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>
44 #include <linux/init.h>
45 #include <linux/i2c.h>
46 #include <linux/videotext.h>
47 #include <linux/videodev.h>
48 #include <media/v4l2-common.h>
49 #include <linux/mutex.h>
53 MODULE_AUTHOR("Michael Geng <linux@MichaelGeng.de>");
54 MODULE_DESCRIPTION("Philips SAA5246A, SAA5281 Teletext decoder driver");
55 MODULE_LICENSE("GPL");
57 struct saa5246a_device
59 u8 pgbuf[NUM_DAUS][VTX_VIRTUALSIZE];
60 int is_searching[NUM_DAUS];
61 struct i2c_client *client;
65 static struct video_device saa_template; /* Declared near bottom */
67 /* Addresses to scan */
68 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)
199 return i2c_sendbuf(t, buf[0], ct-1, buf+1);
202 /* Get count number of bytes from I²C-device at address adr, store them in buf.
203 * Start & stop handshaking is done by this routine, ack will be sent after the
204 * last byte to inhibit further sending of data. If uaccess is 'true', data is
205 * written to user-space with put_user. Returns -1 if I²C-device didn't send
206 * acknowledge, 0 otherwise
208 static int i2c_getdata(struct saa5246a_device *t, int count, u8 *buf)
210 if(i2c_master_recv(t->client, buf, count)!=count)
215 /* When a page is found then the not FOUND bit in one of the status registers
216 * of the SAA5264A chip is cleared. Unfortunately this bit is not set
217 * automatically when a new page is requested. Instead this function must be
218 * called after a page has been requested.
220 * Return value: 0 if successful
222 static int saa5246a_clear_found_bit(struct saa5246a_device *t,
223 unsigned char dau_no)
225 unsigned char row_25_column_8;
227 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
230 R8_DO_NOT_CLEAR_MEMORY,
237 i2c_getdata(t, 1, &row_25_column_8))
241 row_25_column_8 |= ROW25_COLUMN8_PAGE_NOT_FOUND;
242 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
245 R8_DO_NOT_CLEAR_MEMORY,
261 /* Requests one videotext page as described in req. The fields of req are
262 * checked and an error is returned if something is invalid.
264 * Return value: 0 if successful
266 static int saa5246a_request_page(struct saa5246a_device *t,
269 if (req->pagemask < 0 || req->pagemask >= PGMASK_MAX)
271 if (req->pagemask & PGMASK_PAGE)
272 if (req->page < 0 || req->page > PAGE_MAX)
274 if (req->pagemask & PGMASK_HOUR)
275 if (req->hour < 0 || req->hour > HOUR_MAX)
277 if (req->pagemask & PGMASK_MINUTE)
278 if (req->minute < 0 || req->minute > MINUTE_MAX)
280 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
283 if (i2c_senddata(t, SAA5246A_REGISTER_R2,
285 R2_IN_R3_SELECT_PAGE_HUNDREDS |
288 R2_HAMMING_CHECK_OFF,
290 HUNDREDS_OF_PAGE(req->page) |
292 (req->pagemask & PG_HUND ?
293 R3_PAGE_HUNDREDS_DO_CARE :
294 R3_PAGE_HUNDREDS_DO_NOT_CARE),
296 TENS_OF_PAGE(req->page) |
297 (req->pagemask & PG_TEN ?
298 R3_PAGE_TENS_DO_CARE :
299 R3_PAGE_TENS_DO_NOT_CARE),
301 UNITS_OF_PAGE(req->page) |
302 (req->pagemask & PG_UNIT ?
303 R3_PAGE_UNITS_DO_CARE :
304 R3_PAGE_UNITS_DO_NOT_CARE),
306 TENS_OF_HOUR(req->hour) |
307 (req->pagemask & HR_TEN ?
308 R3_HOURS_TENS_DO_CARE :
309 R3_HOURS_TENS_DO_NOT_CARE),
311 UNITS_OF_HOUR(req->hour) |
312 (req->pagemask & HR_UNIT ?
313 R3_HOURS_UNITS_DO_CARE :
314 R3_HOURS_UNITS_DO_NOT_CARE),
316 TENS_OF_MINUTE(req->minute) |
317 (req->pagemask & MIN_TEN ?
318 R3_MINUTES_TENS_DO_CARE :
319 R3_MINUTES_TENS_DO_NOT_CARE),
321 UNITS_OF_MINUTE(req->minute) |
322 (req->pagemask & MIN_UNIT ?
323 R3_MINUTES_UNITS_DO_CARE :
324 R3_MINUTES_UNITS_DO_NOT_CARE),
326 COMMAND_END) || i2c_senddata(t, SAA5246A_REGISTER_R2,
328 R2_IN_R3_SELECT_PAGE_HUNDREDS |
331 R2_HAMMING_CHECK_OFF,
333 HUNDREDS_OF_PAGE(req->page) |
335 (req->pagemask & PG_HUND ?
336 R3_PAGE_HUNDREDS_DO_CARE :
337 R3_PAGE_HUNDREDS_DO_NOT_CARE),
344 t->is_searching[req->pgbuf] = true;
348 /* This routine decodes the page number from the infobits contained in line 25.
351 * infobits: must be bits 0 to 9 of column 25
353 * Return value: page number coded in hexadecimal, i. e. page 123 is coded 0x123
355 static inline int saa5246a_extract_pagenum_from_infobits(
356 unsigned char infobits[10])
358 int page_hundreds, page_tens, page_units;
360 page_units = infobits[0] & ROW25_COLUMN0_PAGE_UNITS;
361 page_tens = infobits[1] & ROW25_COLUMN1_PAGE_TENS;
362 page_hundreds = infobits[8] & ROW25_COLUMN8_PAGE_HUNDREDS;
364 /* page 0x.. means page 8.. */
365 if (page_hundreds == 0)
368 return((page_hundreds << 8) | (page_tens << 4) | page_units);
371 /* Decodes the hour from the infobits contained in line 25.
374 * infobits: must be bits 0 to 9 of column 25
376 * Return: hour coded in hexadecimal, i. e. 12h is coded 0x12
378 static inline int saa5246a_extract_hour_from_infobits(
379 unsigned char infobits[10])
381 int hour_tens, hour_units;
383 hour_units = infobits[4] & ROW25_COLUMN4_HOUR_UNITS;
384 hour_tens = infobits[5] & ROW25_COLUMN5_HOUR_TENS;
386 return((hour_tens << 4) | hour_units);
389 /* Decodes the minutes from the infobits contained in line 25.
392 * infobits: must be bits 0 to 9 of column 25
394 * Return: minutes coded in hexadecimal, i. e. 10min is coded 0x10
396 static inline int saa5246a_extract_minutes_from_infobits(
397 unsigned char infobits[10])
399 int minutes_tens, minutes_units;
401 minutes_units = infobits[2] & ROW25_COLUMN2_MINUTES_UNITS;
402 minutes_tens = infobits[3] & ROW25_COLUMN3_MINUTES_TENS;
404 return((minutes_tens << 4) | minutes_units);
407 /* Reads the status bits contained in the first 10 columns of the first line
408 * and extracts the information into info.
410 * Return value: 0 if successful
412 static inline int saa5246a_get_status(struct saa5246a_device *t,
413 vtx_pageinfo_t *info, unsigned char dau_no)
415 unsigned char infobits[10];
418 if (dau_no >= NUM_DAUS)
421 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
424 R8_DO_NOT_CLEAR_MEMORY,
431 i2c_getdata(t, 10, infobits))
436 info->pagenum = saa5246a_extract_pagenum_from_infobits(infobits);
437 info->hour = saa5246a_extract_hour_from_infobits(infobits);
438 info->minute = saa5246a_extract_minutes_from_infobits(infobits);
439 info->charset = ((infobits[7] & ROW25_COLUMN7_CHARACTER_SET) >> 1);
440 info->delete = !!(infobits[3] & ROW25_COLUMN3_DELETE_PAGE);
441 info->headline = !!(infobits[5] & ROW25_COLUMN5_INSERT_HEADLINE);
442 info->subtitle = !!(infobits[5] & ROW25_COLUMN5_INSERT_SUBTITLE);
443 info->supp_header = !!(infobits[6] & ROW25_COLUMN6_SUPPRESS_HEADER);
444 info->update = !!(infobits[6] & ROW25_COLUMN6_UPDATE_PAGE);
445 info->inter_seq = !!(infobits[6] & ROW25_COLUMN6_INTERRUPTED_SEQUENCE);
446 info->dis_disp = !!(infobits[6] & ROW25_COLUMN6_SUPPRESS_DISPLAY);
447 info->serial = !!(infobits[7] & ROW25_COLUMN7_SERIAL_MODE);
448 info->notfound = !!(infobits[8] & ROW25_COLUMN8_PAGE_NOT_FOUND);
449 info->pblf = !!(infobits[9] & ROW25_COLUMN9_PAGE_BEING_LOOKED_FOR);
451 for (column = 0; column <= 7; column++) {
452 if (infobits[column] & ROW25_COLUMN0_TO_7_HAMMING_ERROR) {
457 if (!info->hamming && !info->notfound)
458 t->is_searching[dau_no] = false;
462 /* Reads 1 videotext page buffer of the SAA5246A.
464 * req is used both as input and as output. It contains information which part
465 * must be read. The videotext page is copied into req->buffer.
467 * Return value: 0 if successful
469 static inline int saa5246a_get_page(struct saa5246a_device *t,
472 int start, end, size;
476 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS ||
477 req->start < 0 || req->start > req->end || req->end >= VTX_PAGESIZE)
480 buf = kmalloc(VTX_PAGESIZE, GFP_KERNEL);
484 /* Read "normal" part of page */
487 end = min(req->end, VTX_PAGESIZE - 1);
488 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
489 req->pgbuf | R8_DO_NOT_CLEAR_MEMORY,
490 ROW(req->start), COLUMN(req->start), COMMAND_END))
492 if (i2c_getdata(t, end - req->start + 1, buf))
495 if (copy_to_user(req->buffer, buf, end - req->start + 1))
498 /* Always get the time from buffer 4, since this stupid SAA5246A only
499 * updates the currently displayed buffer...
501 if (REQ_CONTAINS_TIME(req)) {
502 start = max(req->start, POS_TIME_START);
503 end = min(req->end, POS_TIME_END);
504 size = end - start + 1;
509 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
510 R8_ACTIVE_CHAPTER_4 | R8_DO_NOT_CLEAR_MEMORY,
511 R9_CURSER_ROW_0, start, COMMAND_END))
513 if (i2c_getdata(t, size, buf))
516 if (copy_to_user(req->buffer + start - req->start, buf, size))
519 /* Insert the header from buffer 4 only, if acquisition circuit is still searching for a page */
520 if (REQ_CONTAINS_HEADER(req) && t->is_searching[req->pgbuf]) {
521 start = max(req->start, POS_HEADER_START);
522 end = min(req->end, POS_HEADER_END);
523 size = end - start + 1;
528 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
529 R8_ACTIVE_CHAPTER_4 | R8_DO_NOT_CLEAR_MEMORY,
530 R9_CURSER_ROW_0, start, COMMAND_END))
532 if (i2c_getdata(t, end - start + 1, buf))
535 if (copy_to_user(req->buffer + start - req->start, buf, size))
544 /* Stops the acquisition circuit given in dau_no. The page buffer associated
545 * with this acquisition circuit will no more be updated. The other daus are
548 * Return value: 0 if successful
550 static inline int saa5246a_stop_dau(struct saa5246a_device *t,
551 unsigned char dau_no)
553 if (dau_no >= NUM_DAUS)
555 if (i2c_senddata(t, SAA5246A_REGISTER_R2,
557 R2_IN_R3_SELECT_PAGE_HUNDREDS |
560 R2_HAMMING_CHECK_OFF,
564 R3_PAGE_HUNDREDS_DO_NOT_CARE,
570 t->is_searching[dau_no] = false;
574 /* Handles ioctls defined in videotext.h
576 * Returns 0 if successful
578 static int do_saa5246a_ioctl(struct inode *inode, struct file *file,
579 unsigned int cmd, void *arg)
581 struct video_device *vd = video_devdata(file);
582 struct saa5246a_device *t=vd->priv;
587 vtx_info_t *info = arg;
589 info->version_major = MAJOR_VERSION;
590 info->version_minor = MINOR_VERSION;
591 info->numpages = NUM_DAUS;
597 vtx_pagereq_t *req = arg;
599 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
601 memset(t->pgbuf[req->pgbuf], ' ', sizeof(t->pgbuf[0]));
607 vtx_pagereq_t *req = arg;
609 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
611 return(saa5246a_clear_found_bit(t, req->pgbuf));
616 vtx_pagereq_t *req = arg;
618 return(saa5246a_request_page(t, req));
623 vtx_pagereq_t *req = arg;
627 if ((rval = saa5246a_get_status(t, &info, req->pgbuf)))
629 if(copy_to_user(req->buffer, &info,
630 sizeof(vtx_pageinfo_t)))
637 vtx_pagereq_t *req = arg;
639 return(saa5246a_get_page(t, req));
644 vtx_pagereq_t *req = arg;
646 return(saa5246a_stop_dau(t, req->pgbuf));
661 /* I do not know what "virtual mode" means */
669 * Translates old vtx IOCTLs to new ones
671 * This keeps new kernel versions compatible with old userspace programs.
673 static inline unsigned int vtx_fix_command(unsigned int cmd)
676 case VTXIOCGETINFO_OLD:
679 case VTXIOCCLRPAGE_OLD:
682 case VTXIOCCLRFOUND_OLD:
683 cmd = VTXIOCCLRFOUND;
685 case VTXIOCPAGEREQ_OLD:
688 case VTXIOCGETSTAT_OLD:
691 case VTXIOCGETPAGE_OLD:
694 case VTXIOCSTOPDAU_OLD:
697 case VTXIOCPUTPAGE_OLD:
700 case VTXIOCSETDISP_OLD:
703 case VTXIOCPUTSTAT_OLD:
706 case VTXIOCCLRCACHE_OLD:
707 cmd = VTXIOCCLRCACHE;
709 case VTXIOCSETVIRT_OLD:
719 static int saa5246a_ioctl(struct inode *inode, struct file *file,
720 unsigned int cmd, unsigned long arg)
722 struct video_device *vd = video_devdata(file);
723 struct saa5246a_device *t = vd->priv;
726 cmd = vtx_fix_command(cmd);
727 mutex_lock(&t->lock);
728 err = video_usercopy(inode, file, cmd, arg, do_saa5246a_ioctl);
729 mutex_unlock(&t->lock);
733 static int saa5246a_open(struct inode *inode, struct file *file)
735 struct video_device *vd = video_devdata(file);
736 struct saa5246a_device *t = vd->priv;
739 err = video_exclusive_open(inode,file);
743 if (t->client==NULL) {
748 if (i2c_senddata(t, SAA5246A_REGISTER_R0,
751 R0_PLL_TIME_CONSTANT_LONG |
752 R0_ENABLE_nODD_EVEN_OUTPUT |
754 R0_DO_NOT_FORCE_nODD_EVEN_LOW_IF_PICTURE_DISPLAYED |
756 R0_NO_AUTOMATIC_FASTEXT_PROMPT,
758 R1_NON_INTERLACED_312_312_LINES |
760 R1_EXTENDED_PACKET_DISABLE |
762 R1_8_BITS_NO_PARITY |
766 i2c_senddata(t, SAA5246A_REGISTER_R4,
768 /* We do not care much for the TV display but nevertheless we
769 * need the currently displayed page later because only on that
770 * page the time is updated. */
782 video_exclusive_release(inode,file);
786 static int saa5246a_release(struct inode *inode, struct file *file)
788 struct video_device *vd = video_devdata(file);
789 struct saa5246a_device *t = vd->priv;
791 /* Stop all acquisition circuits. */
792 i2c_senddata(t, SAA5246A_REGISTER_R1,
794 R1_INTERLACED_312_AND_HALF_312_AND_HALF_LINES |
796 R1_EXTENDED_PACKET_DISABLE |
798 R1_8_BITS_NO_PARITY |
802 video_exclusive_release(inode,file);
806 static int __init init_saa_5246a (void)
809 "SAA5246A (or compatible) Teletext decoder driver version %d.%d\n",
810 MAJOR_VERSION, MINOR_VERSION);
811 return i2c_add_driver(&i2c_driver_videotext);
814 static void __exit cleanup_saa_5246a (void)
816 i2c_del_driver(&i2c_driver_videotext);
819 module_init(init_saa_5246a);
820 module_exit(cleanup_saa_5246a);
822 static const struct file_operations saa_fops = {
823 .owner = THIS_MODULE,
824 .open = saa5246a_open,
825 .release = saa5246a_release,
826 .ioctl = saa5246a_ioctl,
830 static struct video_device saa_template =
832 .owner = THIS_MODULE,
834 .type = VID_TYPE_TELETEXT,
836 .release = video_device_release,