| /* |
| * 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 = kzalloc(sizeof(struct attached_list), GFP_KERNEL); |
| if (!ptr) { |
| dprintk(1, |
| KERN_ERR |
| "videocodec_attach: no memory\n"); |
| goto out_kfree; |
| } |
| 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 = kzalloc(sizeof(struct codec_list), GFP_KERNEL); |
| if (!ptr) { |
| dprintk(1, KERN_ERR "videocodec_register: no memory\n"); |
| return -ENOMEM; |
| } |
| 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); |
| |
| 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); |
| 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"); |