2 * Driver for the SAA5246A or SAA5281 Teletext (=Videotext) decoder chips from
5 * Only capturing of Teletext pages is tested. The videotext chips also have a
6 * TV output but my hardware doesn't use it. For this reason this driver does
7 * not support changing any TV display settings.
9 * Copyright (C) 2004 Michael Geng <linux@MichaelGeng.de>
14 * Copyright (C) 1998 Richard Guenther
15 * <richard.guenther@student.uni-tuebingen.de>
18 * Alan Cox <Alan.Cox@linux.org>
23 * Copyright (C) 1994-97 Martin Buck <martin-2.buck@student.uni-ulm.de>
25 * This program is free software; you can redistribute it and/or modify
26 * it under the terms of the GNU General Public License as published by
27 * the Free Software Foundation; either version 2 of the License, or
28 * (at your option) any later version.
30 * This program is distributed in the hope that it will be useful,
31 * but WITHOUT ANY WARRANTY; without even the implied warranty of
32 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
33 * GNU General Public License for more details.
35 * You should have received a copy of the GNU General Public License
36 * along with this program; if not, write to the Free Software
37 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
41 #include <linux/module.h>
42 #include <linux/kernel.h>
43 #include <linux/sched.h>
45 #include <linux/init.h>
46 #include <linux/i2c.h>
47 #include <linux/videotext.h>
48 #include <linux/videodev.h>
49 #include <media/v4l2-common.h>
50 #include <linux/mutex.h>
54 MODULE_AUTHOR("Michael Geng <linux@MichaelGeng.de>");
55 MODULE_DESCRIPTION("Philips SAA5246A, SAA5281 Teletext decoder driver");
56 MODULE_LICENSE("GPL");
58 struct saa5246a_device
60 u8 pgbuf[NUM_DAUS][VTX_VIRTUALSIZE];
61 int is_searching[NUM_DAUS];
62 struct i2c_client *client;
66 static struct video_device saa_template; /* Declared near bottom */
68 /* Addresses to scan */
69 static unsigned short normal_i2c[] = { I2C_ADDRESS, I2C_CLIENT_END };
72 static struct i2c_client client_template;
74 static int saa5246a_attach(struct i2c_adapter *adap, int addr, int kind)
78 struct i2c_client *client;
79 struct video_device *vd;
80 struct saa5246a_device *t;
82 printk(KERN_INFO "saa5246a: teletext chip found.\n");
83 client=kmalloc(sizeof(*client), GFP_KERNEL);
86 client_template.adapter = adap;
87 client_template.addr = addr;
88 memcpy(client, &client_template, sizeof(*client));
89 t = kzalloc(sizeof(*t), GFP_KERNEL);
95 strlcpy(client->name, IF_NAME, I2C_NAME_SIZE);
99 * Now create a video4linux device
102 vd = video_device_alloc();
109 i2c_set_clientdata(client, vd);
110 memcpy(vd, &saa_template, sizeof(*vd));
112 for (pgbuf = 0; pgbuf < NUM_DAUS; pgbuf++)
114 memset(t->pgbuf[pgbuf], ' ', sizeof(t->pgbuf[0]));
115 t->is_searching[pgbuf] = FALSE;
124 if((err=video_register_device(vd, VFL_TYPE_VTX,-1))<0)
128 video_device_release(vd);
132 i2c_attach_client(client);
137 * We do most of the hard work when we become a device on the i2c.
139 static int saa5246a_probe(struct i2c_adapter *adap)
141 if (adap->class & I2C_CLASS_TV_ANALOG)
142 return i2c_probe(adap, &addr_data, saa5246a_attach);
146 static int saa5246a_detach(struct i2c_client *client)
148 struct video_device *vd = i2c_get_clientdata(client);
149 i2c_detach_client(client);
150 video_unregister_device(vd);
160 static struct i2c_driver i2c_driver_videotext =
163 .name = IF_NAME, /* name */
165 .id = I2C_DRIVERID_SAA5249, /* in i2c.h */
166 .attach_adapter = saa5246a_probe,
167 .detach_client = saa5246a_detach,
170 static struct i2c_client client_template = {
171 .driver = &i2c_driver_videotext,
175 static int i2c_sendbuf(struct saa5246a_device *t, int reg, int count, u8 *data)
180 memcpy(buf+1, data, count);
182 if(i2c_master_send(t->client, buf, count+1)==count+1)
187 static int i2c_senddata(struct saa5246a_device *t, ...)
189 unsigned char buf[64];
195 while((v=va_arg(argp,int))!=-1)
197 return i2c_sendbuf(t, buf[0], ct-1, buf+1);
200 /* Get count number of bytes from I²C-device at address adr, store them in buf.
201 * Start & stop handshaking is done by this routine, ack will be sent after the
202 * last byte to inhibit further sending of data. If uaccess is TRUE, data is
203 * written to user-space with put_user. Returns -1 if I²C-device didn't send
204 * acknowledge, 0 otherwise
206 static int i2c_getdata(struct saa5246a_device *t, int count, u8 *buf)
208 if(i2c_master_recv(t->client, buf, count)!=count)
213 /* When a page is found then the not FOUND bit in one of the status registers
214 * of the SAA5264A chip is cleared. Unfortunately this bit is not set
215 * automatically when a new page is requested. Instead this function must be
216 * called after a page has been requested.
218 * Return value: 0 if successful
220 static int saa5246a_clear_found_bit(struct saa5246a_device *t,
221 unsigned char dau_no)
223 unsigned char row_25_column_8;
225 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
228 R8_DO_NOT_CLEAR_MEMORY,
235 i2c_getdata(t, 1, &row_25_column_8))
239 row_25_column_8 |= ROW25_COLUMN8_PAGE_NOT_FOUND;
240 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
243 R8_DO_NOT_CLEAR_MEMORY,
259 /* Requests one videotext page as described in req. The fields of req are
260 * checked and an error is returned if something is invalid.
262 * Return value: 0 if successful
264 static int saa5246a_request_page(struct saa5246a_device *t,
267 if (req->pagemask < 0 || req->pagemask >= PGMASK_MAX)
269 if (req->pagemask & PGMASK_PAGE)
270 if (req->page < 0 || req->page > PAGE_MAX)
272 if (req->pagemask & PGMASK_HOUR)
273 if (req->hour < 0 || req->hour > HOUR_MAX)
275 if (req->pagemask & PGMASK_MINUTE)
276 if (req->minute < 0 || req->minute > MINUTE_MAX)
278 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
281 if (i2c_senddata(t, SAA5246A_REGISTER_R2,
283 R2_IN_R3_SELECT_PAGE_HUNDREDS |
286 R2_HAMMING_CHECK_OFF,
288 HUNDREDS_OF_PAGE(req->page) |
290 (req->pagemask & PG_HUND ?
291 R3_PAGE_HUNDREDS_DO_CARE :
292 R3_PAGE_HUNDREDS_DO_NOT_CARE),
294 TENS_OF_PAGE(req->page) |
295 (req->pagemask & PG_TEN ?
296 R3_PAGE_TENS_DO_CARE :
297 R3_PAGE_TENS_DO_NOT_CARE),
299 UNITS_OF_PAGE(req->page) |
300 (req->pagemask & PG_UNIT ?
301 R3_PAGE_UNITS_DO_CARE :
302 R3_PAGE_UNITS_DO_NOT_CARE),
304 TENS_OF_HOUR(req->hour) |
305 (req->pagemask & HR_TEN ?
306 R3_HOURS_TENS_DO_CARE :
307 R3_HOURS_TENS_DO_NOT_CARE),
309 UNITS_OF_HOUR(req->hour) |
310 (req->pagemask & HR_UNIT ?
311 R3_HOURS_UNITS_DO_CARE :
312 R3_HOURS_UNITS_DO_NOT_CARE),
314 TENS_OF_MINUTE(req->minute) |
315 (req->pagemask & MIN_TEN ?
316 R3_MINUTES_TENS_DO_CARE :
317 R3_MINUTES_TENS_DO_NOT_CARE),
319 UNITS_OF_MINUTE(req->minute) |
320 (req->pagemask & MIN_UNIT ?
321 R3_MINUTES_UNITS_DO_CARE :
322 R3_MINUTES_UNITS_DO_NOT_CARE),
324 COMMAND_END) || i2c_senddata(t, SAA5246A_REGISTER_R2,
326 R2_IN_R3_SELECT_PAGE_HUNDREDS |
329 R2_HAMMING_CHECK_OFF,
331 HUNDREDS_OF_PAGE(req->page) |
333 (req->pagemask & PG_HUND ?
334 R3_PAGE_HUNDREDS_DO_CARE :
335 R3_PAGE_HUNDREDS_DO_NOT_CARE),
342 t->is_searching[req->pgbuf] = TRUE;
346 /* This routine decodes the page number from the infobits contained in line 25.
349 * infobits: must be bits 0 to 9 of column 25
351 * Return value: page number coded in hexadecimal, i. e. page 123 is coded 0x123
353 static inline int saa5246a_extract_pagenum_from_infobits(
354 unsigned char infobits[10])
356 int page_hundreds, page_tens, page_units;
358 page_units = infobits[0] & ROW25_COLUMN0_PAGE_UNITS;
359 page_tens = infobits[1] & ROW25_COLUMN1_PAGE_TENS;
360 page_hundreds = infobits[8] & ROW25_COLUMN8_PAGE_HUNDREDS;
362 /* page 0x.. means page 8.. */
363 if (page_hundreds == 0)
366 return((page_hundreds << 8) | (page_tens << 4) | page_units);
369 /* Decodes the hour from the infobits contained in line 25.
372 * infobits: must be bits 0 to 9 of column 25
374 * Return: hour coded in hexadecimal, i. e. 12h is coded 0x12
376 static inline int saa5246a_extract_hour_from_infobits(
377 unsigned char infobits[10])
379 int hour_tens, hour_units;
381 hour_units = infobits[4] & ROW25_COLUMN4_HOUR_UNITS;
382 hour_tens = infobits[5] & ROW25_COLUMN5_HOUR_TENS;
384 return((hour_tens << 4) | hour_units);
387 /* Decodes the minutes from the infobits contained in line 25.
390 * infobits: must be bits 0 to 9 of column 25
392 * Return: minutes coded in hexadecimal, i. e. 10min is coded 0x10
394 static inline int saa5246a_extract_minutes_from_infobits(
395 unsigned char infobits[10])
397 int minutes_tens, minutes_units;
399 minutes_units = infobits[2] & ROW25_COLUMN2_MINUTES_UNITS;
400 minutes_tens = infobits[3] & ROW25_COLUMN3_MINUTES_TENS;
402 return((minutes_tens << 4) | minutes_units);
405 /* Reads the status bits contained in the first 10 columns of the first line
406 * and extracts the information into info.
408 * Return value: 0 if successful
410 static inline int saa5246a_get_status(struct saa5246a_device *t,
411 vtx_pageinfo_t *info, unsigned char dau_no)
413 unsigned char infobits[10];
416 if (dau_no >= NUM_DAUS)
419 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
422 R8_DO_NOT_CLEAR_MEMORY,
429 i2c_getdata(t, 10, infobits))
434 info->pagenum = saa5246a_extract_pagenum_from_infobits(infobits);
435 info->hour = saa5246a_extract_hour_from_infobits(infobits);
436 info->minute = saa5246a_extract_minutes_from_infobits(infobits);
437 info->charset = ((infobits[7] & ROW25_COLUMN7_CHARACTER_SET) >> 1);
438 info->delete = !!(infobits[3] & ROW25_COLUMN3_DELETE_PAGE);
439 info->headline = !!(infobits[5] & ROW25_COLUMN5_INSERT_HEADLINE);
440 info->subtitle = !!(infobits[5] & ROW25_COLUMN5_INSERT_SUBTITLE);
441 info->supp_header = !!(infobits[6] & ROW25_COLUMN6_SUPPRESS_HEADER);
442 info->update = !!(infobits[6] & ROW25_COLUMN6_UPDATE_PAGE);
443 info->inter_seq = !!(infobits[6] & ROW25_COLUMN6_INTERRUPTED_SEQUENCE);
444 info->dis_disp = !!(infobits[6] & ROW25_COLUMN6_SUPPRESS_DISPLAY);
445 info->serial = !!(infobits[7] & ROW25_COLUMN7_SERIAL_MODE);
446 info->notfound = !!(infobits[8] & ROW25_COLUMN8_PAGE_NOT_FOUND);
447 info->pblf = !!(infobits[9] & ROW25_COLUMN9_PAGE_BEING_LOOKED_FOR);
449 for (column = 0; column <= 7; column++) {
450 if (infobits[column] & ROW25_COLUMN0_TO_7_HAMMING_ERROR) {
455 if (!info->hamming && !info->notfound)
456 t->is_searching[dau_no] = FALSE;
460 /* Reads 1 videotext page buffer of the SAA5246A.
462 * req is used both as input and as output. It contains information which part
463 * must be read. The videotext page is copied into req->buffer.
465 * Return value: 0 if successful
467 static inline int saa5246a_get_page(struct saa5246a_device *t,
470 int start, end, size;
474 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS ||
475 req->start < 0 || req->start > req->end || req->end >= VTX_PAGESIZE)
478 buf = kmalloc(VTX_PAGESIZE, GFP_KERNEL);
482 /* Read "normal" part of page */
485 end = min(req->end, VTX_PAGESIZE - 1);
486 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
487 req->pgbuf | R8_DO_NOT_CLEAR_MEMORY,
488 ROW(req->start), COLUMN(req->start), COMMAND_END))
490 if (i2c_getdata(t, end - req->start + 1, buf))
493 if (copy_to_user(req->buffer, buf, end - req->start + 1))
496 /* Always get the time from buffer 4, since this stupid SAA5246A only
497 * updates the currently displayed buffer...
499 if (REQ_CONTAINS_TIME(req)) {
500 start = max(req->start, POS_TIME_START);
501 end = min(req->end, POS_TIME_END);
502 size = end - start + 1;
507 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
508 R8_ACTIVE_CHAPTER_4 | R8_DO_NOT_CLEAR_MEMORY,
509 R9_CURSER_ROW_0, start, COMMAND_END))
511 if (i2c_getdata(t, size, buf))
514 if (copy_to_user(req->buffer + start - req->start, buf, size))
517 /* Insert the header from buffer 4 only, if acquisition circuit is still searching for a page */
518 if (REQ_CONTAINS_HEADER(req) && t->is_searching[req->pgbuf]) {
519 start = max(req->start, POS_HEADER_START);
520 end = min(req->end, POS_HEADER_END);
521 size = end - start + 1;
526 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
527 R8_ACTIVE_CHAPTER_4 | R8_DO_NOT_CLEAR_MEMORY,
528 R9_CURSER_ROW_0, start, COMMAND_END))
530 if (i2c_getdata(t, end - start + 1, buf))
533 if (copy_to_user(req->buffer + start - req->start, buf, size))
542 /* Stops the acquisition circuit given in dau_no. The page buffer associated
543 * with this acquisition circuit will no more be updated. The other daus are
546 * Return value: 0 if successful
548 static inline int saa5246a_stop_dau(struct saa5246a_device *t,
549 unsigned char dau_no)
551 if (dau_no >= NUM_DAUS)
553 if (i2c_senddata(t, SAA5246A_REGISTER_R2,
555 R2_IN_R3_SELECT_PAGE_HUNDREDS |
558 R2_HAMMING_CHECK_OFF,
562 R3_PAGE_HUNDREDS_DO_NOT_CARE,
568 t->is_searching[dau_no] = FALSE;
572 /* Handles ioctls defined in videotext.h
574 * Returns 0 if successful
576 static int do_saa5246a_ioctl(struct inode *inode, struct file *file,
577 unsigned int cmd, void *arg)
579 struct video_device *vd = video_devdata(file);
580 struct saa5246a_device *t=vd->priv;
585 vtx_info_t *info = arg;
587 info->version_major = MAJOR_VERSION;
588 info->version_minor = MINOR_VERSION;
589 info->numpages = NUM_DAUS;
595 vtx_pagereq_t *req = arg;
597 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
599 memset(t->pgbuf[req->pgbuf], ' ', sizeof(t->pgbuf[0]));
605 vtx_pagereq_t *req = arg;
607 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
609 return(saa5246a_clear_found_bit(t, req->pgbuf));
614 vtx_pagereq_t *req = arg;
616 return(saa5246a_request_page(t, req));
621 vtx_pagereq_t *req = arg;
625 if ((rval = saa5246a_get_status(t, &info, req->pgbuf)))
627 if(copy_to_user(req->buffer, &info,
628 sizeof(vtx_pageinfo_t)))
635 vtx_pagereq_t *req = arg;
637 return(saa5246a_get_page(t, req));
642 vtx_pagereq_t *req = arg;
644 return(saa5246a_stop_dau(t, req->pgbuf));
659 /* I do not know what "virtual mode" means */
667 * Translates old vtx IOCTLs to new ones
669 * This keeps new kernel versions compatible with old userspace programs.
671 static inline unsigned int vtx_fix_command(unsigned int cmd)
674 case VTXIOCGETINFO_OLD:
677 case VTXIOCCLRPAGE_OLD:
680 case VTXIOCCLRFOUND_OLD:
681 cmd = VTXIOCCLRFOUND;
683 case VTXIOCPAGEREQ_OLD:
686 case VTXIOCGETSTAT_OLD:
689 case VTXIOCGETPAGE_OLD:
692 case VTXIOCSTOPDAU_OLD:
695 case VTXIOCPUTPAGE_OLD:
698 case VTXIOCSETDISP_OLD:
701 case VTXIOCPUTSTAT_OLD:
704 case VTXIOCCLRCACHE_OLD:
705 cmd = VTXIOCCLRCACHE;
707 case VTXIOCSETVIRT_OLD:
717 static int saa5246a_ioctl(struct inode *inode, struct file *file,
718 unsigned int cmd, unsigned long arg)
720 struct video_device *vd = video_devdata(file);
721 struct saa5246a_device *t = vd->priv;
724 cmd = vtx_fix_command(cmd);
725 mutex_lock(&t->lock);
726 err = video_usercopy(inode, file, cmd, arg, do_saa5246a_ioctl);
727 mutex_unlock(&t->lock);
731 static int saa5246a_open(struct inode *inode, struct file *file)
733 struct video_device *vd = video_devdata(file);
734 struct saa5246a_device *t = vd->priv;
737 err = video_exclusive_open(inode,file);
741 if (t->client==NULL) {
746 if (i2c_senddata(t, SAA5246A_REGISTER_R0,
749 R0_PLL_TIME_CONSTANT_LONG |
750 R0_ENABLE_nODD_EVEN_OUTPUT |
752 R0_DO_NOT_FORCE_nODD_EVEN_LOW_IF_PICTURE_DISPLAYED |
754 R0_NO_AUTOMATIC_FASTEXT_PROMPT,
756 R1_NON_INTERLACED_312_312_LINES |
758 R1_EXTENDED_PACKET_DISABLE |
760 R1_8_BITS_NO_PARITY |
764 i2c_senddata(t, SAA5246A_REGISTER_R4,
766 /* We do not care much for the TV display but nevertheless we
767 * need the currently displayed page later because only on that
768 * page the time is updated. */
780 video_exclusive_release(inode,file);
784 static int saa5246a_release(struct inode *inode, struct file *file)
786 struct video_device *vd = video_devdata(file);
787 struct saa5246a_device *t = vd->priv;
789 /* Stop all acquisition circuits. */
790 i2c_senddata(t, SAA5246A_REGISTER_R1,
792 R1_INTERLACED_312_AND_HALF_312_AND_HALF_LINES |
794 R1_EXTENDED_PACKET_DISABLE |
796 R1_8_BITS_NO_PARITY |
800 video_exclusive_release(inode,file);
804 static int __init init_saa_5246a (void)
807 "SAA5246A (or compatible) Teletext decoder driver version %d.%d\n",
808 MAJOR_VERSION, MINOR_VERSION);
809 return i2c_add_driver(&i2c_driver_videotext);
812 static void __exit cleanup_saa_5246a (void)
814 i2c_del_driver(&i2c_driver_videotext);
817 module_init(init_saa_5246a);
818 module_exit(cleanup_saa_5246a);
820 static struct file_operations saa_fops = {
821 .owner = THIS_MODULE,
822 .open = saa5246a_open,
823 .release = saa5246a_release,
824 .ioctl = saa5246a_ioctl,
828 static struct video_device saa_template =
830 .owner = THIS_MODULE,
832 .type = VID_TYPE_TELETEXT,
833 .hardware = VID_HARDWARE_SAA5249,
835 .release = video_device_release,