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 | ||
57a4a3d7 | 7 | #include <linux/device.h> |
1da177e4 LT |
8 | #include <linux/kernel.h> |
9 | #include <linux/module.h> | |
10 | #include <linux/fs.h> | |
11 | #include <linux/errno.h> | |
12 | #include <linux/major.h> | |
1da177e4 | 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> |
7c0f6ba6 | 20 | #include <linux/uaccess.h> /* put_/get_user */ |
3049f89d | 21 | #include <asm/io.h> |
1da177e4 LT |
22 | |
23 | #include <asm/display7seg.h> | |
24 | ||
95d43905 DM |
25 | #define DRIVER_NAME "d7s" |
26 | #define PFX DRIVER_NAME ": " | |
1da177e4 | 27 | |
a3108ca2 | 28 | static DEFINE_MUTEX(d7s_mutex); |
1da177e4 LT |
29 | static int sol_compat = 0; /* Solaris compatibility mode */ |
30 | ||
1da177e4 LT |
31 | /* Solaris compatibility flag - |
32 | * The Solaris implementation omits support for several | |
33 | * documented driver features (ref Sun doc 806-0180-03). | |
34 | * By default, this module supports the documented driver | |
35 | * abilities, rather than the Solaris implementation: | |
36 | * | |
37 | * 1) Device ALWAYS reverts to OBP-specified FLIPPED mode | |
38 | * upon closure of device or module unload. | |
39 | * 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of | |
40 | * FLIP bit | |
41 | * | |
42 | * If you wish the device to operate as under Solaris, | |
43 | * omitting above features, set this parameter to non-zero. | |
44 | */ | |
95d43905 DM |
45 | module_param(sol_compat, int, 0); |
46 | MODULE_PARM_DESC(sol_compat, | |
47 | "Disables documented functionality omitted from Solaris driver"); | |
48 | ||
49 | MODULE_AUTHOR("Eric Brower <ebrower@usa.net>"); | |
50 | MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500"); | |
1da177e4 | 51 | MODULE_LICENSE("GPL"); |
95d43905 DM |
52 | MODULE_SUPPORTED_DEVICE("d7s"); |
53 | ||
54 | struct d7s { | |
55 | void __iomem *regs; | |
56 | bool flipped; | |
57 | }; | |
58 | struct d7s *d7s_device; | |
1da177e4 LT |
59 | |
60 | /* | |
61 | * Register block address- see header for details | |
62 | * ----------------------------------------- | |
63 | * | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 | | |
64 | * ----------------------------------------- | |
65 | * | |
66 | * DP - Toggles decimal point on/off | |
67 | * ALARM - Toggles "Alarm" LED green/red | |
68 | * FLIP - Inverts display for upside-down mounted board | |
69 | * bits 0-4 - 7-segment display contents | |
70 | */ | |
1da177e4 LT |
71 | static atomic_t d7s_users = ATOMIC_INIT(0); |
72 | ||
73 | static int d7s_open(struct inode *inode, struct file *f) | |
74 | { | |
75 | if (D7S_MINOR != iminor(inode)) | |
76 | return -ENODEV; | |
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 | |
496ad9aa | 109 | if (D7S_MINOR != iminor(file_inode(file))) |
1da177e4 LT |
110 | return -ENODEV; |
111 | ||
a3108ca2 | 112 | mutex_lock(&d7s_mutex); |
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 */ | |
54dcf0ce | 146 | regs ^= D7S_FLIP; |
95d43905 | 147 | writeb(regs, p->regs); |
1da177e4 | 148 | break; |
da201161 | 149 | } |
a3108ca2 | 150 | mutex_unlock(&d7s_mutex); |
1da177e4 | 151 | |
1d5d00bd | 152 | return error; |
1da177e4 LT |
153 | } |
154 | ||
00977a59 | 155 | static const struct file_operations d7s_fops = { |
1d5d00bd CH |
156 | .owner = THIS_MODULE, |
157 | .unlocked_ioctl = d7s_ioctl, | |
158 | .compat_ioctl = d7s_ioctl, | |
159 | .open = d7s_open, | |
160 | .release = d7s_release, | |
6038f373 | 161 | .llseek = noop_llseek, |
1da177e4 LT |
162 | }; |
163 | ||
95d43905 DM |
164 | static struct miscdevice d7s_miscdev = { |
165 | .minor = D7S_MINOR, | |
166 | .name = DRIVER_NAME, | |
167 | .fops = &d7s_fops | |
168 | }; | |
1da177e4 | 169 | |
082a2004 | 170 | static int d7s_probe(struct platform_device *op) |
1da177e4 | 171 | { |
95d43905 DM |
172 | struct device_node *opts; |
173 | int err = -EINVAL; | |
174 | struct d7s *p; | |
175 | u8 regs; | |
176 | ||
177 | if (d7s_device) | |
178 | goto out; | |
179 | ||
57a4a3d7 | 180 | p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL); |
95d43905 DM |
181 | err = -ENOMEM; |
182 | if (!p) | |
183 | goto out; | |
184 | ||
185 | p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s"); | |
186 | if (!p->regs) { | |
187 | printk(KERN_ERR PFX "Cannot map chip registers\n"); | |
188 | goto out_free; | |
1da177e4 LT |
189 | } |
190 | ||
95d43905 DM |
191 | err = misc_register(&d7s_miscdev); |
192 | if (err) { | |
193 | printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n", | |
194 | D7S_MINOR); | |
195 | goto out_iounmap; | |
1da177e4 LT |
196 | } |
197 | ||
95d43905 DM |
198 | /* OBP option "d7s-flipped?" is honored as default for the |
199 | * device, and reset default when detached | |
1da177e4 | 200 | */ |
95d43905 DM |
201 | regs = readb(p->regs); |
202 | opts = of_find_node_by_path("/options"); | |
203 | if (opts && | |
204 | of_get_property(opts, "d7s-flipped?", NULL)) | |
205 | p->flipped = true; | |
206 | ||
207 | if (p->flipped) | |
208 | regs |= D7S_FLIP; | |
209 | else | |
210 | regs &= ~D7S_FLIP; | |
211 | ||
212 | writeb(regs, p->regs); | |
213 | ||
8cd3ec51 RH |
214 | printk(KERN_INFO PFX "7-Segment Display%pOF at [%s:0x%llx] %s\n", |
215 | op->dev.of_node, | |
95d43905 DM |
216 | (regs & D7S_FLIP) ? " (FLIPPED)" : "", |
217 | op->resource[0].start, | |
218 | sol_compat ? "in sol_compat mode" : ""); | |
219 | ||
220 | dev_set_drvdata(&op->dev, p); | |
221 | d7s_device = p; | |
222 | err = 0; | |
87d81a23 | 223 | of_node_put(opts); |
95d43905 DM |
224 | |
225 | out: | |
226 | return err; | |
227 | ||
228 | out_iounmap: | |
229 | of_iounmap(&op->resource[0], p->regs, sizeof(u8)); | |
230 | ||
231 | out_free: | |
95d43905 | 232 | goto out; |
1da177e4 LT |
233 | } |
234 | ||
082a2004 | 235 | static int d7s_remove(struct platform_device *op) |
1da177e4 | 236 | { |
95d43905 DM |
237 | struct d7s *p = dev_get_drvdata(&op->dev); |
238 | u8 regs = readb(p->regs); | |
1da177e4 LT |
239 | |
240 | /* Honor OBP d7s-flipped? unless operating in solaris-compat mode */ | |
95d43905 DM |
241 | if (sol_compat) { |
242 | if (p->flipped) | |
243 | regs |= D7S_FLIP; | |
244 | else | |
245 | regs &= ~D7S_FLIP; | |
246 | writeb(regs, p->regs); | |
1da177e4 LT |
247 | } |
248 | ||
249 | misc_deregister(&d7s_miscdev); | |
95d43905 | 250 | of_iounmap(&op->resource[0], p->regs, sizeof(u8)); |
95d43905 DM |
251 | |
252 | return 0; | |
253 | } | |
254 | ||
fd098316 | 255 | static const struct of_device_id d7s_match[] = { |
95d43905 DM |
256 | { |
257 | .name = "display7seg", | |
258 | }, | |
259 | {}, | |
260 | }; | |
261 | MODULE_DEVICE_TABLE(of, d7s_match); | |
262 | ||
4ebb24f7 | 263 | static struct platform_driver d7s_driver = { |
4018294b GL |
264 | .driver = { |
265 | .name = DRIVER_NAME, | |
4018294b GL |
266 | .of_match_table = d7s_match, |
267 | }, | |
95d43905 | 268 | .probe = d7s_probe, |
082a2004 | 269 | .remove = d7s_remove, |
95d43905 DM |
270 | }; |
271 | ||
dbf2b92d | 272 | module_platform_driver(d7s_driver); |