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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 */ |
5a0e3ad6 | 15 | #include <linux/slab.h> |
a3108ca2 | 16 | #include <linux/mutex.h> |
95d43905 DM |
17 | #include <linux/of.h> |
18 | #include <linux/of_device.h> | |
60063497 | 19 | #include <linux/atomic.h> |
1da177e4 | 20 | #include <asm/uaccess.h> /* put_/get_user */ |
3049f89d | 21 | #include <asm/io.h> |
1da177e4 LT |
22 | |
23 | #include <asm/display7seg.h> | |
24 | ||
25 | #define D7S_MINOR 193 | |
95d43905 DM |
26 | #define DRIVER_NAME "d7s" |
27 | #define PFX DRIVER_NAME ": " | |
1da177e4 | 28 | |
a3108ca2 | 29 | static DEFINE_MUTEX(d7s_mutex); |
1da177e4 LT |
30 | static int sol_compat = 0; /* Solaris compatibility mode */ |
31 | ||
1da177e4 LT |
32 | /* Solaris compatibility flag - |
33 | * The Solaris implementation omits support for several | |
34 | * documented driver features (ref Sun doc 806-0180-03). | |
35 | * By default, this module supports the documented driver | |
36 | * abilities, rather than the Solaris implementation: | |
37 | * | |
38 | * 1) Device ALWAYS reverts to OBP-specified FLIPPED mode | |
39 | * upon closure of device or module unload. | |
40 | * 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of | |
41 | * FLIP bit | |
42 | * | |
43 | * If you wish the device to operate as under Solaris, | |
44 | * omitting above features, set this parameter to non-zero. | |
45 | */ | |
95d43905 DM |
46 | module_param(sol_compat, int, 0); |
47 | MODULE_PARM_DESC(sol_compat, | |
48 | "Disables documented functionality omitted from Solaris driver"); | |
49 | ||
50 | MODULE_AUTHOR("Eric Brower <ebrower@usa.net>"); | |
51 | MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500"); | |
1da177e4 | 52 | MODULE_LICENSE("GPL"); |
95d43905 DM |
53 | MODULE_SUPPORTED_DEVICE("d7s"); |
54 | ||
55 | struct d7s { | |
56 | void __iomem *regs; | |
57 | bool flipped; | |
58 | }; | |
59 | struct d7s *d7s_device; | |
1da177e4 LT |
60 | |
61 | /* | |
62 | * Register block address- see header for details | |
63 | * ----------------------------------------- | |
64 | * | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 | | |
65 | * ----------------------------------------- | |
66 | * | |
67 | * DP - Toggles decimal point on/off | |
68 | * ALARM - Toggles "Alarm" LED green/red | |
69 | * FLIP - Inverts display for upside-down mounted board | |
70 | * bits 0-4 - 7-segment display contents | |
71 | */ | |
1da177e4 LT |
72 | static atomic_t d7s_users = ATOMIC_INIT(0); |
73 | ||
74 | static 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 | ||
82 | static int d7s_release(struct inode *inode, struct file *f) | |
83 | { | |
84 | /* Reset flipped state to OBP default only if | |
85 | * no other users have the device open and we | |
86 | * are not operating in solaris-compat mode | |
87 | */ | |
88 | if (atomic_dec_and_test(&d7s_users) && !sol_compat) { | |
95d43905 DM |
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); | |
1da177e4 LT |
98 | } |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
1d5d00bd | 103 | static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 104 | { |
95d43905 DM |
105 | struct d7s *p = d7s_device; |
106 | u8 regs = readb(p->regs); | |
a5aac37f | 107 | int error = 0; |
95d43905 | 108 | u8 ireg = 0; |
1da177e4 | 109 | |
7fa95f72 | 110 | if (D7S_MINOR != iminor(file->f_path.dentry->d_inode)) |
1da177e4 LT |
111 | return -ENODEV; |
112 | ||
a3108ca2 | 113 | mutex_lock(&d7s_mutex); |
1da177e4 LT |
114 | switch (cmd) { |
115 | case D7SIOCWR: | |
95d43905 DM |
116 | /* assign device register values we mask-out D7S_FLIP |
117 | * if in sol_compat mode | |
1da177e4 | 118 | */ |
1d5d00bd CH |
119 | if (get_user(ireg, (int __user *) arg)) { |
120 | error = -EFAULT; | |
121 | break; | |
122 | } | |
95d43905 DM |
123 | if (sol_compat) { |
124 | if (regs & D7S_FLIP) | |
125 | ireg |= D7S_FLIP; | |
126 | else | |
127 | ireg &= ~D7S_FLIP; | |
1da177e4 | 128 | } |
95d43905 | 129 | writeb(ireg, p->regs); |
1da177e4 LT |
130 | break; |
131 | ||
132 | case D7SIOCRD: | |
133 | /* retrieve device register values | |
134 | * NOTE: Solaris implementation returns D7S_FLIP bit | |
135 | * as toggled by user, even though it does not honor it. | |
136 | * This driver will not misinform you about the state | |
137 | * of your hardware while in sol_compat mode | |
138 | */ | |
1d5d00bd CH |
139 | if (put_user(regs, (int __user *) arg)) { |
140 | error = -EFAULT; | |
141 | break; | |
142 | } | |
1da177e4 LT |
143 | break; |
144 | ||
145 | case D7SIOCTM: | |
146 | /* toggle device mode-- flip display orientation */ | |
95d43905 DM |
147 | if (regs & D7S_FLIP) |
148 | regs &= ~D7S_FLIP; | |
149 | else | |
150 | regs |= D7S_FLIP; | |
151 | writeb(regs, p->regs); | |
1da177e4 LT |
152 | break; |
153 | }; | |
a3108ca2 | 154 | mutex_unlock(&d7s_mutex); |
1da177e4 | 155 | |
1d5d00bd | 156 | return error; |
1da177e4 LT |
157 | } |
158 | ||
00977a59 | 159 | static const struct file_operations d7s_fops = { |
1d5d00bd CH |
160 | .owner = THIS_MODULE, |
161 | .unlocked_ioctl = d7s_ioctl, | |
162 | .compat_ioctl = d7s_ioctl, | |
163 | .open = d7s_open, | |
164 | .release = d7s_release, | |
6038f373 | 165 | .llseek = noop_llseek, |
1da177e4 LT |
166 | }; |
167 | ||
95d43905 DM |
168 | static struct miscdevice d7s_miscdev = { |
169 | .minor = D7S_MINOR, | |
170 | .name = DRIVER_NAME, | |
171 | .fops = &d7s_fops | |
172 | }; | |
1da177e4 | 173 | |
4ebb24f7 | 174 | static int __devinit d7s_probe(struct platform_device *op) |
1da177e4 | 175 | { |
95d43905 DM |
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; | |
1da177e4 LT |
193 | } |
194 | ||
95d43905 DM |
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; | |
1da177e4 LT |
200 | } |
201 | ||
95d43905 DM |
202 | /* OBP option "d7s-flipped?" is honored as default for the |
203 | * device, and reset default when detached | |
1da177e4 | 204 | */ |
95d43905 DM |
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 | ||
3f4528d6 | 218 | printk(KERN_INFO PFX "7-Segment Display%s at [%s:0x%llx] %s\n", |
61c7a080 | 219 | op->dev.of_node->full_name, |
95d43905 DM |
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 | ||
228 | out: | |
229 | return err; | |
230 | ||
231 | out_iounmap: | |
232 | of_iounmap(&op->resource[0], p->regs, sizeof(u8)); | |
233 | ||
234 | out_free: | |
235 | kfree(p); | |
236 | goto out; | |
1da177e4 LT |
237 | } |
238 | ||
2dc11581 | 239 | static int __devexit d7s_remove(struct platform_device *op) |
1da177e4 | 240 | { |
95d43905 DM |
241 | struct d7s *p = dev_get_drvdata(&op->dev); |
242 | u8 regs = readb(p->regs); | |
1da177e4 LT |
243 | |
244 | /* Honor OBP d7s-flipped? unless operating in solaris-compat mode */ | |
95d43905 DM |
245 | if (sol_compat) { |
246 | if (p->flipped) | |
247 | regs |= D7S_FLIP; | |
248 | else | |
249 | regs &= ~D7S_FLIP; | |
250 | writeb(regs, p->regs); | |
1da177e4 LT |
251 | } |
252 | ||
253 | misc_deregister(&d7s_miscdev); | |
95d43905 DM |
254 | of_iounmap(&op->resource[0], p->regs, sizeof(u8)); |
255 | kfree(p); | |
256 | ||
257 | return 0; | |
258 | } | |
259 | ||
fd098316 | 260 | static const struct of_device_id d7s_match[] = { |
95d43905 DM |
261 | { |
262 | .name = "display7seg", | |
263 | }, | |
264 | {}, | |
265 | }; | |
266 | MODULE_DEVICE_TABLE(of, d7s_match); | |
267 | ||
4ebb24f7 | 268 | static struct platform_driver d7s_driver = { |
4018294b GL |
269 | .driver = { |
270 | .name = DRIVER_NAME, | |
271 | .owner = THIS_MODULE, | |
272 | .of_match_table = d7s_match, | |
273 | }, | |
95d43905 DM |
274 | .probe = d7s_probe, |
275 | .remove = __devexit_p(d7s_remove), | |
276 | }; | |
277 | ||
dbf2b92d | 278 | module_platform_driver(d7s_driver); |