282 | } |
283 | ||
284 | module_init(d7s_init); | |
95d43905 | 285 | module_exit(d7s_exit); |