diff options
Diffstat (limited to 'drivers/media/video/videocodec.c')
| -rw-r--r-- | drivers/media/video/videocodec.c | 490 |
1 files changed, 490 insertions, 0 deletions
diff --git a/drivers/media/video/videocodec.c b/drivers/media/video/videocodec.c new file mode 100644 index 00000000000..c9d5f1a873c --- /dev/null +++ b/drivers/media/video/videocodec.c @@ -0,0 +1,490 @@ +/* + * VIDEO MOTION CODECs internal API for video devices + * + * Interface for MJPEG (and maybe later MPEG/WAVELETS) codec's + * bound to a master device. + * + * (c) 2002 Wolfgang Scherr <scherr@net4you.at> + * + * $Id: videocodec.c,v 1.1.2.8 2003/03/29 07:16:04 rbultje Exp $ + * + * ------------------------------------------------------------------------ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * ------------------------------------------------------------------------ + */ + +#define VIDEOCODEC_VERSION "v0.2" + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> + +// kernel config is here (procfs flag) +#include <linux/config.h> + +#ifdef CONFIG_PROC_FS +#include <linux/proc_fs.h> +#include <asm/uaccess.h> +#endif + +#include "videocodec.h" + +static int debug = 0; +module_param(debug, int, 0); +MODULE_PARM_DESC(debug, "Debug level (0-4)"); + +#define dprintk(num, format, args...) \ + do { \ + if (debug >= num) \ + printk(format, ##args); \ + } while (0) + +struct attached_list { + struct videocodec *codec; + struct attached_list *next; +}; + +struct codec_list { + const struct videocodec *codec; + int attached; + struct attached_list *list; + struct codec_list *next; +}; + +static struct codec_list *codeclist_top = NULL; + +/* ================================================= */ +/* function prototypes of the master/slave interface */ +/* ================================================= */ + +struct videocodec * +videocodec_attach (struct videocodec_master *master) +{ + struct codec_list *h = codeclist_top; + struct attached_list *a, *ptr; + struct videocodec *codec; + int res; + + if (!master) { + dprintk(1, KERN_ERR "videocodec_attach: no data\n"); + return NULL; + } + + dprintk(2, + "videocodec_attach: '%s', type: %x, flags %lx, magic %lx\n", + master->name, master->type, master->flags, master->magic); + + if (!h) { + dprintk(1, + KERN_ERR + "videocodec_attach: no device available\n"); + return NULL; + } + + while (h) { + // attach only if the slave has at least the flags + // expected by the master + if ((master->flags & h->codec->flags) == master->flags) { + dprintk(4, "videocodec_attach: try '%s'\n", + h->codec->name); + + if (!try_module_get(h->codec->owner)) + return NULL; + + codec = + kmalloc(sizeof(struct videocodec), GFP_KERNEL); + if (!codec) { + dprintk(1, + KERN_ERR + "videocodec_attach: no mem\n"); + goto out_module_put; + } + memcpy(codec, h->codec, sizeof(struct videocodec)); + + snprintf(codec->name, sizeof(codec->name), + "%s[%d]", codec->name, h->attached); + codec->master_data = master; + res = codec->setup(codec); + if (res == 0) { + dprintk(3, "videocodec_attach '%s'\n", + codec->name); + ptr = (struct attached_list *) + kmalloc(sizeof(struct attached_list), + GFP_KERNEL); + if (!ptr) { + dprintk(1, + KERN_ERR + "videocodec_attach: no memory\n"); + goto out_kfree; + } + memset(ptr, 0, + sizeof(struct attached_list)); + ptr->codec = codec; + + a = h->list; + if (!a) { + h->list = ptr; + dprintk(4, + "videocodec: first element\n"); + } else { + while (a->next) + a = a->next; // find end + a->next = ptr; + dprintk(4, + "videocodec: in after '%s'\n", + h->codec->name); + } + + h->attached += 1; + return codec; + } else { + kfree(codec); + } + } + h = h->next; + } + + dprintk(1, KERN_ERR "videocodec_attach: no codec found!\n"); + return NULL; + + out_module_put: + module_put(h->codec->owner); + out_kfree: + kfree(codec); + return NULL; +} + +int +videocodec_detach (struct videocodec *codec) +{ + struct codec_list *h = codeclist_top; + struct attached_list *a, *prev; + int res; + + if (!codec) { + dprintk(1, KERN_ERR "videocodec_detach: no data\n"); + return -EINVAL; + } + + dprintk(2, + "videocodec_detach: '%s', type: %x, flags %lx, magic %lx\n", + codec->name, codec->type, codec->flags, codec->magic); + + if (!h) { + dprintk(1, + KERN_ERR "videocodec_detach: no device left...\n"); + return -ENXIO; + } + + while (h) { + a = h->list; + prev = NULL; + while (a) { + if (codec == a->codec) { + res = a->codec->unset(a->codec); + if (res >= 0) { + dprintk(3, + "videocodec_detach: '%s'\n", + a->codec->name); + a->codec->master_data = NULL; + } else { + dprintk(1, + KERN_ERR + "videocodec_detach: '%s'\n", + a->codec->name); + a->codec->master_data = NULL; + } + if (prev == NULL) { + h->list = a->next; + dprintk(4, + "videocodec: delete first\n"); + } else { + prev->next = a->next; + dprintk(4, + "videocodec: delete middle\n"); + } + module_put(a->codec->owner); + kfree(a->codec); + kfree(a); + h->attached -= 1; + return 0; + } + prev = a; + a = a->next; + } + h = h->next; + } + + dprintk(1, KERN_ERR "videocodec_detach: given codec not found!\n"); + return -EINVAL; +} + +int +videocodec_register (const struct videocodec *codec) +{ + struct codec_list *ptr, *h = codeclist_top; + + if (!codec) { + dprintk(1, KERN_ERR "videocodec_register: no data!\n"); + return -EINVAL; + } + + dprintk(2, + "videocodec: register '%s', type: %x, flags %lx, magic %lx\n", + codec->name, codec->type, codec->flags, codec->magic); + + ptr = + (struct codec_list *) kmalloc(sizeof(struct codec_list), + GFP_KERNEL); + if (!ptr) { + dprintk(1, KERN_ERR "videocodec_register: no memory\n"); + return -ENOMEM; + } + memset(ptr, 0, sizeof(struct codec_list)); + ptr->codec = codec; + + if (!h) { + codeclist_top = ptr; + dprintk(4, "videocodec: hooked in as first element\n"); + } else { + while (h->next) + h = h->next; // find the end + h->next = ptr; + dprintk(4, "videocodec: hooked in after '%s'\n", + h->codec->name); + } + + return 0; +} + +int +videocodec_unregister (const struct videocodec *codec) +{ + struct codec_list *prev = NULL, *h = codeclist_top; + + if (!codec) { + dprintk(1, KERN_ERR "videocodec_unregister: no data!\n"); + return -EINVAL; + } + + dprintk(2, + "videocodec: unregister '%s', type: %x, flags %lx, magic %lx\n", + codec->name, codec->type, codec->flags, codec->magic); + + if (!h) { + dprintk(1, + KERN_ERR + "videocodec_unregister: no device left...\n"); + return -ENXIO; + } + + while (h) { + if (codec == h->codec) { + if (h->attached) { + dprintk(1, + KERN_ERR + "videocodec: '%s' is used\n", + h->codec->name); + return -EBUSY; + } + dprintk(3, "videocodec: unregister '%s' is ok.\n", + h->codec->name); + if (prev == NULL) { + codeclist_top = h->next; + dprintk(4, + "videocodec: delete first element\n"); + } else { + prev->next = h->next; + dprintk(4, + "videocodec: delete middle element\n"); + } + kfree(h); + return 0; + } + prev = h; + h = h->next; + } + + dprintk(1, + KERN_ERR + "videocodec_unregister: given codec not found!\n"); + return -EINVAL; +} + +#ifdef CONFIG_PROC_FS +/* ============ */ +/* procfs stuff */ +/* ============ */ + +static char *videocodec_buf = NULL; +static int videocodec_bufsize = 0; + +static int +videocodec_build_table (void) +{ + struct codec_list *h = codeclist_top; + struct attached_list *a; + int i = 0, size; + + // sum up amount of slaves plus their attached masters + while (h) { + i += h->attached + 1; + h = h->next; + } +#define LINESIZE 100 + size = LINESIZE * (i + 1); + + dprintk(3, "videocodec_build table: %d entries, %d bytes\n", i, + size); + + if (videocodec_buf) + kfree(videocodec_buf); + videocodec_buf = (char *) kmalloc(size, GFP_KERNEL); + + i = 0; + i += scnprintf(videocodec_buf + i, size - 1, + "<S>lave or attached <M>aster name type flags magic "); + i += scnprintf(videocodec_buf + i, size -i - 1, "(connected as)\n"); + + h = codeclist_top; + while (h) { + if (i > (size - LINESIZE)) + break; // security check + i += scnprintf(videocodec_buf + i, size -i -1, + "S %32s %04x %08lx %08lx (TEMPLATE)\n", + h->codec->name, h->codec->type, + h->codec->flags, h->codec->magic); + a = h->list; + while (a) { + if (i > (size - LINESIZE)) + break; // security check + i += scnprintf(videocodec_buf + i, size -i -1, + "M %32s %04x %08lx %08lx (%s)\n", + a->codec->master_data->name, + a->codec->master_data->type, + a->codec->master_data->flags, + a->codec->master_data->magic, + a->codec->name); + a = a->next; + } + h = h->next; + } + + return i; +} + +//The definition: +//typedef int (read_proc_t)(char *page, char **start, off_t off, +// int count, int *eof, void *data); + +static int +videocodec_info (char *buffer, + char **buffer_location, + off_t offset, + int buffer_length, + int *eof, + void *data) +{ + int size; + + dprintk(3, "videocodec_info: offset: %ld, len %d / size %d\n", + offset, buffer_length, videocodec_bufsize); + + if (offset == 0) { + videocodec_bufsize = videocodec_build_table(); + } + if ((offset < 0) || (offset >= videocodec_bufsize)) { + dprintk(4, + "videocodec_info: call delivers no result, return 0\n"); + *eof = 1; + return 0; + } + + if (buffer_length < (videocodec_bufsize - offset)) { + dprintk(4, "videocodec_info: %ld needed, %d got\n", + videocodec_bufsize - offset, buffer_length); + size = buffer_length; + } else { + dprintk(4, "videocodec_info: last reading of %ld bytes\n", + videocodec_bufsize - offset); + size = videocodec_bufsize - offset; + *eof = 1; + } + + memcpy(buffer, videocodec_buf + offset, size); + /* doesn't work... */ + /* copy_to_user(buffer, videocodec_buf+offset, size); */ + /* *buffer_location = videocodec_buf+offset; */ + + return size; +} +#endif + +/* ===================== */ +/* hook in driver module */ +/* ===================== */ +static int __init +videocodec_init (void) +{ +#ifdef CONFIG_PROC_FS + static struct proc_dir_entry *videocodec_proc_entry; +#endif + + printk(KERN_INFO "Linux video codec intermediate layer: %s\n", + VIDEOCODEC_VERSION); + +#ifdef CONFIG_PROC_FS + videocodec_buf = NULL; + videocodec_bufsize = 0; + + videocodec_proc_entry = create_proc_entry("videocodecs", 0, NULL); + if (videocodec_proc_entry) { + videocodec_proc_entry->read_proc = videocodec_info; + videocodec_proc_entry->write_proc = NULL; + videocodec_proc_entry->data = NULL; + videocodec_proc_entry->owner = THIS_MODULE; + } else { + dprintk(1, KERN_ERR "videocodec: can't init procfs.\n"); + } +#endif + return 0; +} + +static void __exit +videocodec_exit (void) +{ +#ifdef CONFIG_PROC_FS + remove_proc_entry("videocodecs", NULL); + if (videocodec_buf) + kfree(videocodec_buf); +#endif +} + +EXPORT_SYMBOL(videocodec_attach); +EXPORT_SYMBOL(videocodec_detach); +EXPORT_SYMBOL(videocodec_register); +EXPORT_SYMBOL(videocodec_unregister); + +module_init(videocodec_init); +module_exit(videocodec_exit); + +MODULE_AUTHOR("Wolfgang Scherr <scherr@net4you.at>"); +MODULE_DESCRIPTION("Intermediate API module for video codecs " + VIDEOCODEC_VERSION); +MODULE_LICENSE("GPL"); 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