include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-2.6.git] / drivers / auxdisplay / cfag12864b.c
1 /*
2  *    Filename: cfag12864b.c
3  *     Version: 0.1.0
4  * Description: cfag12864b LCD driver
5  *     License: GPLv2
6  *     Depends: ks0108
7  *
8  *      Author: Copyright (C) Miguel Ojeda Sandonis
9  *        Date: 2006-10-31
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License version 2 as
13  *  published by the Free Software Foundation.
14  *
15  *  This program is distributed in the hope that it will be useful,
16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *  GNU General Public License for more details.
19  *
20  *  You should have received a copy of the GNU General Public License
21  *  along with this program; if not, write to the Free Software
22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
23  *
24  */
25
26 #include <linux/init.h>
27 #include <linux/module.h>
28 #include <linux/kernel.h>
29 #include <linux/fs.h>
30 #include <linux/slab.h>
31 #include <linux/cdev.h>
32 #include <linux/delay.h>
33 #include <linux/device.h>
34 #include <linux/jiffies.h>
35 #include <linux/mutex.h>
36 #include <linux/uaccess.h>
37 #include <linux/vmalloc.h>
38 #include <linux/workqueue.h>
39 #include <linux/ks0108.h>
40 #include <linux/cfag12864b.h>
41
42
43 #define CFAG12864B_NAME "cfag12864b"
44
45 /*
46  * Module Parameters
47  */
48
49 static unsigned int cfag12864b_rate = CONFIG_CFAG12864B_RATE;
50 module_param(cfag12864b_rate, uint, S_IRUGO);
51 MODULE_PARM_DESC(cfag12864b_rate,
52         "Refresh rate (hertzs)");
53
54 unsigned int cfag12864b_getrate(void)
55 {
56         return cfag12864b_rate;
57 }
58
59 /*
60  * cfag12864b Commands
61  *
62  *      E = Enable signal
63  *              Everytime E switch from low to high,
64  *              cfag12864b/ks0108 reads the command/data.
65  *
66  *      CS1 = First ks0108controller.
67  *              If high, the first ks0108 controller receives commands/data.
68  *
69  *      CS2 = Second ks0108 controller
70  *              If high, the second ks0108 controller receives commands/data.
71  *
72  *      DI = Data/Instruction
73  *              If low, cfag12864b will expect commands.
74  *              If high, cfag12864b will expect data.
75  *
76  */
77
78 #define bit(n) (((unsigned char)1)<<(n))
79
80 #define CFAG12864B_BIT_E        (0)
81 #define CFAG12864B_BIT_CS1      (2)
82 #define CFAG12864B_BIT_CS2      (1)
83 #define CFAG12864B_BIT_DI       (3)
84
85 static unsigned char cfag12864b_state;
86
87 static void cfag12864b_set(void)
88 {
89         ks0108_writecontrol(cfag12864b_state);
90 }
91
92 static void cfag12864b_setbit(unsigned char state, unsigned char n)
93 {
94         if (state)
95                 cfag12864b_state |= bit(n);
96         else
97                 cfag12864b_state &= ~bit(n);
98 }
99
100 static void cfag12864b_e(unsigned char state)
101 {
102         cfag12864b_setbit(state, CFAG12864B_BIT_E);
103         cfag12864b_set();
104 }
105
106 static void cfag12864b_cs1(unsigned char state)
107 {
108         cfag12864b_setbit(state, CFAG12864B_BIT_CS1);
109 }
110
111 static void cfag12864b_cs2(unsigned char state)
112 {
113         cfag12864b_setbit(state, CFAG12864B_BIT_CS2);
114 }
115
116 static void cfag12864b_di(unsigned char state)
117 {
118         cfag12864b_setbit(state, CFAG12864B_BIT_DI);
119 }
120
121 static void cfag12864b_setcontrollers(unsigned char first,
122         unsigned char second)
123 {
124         if (first)
125                 cfag12864b_cs1(0);
126         else
127                 cfag12864b_cs1(1);
128
129         if (second)
130                 cfag12864b_cs2(0);
131         else
132                 cfag12864b_cs2(1);
133 }
134
135 static void cfag12864b_controller(unsigned char which)
136 {
137         if (which == 0)
138                 cfag12864b_setcontrollers(1, 0);
139         else if (which == 1)
140                 cfag12864b_setcontrollers(0, 1);
141 }
142
143 static void cfag12864b_displaystate(unsigned char state)
144 {
145         cfag12864b_di(0);
146         cfag12864b_e(1);
147         ks0108_displaystate(state);
148         cfag12864b_e(0);
149 }
150
151 static void cfag12864b_address(unsigned char address)
152 {
153         cfag12864b_di(0);
154         cfag12864b_e(1);
155         ks0108_address(address);
156         cfag12864b_e(0);
157 }
158
159 static void cfag12864b_page(unsigned char page)
160 {
161         cfag12864b_di(0);
162         cfag12864b_e(1);
163         ks0108_page(page);
164         cfag12864b_e(0);
165 }
166
167 static void cfag12864b_startline(unsigned char startline)
168 {
169         cfag12864b_di(0);
170         cfag12864b_e(1);
171         ks0108_startline(startline);
172         cfag12864b_e(0);
173 }
174
175 static void cfag12864b_writebyte(unsigned char byte)
176 {
177         cfag12864b_di(1);
178         cfag12864b_e(1);
179         ks0108_writedata(byte);
180         cfag12864b_e(0);
181 }
182
183 static void cfag12864b_nop(void)
184 {
185         cfag12864b_startline(0);
186 }
187
188 /*
189  * cfag12864b Internal Commands
190  */
191
192 static void cfag12864b_on(void)
193 {
194         cfag12864b_setcontrollers(1, 1);
195         cfag12864b_displaystate(1);
196 }
197
198 static void cfag12864b_off(void)
199 {
200         cfag12864b_setcontrollers(1, 1);
201         cfag12864b_displaystate(0);
202 }
203
204 static void cfag12864b_clear(void)
205 {
206         unsigned char i, j;
207
208         cfag12864b_setcontrollers(1, 1);
209         for (i = 0; i < CFAG12864B_PAGES; i++) {
210                 cfag12864b_page(i);
211                 cfag12864b_address(0);
212                 for (j = 0; j < CFAG12864B_ADDRESSES; j++)
213                         cfag12864b_writebyte(0);
214         }
215 }
216
217 /*
218  * Update work
219  */
220
221 unsigned char *cfag12864b_buffer;
222 static unsigned char *cfag12864b_cache;
223 static DEFINE_MUTEX(cfag12864b_mutex);
224 static unsigned char cfag12864b_updating;
225 static void cfag12864b_update(struct work_struct *delayed_work);
226 static struct workqueue_struct *cfag12864b_workqueue;
227 static DECLARE_DELAYED_WORK(cfag12864b_work, cfag12864b_update);
228
229 static void cfag12864b_queue(void)
230 {
231         queue_delayed_work(cfag12864b_workqueue, &cfag12864b_work,
232                 HZ / cfag12864b_rate);
233 }
234
235 unsigned char cfag12864b_enable(void)
236 {
237         unsigned char ret;
238
239         mutex_lock(&cfag12864b_mutex);
240
241         if (!cfag12864b_updating) {
242                 cfag12864b_updating = 1;
243                 cfag12864b_queue();
244                 ret = 0;
245         } else
246                 ret = 1;
247
248         mutex_unlock(&cfag12864b_mutex);
249
250         return ret;
251 }
252
253 void cfag12864b_disable(void)
254 {
255         mutex_lock(&cfag12864b_mutex);
256
257         if (cfag12864b_updating) {
258                 cfag12864b_updating = 0;
259                 cancel_delayed_work(&cfag12864b_work);
260                 flush_workqueue(cfag12864b_workqueue);
261         }
262
263         mutex_unlock(&cfag12864b_mutex);
264 }
265
266 unsigned char cfag12864b_isenabled(void)
267 {
268         return cfag12864b_updating;
269 }
270
271 static void cfag12864b_update(struct work_struct *work)
272 {
273         unsigned char c;
274         unsigned short i, j, k, b;
275
276         if (memcmp(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE)) {
277                 for (i = 0; i < CFAG12864B_CONTROLLERS; i++) {
278                         cfag12864b_controller(i);
279                         cfag12864b_nop();
280                         for (j = 0; j < CFAG12864B_PAGES; j++) {
281                                 cfag12864b_page(j);
282                                 cfag12864b_nop();
283                                 cfag12864b_address(0);
284                                 cfag12864b_nop();
285                                 for (k = 0; k < CFAG12864B_ADDRESSES; k++) {
286                                         for (c = 0, b = 0; b < 8; b++)
287                                                 if (cfag12864b_buffer
288                                                         [i * CFAG12864B_ADDRESSES / 8
289                                                         + k / 8 + (j * 8 + b) *
290                                                         CFAG12864B_WIDTH / 8]
291                                                         & bit(k % 8))
292                                                         c |= bit(b);
293                                         cfag12864b_writebyte(c);
294                                 }
295                         }
296                 }
297
298                 memcpy(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE);
299         }
300
301         if (cfag12864b_updating)
302                 cfag12864b_queue();
303 }
304
305 /*
306  * cfag12864b Exported Symbols
307  */
308
309 EXPORT_SYMBOL_GPL(cfag12864b_buffer);
310 EXPORT_SYMBOL_GPL(cfag12864b_getrate);
311 EXPORT_SYMBOL_GPL(cfag12864b_enable);
312 EXPORT_SYMBOL_GPL(cfag12864b_disable);
313 EXPORT_SYMBOL_GPL(cfag12864b_isenabled);
314
315 /*
316  * Is the module inited?
317  */
318
319 static unsigned char cfag12864b_inited;
320 unsigned char cfag12864b_isinited(void)
321 {
322         return cfag12864b_inited;
323 }
324 EXPORT_SYMBOL_GPL(cfag12864b_isinited);
325
326 /*
327  * Module Init & Exit
328  */
329
330 static int __init cfag12864b_init(void)
331 {
332         int ret = -EINVAL;
333
334         /* ks0108_init() must be called first */
335         if (!ks0108_isinited()) {
336                 printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
337                         "ks0108 is not initialized\n");
338                 goto none;
339         }
340         BUILD_BUG_ON(PAGE_SIZE < CFAG12864B_SIZE);
341
342         cfag12864b_buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
343         if (cfag12864b_buffer == NULL) {
344                 printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
345                         "can't get a free page\n");
346                 ret = -ENOMEM;
347                 goto none;
348         }
349
350         cfag12864b_cache = kmalloc(sizeof(unsigned char) *
351                 CFAG12864B_SIZE, GFP_KERNEL);
352         if (cfag12864b_cache == NULL) {
353                 printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
354                         "can't alloc cache buffer (%i bytes)\n",
355                         CFAG12864B_SIZE);
356                 ret = -ENOMEM;
357                 goto bufferalloced;
358         }
359
360         cfag12864b_workqueue = create_singlethread_workqueue(CFAG12864B_NAME);
361         if (cfag12864b_workqueue == NULL)
362                 goto cachealloced;
363
364         cfag12864b_clear();
365         cfag12864b_on();
366
367         cfag12864b_inited = 1;
368         return 0;
369
370 cachealloced:
371         kfree(cfag12864b_cache);
372
373 bufferalloced:
374         free_page((unsigned long) cfag12864b_buffer);
375
376 none:
377         return ret;
378 }
379
380 static void __exit cfag12864b_exit(void)
381 {
382         cfag12864b_disable();
383         cfag12864b_off();
384         destroy_workqueue(cfag12864b_workqueue);
385         kfree(cfag12864b_cache);
386         free_page((unsigned long) cfag12864b_buffer);
387 }
388
389 module_init(cfag12864b_init);
390 module_exit(cfag12864b_exit);
391
392 MODULE_LICENSE("GPL v2");
393 MODULE_AUTHOR("Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>");
394 MODULE_DESCRIPTION("cfag12864b LCD driver");