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David S. Miller95d43902008-08-29 18:01:58 -07001/* display7seg.c - Driver implementation for the 7-segment display
2 * present on Sun Microsystems CP1400 and CP1500
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 */
6
Himangi Saraogi57a4a3d2014-05-27 03:02:07 +05307#include <linux/device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/fs.h>
11#include <linux/errno.h>
12#include <linux/major.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/miscdevice.h>
Peter Osterlundfb911ee2005-09-13 01:25:15 -070014#include <linux/ioport.h> /* request_region */
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090015#include <linux/slab.h>
Arnd Bergmanna3108ca2010-07-20 23:36:39 -070016#include <linux/mutex.h>
David S. Miller95d43902008-08-29 18:01:58 -070017#include <linux/of.h>
18#include <linux/of_device.h>
Arun Sharma600634972011-07-26 16:09:06 -070019#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/uaccess.h> /* put_/get_user */
David S. Miller3049f892007-05-13 22:22:47 -070021#include <asm/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#include <asm/display7seg.h>
24
25#define D7S_MINOR 193
David S. Miller95d43902008-08-29 18:01:58 -070026#define DRIVER_NAME "d7s"
27#define PFX DRIVER_NAME ": "
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
Arnd Bergmanna3108ca2010-07-20 23:36:39 -070029static DEFINE_MUTEX(d7s_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070030static int sol_compat = 0; /* Solaris compatibility mode */
31
Linus Torvalds1da177e2005-04-16 15:20:36 -070032/* 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 */
David S. Miller95d43902008-08-29 18:01:58 -070046module_param(sol_compat, int, 0);
47MODULE_PARM_DESC(sol_compat,
48 "Disables documented functionality omitted from Solaris driver");
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
David S. Miller95d43902008-08-29 18:01:58 -070050MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
51MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500");
Linus Torvalds1da177e2005-04-16 15:20:36 -070052MODULE_LICENSE("GPL");
David S. Miller95d43902008-08-29 18:01:58 -070053MODULE_SUPPORTED_DEVICE("d7s");
54
55struct d7s {
56 void __iomem *regs;
57 bool flipped;
58};
59struct d7s *d7s_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070072static 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 /* 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) {
David S. Miller95d43902008-08-29 18:01:58 -070089 struct d7s *p = d7s_device;
90 u8 regval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
David S. Miller95d43902008-08-29 18:01:58 -070092 regval = readb(p->regs);
93 if (p->flipped)
94 regval |= D7S_FLIP;
95 else
96 regval &= ~D7S_FLIP;
97 writeb(regval, p->regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 }
99
100 return 0;
101}
102
Christoph Hellwig1d5d00b2005-11-07 14:13:01 -0800103static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104{
David S. Miller95d43902008-08-29 18:01:58 -0700105 struct d7s *p = d7s_device;
106 u8 regs = readb(p->regs);
Andrew Mortona5aac372005-11-10 21:14:16 -0800107 int error = 0;
David S. Miller95d43902008-08-29 18:01:58 -0700108 u8 ireg = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
Al Viro496ad9a2013-01-23 17:07:38 -0500110 if (D7S_MINOR != iminor(file_inode(file)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 return -ENODEV;
112
Arnd Bergmanna3108ca2010-07-20 23:36:39 -0700113 mutex_lock(&d7s_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 switch (cmd) {
115 case D7SIOCWR:
David S. Miller95d43902008-08-29 18:01:58 -0700116 /* assign device register values we mask-out D7S_FLIP
117 * if in sol_compat mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 */
Christoph Hellwig1d5d00b2005-11-07 14:13:01 -0800119 if (get_user(ireg, (int __user *) arg)) {
120 error = -EFAULT;
121 break;
122 }
David S. Miller95d43902008-08-29 18:01:58 -0700123 if (sol_compat) {
124 if (regs & D7S_FLIP)
125 ireg |= D7S_FLIP;
126 else
127 ireg &= ~D7S_FLIP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 }
David S. Miller95d43902008-08-29 18:01:58 -0700129 writeb(ireg, p->regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 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 */
Christoph Hellwig1d5d00b2005-11-07 14:13:01 -0800139 if (put_user(regs, (int __user *) arg)) {
140 error = -EFAULT;
141 break;
142 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 break;
144
145 case D7SIOCTM:
146 /* toggle device mode-- flip display orientation */
Rasmus Villemoes54dcf0c2014-06-19 14:31:52 +0200147 regs ^= D7S_FLIP;
David S. Miller95d43902008-08-29 18:01:58 -0700148 writeb(regs, p->regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 break;
Peter Senna Tschudinda201162012-09-12 07:03:12 +0000150 }
Arnd Bergmanna3108ca2010-07-20 23:36:39 -0700151 mutex_unlock(&d7s_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Christoph Hellwig1d5d00b2005-11-07 14:13:01 -0800153 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154}
155
Arjan van de Ven00977a52007-02-12 00:55:34 -0800156static const struct file_operations d7s_fops = {
Christoph Hellwig1d5d00b2005-11-07 14:13:01 -0800157 .owner = THIS_MODULE,
158 .unlocked_ioctl = d7s_ioctl,
159 .compat_ioctl = d7s_ioctl,
160 .open = d7s_open,
161 .release = d7s_release,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200162 .llseek = noop_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163};
164
David S. Miller95d43902008-08-29 18:01:58 -0700165static struct miscdevice d7s_miscdev = {
166 .minor = D7S_MINOR,
167 .name = DRIVER_NAME,
168 .fops = &d7s_fops
169};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Greg Kroah-Hartman082a2002012-12-21 13:24:23 -0800171static int d7s_probe(struct platform_device *op)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172{
David S. Miller95d43902008-08-29 18:01:58 -0700173 struct device_node *opts;
174 int err = -EINVAL;
175 struct d7s *p;
176 u8 regs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
David S. Miller95d43902008-08-29 18:01:58 -0700178 if (d7s_device)
179 goto out;
180
Himangi Saraogi57a4a3d2014-05-27 03:02:07 +0530181 p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);
David S. Miller95d43902008-08-29 18:01:58 -0700182 err = -ENOMEM;
183 if (!p)
184 goto out;
185
186 p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s");
187 if (!p->regs) {
188 printk(KERN_ERR PFX "Cannot map chip registers\n");
189 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 }
191
David S. Miller95d43902008-08-29 18:01:58 -0700192 err = misc_register(&d7s_miscdev);
193 if (err) {
194 printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n",
195 D7S_MINOR);
196 goto out_iounmap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 }
198
David S. Miller95d43902008-08-29 18:01:58 -0700199 /* OBP option "d7s-flipped?" is honored as default for the
200 * device, and reset default when detached
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 */
David S. Miller95d43902008-08-29 18:01:58 -0700202 regs = readb(p->regs);
203 opts = of_find_node_by_path("/options");
204 if (opts &&
205 of_get_property(opts, "d7s-flipped?", NULL))
206 p->flipped = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
David S. Miller95d43902008-08-29 18:01:58 -0700208 if (p->flipped)
209 regs |= D7S_FLIP;
210 else
211 regs &= ~D7S_FLIP;
212
213 writeb(regs, p->regs);
214
Sam Ravnborg3f4528d2009-01-06 13:20:38 -0800215 printk(KERN_INFO PFX "7-Segment Display%s at [%s:0x%llx] %s\n",
Grant Likely61c7a082010-04-13 16:12:29 -0700216 op->dev.of_node->full_name,
David S. Miller95d43902008-08-29 18:01:58 -0700217 (regs & D7S_FLIP) ? " (FLIPPED)" : "",
218 op->resource[0].start,
219 sol_compat ? "in sol_compat mode" : "");
220
221 dev_set_drvdata(&op->dev, p);
222 d7s_device = p;
223 err = 0;
224
225out:
226 return err;
227
228out_iounmap:
229 of_iounmap(&op->resource[0], p->regs, sizeof(u8));
230
231out_free:
David S. Miller95d43902008-08-29 18:01:58 -0700232 goto out;
233}
234
Greg Kroah-Hartman082a2002012-12-21 13:24:23 -0800235static int d7s_remove(struct platform_device *op)
David S. Miller95d43902008-08-29 18:01:58 -0700236{
237 struct d7s *p = dev_get_drvdata(&op->dev);
238 u8 regs = readb(p->regs);
239
240 /* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
241 if (sol_compat) {
242 if (p->flipped)
243 regs |= D7S_FLIP;
244 else
245 regs &= ~D7S_FLIP;
246 writeb(regs, p->regs);
247 }
248
249 misc_deregister(&d7s_miscdev);
250 of_iounmap(&op->resource[0], p->regs, sizeof(u8));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 return 0;
253}
254
David S. Millerfd098312008-08-31 01:23:17 -0700255static const struct of_device_id d7s_match[] = {
David S. Miller95d43902008-08-29 18:01:58 -0700256 {
257 .name = "display7seg",
258 },
259 {},
260};
261MODULE_DEVICE_TABLE(of, d7s_match);
262
Grant Likely4ebb24f2011-02-22 20:01:33 -0700263static struct platform_driver d7s_driver = {
Grant Likely40182942010-04-13 16:13:02 -0700264 .driver = {
265 .name = DRIVER_NAME,
Grant Likely40182942010-04-13 16:13:02 -0700266 .of_match_table = d7s_match,
267 },
David S. Miller95d43902008-08-29 18:01:58 -0700268 .probe = d7s_probe,
Greg Kroah-Hartman082a2002012-12-21 13:24:23 -0800269 .remove = d7s_remove,
David S. Miller95d43902008-08-29 18:01:58 -0700270};
271
Axel Lindbf2b922011-11-26 19:04:25 +0000272module_platform_driver(d7s_driver);