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 };
71 static struct i2c_client client_template;
73 static int saa5246a_attach(struct i2c_adapter *adap, int addr, int kind)
77 struct i2c_client *client;
78 struct video_device *vd;
79 struct saa5246a_device *t;
81 printk(KERN_INFO "saa5246a: teletext chip found.\n");
82 client=kmalloc(sizeof(*client), GFP_KERNEL);
85 client_template.adapter = adap;
86 client_template.addr = addr;
87 memcpy(client, &client_template, sizeof(*client));
88 t = kzalloc(sizeof(*t), GFP_KERNEL);
94 strlcpy(client->name, IF_NAME, I2C_NAME_SIZE);
98 * Now create a video4linux device
101 vd = video_device_alloc();
108 i2c_set_clientdata(client, vd);
109 memcpy(vd, &saa_template, sizeof(*vd));
111 for (pgbuf = 0; pgbuf < NUM_DAUS; pgbuf++)
113 memset(t->pgbuf[pgbuf], ' ', sizeof(t->pgbuf[0]));
114 t->is_searching[pgbuf] = false;
123 if((err=video_register_device(vd, VFL_TYPE_VTX,-1))<0)
127 video_device_release(vd);
131 i2c_attach_client(client);
136 * We do most of the hard work when we become a device on the i2c.
138 static int saa5246a_probe(struct i2c_adapter *adap)
140 if (adap->class & I2C_CLASS_TV_ANALOG)
141 return i2c_probe(adap, &addr_data, saa5246a_attach);
145 static int saa5246a_detach(struct i2c_client *client)
147 struct video_device *vd = i2c_get_clientdata(client);
148 i2c_detach_client(client);
149 video_unregister_device(vd);
159 static struct i2c_driver i2c_driver_videotext =
162 .name = IF_NAME, /* name */
164 .id = I2C_DRIVERID_SAA5249, /* in i2c.h */
165 .attach_adapter = saa5246a_probe,
166 .detach_client = saa5246a_detach,
169 static struct i2c_client client_template = {
170 .driver = &i2c_driver_videotext,
174 static int i2c_sendbuf(struct saa5246a_device *t, int reg, int count, u8 *data)
179 memcpy(buf+1, data, count);
181 if(i2c_master_send(t->client, buf, count+1)==count+1)
186 static int i2c_senddata(struct saa5246a_device *t, ...)
188 unsigned char buf[64];
194 while ((v = va_arg(argp, int)) != -1)
198 return i2c_sendbuf(t, buf[0], ct-1, buf+1);
201 /* Get count number of bytes from I²C-device at address adr, store them in buf.
202 * Start & stop handshaking is done by this routine, ack will be sent after the
203 * last byte to inhibit further sending of data. If uaccess is 'true', data is
204 * written to user-space with put_user. Returns -1 if I²C-device didn't send
205 * acknowledge, 0 otherwise
207 static int i2c_getdata(struct saa5246a_device *t, int count, u8 *buf)
209 if(i2c_master_recv(t->client, buf, count)!=count)
214 /* When a page is found then the not FOUND bit in one of the status registers
215 * of the SAA5264A chip is cleared. Unfortunately this bit is not set
216 * automatically when a new page is requested. Instead this function must be
217 * called after a page has been requested.
219 * Return value: 0 if successful
221 static int saa5246a_clear_found_bit(struct saa5246a_device *t,
222 unsigned char dau_no)
224 unsigned char row_25_column_8;
226 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
229 R8_DO_NOT_CLEAR_MEMORY,
236 i2c_getdata(t, 1, &row_25_column_8))
240 row_25_column_8 |= ROW25_COLUMN8_PAGE_NOT_FOUND;
241 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
244 R8_DO_NOT_CLEAR_MEMORY,
260 /* Requests one videotext page as described in req. The fields of req are
261 * checked and an error is returned if something is invalid.
263 * Return value: 0 if successful
265 static int saa5246a_request_page(struct saa5246a_device *t,
268 if (req->pagemask < 0 || req->pagemask >= PGMASK_MAX)
270 if (req->pagemask & PGMASK_PAGE)
271 if (req->page < 0 || req->page > PAGE_MAX)
273 if (req->pagemask & PGMASK_HOUR)
274 if (req->hour < 0 || req->hour > HOUR_MAX)
276 if (req->pagemask & PGMASK_MINUTE)
277 if (req->minute < 0 || req->minute > MINUTE_MAX)
279 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
282 if (i2c_senddata(t, SAA5246A_REGISTER_R2,
284 R2_IN_R3_SELECT_PAGE_HUNDREDS |
287 R2_HAMMING_CHECK_OFF,
289 HUNDREDS_OF_PAGE(req->page) |
291 (req->pagemask & PG_HUND ?
292 R3_PAGE_HUNDREDS_DO_CARE :
293 R3_PAGE_HUNDREDS_DO_NOT_CARE),
295 TENS_OF_PAGE(req->page) |
296 (req->pagemask & PG_TEN ?
297 R3_PAGE_TENS_DO_CARE :
298 R3_PAGE_TENS_DO_NOT_CARE),
300 UNITS_OF_PAGE(req->page) |
301 (req->pagemask & PG_UNIT ?
302 R3_PAGE_UNITS_DO_CARE :
303 R3_PAGE_UNITS_DO_NOT_CARE),
305 TENS_OF_HOUR(req->hour) |
306 (req->pagemask & HR_TEN ?
307 R3_HOURS_TENS_DO_CARE :
308 R3_HOURS_TENS_DO_NOT_CARE),
310 UNITS_OF_HOUR(req->hour) |
311 (req->pagemask & HR_UNIT ?
312 R3_HOURS_UNITS_DO_CARE :
313 R3_HOURS_UNITS_DO_NOT_CARE),
315 TENS_OF_MINUTE(req->minute) |
316 (req->pagemask & MIN_TEN ?
317 R3_MINUTES_TENS_DO_CARE :
318 R3_MINUTES_TENS_DO_NOT_CARE),
320 UNITS_OF_MINUTE(req->minute) |
321 (req->pagemask & MIN_UNIT ?
322 R3_MINUTES_UNITS_DO_CARE :
323 R3_MINUTES_UNITS_DO_NOT_CARE),
325 COMMAND_END) || i2c_senddata(t, SAA5246A_REGISTER_R2,
327 R2_IN_R3_SELECT_PAGE_HUNDREDS |
330 R2_HAMMING_CHECK_OFF,
332 HUNDREDS_OF_PAGE(req->page) |
334 (req->pagemask & PG_HUND ?
335 R3_PAGE_HUNDREDS_DO_CARE :
336 R3_PAGE_HUNDREDS_DO_NOT_CARE),
343 t->is_searching[req->pgbuf] = true;
347 /* This routine decodes the page number from the infobits contained in line 25.
350 * infobits: must be bits 0 to 9 of column 25
352 * Return value: page number coded in hexadecimal, i. e. page 123 is coded 0x123
354 static inline int saa5246a_extract_pagenum_from_infobits(
355 unsigned char infobits[10])
357 int page_hundreds, page_tens, page_units;
359 page_units = infobits[0] & ROW25_COLUMN0_PAGE_UNITS;
360 page_tens = infobits[1] & ROW25_COLUMN1_PAGE_TENS;
361 page_hundreds = infobits[8] & ROW25_COLUMN8_PAGE_HUNDREDS;
363 /* page 0x.. means page 8.. */
364 if (page_hundreds == 0)
367 return((page_hundreds << 8) | (page_tens << 4) | page_units);
370 /* Decodes the hour from the infobits contained in line 25.
373 * infobits: must be bits 0 to 9 of column 25
375 * Return: hour coded in hexadecimal, i. e. 12h is coded 0x12
377 static inline int saa5246a_extract_hour_from_infobits(
378 unsigned char infobits[10])
380 int hour_tens, hour_units;
382 hour_units = infobits[4] & ROW25_COLUMN4_HOUR_UNITS;
383 hour_tens = infobits[5] & ROW25_COLUMN5_HOUR_TENS;
385 return((hour_tens << 4) | hour_units);
388 /* Decodes the minutes from the infobits contained in line 25.
391 * infobits: must be bits 0 to 9 of column 25
393 * Return: minutes coded in hexadecimal, i. e. 10min is coded 0x10
395 static inline int saa5246a_extract_minutes_from_infobits(
396 unsigned char infobits[10])
398 int minutes_tens, minutes_units;
400 minutes_units = infobits[2] & ROW25_COLUMN2_MINUTES_UNITS;
401 minutes_tens = infobits[3] & ROW25_COLUMN3_MINUTES_TENS;
403 return((minutes_tens << 4) | minutes_units);
406 /* Reads the status bits contained in the first 10 columns of the first line
407 * and extracts the information into info.
409 * Return value: 0 if successful
411 static inline int saa5246a_get_status(struct saa5246a_device *t,
412 vtx_pageinfo_t *info, unsigned char dau_no)
414 unsigned char infobits[10];
417 if (dau_no >= NUM_DAUS)
420 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
423 R8_DO_NOT_CLEAR_MEMORY,
430 i2c_getdata(t, 10, infobits))
435 info->pagenum = saa5246a_extract_pagenum_from_infobits(infobits);
436 info->hour = saa5246a_extract_hour_from_infobits(infobits);
437 info->minute = saa5246a_extract_minutes_from_infobits(infobits);
438 info->charset = ((infobits[7] & ROW25_COLUMN7_CHARACTER_SET) >> 1);
439 info->delete = !!(infobits[3] & ROW25_COLUMN3_DELETE_PAGE);
440 info->headline = !!(infobits[5] & ROW25_COLUMN5_INSERT_HEADLINE);
441 info->subtitle = !!(infobits[5] & ROW25_COLUMN5_INSERT_SUBTITLE);
442 info->supp_header = !!(infobits[6] & ROW25_COLUMN6_SUPPRESS_HEADER);
443 info->update = !!(infobits[6] & ROW25_COLUMN6_UPDATE_PAGE);
444 info->inter_seq = !!(infobits[6] & ROW25_COLUMN6_INTERRUPTED_SEQUENCE);
445 info->dis_disp = !!(infobits[6] & ROW25_COLUMN6_SUPPRESS_DISPLAY);
446 info->serial = !!(infobits[7] & ROW25_COLUMN7_SERIAL_MODE);
447 info->notfound = !!(infobits[8] & ROW25_COLUMN8_PAGE_NOT_FOUND);
448 info->pblf = !!(infobits[9] & ROW25_COLUMN9_PAGE_BEING_LOOKED_FOR);
450 for (column = 0; column <= 7; column++) {
451 if (infobits[column] & ROW25_COLUMN0_TO_7_HAMMING_ERROR) {
456 if (!info->hamming && !info->notfound)
457 t->is_searching[dau_no] = false;
461 /* Reads 1 videotext page buffer of the SAA5246A.
463 * req is used both as input and as output. It contains information which part
464 * must be read. The videotext page is copied into req->buffer.
466 * Return value: 0 if successful
468 static inline int saa5246a_get_page(struct saa5246a_device *t,
471 int start, end, size;
475 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS ||
476 req->start < 0 || req->start > req->end || req->end >= VTX_PAGESIZE)
479 buf = kmalloc(VTX_PAGESIZE, GFP_KERNEL);
483 /* Read "normal" part of page */
486 end = min(req->end, VTX_PAGESIZE - 1);
487 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
488 req->pgbuf | R8_DO_NOT_CLEAR_MEMORY,
489 ROW(req->start), COLUMN(req->start), COMMAND_END))
491 if (i2c_getdata(t, end - req->start + 1, buf))
494 if (copy_to_user(req->buffer, buf, end - req->start + 1))
497 /* Always get the time from buffer 4, since this stupid SAA5246A only
498 * updates the currently displayed buffer...
500 if (REQ_CONTAINS_TIME(req)) {
501 start = max(req->start, POS_TIME_START);
502 end = min(req->end, POS_TIME_END);
503 size = end - start + 1;
508 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
509 R8_ACTIVE_CHAPTER_4 | R8_DO_NOT_CLEAR_MEMORY,
510 R9_CURSER_ROW_0, start, COMMAND_END))
512 if (i2c_getdata(t, size, buf))
515 if (copy_to_user(req->buffer + start - req->start, buf, size))
518 /* Insert the header from buffer 4 only, if acquisition circuit is still searching for a page */
519 if (REQ_CONTAINS_HEADER(req) && t->is_searching[req->pgbuf]) {
520 start = max(req->start, POS_HEADER_START);
521 end = min(req->end, POS_HEADER_END);
522 size = end - start + 1;
527 if (i2c_senddata(t, SAA5246A_REGISTER_R8,
528 R8_ACTIVE_CHAPTER_4 | R8_DO_NOT_CLEAR_MEMORY,
529 R9_CURSER_ROW_0, start, COMMAND_END))
531 if (i2c_getdata(t, end - start + 1, buf))
534 if (copy_to_user(req->buffer + start - req->start, buf, size))
543 /* Stops the acquisition circuit given in dau_no. The page buffer associated
544 * with this acquisition circuit will no more be updated. The other daus are
547 * Return value: 0 if successful
549 static inline int saa5246a_stop_dau(struct saa5246a_device *t,
550 unsigned char dau_no)
552 if (dau_no >= NUM_DAUS)
554 if (i2c_senddata(t, SAA5246A_REGISTER_R2,
556 R2_IN_R3_SELECT_PAGE_HUNDREDS |
559 R2_HAMMING_CHECK_OFF,
563 R3_PAGE_HUNDREDS_DO_NOT_CARE,
569 t->is_searching[dau_no] = false;
573 /* Handles ioctls defined in videotext.h
575 * Returns 0 if successful
577 static int do_saa5246a_ioctl(struct inode *inode, struct file *file,
578 unsigned int cmd, void *arg)
580 struct video_device *vd = video_devdata(file);
581 struct saa5246a_device *t=vd->priv;
586 vtx_info_t *info = arg;
588 info->version_major = MAJOR_VERSION;
589 info->version_minor = MINOR_VERSION;
590 info->numpages = NUM_DAUS;
596 vtx_pagereq_t *req = arg;
598 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
600 memset(t->pgbuf[req->pgbuf], ' ', sizeof(t->pgbuf[0]));
606 vtx_pagereq_t *req = arg;
608 if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
610 return(saa5246a_clear_found_bit(t, req->pgbuf));
615 vtx_pagereq_t *req = arg;
617 return(saa5246a_request_page(t, req));
622 vtx_pagereq_t *req = arg;
626 if ((rval = saa5246a_get_status(t, &info, req->pgbuf)))
628 if(copy_to_user(req->buffer, &info,
629 sizeof(vtx_pageinfo_t)))
636 vtx_pagereq_t *req = arg;
638 return(saa5246a_get_page(t, req));
643 vtx_pagereq_t *req = arg;
645 return(saa5246a_stop_dau(t, req->pgbuf));
660 /* I do not know what "virtual mode" means */
668 * Translates old vtx IOCTLs to new ones
670 * This keeps new kernel versions compatible with old userspace programs.
672 static inline unsigned int vtx_fix_command(unsigned int cmd)
675 case VTXIOCGETINFO_OLD:
678 case VTXIOCCLRPAGE_OLD:
681 case VTXIOCCLRFOUND_OLD:
682 cmd = VTXIOCCLRFOUND;
684 case VTXIOCPAGEREQ_OLD:
687 case VTXIOCGETSTAT_OLD:
690 case VTXIOCGETPAGE_OLD:
693 case VTXIOCSTOPDAU_OLD:
696 case VTXIOCPUTPAGE_OLD:
699 case VTXIOCSETDISP_OLD:
702 case VTXIOCPUTSTAT_OLD:
705 case VTXIOCCLRCACHE_OLD:
706 cmd = VTXIOCCLRCACHE;
708 case VTXIOCSETVIRT_OLD:
718 static int saa5246a_ioctl(struct inode *inode, struct file *file,
719 unsigned int cmd, unsigned long arg)
721 struct video_device *vd = video_devdata(file);
722 struct saa5246a_device *t = vd->priv;
725 cmd = vtx_fix_command(cmd);
726 mutex_lock(&t->lock);
727 err = video_usercopy(inode, file, cmd, arg, do_saa5246a_ioctl);
728 mutex_unlock(&t->lock);
732 static int saa5246a_open(struct inode *inode, struct file *file)
734 struct video_device *vd = video_devdata(file);
735 struct saa5246a_device *t = vd->priv;
738 err = video_exclusive_open(inode,file);
742 if (t->client==NULL) {
747 if (i2c_senddata(t, SAA5246A_REGISTER_R0,
750 R0_PLL_TIME_CONSTANT_LONG |
751 R0_ENABLE_nODD_EVEN_OUTPUT |
753 R0_DO_NOT_FORCE_nODD_EVEN_LOW_IF_PICTURE_DISPLAYED |
755 R0_NO_AUTOMATIC_FASTEXT_PROMPT,
757 R1_NON_INTERLACED_312_312_LINES |
759 R1_EXTENDED_PACKET_DISABLE |
761 R1_8_BITS_NO_PARITY |
765 i2c_senddata(t, SAA5246A_REGISTER_R4,
767 /* We do not care much for the TV display but nevertheless we
768 * need the currently displayed page later because only on that
769 * page the time is updated. */
781 video_exclusive_release(inode,file);
785 static int saa5246a_release(struct inode *inode, struct file *file)
787 struct video_device *vd = video_devdata(file);
788 struct saa5246a_device *t = vd->priv;
790 /* Stop all acquisition circuits. */
791 i2c_senddata(t, SAA5246A_REGISTER_R1,
793 R1_INTERLACED_312_AND_HALF_312_AND_HALF_LINES |
795 R1_EXTENDED_PACKET_DISABLE |
797 R1_8_BITS_NO_PARITY |
801 video_exclusive_release(inode,file);
805 static int __init init_saa_5246a (void)
808 "SAA5246A (or compatible) Teletext decoder driver version %d.%d\n",
809 MAJOR_VERSION, MINOR_VERSION);
810 return i2c_add_driver(&i2c_driver_videotext);
813 static void __exit cleanup_saa_5246a (void)
815 i2c_del_driver(&i2c_driver_videotext);
818 module_init(init_saa_5246a);
819 module_exit(cleanup_saa_5246a);
821 static const struct file_operations saa_fops = {
822 .owner = THIS_MODULE,
823 .open = saa5246a_open,
824 .release = saa5246a_release,
825 .ioctl = saa5246a_ioctl,
829 static struct video_device saa_template =
831 .owner = THIS_MODULE,
833 .type = VID_TYPE_TELETEXT,
835 .release = video_device_release,