drivers/staging/media/zoran/videocodec.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * VIDEO MOTION CODECs internal API for video devices
   4  *
   5  * Interface for MJPEG (and maybe later MPEG/WAVELETS) codec's
   6  * bound to a master device.
   7  *
   8  * (c) 2002 Wolfgang Scherr <scherr@net4you.at>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/types.h>
  15 #include <linux/slab.h>
  16
  17 #include "videocodec.h"
  18
  19 static int videocodec_debug;
  20 module_param(videocodec_debug, int, 0);
  21 MODULE_PARM_DESC(videocodec_debug, "Debug level (0-4)");
  22
  23 #define dprintk(num, format, args...) \
  24         do { \
  25                 if (videocodec_debug >= num) \
  26                         printk(format, ##args); \
  27         } while (0)
  28
  29 struct attached_list {
  30         struct videocodec *codec;
  31         struct attached_list *next;
  32 };
  33
  34 struct codec_list {
  35         const struct videocodec *codec;
  36         int attached;
  37         struct attached_list *list;
  38         struct codec_list *next;
  39 };
  40
  41 static struct codec_list *codeclist_top;
  42
  43 /* ================================================= */
  44 /* function prototypes of the master/slave interface */
  45 /* ================================================= */
  46
  47 struct videocodec *videocodec_attach(struct videocodec_master *master)
  48 {
  49         struct codec_list *h = codeclist_top;
  50         struct attached_list *a, *ptr;
  51         struct videocodec *codec;
  52         int res;
  53
  54         if (!master) {
  55                 pr_err("%s: no data\n", __func__);
  56                 return NULL;
  57         }
  58
  59         dprintk(2, "%s: '%s', flags %lx, magic %lx\n", __func__,
  60                 master->name, master->flags, master->magic);
  61
  62         if (!h) {
  63                 pr_err("%s: no device available\n", __func__);
  64                 return NULL;
  65         }
  66
  67         while (h) {
  68                 // attach only if the slave has at least the flags
  69                 // expected by the master
  70                 if ((master->flags & h->codec->flags) == master->flags) {
  71                         dprintk(4, "%s: try '%s'\n", __func__, h->codec->name);
  72
  73                         codec = kmemdup(h->codec, sizeof(struct videocodec), GFP_KERNEL);
  74                         if (!codec)
  75                                 goto out_kfree;
  76
  77                         res = strlen(codec->name);
  78                         snprintf(codec->name + res, sizeof(codec->name) - res, "[%d]", h->attached);
  79                         codec->master_data = master;
  80                         res = codec->setup(codec);
  81                         if (res == 0) {
  82                                 dprintk(3, "%s: '%s'\n", __func__, codec->name);
  83                                 ptr = kzalloc(sizeof(*ptr), GFP_KERNEL);
  84                                 if (!ptr)
  85                                         goto out_kfree;
  86                                 ptr->codec = codec;
  87
  88                                 a = h->list;
  89                                 if (!a) {
  90                                         h->list = ptr;
  91                                         dprintk(4, "videocodec: first element\n");
  92                                 } else {
  93                                         while (a->next)
  94                                                 a = a->next;    // find end
  95                                         a->next = ptr;
  96                                         dprintk(4, "videocodec: in after '%s'\n", h->codec->name);
  97                                 }
  98
  99                                 h->attached += 1;
 100                                 return codec;
 101                         } else {
 102                                 kfree(codec);
 103                         }
 104                 }
 105                 h = h->next;
 106         }
 107
 108         pr_err("%s: no codec found!\n", __func__);
 109         return NULL;
 110
 111  out_kfree:
 112         kfree(codec);
 113         return NULL;
 114 }
 115
 116 int videocodec_detach(struct videocodec *codec)
 117 {
 118         struct codec_list *h = codeclist_top;
 119         struct attached_list *a, *prev;
 120         int res;
 121
 122         if (!codec) {
 123                 pr_err("%s: no data\n", __func__);
 124                 return -EINVAL;
 125         }
 126
 127         dprintk(2, "%s: '%s', type: %x, flags %lx, magic %lx\n", __func__,
 128                 codec->name, codec->type, codec->flags, codec->magic);
 129
 130         if (!h) {
 131                 pr_err("%s: no device left...\n", __func__);
 132                 return -ENXIO;
 133         }
 134
 135         while (h) {
 136                 a = h->list;
 137                 prev = NULL;
 138                 while (a) {
 139                         if (codec == a->codec) {
 140                                 res = a->codec->unset(a->codec);
 141                                 if (res >= 0) {
 142                                         dprintk(3, "%s: '%s'\n", __func__, a->codec->name);
 143                                         a->codec->master_data = NULL;
 144                                 } else {
 145                                         pr_err("%s: '%s'\n", __func__, a->codec->name);
 146                                         a->codec->master_data = NULL;
 147                                 }
 148                                 if (!prev) {
 149                                         h->list = a->next;
 150                                         dprintk(4, "videocodec: delete first\n");
 151                                 } else {
 152                                         prev->next = a->next;
 153                                         dprintk(4, "videocodec: delete middle\n");
 154                                 }
 155                                 kfree(a->codec);
 156                                 kfree(a);
 157                                 h->attached -= 1;
 158                                 return 0;
 159                         }
 160                         prev = a;
 161                         a = a->next;
 162                 }
 163                 h = h->next;
 164         }
 165
 166         pr_err("%s: given codec not found!\n", __func__);
 167         return -EINVAL;
 168 }
 169
 170 int videocodec_register(const struct videocodec *codec)
 171 {
 172         struct codec_list *ptr, *h = codeclist_top;
 173
 174         if (!codec) {
 175                 pr_err("%s: no data!\n", __func__);
 176                 return -EINVAL;
 177         }
 178
 179         dprintk(2,
 180                 "videocodec: register '%s', type: %x, flags %lx, magic %lx\n",
 181                 codec->name, codec->type, codec->flags, codec->magic);
 182
 183         ptr = kzalloc(sizeof(*ptr), GFP_KERNEL);
 184         if (!ptr)
 185                 return -ENOMEM;
 186         ptr->codec = codec;
 187
 188         if (!h) {
 189                 codeclist_top = ptr;
 190                 dprintk(4, "videocodec: hooked in as first element\n");
 191         } else {
 192                 while (h->next)
 193                         h = h->next;    // find the end
 194                 h->next = ptr;
 195                 dprintk(4, "videocodec: hooked in after '%s'\n",
 196                         h->codec->name);
 197         }
 198
 199         return 0;
 200 }
 201
 202 int videocodec_unregister(const struct videocodec *codec)
 203 {
 204         struct codec_list *prev = NULL, *h = codeclist_top;
 205
 206         if (!codec) {
 207                 pr_err("%s: no data!\n", __func__);
 208                 return -EINVAL;
 209         }
 210
 211         dprintk(2,
 212                 "videocodec: unregister '%s', type: %x, flags %lx, magic %lx\n",
 213                 codec->name, codec->type, codec->flags, codec->magic);
 214
 215         if (!h) {
 216                 pr_err("%s: no device left...\n", __func__);
 217                 return -ENXIO;
 218         }
 219
 220         while (h) {
 221                 if (codec == h->codec) {
 222                         if (h->attached) {
 223                                 pr_err("videocodec: '%s' is used\n", h->codec->name);
 224                                 return -EBUSY;
 225                         }
 226                         dprintk(3, "videocodec: unregister '%s' is ok.\n",
 227                                 h->codec->name);
 228                         if (!prev) {
 229                                 codeclist_top = h->next;
 230                                 dprintk(4,
 231                                         "videocodec: delete first element\n");
 232                         } else {
 233                                 prev->next = h->next;
 234                                 dprintk(4,
 235                                         "videocodec: delete middle element\n");
 236                         }
 237                         kfree(h);
 238                         return 0;
 239                 }
 240                 prev = h;
 241                 h = h->next;
 242         }
 243
 244         pr_err("%s: given codec not found!\n", __func__);
 245         return -EINVAL;
 246 }
 247
 248 int videocodec_debugfs_show(struct seq_file *m)
 249 {
 250         struct codec_list *h = codeclist_top;
 251         struct attached_list *a;
 252
 253         seq_printf(m, "<S>lave or attached <M>aster name  type flags    magic    ");
 254         seq_printf(m, "(connected as)\n");
 255
 256         while (h) {
 257                 seq_printf(m, "S %32s %04x %08lx %08lx (TEMPLATE)\n",
 258                            h->codec->name, h->codec->type,
 259                               h->codec->flags, h->codec->magic);
 260                 a = h->list;
 261                 while (a) {
 262                         seq_printf(m, "M %32s %04x %08lx %08lx (%s)\n",
 263                                    a->codec->master_data->name,
 264                                       a->codec->master_data->type,
 265                                       a->codec->master_data->flags,
 266                                       a->codec->master_data->magic,
 267                                       a->codec->name);
 268                         a = a->next;
 269                 }
 270                 h = h->next;
 271         }
 272
 273         return 0;
 274 }