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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> | |
5a0e3ad6 | 30 | #include <linux/slab.h> |
70e84049 MOS |
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, | |
25985edc | 52 | "Refresh rate (hertz)"); |
70e84049 MOS |
53 | |
54 | unsigned int cfag12864b_getrate(void) | |
55 | { | |
56 | return cfag12864b_rate; | |
57 | } | |
58 | ||
59 | /* | |
60 | * cfag12864b Commands | |
61 | * | |
62 | * E = Enable signal | |
25985edc | 63 | * Every time E switch from low to high, |
70e84049 MOS |
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 | ||
34173a4a MO |
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 | ||
70e84049 MOS |
326 | /* |
327 | * Module Init & Exit | |
328 | */ | |
329 | ||
330 | static int __init cfag12864b_init(void) | |
331 | { | |
332 | int ret = -EINVAL; | |
333 | ||
34173a4a MO |
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 | } | |
b340e8a5 | 340 | BUILD_BUG_ON(PAGE_SIZE < CFAG12864B_SIZE); |
34173a4a | 341 | |
b340e8a5 | 342 | cfag12864b_buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL); |
70e84049 MOS |
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); | |
fe58103a | 352 | if (cfag12864b_cache == NULL) { |
70e84049 MOS |
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 | ||
70e84049 MOS |
364 | cfag12864b_clear(); |
365 | cfag12864b_on(); | |
366 | ||
34173a4a | 367 | cfag12864b_inited = 1; |
70e84049 MOS |
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"); | |
450c622e | 393 | MODULE_AUTHOR("Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>"); |
70e84049 | 394 | MODULE_DESCRIPTION("cfag12864b LCD driver"); |