Staging: speakup: don't die if accessing sysfs without synth
[cascardo/linux.git] / drivers / staging / speakup / synth.c
1 #include <linux/types.h>
2 #include <linux/ctype.h>        /* for isdigit() and friends */
3 #include <linux/fs.h>
4 #include <linux/mm.h>           /* for verify_area */
5 #include <linux/errno.h>        /* for -EBUSY */
6 #include <linux/ioport.h>       /* for check_region, request_region */
7 #include <linux/interrupt.h>
8 #include <linux/delay.h>        /* for loops_per_sec */
9 #include <linux/kmod.h>
10 #include <linux/jiffies.h>
11 #include <linux/uaccess.h> /* for copy_from_user */
12 #include <linux/sched.h>
13 #include <linux/timer.h>
14 #include <linux/kthread.h>
15
16 #include "spk_priv.h"
17 #include "speakup.h"
18 #include "serialio.h"
19
20 #define MAXSYNTHS       16      /* Max number of synths in array. */
21 static struct spk_synth *synths[MAXSYNTHS];
22 struct spk_synth *synth;
23 char spk_pitch_buff[32] = "";
24 static int module_status;
25 bool spk_quiet_boot;
26
27 struct speakup_info_t speakup_info = {
28         /*
29          * This spinlock is used to protect the entire speakup machinery, and
30          * must be taken at each kernel->speakup transition and released at
31          * each corresponding speakup->kernel transition.
32          *
33          * The progression thread only interferes with the speakup machinery through
34          * the synth buffer, so only needs to take the lock while tinkering with
35          * the buffer.
36          *
37          * We use spin_lock/trylock_irqsave and spin_unlock_irqrestore with this
38          * spinlock because speakup needs to disable the keyboard IRQ.
39          */
40         .spinlock = __SPIN_LOCK_UNLOCKED(speakup_info.spinlock),
41         .flushing = 0,
42 };
43 EXPORT_SYMBOL_GPL(speakup_info);
44
45 static int do_synth_init(struct spk_synth *in_synth);
46
47 int spk_serial_synth_probe(struct spk_synth *synth)
48 {
49         const struct old_serial_port *ser;
50         int failed = 0;
51
52         if ((synth->ser >= SPK_LO_TTY) && (synth->ser <= SPK_HI_TTY)) {
53                 ser = spk_serial_init(synth->ser);
54                 if (ser == NULL) {
55                         failed = -1;
56                 } else {
57                         outb_p(0, ser->port);
58                         mdelay(1);
59                         outb_p('\r', ser->port);
60                 }
61         } else {
62                 failed = -1;
63                 pr_warn("ttyS%i is an invalid port\n", synth->ser);
64         }
65         if (failed) {
66                 pr_info("%s: not found\n", synth->long_name);
67                 return -ENODEV;
68         }
69         pr_info("%s: ttyS%i, Driver Version %s\n",
70                         synth->long_name, synth->ser, synth->version);
71         synth->alive = 1;
72         return 0;
73 }
74 EXPORT_SYMBOL_GPL(spk_serial_synth_probe);
75
76 /* Main loop of the progression thread: keep eating from the buffer
77  * and push to the serial port, waiting as needed
78  *
79  * For devices that have a "full" notification mechanism, the driver can
80  * adapt the loop the way they prefer.
81  */
82 void spk_do_catch_up(struct spk_synth *synth)
83 {
84         u_char ch;
85         unsigned long flags;
86         unsigned long jiff_max;
87         struct var_t *delay_time;
88         struct var_t *full_time;
89         struct var_t *jiffy_delta;
90         int jiffy_delta_val;
91         int delay_time_val;
92         int full_time_val;
93
94         jiffy_delta = spk_get_var(JIFFY);
95         full_time = spk_get_var(FULL);
96         delay_time = spk_get_var(DELAY);
97
98         spin_lock_irqsave(&speakup_info.spinlock, flags);
99         jiffy_delta_val = jiffy_delta->u.n.value;
100         spin_unlock_irqrestore(&speakup_info.spinlock, flags);
101
102         jiff_max = jiffies + jiffy_delta_val;
103         while (!kthread_should_stop()) {
104                 spin_lock_irqsave(&speakup_info.spinlock, flags);
105                 if (speakup_info.flushing) {
106                         speakup_info.flushing = 0;
107                         spin_unlock_irqrestore(&speakup_info.spinlock, flags);
108                         synth->flush(synth);
109                         continue;
110                 }
111                 if (synth_buffer_empty()) {
112                         spin_unlock_irqrestore(&speakup_info.spinlock, flags);
113                         break;
114                 }
115                 ch = synth_buffer_peek();
116                 set_current_state(TASK_INTERRUPTIBLE);
117                 full_time_val = full_time->u.n.value;
118                 spin_unlock_irqrestore(&speakup_info.spinlock, flags);
119                 if (ch == '\n')
120                         ch = synth->procspeech;
121                 if (!spk_serial_out(ch)) {
122                         schedule_timeout(msecs_to_jiffies(full_time_val));
123                         continue;
124                 }
125                 if ((jiffies >= jiff_max) && (ch == SPACE)) {
126                         spin_lock_irqsave(&speakup_info.spinlock, flags);
127                         jiffy_delta_val = jiffy_delta->u.n.value;
128                         delay_time_val = delay_time->u.n.value;
129                         full_time_val = full_time->u.n.value;
130                         spin_unlock_irqrestore(&speakup_info.spinlock, flags);
131                         if (spk_serial_out(synth->procspeech))
132                                 schedule_timeout(
133                                         msecs_to_jiffies(delay_time_val));
134                         else
135                                 schedule_timeout(
136                                         msecs_to_jiffies(full_time_val));
137                         jiff_max = jiffies + jiffy_delta_val;
138                 }
139                 set_current_state(TASK_RUNNING);
140                 spin_lock_irqsave(&speakup_info.spinlock, flags);
141                 synth_buffer_getc();
142                 spin_unlock_irqrestore(&speakup_info.spinlock, flags);
143         }
144         spk_serial_out(synth->procspeech);
145 }
146 EXPORT_SYMBOL_GPL(spk_do_catch_up);
147
148 const char *spk_synth_immediate(struct spk_synth *synth, const char *buff)
149 {
150         u_char ch;
151         while ((ch = *buff)) {
152                 if (ch == '\n')
153                         ch = synth->procspeech;
154                 if (spk_wait_for_xmitr())
155                         outb(ch, speakup_info.port_tts);
156                 else
157                         return buff;
158                 buff++;
159         }
160         return NULL;
161 }
162 EXPORT_SYMBOL_GPL(spk_synth_immediate);
163
164 void spk_synth_flush(struct spk_synth *synth)
165 {
166         spk_serial_out(synth->clear);
167 }
168 EXPORT_SYMBOL_GPL(spk_synth_flush);
169
170 int spk_synth_is_alive_nop(struct spk_synth *synth)
171 {
172         synth->alive = 1;
173         return 1;
174 }
175 EXPORT_SYMBOL_GPL(spk_synth_is_alive_nop);
176
177 int spk_synth_is_alive_restart(struct spk_synth *synth)
178 {
179         if (synth->alive)
180                 return 1;
181         if (!synth->alive && spk_wait_for_xmitr() > 0) {
182                 /* restart */
183                 synth->alive = 1;
184                 synth_printf("%s", synth->init);
185                 return 2; /* reenabled */
186         }
187         pr_warn("%s: can't restart synth\n", synth->long_name);
188         return 0;
189 }
190 EXPORT_SYMBOL_GPL(spk_synth_is_alive_restart);
191
192 static void thread_wake_up(u_long data)
193 {
194         wake_up_interruptible_all(&speakup_event);
195 }
196
197 static DEFINE_TIMER(thread_timer, thread_wake_up, 0, 0);
198
199 void synth_start(void)
200 {
201         struct var_t *trigger_time;
202
203         if (!synth->alive) {
204                 synth_buffer_clear();
205                 return;
206         }
207         trigger_time = spk_get_var(TRIGGER);
208         if (!timer_pending(&thread_timer))
209                 mod_timer(&thread_timer, jiffies +
210                         msecs_to_jiffies(trigger_time->u.n.value));
211 }
212
213 void spk_do_flush(void)
214 {
215         if (!synth)
216                 return;
217
218         speakup_info.flushing = 1;
219         synth_buffer_clear();
220         if (synth->alive) {
221                 if (spk_pitch_shift) {
222                         synth_printf("%s", spk_pitch_buff);
223                         spk_pitch_shift = 0;
224                 }
225         }
226         wake_up_interruptible_all(&speakup_event);
227         wake_up_process(speakup_task);
228 }
229
230 void synth_write(const char *buf, size_t count)
231 {
232         while (count--)
233                 synth_buffer_add(*buf++);
234         synth_start();
235 }
236
237 void synth_printf(const char *fmt, ...)
238 {
239         va_list args;
240         unsigned char buf[160], *p;
241         int r;
242
243         va_start(args, fmt);
244         r = vsnprintf(buf, sizeof(buf), fmt, args);
245         va_end(args);
246         if (r > sizeof(buf) - 1)
247                 r = sizeof(buf) - 1;
248
249         p = buf;
250         while (r--)
251                 synth_buffer_add(*p++);
252         synth_start();
253 }
254 EXPORT_SYMBOL_GPL(synth_printf);
255
256 static int index_count;
257 static int sentence_count;
258
259 void spk_reset_index_count(int sc)
260 {
261         static int first = 1;
262         if (first)
263                 first = 0;
264         else
265                 synth->get_index();
266         index_count = 0;
267         sentence_count = sc;
268 }
269
270 int synth_supports_indexing(void)
271 {
272         if (synth->get_index != NULL)
273                 return 1;
274         return 0;
275 }
276
277 void synth_insert_next_index(int sent_num)
278 {
279         int out;
280         if (synth->alive) {
281                 if (sent_num == 0) {
282                         synth->indexing.currindex++;
283                         index_count++;
284                         if (synth->indexing.currindex >
285                                         synth->indexing.highindex)
286                                 synth->indexing.currindex =
287                                         synth->indexing.lowindex;
288                 }
289
290                 out = synth->indexing.currindex * 10 + sent_num;
291                 synth_printf(synth->indexing.command, out, out);
292         }
293 }
294
295 void spk_get_index_count(int *linecount, int *sentcount)
296 {
297         int ind = synth->get_index();
298         if (ind) {
299                 sentence_count = ind % 10;
300
301                 if ((ind / 10) <= synth->indexing.currindex)
302                         index_count = synth->indexing.currindex-(ind/10);
303                 else
304                         index_count = synth->indexing.currindex
305                                 -synth->indexing.lowindex
306                                 + synth->indexing.highindex-(ind/10)+1;
307
308         }
309         *sentcount = sentence_count;
310         *linecount = index_count;
311 }
312
313 static struct resource synth_res;
314
315 int synth_request_region(unsigned long start, unsigned long n)
316 {
317         struct resource *parent = &ioport_resource;
318         memset(&synth_res, 0, sizeof(synth_res));
319         synth_res.name = synth->name;
320         synth_res.start = start;
321         synth_res.end = start + n - 1;
322         synth_res.flags = IORESOURCE_BUSY;
323         return request_resource(parent, &synth_res);
324 }
325 EXPORT_SYMBOL_GPL(synth_request_region);
326
327 int synth_release_region(unsigned long start, unsigned long n)
328 {
329         return release_resource(&synth_res);
330 }
331 EXPORT_SYMBOL_GPL(synth_release_region);
332
333 struct var_t synth_time_vars[] = {
334         { DELAY, .u.n = {NULL, 100, 100, 2000, 0, 0, NULL } },
335         { TRIGGER, .u.n = {NULL, 20, 10, 2000, 0, 0, NULL } },
336         { JIFFY, .u.n = {NULL, 50, 20, 200, 0, 0, NULL } },
337         { FULL, .u.n = {NULL, 400, 200, 60000, 0, 0, NULL } },
338         V_LAST_VAR
339 };
340
341 /* called by: speakup_init() */
342 int synth_init(char *synth_name)
343 {
344         int i;
345         int ret = 0;
346         struct spk_synth *synth = NULL;
347
348         if (synth_name == NULL)
349                 return 0;
350
351         if (strcmp(synth_name, "none") == 0) {
352                 mutex_lock(&spk_mutex);
353                 synth_release();
354                 mutex_unlock(&spk_mutex);
355                 return 0;
356         }
357
358         mutex_lock(&spk_mutex);
359         /* First, check if we already have it loaded. */
360         for (i = 0; i < MAXSYNTHS && synths[i] != NULL; i++)
361                 if (strcmp(synths[i]->name, synth_name) == 0)
362                         synth = synths[i];
363
364         /* If we got one, initialize it now. */
365         if (synth)
366                 ret = do_synth_init(synth);
367         else
368                 ret = -ENODEV;
369         mutex_unlock(&spk_mutex);
370
371         return ret;
372 }
373
374 /* called by: synth_add() */
375 static int do_synth_init(struct spk_synth *in_synth)
376 {
377         struct var_t *var;
378
379         synth_release();
380         if (in_synth->checkval != SYNTH_CHECK)
381                 return -EINVAL;
382         synth = in_synth;
383         synth->alive = 0;
384         pr_warn("synth probe\n");
385         if (synth->probe(synth) < 0) {
386                 pr_warn("%s: device probe failed\n", in_synth->name);
387                 synth = NULL;
388                 return -ENODEV;
389         }
390         synth_time_vars[0].u.n.value =
391                 synth_time_vars[0].u.n.default_val = synth->delay;
392         synth_time_vars[1].u.n.value =
393                 synth_time_vars[1].u.n.default_val = synth->trigger;
394         synth_time_vars[2].u.n.value =
395                 synth_time_vars[2].u.n.default_val = synth->jiffies;
396         synth_time_vars[3].u.n.value =
397                 synth_time_vars[3].u.n.default_val = synth->full;
398         synth_printf("%s", synth->init);
399         for (var = synth->vars;
400                 (var->var_id >= 0) && (var->var_id < MAXVARS); var++)
401                 speakup_register_var(var);
402         if (!spk_quiet_boot)
403                 synth_printf("%s found\n", synth->long_name);
404         if (synth->attributes.name
405         && sysfs_create_group(speakup_kobj, &(synth->attributes)) < 0)
406                 return -ENOMEM;
407         synth_flags = synth->flags;
408         wake_up_interruptible_all(&speakup_event);
409         if (speakup_task)
410                 wake_up_process(speakup_task);
411         return 0;
412 }
413
414 void synth_release(void)
415 {
416         struct var_t *var;
417         unsigned long flags;
418
419         if (synth == NULL)
420                 return;
421         spin_lock_irqsave(&speakup_info.spinlock, flags);
422         pr_info("releasing synth %s\n", synth->name);
423         synth->alive = 0;
424         del_timer(&thread_timer);
425         spin_unlock_irqrestore(&speakup_info.spinlock, flags);
426         if (synth->attributes.name)
427                 sysfs_remove_group(speakup_kobj, &(synth->attributes));
428         for (var = synth->vars; var->var_id != MAXVARS; var++)
429                 speakup_unregister_var(var->var_id);
430         spk_stop_serial_interrupt();
431         synth->release();
432         synth = NULL;
433 }
434
435 /* called by: all_driver_init() */
436 int synth_add(struct spk_synth *in_synth)
437 {
438         int i;
439         int status = 0;
440         mutex_lock(&spk_mutex);
441         for (i = 0; i < MAXSYNTHS && synths[i] != NULL; i++)
442                 /* synth_remove() is responsible for rotating the array down */
443                 if (in_synth == synths[i]) {
444                         mutex_unlock(&spk_mutex);
445                         return 0;
446                 }
447         if (i == MAXSYNTHS) {
448                 pr_warn("Error: attempting to add a synth past end of array\n");
449                 mutex_unlock(&spk_mutex);
450                 return -1;
451         }
452         synths[i++] = in_synth;
453         synths[i] = NULL;
454         if (in_synth->startup)
455                 status = do_synth_init(in_synth);
456         mutex_unlock(&spk_mutex);
457         return status;
458 }
459 EXPORT_SYMBOL_GPL(synth_add);
460
461 void synth_remove(struct spk_synth *in_synth)
462 {
463         int i;
464         mutex_lock(&spk_mutex);
465         if (synth == in_synth)
466                 synth_release();
467         for (i = 0; synths[i] != NULL; i++) {
468                 if (in_synth == synths[i])
469                         break;
470         }
471         for ( ; synths[i] != NULL; i++) /* compress table */
472                 synths[i] = synths[i+1];
473         module_status = 0;
474         mutex_unlock(&spk_mutex);
475 }
476 EXPORT_SYMBOL_GPL(synth_remove);
477
478 short spk_punc_masks[] = { 0, SOME, MOST, PUNC, PUNC|B_SYM };