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-rw-r--r--drivers/sbus/char/display7seg.c234
1 files changed, 234 insertions, 0 deletions
diff --git a/drivers/sbus/char/display7seg.c b/drivers/sbus/char/display7seg.c
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index 000000000000..dbad7f35eb0a
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+++ b/drivers/sbus/char/display7seg.c
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1/* $Id: display7seg.c,v 1.6 2002/01/08 16:00:16 davem Exp $
2 *
3 * display7seg - Driver implementation for the 7-segment display
4 * present on Sun Microsystems CP1400 and CP1500
5 *
6 * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
7 *
8 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/fs.h>
13#include <linux/errno.h>
14#include <linux/major.h>
15#include <linux/init.h>
16#include <linux/miscdevice.h>
17#include <linux/ioport.h> /* request_region, check_region */
18#include <asm/atomic.h>
19#include <asm/ebus.h> /* EBus device */
20#include <asm/oplib.h> /* OpenProm Library */
21#include <asm/uaccess.h> /* put_/get_user */
22
23#include <asm/display7seg.h>
24
25#define D7S_MINOR 193
26#define D7S_OBPNAME "display7seg"
27#define D7S_DEVNAME "d7s"
28
29static int sol_compat = 0; /* Solaris compatibility mode */
30
31#ifdef MODULE
32
33/* Solaris compatibility flag -
34 * The Solaris implementation omits support for several
35 * documented driver features (ref Sun doc 806-0180-03).
36 * By default, this module supports the documented driver
37 * abilities, rather than the Solaris implementation:
38 *
39 * 1) Device ALWAYS reverts to OBP-specified FLIPPED mode
40 * upon closure of device or module unload.
41 * 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
42 * FLIP bit
43 *
44 * If you wish the device to operate as under Solaris,
45 * omitting above features, set this parameter to non-zero.
46 */
47module_param
48 (sol_compat, int, 0);
49MODULE_PARM_DESC
50 (sol_compat,
51 "Disables documented functionality omitted from Solaris driver");
52
53MODULE_AUTHOR
54 ("Eric Brower <ebrower@usa.net>");
55MODULE_DESCRIPTION
56 ("7-Segment Display driver for Sun Microsystems CP1400/1500");
57MODULE_LICENSE("GPL");
58MODULE_SUPPORTED_DEVICE
59 ("d7s");
60#endif /* ifdef MODULE */
61
62/*
63 * Register block address- see header for details
64 * -----------------------------------------
65 * | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 |
66 * -----------------------------------------
67 *
68 * DP - Toggles decimal point on/off
69 * ALARM - Toggles "Alarm" LED green/red
70 * FLIP - Inverts display for upside-down mounted board
71 * bits 0-4 - 7-segment display contents
72 */
73static void __iomem* d7s_regs;
74
75static inline void d7s_free(void)
76{
77 iounmap(d7s_regs);
78}
79
80static inline int d7s_obpflipped(void)
81{
82 int opt_node;
83
84 opt_node = prom_getchild(prom_root_node);
85 opt_node = prom_searchsiblings(opt_node, "options");
86 return ((-1 != prom_getintdefault(opt_node, "d7s-flipped?", -1)) ? 0 : 1);
87}
88
89static atomic_t d7s_users = ATOMIC_INIT(0);
90
91static int d7s_open(struct inode *inode, struct file *f)
92{
93 if (D7S_MINOR != iminor(inode))
94 return -ENODEV;
95 atomic_inc(&d7s_users);
96 return 0;
97}
98
99static int d7s_release(struct inode *inode, struct file *f)
100{
101 /* Reset flipped state to OBP default only if
102 * no other users have the device open and we
103 * are not operating in solaris-compat mode
104 */
105 if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
106 int regval = 0;
107
108 regval = readb(d7s_regs);
109 (0 == d7s_obpflipped()) ?
110 writeb(regval |= D7S_FLIP, d7s_regs):
111 writeb(regval &= ~D7S_FLIP, d7s_regs);
112 }
113
114 return 0;
115}
116
117static int d7s_ioctl(struct inode *inode, struct file *f,
118 unsigned int cmd, unsigned long arg)
119{
120 __u8 regs = readb(d7s_regs);
121 __u8 ireg = 0;
122
123 if (D7S_MINOR != iminor(inode))
124 return -ENODEV;
125
126 switch (cmd) {
127 case D7SIOCWR:
128 /* assign device register values
129 * we mask-out D7S_FLIP if in sol_compat mode
130 */
131 if (get_user(ireg, (int __user *) arg))
132 return -EFAULT;
133 if (0 != sol_compat) {
134 (regs & D7S_FLIP) ?
135 (ireg |= D7S_FLIP) : (ireg &= ~D7S_FLIP);
136 }
137 writeb(ireg, d7s_regs);
138 break;
139
140 case D7SIOCRD:
141 /* retrieve device register values
142 * NOTE: Solaris implementation returns D7S_FLIP bit
143 * as toggled by user, even though it does not honor it.
144 * This driver will not misinform you about the state
145 * of your hardware while in sol_compat mode
146 */
147 if (put_user(regs, (int __user *) arg))
148 return -EFAULT;
149 break;
150
151 case D7SIOCTM:
152 /* toggle device mode-- flip display orientation */
153 (regs & D7S_FLIP) ?
154 (regs &= ~D7S_FLIP) : (regs |= D7S_FLIP);
155 writeb(regs, d7s_regs);
156 break;
157 };
158
159 return 0;
160}
161
162static struct file_operations d7s_fops = {
163 .owner = THIS_MODULE,
164 .ioctl = d7s_ioctl,
165 .open = d7s_open,
166 .release = d7s_release,
167};
168
169static struct miscdevice d7s_miscdev = { D7S_MINOR, D7S_DEVNAME, &d7s_fops };
170
171static int __init d7s_init(void)
172{
173 struct linux_ebus *ebus = NULL;
174 struct linux_ebus_device *edev = NULL;
175 int iTmp = 0, regs = 0;
176
177 for_each_ebus(ebus) {
178 for_each_ebusdev(edev, ebus) {
179 if (!strcmp(edev->prom_name, D7S_OBPNAME))
180 goto ebus_done;
181 }
182 }
183
184ebus_done:
185 if(!edev) {
186 printk("%s: unable to locate device\n", D7S_DEVNAME);
187 return -ENODEV;
188 }
189
190 d7s_regs = ioremap(edev->resource[0].start, sizeof(__u8));
191
192 iTmp = misc_register(&d7s_miscdev);
193 if (0 != iTmp) {
194 printk("%s: unable to acquire miscdevice minor %i\n",
195 D7S_DEVNAME, D7S_MINOR);
196 iounmap(d7s_regs);
197 return iTmp;
198 }
199
200 /* OBP option "d7s-flipped?" is honored as default
201 * for the device, and reset default when detached
202 */
203 regs = readb(d7s_regs);
204 iTmp = d7s_obpflipped();
205 (0 == iTmp) ?
206 writeb(regs |= D7S_FLIP, d7s_regs):
207 writeb(regs &= ~D7S_FLIP, d7s_regs);
208
209 printk("%s: 7-Segment Display%s at 0x%lx %s\n",
210 D7S_DEVNAME,
211 (0 == iTmp) ? (" (FLIPPED)") : (""),
212 edev->resource[0].start,
213 (0 != sol_compat) ? ("in sol_compat mode") : (""));
214
215 return 0;
216}
217
218static void __exit d7s_cleanup(void)
219{
220 int regs = readb(d7s_regs);
221
222 /* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
223 if (0 == sol_compat) {
224 (0 == d7s_obpflipped()) ?
225 writeb(regs |= D7S_FLIP, d7s_regs):
226 writeb(regs &= ~D7S_FLIP, d7s_regs);
227 }
228
229 misc_deregister(&d7s_miscdev);
230 d7s_free();
231}
232
233module_init(d7s_init);
234module_exit(d7s_cleanup);