/* * 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");