Commit | Line | Data |
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70e84049 MOS |
1 | /* |
2 | * Filename: cfag12864b.c | |
3 | * Version: 0.1.0 | |
4 | * Description: cfag12864b LCD driver | |
5 | * License: GPLv2 | |
6 | * Depends: ks0108 | |
7 | * | |
450c622e | 8 | * Author: Copyright (C) Miguel Ojeda Sandonis |
70e84049 MOS |
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/cdev.h> | |
31 | #include <linux/delay.h> | |
32 | #include <linux/device.h> | |
33 | #include <linux/jiffies.h> | |
34 | #include <linux/mutex.h> | |
35 | #include <linux/uaccess.h> | |
36 | #include <linux/vmalloc.h> | |
37 | #include <linux/workqueue.h> | |
38 | #include <linux/ks0108.h> | |
39 | #include <linux/cfag12864b.h> | |
40 | ||
41 | ||
42 | #define CFAG12864B_NAME "cfag12864b" | |
43 | ||
44 | /* | |
45 | * Module Parameters | |
46 | */ | |
47 | ||
48 | static unsigned int cfag12864b_rate = CONFIG_CFAG12864B_RATE; | |
49 | module_param(cfag12864b_rate, uint, S_IRUGO); | |
50 | MODULE_PARM_DESC(cfag12864b_rate, | |
51 | "Refresh rate (hertzs)"); | |
52 | ||
53 | unsigned int cfag12864b_getrate(void) | |
54 | { | |
55 | return cfag12864b_rate; | |
56 | } | |
57 | ||
58 | /* | |
59 | * cfag12864b Commands | |
60 | * | |
61 | * E = Enable signal | |
62 | * Everytime E switch from low to high, | |
63 | * cfag12864b/ks0108 reads the command/data. | |
64 | * | |
65 | * CS1 = First ks0108controller. | |
66 | * If high, the first ks0108 controller receives commands/data. | |
67 | * | |
68 | * CS2 = Second ks0108 controller | |
69 | * If high, the second ks0108 controller receives commands/data. | |
70 | * | |
71 | * DI = Data/Instruction | |
72 | * If low, cfag12864b will expect commands. | |
73 | * If high, cfag12864b will expect data. | |
74 | * | |
75 | */ | |
76 | ||
77 | #define bit(n) (((unsigned char)1)<<(n)) | |
78 | ||
79 | #define CFAG12864B_BIT_E (0) | |
80 | #define CFAG12864B_BIT_CS1 (2) | |
81 | #define CFAG12864B_BIT_CS2 (1) | |
82 | #define CFAG12864B_BIT_DI (3) | |
83 | ||
84 | static unsigned char cfag12864b_state; | |
85 | ||
86 | static void cfag12864b_set(void) | |
87 | { | |
88 | ks0108_writecontrol(cfag12864b_state); | |
89 | } | |
90 | ||
91 | static void cfag12864b_setbit(unsigned char state, unsigned char n) | |
92 | { | |
93 | if (state) | |
94 | cfag12864b_state |= bit(n); | |
95 | else | |
96 | cfag12864b_state &= ~bit(n); | |
97 | } | |
98 | ||
99 | static void cfag12864b_e(unsigned char state) | |
100 | { | |
101 | cfag12864b_setbit(state, CFAG12864B_BIT_E); | |
102 | cfag12864b_set(); | |
103 | } | |
104 | ||
105 | static void cfag12864b_cs1(unsigned char state) | |
106 | { | |
107 | cfag12864b_setbit(state, CFAG12864B_BIT_CS1); | |
108 | } | |
109 | ||
110 | static void cfag12864b_cs2(unsigned char state) | |
111 | { | |
112 | cfag12864b_setbit(state, CFAG12864B_BIT_CS2); | |
113 | } | |
114 | ||
115 | static void cfag12864b_di(unsigned char state) | |
116 | { | |
117 | cfag12864b_setbit(state, CFAG12864B_BIT_DI); | |
118 | } | |
119 | ||
120 | static void cfag12864b_setcontrollers(unsigned char first, | |
121 | unsigned char second) | |
122 | { | |
123 | if (first) | |
124 | cfag12864b_cs1(0); | |
125 | else | |
126 | cfag12864b_cs1(1); | |
127 | ||
128 | if (second) | |
129 | cfag12864b_cs2(0); | |
130 | else | |
131 | cfag12864b_cs2(1); | |
132 | } | |
133 | ||
134 | static void cfag12864b_controller(unsigned char which) | |
135 | { | |
136 | if (which == 0) | |
137 | cfag12864b_setcontrollers(1, 0); | |
138 | else if (which == 1) | |
139 | cfag12864b_setcontrollers(0, 1); | |
140 | } | |
141 | ||
142 | static void cfag12864b_displaystate(unsigned char state) | |
143 | { | |
144 | cfag12864b_di(0); | |
145 | cfag12864b_e(1); | |
146 | ks0108_displaystate(state); | |
147 | cfag12864b_e(0); | |
148 | } | |
149 | ||
150 | static void cfag12864b_address(unsigned char address) | |
151 | { | |
152 | cfag12864b_di(0); | |
153 | cfag12864b_e(1); | |
154 | ks0108_address(address); | |
155 | cfag12864b_e(0); | |
156 | } | |
157 | ||
158 | static void cfag12864b_page(unsigned char page) | |
159 | { | |
160 | cfag12864b_di(0); | |
161 | cfag12864b_e(1); | |
162 | ks0108_page(page); | |
163 | cfag12864b_e(0); | |
164 | } | |
165 | ||
166 | static void cfag12864b_startline(unsigned char startline) | |
167 | { | |
168 | cfag12864b_di(0); | |
169 | cfag12864b_e(1); | |
170 | ks0108_startline(startline); | |
171 | cfag12864b_e(0); | |
172 | } | |
173 | ||
174 | static void cfag12864b_writebyte(unsigned char byte) | |
175 | { | |
176 | cfag12864b_di(1); | |
177 | cfag12864b_e(1); | |
178 | ks0108_writedata(byte); | |
179 | cfag12864b_e(0); | |
180 | } | |
181 | ||
182 | static void cfag12864b_nop(void) | |
183 | { | |
184 | cfag12864b_startline(0); | |
185 | } | |
186 | ||
187 | /* | |
188 | * cfag12864b Internal Commands | |
189 | */ | |
190 | ||
191 | static void cfag12864b_on(void) | |
192 | { | |
193 | cfag12864b_setcontrollers(1, 1); | |
194 | cfag12864b_displaystate(1); | |
195 | } | |
196 | ||
197 | static void cfag12864b_off(void) | |
198 | { | |
199 | cfag12864b_setcontrollers(1, 1); | |
200 | cfag12864b_displaystate(0); | |
201 | } | |
202 | ||
203 | static void cfag12864b_clear(void) | |
204 | { | |
205 | unsigned char i, j; | |
206 | ||
207 | cfag12864b_setcontrollers(1, 1); | |
208 | for (i = 0; i < CFAG12864B_PAGES; i++) { | |
209 | cfag12864b_page(i); | |
210 | cfag12864b_address(0); | |
211 | for (j = 0; j < CFAG12864B_ADDRESSES; j++) | |
212 | cfag12864b_writebyte(0); | |
213 | } | |
214 | } | |
215 | ||
216 | /* | |
217 | * Update work | |
218 | */ | |
219 | ||
220 | unsigned char *cfag12864b_buffer; | |
221 | static unsigned char *cfag12864b_cache; | |
222 | static DEFINE_MUTEX(cfag12864b_mutex); | |
223 | static unsigned char cfag12864b_updating; | |
224 | static void cfag12864b_update(struct work_struct *delayed_work); | |
225 | static struct workqueue_struct *cfag12864b_workqueue; | |
226 | static DECLARE_DELAYED_WORK(cfag12864b_work, cfag12864b_update); | |
227 | ||
228 | static void cfag12864b_queue(void) | |
229 | { | |
230 | queue_delayed_work(cfag12864b_workqueue, &cfag12864b_work, | |
231 | HZ / cfag12864b_rate); | |
232 | } | |
233 | ||
234 | unsigned char cfag12864b_enable(void) | |
235 | { | |
236 | unsigned char ret; | |
237 | ||
238 | mutex_lock(&cfag12864b_mutex); | |
239 | ||
240 | if (!cfag12864b_updating) { | |
241 | cfag12864b_updating = 1; | |
242 | cfag12864b_queue(); | |
243 | ret = 0; | |
244 | } else | |
245 | ret = 1; | |
246 | ||
247 | mutex_unlock(&cfag12864b_mutex); | |
248 | ||
249 | return ret; | |
250 | } | |
251 | ||
252 | void cfag12864b_disable(void) | |
253 | { | |
254 | mutex_lock(&cfag12864b_mutex); | |
255 | ||
256 | if (cfag12864b_updating) { | |
257 | cfag12864b_updating = 0; | |
258 | cancel_delayed_work(&cfag12864b_work); | |
259 | flush_workqueue(cfag12864b_workqueue); | |
260 | } | |
261 | ||
262 | mutex_unlock(&cfag12864b_mutex); | |
263 | } | |
264 | ||
265 | unsigned char cfag12864b_isenabled(void) | |
266 | { | |
267 | return cfag12864b_updating; | |
268 | } | |
269 | ||
270 | static void cfag12864b_update(struct work_struct *work) | |
271 | { | |
272 | unsigned char c; | |
273 | unsigned short i, j, k, b; | |
274 | ||
275 | if (memcmp(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE)) { | |
276 | for (i = 0; i < CFAG12864B_CONTROLLERS; i++) { | |
277 | cfag12864b_controller(i); | |
278 | cfag12864b_nop(); | |
279 | for (j = 0; j < CFAG12864B_PAGES; j++) { | |
280 | cfag12864b_page(j); | |
281 | cfag12864b_nop(); | |
282 | cfag12864b_address(0); | |
283 | cfag12864b_nop(); | |
284 | for (k = 0; k < CFAG12864B_ADDRESSES; k++) { | |
285 | for (c = 0, b = 0; b < 8; b++) | |
286 | if (cfag12864b_buffer | |
287 | [i * CFAG12864B_ADDRESSES / 8 | |
288 | + k / 8 + (j * 8 + b) * | |
289 | CFAG12864B_WIDTH / 8] | |
290 | & bit(k % 8)) | |
291 | c |= bit(b); | |
292 | cfag12864b_writebyte(c); | |
293 | } | |
294 | } | |
295 | } | |
296 | ||
297 | memcpy(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE); | |
298 | } | |
299 | ||
300 | if (cfag12864b_updating) | |
301 | cfag12864b_queue(); | |
302 | } | |
303 | ||
304 | /* | |
305 | * cfag12864b Exported Symbols | |
306 | */ | |
307 | ||
308 | EXPORT_SYMBOL_GPL(cfag12864b_buffer); | |
309 | EXPORT_SYMBOL_GPL(cfag12864b_getrate); | |
310 | EXPORT_SYMBOL_GPL(cfag12864b_enable); | |
311 | EXPORT_SYMBOL_GPL(cfag12864b_disable); | |
312 | EXPORT_SYMBOL_GPL(cfag12864b_isenabled); | |
313 | ||
34173a4a MO |
314 | /* |
315 | * Is the module inited? | |
316 | */ | |
317 | ||
318 | static unsigned char cfag12864b_inited; | |
319 | unsigned char cfag12864b_isinited(void) | |
320 | { | |
321 | return cfag12864b_inited; | |
322 | } | |
323 | EXPORT_SYMBOL_GPL(cfag12864b_isinited); | |
324 | ||
70e84049 MOS |
325 | /* |
326 | * Module Init & Exit | |
327 | */ | |
328 | ||
329 | static int __init cfag12864b_init(void) | |
330 | { | |
331 | int ret = -EINVAL; | |
332 | ||
34173a4a MO |
333 | /* ks0108_init() must be called first */ |
334 | if (!ks0108_isinited()) { | |
335 | printk(KERN_ERR CFAG12864B_NAME ": ERROR: " | |
336 | "ks0108 is not initialized\n"); | |
337 | goto none; | |
338 | } | |
b340e8a5 | 339 | BUILD_BUG_ON(PAGE_SIZE < CFAG12864B_SIZE); |
34173a4a | 340 | |
b340e8a5 | 341 | cfag12864b_buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL); |
70e84049 MOS |
342 | if (cfag12864b_buffer == NULL) { |
343 | printk(KERN_ERR CFAG12864B_NAME ": ERROR: " | |
344 | "can't get a free page\n"); | |
345 | ret = -ENOMEM; | |
346 | goto none; | |
347 | } | |
348 | ||
349 | cfag12864b_cache = kmalloc(sizeof(unsigned char) * | |
350 | CFAG12864B_SIZE, GFP_KERNEL); | |
fe58103a | 351 | if (cfag12864b_cache == NULL) { |
70e84049 MOS |
352 | printk(KERN_ERR CFAG12864B_NAME ": ERROR: " |
353 | "can't alloc cache buffer (%i bytes)\n", | |
354 | CFAG12864B_SIZE); | |
355 | ret = -ENOMEM; | |
356 | goto bufferalloced; | |
357 | } | |
358 | ||
359 | cfag12864b_workqueue = create_singlethread_workqueue(CFAG12864B_NAME); | |
360 | if (cfag12864b_workqueue == NULL) | |
361 | goto cachealloced; | |
362 | ||
70e84049 MOS |
363 | cfag12864b_clear(); |
364 | cfag12864b_on(); | |
365 | ||
34173a4a | 366 | cfag12864b_inited = 1; |
70e84049 MOS |
367 | return 0; |
368 | ||
369 | cachealloced: | |
370 | kfree(cfag12864b_cache); | |
371 | ||
372 | bufferalloced: | |
373 | free_page((unsigned long) cfag12864b_buffer); | |
374 | ||
375 | none: | |
376 | return ret; | |
377 | } | |
378 | ||
379 | static void __exit cfag12864b_exit(void) | |
380 | { | |
381 | cfag12864b_disable(); | |
382 | cfag12864b_off(); | |
383 | destroy_workqueue(cfag12864b_workqueue); | |
384 | kfree(cfag12864b_cache); | |
385 | free_page((unsigned long) cfag12864b_buffer); | |
386 | } | |
387 | ||
388 | module_init(cfag12864b_init); | |
389 | module_exit(cfag12864b_exit); | |
390 | ||
391 | MODULE_LICENSE("GPL v2"); | |
450c622e | 392 | MODULE_AUTHOR("Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>"); |
70e84049 | 393 | MODULE_DESCRIPTION("cfag12864b LCD driver"); |