include/linux/hdlcdrv.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * hdlcdrv.h  -- HDLC packet radio network driver.
   4  * The Linux soundcard driver for 1200 baud and 9600 baud packet radio
   5  * (C) 1996-1998 by Thomas Sailer, HB9JNX/AE4WA
   6  */
   7 #ifndef _HDLCDRV_H
   8 #define _HDLCDRV_H
   9
  10
  11 #include <linux/netdevice.h>
  12 #include <linux/if.h>
  13 #include <linux/spinlock.h>
  14 #include <uapi/linux/hdlcdrv.h>
  15
  16 #define HDLCDRV_MAGIC      0x5ac6e778
  17 #define HDLCDRV_HDLCBUFFER  32 /* should be a power of 2 for speed reasons */
  18 #define HDLCDRV_BITBUFFER  256 /* should be a power of 2 for speed reasons */
  19 #undef HDLCDRV_LOOPBACK  /* define for HDLC debugging purposes */
  20 #define HDLCDRV_DEBUG
  21
  22 /* maximum packet length, excluding CRC */
  23 #define HDLCDRV_MAXFLEN             400
  24
  25
  26 struct hdlcdrv_hdlcbuffer {
  27         spinlock_t lock;
  28         unsigned rd, wr;
  29         unsigned short buf[HDLCDRV_HDLCBUFFER];
  30 };
  31
  32 #ifdef HDLCDRV_DEBUG
  33 struct hdlcdrv_bitbuffer {
  34         unsigned int rd;
  35         unsigned int wr;
  36         unsigned int shreg;
  37         unsigned char buffer[HDLCDRV_BITBUFFER];
  38 };
  39
  40 static inline void hdlcdrv_add_bitbuffer(struct hdlcdrv_bitbuffer *buf,
  41                                          unsigned int bit)
  42 {
  43         unsigned char new;
  44
  45         new = buf->shreg & 1;
  46         buf->shreg >>= 1;
  47         buf->shreg |= (!!bit) << 7;
  48         if (new) {
  49                 buf->buffer[buf->wr] = buf->shreg;
  50                 buf->wr = (buf->wr+1) % sizeof(buf->buffer);
  51                 buf->shreg = 0x80;
  52         }
  53 }
  54
  55 static inline void hdlcdrv_add_bitbuffer_word(struct hdlcdrv_bitbuffer *buf,
  56                                               unsigned int bits)
  57 {
  58         buf->buffer[buf->wr] = bits & 0xff;
  59         buf->wr = (buf->wr+1) % sizeof(buf->buffer);
  60         buf->buffer[buf->wr] = (bits >> 8) & 0xff;
  61         buf->wr = (buf->wr+1) % sizeof(buf->buffer);
  62
  63 }
  64 #endif /* HDLCDRV_DEBUG */
  65
  66 /* -------------------------------------------------------------------- */
  67 /*
  68  * Information that need to be kept for each driver.
  69  */
  70
  71 struct hdlcdrv_ops {
  72         /*
  73          * first some informations needed by the hdlcdrv routines
  74          */
  75         const char *drvname;
  76         const char *drvinfo;
  77         /*
  78          * the routines called by the hdlcdrv routines
  79          */
  80         int (*open)(struct net_device *);
  81         int (*close)(struct net_device *);
  82         int (*ioctl)(struct net_device *, struct ifreq *,
  83                      struct hdlcdrv_ioctl *, int);
  84 };
  85
  86 struct hdlcdrv_state {
  87         int magic;
  88         int opened;
  89
  90         const struct hdlcdrv_ops *ops;
  91
  92         struct {
  93                 int bitrate;
  94         } par;
  95
  96         struct hdlcdrv_pttoutput {
  97                 int dma2;
  98                 int seriobase;
  99                 int pariobase;
 100                 int midiiobase;
 101                 unsigned int flags;
 102         } ptt_out;
 103
 104         struct hdlcdrv_channel_params ch_params;
 105
 106         struct hdlcdrv_hdlcrx {
 107                 struct hdlcdrv_hdlcbuffer hbuf;
 108                 unsigned long in_hdlc_rx;
 109                 /* 0 = sync hunt, != 0 receiving */
 110                 int rx_state;
 111                 unsigned int bitstream;
 112                 unsigned int bitbuf;
 113                 int numbits;
 114                 unsigned char dcd;
 115
 116                 int len;
 117                 unsigned char *bp;
 118                 unsigned char buffer[HDLCDRV_MAXFLEN+2];
 119         } hdlcrx;
 120
 121         struct hdlcdrv_hdlctx {
 122                 struct hdlcdrv_hdlcbuffer hbuf;
 123                 unsigned long in_hdlc_tx;
 124                 /*
 125                  * 0 = send flags
 126                  * 1 = send txtail (flags)
 127                  * 2 = send packet
 128                  */
 129                 int tx_state;
 130                 int numflags;
 131                 unsigned int bitstream;
 132                 unsigned char ptt;
 133                 int calibrate;
 134                 int slotcnt;
 135
 136                 unsigned int bitbuf;
 137                 int numbits;
 138
 139                 int len;
 140                 unsigned char *bp;
 141                 unsigned char buffer[HDLCDRV_MAXFLEN+2];
 142         } hdlctx;
 143
 144 #ifdef HDLCDRV_DEBUG
 145         struct hdlcdrv_bitbuffer bitbuf_channel;
 146         struct hdlcdrv_bitbuffer bitbuf_hdlc;
 147 #endif /* HDLCDRV_DEBUG */
 148
 149         int ptt_keyed;
 150
 151         /* queued skb for transmission */
 152         struct sk_buff *skb;
 153 };
 154
 155
 156 /* -------------------------------------------------------------------- */
 157
 158 static inline int hdlcdrv_hbuf_full(struct hdlcdrv_hdlcbuffer *hb)
 159 {
 160         unsigned long flags;
 161         int ret;
 162
 163         spin_lock_irqsave(&hb->lock, flags);
 164         ret = !((HDLCDRV_HDLCBUFFER - 1 + hb->rd - hb->wr) % HDLCDRV_HDLCBUFFER);
 165         spin_unlock_irqrestore(&hb->lock, flags);
 166         return ret;
 167 }
 168
 169 /* -------------------------------------------------------------------- */
 170
 171 static inline int hdlcdrv_hbuf_empty(struct hdlcdrv_hdlcbuffer *hb)
 172 {
 173         unsigned long flags;
 174         int ret;
 175
 176         spin_lock_irqsave(&hb->lock, flags);
 177         ret = (hb->rd == hb->wr);
 178         spin_unlock_irqrestore(&hb->lock, flags);
 179         return ret;
 180 }
 181
 182 /* -------------------------------------------------------------------- */
 183
 184 static inline unsigned short hdlcdrv_hbuf_get(struct hdlcdrv_hdlcbuffer *hb)
 185 {
 186         unsigned long flags;
 187         unsigned short val;
 188         unsigned newr;
 189
 190         spin_lock_irqsave(&hb->lock, flags);
 191         if (hb->rd == hb->wr)
 192                 val = 0;
 193         else {
 194                 newr = (hb->rd+1) % HDLCDRV_HDLCBUFFER;
 195                 val = hb->buf[hb->rd];
 196                 hb->rd = newr;
 197         }
 198         spin_unlock_irqrestore(&hb->lock, flags);
 199         return val;
 200 }
 201
 202 /* -------------------------------------------------------------------- */
 203
 204 static inline void hdlcdrv_hbuf_put(struct hdlcdrv_hdlcbuffer *hb,
 205                                     unsigned short val)
 206 {
 207         unsigned newp;
 208         unsigned long flags;
 209
 210         spin_lock_irqsave(&hb->lock, flags);
 211         newp = (hb->wr+1) % HDLCDRV_HDLCBUFFER;
 212         if (newp != hb->rd) {
 213                 hb->buf[hb->wr] = val & 0xffff;
 214                 hb->wr = newp;
 215         }
 216         spin_unlock_irqrestore(&hb->lock, flags);
 217 }
 218
 219 /* -------------------------------------------------------------------- */
 220
 221 static inline void hdlcdrv_putbits(struct hdlcdrv_state *s, unsigned int bits)
 222 {
 223         hdlcdrv_hbuf_put(&s->hdlcrx.hbuf, bits);
 224 }
 225
 226 static inline unsigned int hdlcdrv_getbits(struct hdlcdrv_state *s)
 227 {
 228         unsigned int ret;
 229
 230         if (hdlcdrv_hbuf_empty(&s->hdlctx.hbuf)) {
 231                 if (s->hdlctx.calibrate > 0)
 232                         s->hdlctx.calibrate--;
 233                 else
 234                         s->hdlctx.ptt = 0;
 235                 ret = 0;
 236         } else
 237                 ret = hdlcdrv_hbuf_get(&s->hdlctx.hbuf);
 238 #ifdef HDLCDRV_LOOPBACK
 239         hdlcdrv_hbuf_put(&s->hdlcrx.hbuf, ret);
 240 #endif /* HDLCDRV_LOOPBACK */
 241         return ret;
 242 }
 243
 244 static inline void hdlcdrv_channelbit(struct hdlcdrv_state *s, unsigned int bit)
 245 {
 246 #ifdef HDLCDRV_DEBUG
 247         hdlcdrv_add_bitbuffer(&s->bitbuf_channel, bit);
 248 #endif /* HDLCDRV_DEBUG */
 249 }
 250
 251 static inline void hdlcdrv_setdcd(struct hdlcdrv_state *s, int dcd)
 252 {
 253         s->hdlcrx.dcd = !!dcd;
 254 }
 255
 256 static inline int hdlcdrv_ptt(struct hdlcdrv_state *s)
 257 {
 258         return s->hdlctx.ptt || (s->hdlctx.calibrate > 0);
 259 }
 260
 261 /* -------------------------------------------------------------------- */
 262
 263 void hdlcdrv_receiver(struct net_device *, struct hdlcdrv_state *);
 264 void hdlcdrv_transmitter(struct net_device *, struct hdlcdrv_state *);
 265 void hdlcdrv_arbitrate(struct net_device *, struct hdlcdrv_state *);
 266 struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
 267                                     unsigned int privsize, const char *ifname,
 268                                     unsigned int baseaddr, unsigned int irq,
 269                                     unsigned int dma);
 270 void hdlcdrv_unregister(struct net_device *dev);
 271
 272 /* -------------------------------------------------------------------- */
 273
 274
 275
 276 #endif /* _HDLCDRV_H */