diff options
Diffstat (limited to 'drivers/isdn/gigaset/asyncdata.c')
| -rw-r--r-- | drivers/isdn/gigaset/asyncdata.c | 597 |
1 files changed, 597 insertions, 0 deletions
diff --git a/drivers/isdn/gigaset/asyncdata.c b/drivers/isdn/gigaset/asyncdata.c new file mode 100644 index 000000000000..171f8b703d61 --- /dev/null +++ b/drivers/isdn/gigaset/asyncdata.c @@ -0,0 +1,597 @@ +/* + * Common data handling layer for ser_gigaset and usb_gigaset + * + * Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>, + * Hansjoerg Lipp <hjlipp@web.de>, + * Stefan Eilers <Eilers.Stefan@epost.de>. + * + * ===================================================================== + * 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. + * ===================================================================== + * ToDo: ... + * ===================================================================== + * Version: $Id: asyncdata.c,v 1.2.2.7 2005/11/13 23:05:18 hjlipp Exp $ + * ===================================================================== + */ + +#include "gigaset.h" +#include <linux/crc-ccitt.h> + +//#define GIG_M10x_STUFF_VOICE_DATA + +/* check if byte must be stuffed/escaped + * I'm not sure which data should be encoded. + * Therefore I will go the hard way and decode every value + * less than 0x20, the flag sequence and the control escape char. + */ +static inline int muststuff(unsigned char c) +{ + if (c < PPP_TRANS) return 1; + if (c == PPP_FLAG) return 1; + if (c == PPP_ESCAPE) return 1; + /* other possible candidates: */ + /* 0x91: XON with parity set */ + /* 0x93: XOFF with parity set */ + return 0; +} + +/* == data input =========================================================== */ + +/* process a block of received bytes in command mode (modem response) + * Return value: + * number of processed bytes + */ +static inline int cmd_loop(unsigned char c, unsigned char *src, int numbytes, + struct inbuf_t *inbuf) +{ + struct cardstate *cs = inbuf->cs; + unsigned cbytes = cs->cbytes; + int inputstate = inbuf->inputstate; + int startbytes = numbytes; + + for (;;) { + cs->respdata[cbytes] = c; + if (c == 10 || c == 13) { + dbg(DEBUG_TRANSCMD, "%s: End of Command (%d Bytes)", + __func__, cbytes); + cs->cbytes = cbytes; + gigaset_handle_modem_response(cs); /* can change cs->dle */ + cbytes = 0; + + if (cs->dle && + !(inputstate & INS_DLE_command)) { + inputstate &= ~INS_command; + break; + } + } else { + /* advance in line buffer, checking for overflow */ + if (cbytes < MAX_RESP_SIZE - 1) + cbytes++; + else + warn("response too large"); + } + + if (!numbytes) + break; + c = *src++; + --numbytes; + if (c == DLE_FLAG && + (cs->dle || inputstate & INS_DLE_command)) { + inputstate |= INS_DLE_char; + break; + } + } + + cs->cbytes = cbytes; + inbuf->inputstate = inputstate; + + return startbytes - numbytes; +} + +/* process a block of received bytes in lock mode (tty i/f) + * Return value: + * number of processed bytes + */ +static inline int lock_loop(unsigned char *src, int numbytes, + struct inbuf_t *inbuf) +{ + struct cardstate *cs = inbuf->cs; + + gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response", numbytes, src, 0); + gigaset_if_receive(cs, src, numbytes); + + return numbytes; +} + +/* process a block of received bytes in HDLC data mode + * Collect HDLC frames, undoing byte stuffing and watching for DLE escapes. + * When a frame is complete, check the FCS and pass valid frames to the LL. + * If DLE is encountered, return immediately to let the caller handle it. + * Return value: + * number of processed bytes + * numbytes (all bytes processed) on error --FIXME + */ +static inline int hdlc_loop(unsigned char c, unsigned char *src, int numbytes, + struct inbuf_t *inbuf) +{ + struct cardstate *cs = inbuf->cs; + struct bc_state *bcs = inbuf->bcs; + int inputstate; + __u16 fcs; + struct sk_buff *skb; + unsigned char error; + struct sk_buff *compskb; + int startbytes = numbytes; + int l; + + IFNULLRETVAL(bcs, numbytes); + inputstate = bcs->inputstate; + fcs = bcs->fcs; + skb = bcs->skb; + IFNULLRETVAL(skb, numbytes); + + if (unlikely(inputstate & INS_byte_stuff)) { + inputstate &= ~INS_byte_stuff; + goto byte_stuff; + } + for (;;) { + if (unlikely(c == PPP_ESCAPE)) { + if (unlikely(!numbytes)) { + inputstate |= INS_byte_stuff; + break; + } + c = *src++; + --numbytes; + if (unlikely(c == DLE_FLAG && + (cs->dle || + inbuf->inputstate & INS_DLE_command))) { + inbuf->inputstate |= INS_DLE_char; + inputstate |= INS_byte_stuff; + break; + } +byte_stuff: + c ^= PPP_TRANS; +#ifdef CONFIG_GIGASET_DEBUG + if (unlikely(!muststuff(c))) + dbg(DEBUG_HDLC, + "byte stuffed: 0x%02x", c); +#endif + } else if (unlikely(c == PPP_FLAG)) { + if (unlikely(inputstate & INS_skip_frame)) { + if (!(inputstate & INS_have_data)) { /* 7E 7E */ + //dbg(DEBUG_HDLC, "(7e)7e------------------------"); +#ifdef CONFIG_GIGASET_DEBUG + ++bcs->emptycount; +#endif + } else + dbg(DEBUG_HDLC, + "7e----------------------------"); + + /* end of frame */ + error = 1; + gigaset_rcv_error(NULL, cs, bcs); + } else if (!(inputstate & INS_have_data)) { /* 7E 7E */ + //dbg(DEBUG_HDLC, "(7e)7e------------------------"); +#ifdef CONFIG_GIGASET_DEBUG + ++bcs->emptycount; +#endif + break; + } else { + dbg(DEBUG_HDLC, + "7e----------------------------"); + + /* end of frame */ + error = 0; + + if (unlikely(fcs != PPP_GOODFCS)) { + err("Packet checksum at %lu failed, " + "packet is corrupted (%u bytes)!", + bcs->rcvbytes, skb->len); + compskb = NULL; + gigaset_rcv_error(compskb, cs, bcs); + error = 1; + } else { + if (likely((l = skb->len) > 2)) { + skb->tail -= 2; + skb->len -= 2; + } else { + dev_kfree_skb(skb); + skb = NULL; + inputstate |= INS_skip_frame; + if (l == 1) { + err("invalid packet size (1)!"); + error = 1; + gigaset_rcv_error(NULL, cs, bcs); + } + } + if (likely(!(error || + (inputstate & + INS_skip_frame)))) { + gigaset_rcv_skb(skb, cs, bcs); + } + } + } + + if (unlikely(error)) + if (skb) + dev_kfree_skb(skb); + + fcs = PPP_INITFCS; + inputstate &= ~(INS_have_data | INS_skip_frame); + if (unlikely(bcs->ignore)) { + inputstate |= INS_skip_frame; + skb = NULL; + } else if (likely((skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)) { + skb_reserve(skb, HW_HDR_LEN); + } else { + warn("could not allocate new skb"); + inputstate |= INS_skip_frame; + } + + break; +#ifdef CONFIG_GIGASET_DEBUG + } else if (unlikely(muststuff(c))) { + /* Should not happen. Possible after ZDLE=1<CR><LF>. */ + dbg(DEBUG_HDLC, "not byte stuffed: 0x%02x", c); +#endif + } + + /* add character */ + +#ifdef CONFIG_GIGASET_DEBUG + if (unlikely(!(inputstate & INS_have_data))) { + dbg(DEBUG_HDLC, + "7e (%d x) ================", bcs->emptycount); + bcs->emptycount = 0; + } +#endif + + inputstate |= INS_have_data; + + if (likely(!(inputstate & INS_skip_frame))) { + if (unlikely(skb->len == SBUFSIZE)) { + warn("received packet too long"); + dev_kfree_skb_any(skb); + skb = NULL; + inputstate |= INS_skip_frame; + break; + } + *gigaset_skb_put_quick(skb, 1) = c; + /* *__skb_put (skb, 1) = c; */ + fcs = crc_ccitt_byte(fcs, c); + } + + if (unlikely(!numbytes)) + break; + c = *src++; + --numbytes; + if (unlikely(c == DLE_FLAG && + (cs->dle || + inbuf->inputstate & INS_DLE_command))) { + inbuf->inputstate |= INS_DLE_char; + break; + } + } + bcs->inputstate = inputstate; + bcs->fcs = fcs; + bcs->skb = skb; + return startbytes - numbytes; +} + +/* process a block of received bytes in transparent data mode + * Invert bytes, undoing byte stuffing and watching for DLE escapes. + * If DLE is encountered, return immediately to let the caller handle it. + * Return value: + * number of processed bytes + * numbytes (all bytes processed) on error --FIXME + */ +static inline int iraw_loop(unsigned char c, unsigned char *src, int numbytes, + struct inbuf_t *inbuf) +{ + struct cardstate *cs = inbuf->cs; + struct bc_state *bcs = inbuf->bcs; + int inputstate; + struct sk_buff *skb; + int startbytes = numbytes; + + IFNULLRETVAL(bcs, numbytes); + inputstate = bcs->inputstate; + skb = bcs->skb; + IFNULLRETVAL(skb, numbytes); + + for (;;) { + /* add character */ + inputstate |= INS_have_data; + + if (likely(!(inputstate & INS_skip_frame))) { + if (unlikely(skb->len == SBUFSIZE)) { + //FIXME just pass skb up and allocate a new one + warn("received packet too long"); + dev_kfree_skb_any(skb); + skb = NULL; + inputstate |= INS_skip_frame; + break; + } + *gigaset_skb_put_quick(skb, 1) = gigaset_invtab[c]; + } + + if (unlikely(!numbytes)) + break; + c = *src++; + --numbytes; + if (unlikely(c == DLE_FLAG && + (cs->dle || + inbuf->inputstate & INS_DLE_command))) { + inbuf->inputstate |= INS_DLE_char; + break; + } + } + + /* pass data up */ + if (likely(inputstate & INS_have_data)) { + if (likely(!(inputstate & INS_skip_frame))) { + gigaset_rcv_skb(skb, cs, bcs); + } + inputstate &= ~(INS_have_data | INS_skip_frame); + if (unlikely(bcs->ignore)) { + inputstate |= INS_skip_frame; + skb = NULL; + } else if (likely((skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) + != NULL)) { + skb_reserve(skb, HW_HDR_LEN); + } else { + warn("could not allocate new skb"); + inputstate |= INS_skip_frame; + } + } + + bcs->inputstate = inputstate; + bcs->skb = skb; + return startbytes - numbytes; +} + +/* process a block of data received from the device + */ +void gigaset_m10x_input(struct inbuf_t *inbuf) +{ + struct cardstate *cs; + unsigned tail, head, numbytes; + unsigned char *src, c; + int procbytes; + + head = atomic_read(&inbuf->head); + tail = atomic_read(&inbuf->tail); + dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail); + + if (head != tail) { + cs = inbuf->cs; + src = inbuf->data + head; + numbytes = (head > tail ? RBUFSIZE : tail) - head; + dbg(DEBUG_INTR, "processing %u bytes", numbytes); + + while (numbytes) { + if (atomic_read(&cs->mstate) == MS_LOCKED) { + procbytes = lock_loop(src, numbytes, inbuf); + src += procbytes; + numbytes -= procbytes; + } else { + c = *src++; + --numbytes; + if (c == DLE_FLAG && (cs->dle || + inbuf->inputstate & INS_DLE_command)) { + if (!(inbuf->inputstate & INS_DLE_char)) { + inbuf->inputstate |= INS_DLE_char; + goto nextbyte; + } + /* <DLE> <DLE> => <DLE> in data stream */ + inbuf->inputstate &= ~INS_DLE_char; + } + + if (!(inbuf->inputstate & INS_DLE_char)) { + + /* FIXME Einfach je nach Modus Funktionszeiger in cs setzen [hier+hdlc_loop]? */ + /* FIXME Spart folgendes "if" und ermoeglicht andere Protokolle */ + if (inbuf->inputstate & INS_command) + procbytes = cmd_loop(c, src, numbytes, inbuf); + else if (inbuf->bcs->proto2 == ISDN_PROTO_L2_HDLC) + procbytes = hdlc_loop(c, src, numbytes, inbuf); + else + procbytes = iraw_loop(c, src, numbytes, inbuf); + + src += procbytes; + numbytes -= procbytes; + } else { /* DLE-char */ + inbuf->inputstate &= ~INS_DLE_char; + switch (c) { + case 'X': /*begin of command*/ +#ifdef CONFIG_GIGASET_DEBUG + if (inbuf->inputstate & INS_command) + err("received <DLE> 'X' in command mode"); +#endif + inbuf->inputstate |= + INS_command | INS_DLE_command; + break; + case '.': /*end of command*/ +#ifdef CONFIG_GIGASET_DEBUG + if (!(inbuf->inputstate & INS_command)) + err("received <DLE> '.' in hdlc mode"); +#endif + inbuf->inputstate &= cs->dle ? + ~(INS_DLE_command|INS_command) + : ~INS_DLE_command; + break; + //case DLE_FLAG: /*DLE_FLAG in data stream*/ /* schon oben behandelt! */ + default: + err("received 0x10 0x%02x!", (int) c); + /* FIXME: reset driver?? */ + } + } + } +nextbyte: + if (!numbytes) { + /* end of buffer, check for wrap */ + if (head > tail) { + head = 0; + src = inbuf->data; + numbytes = tail; + } else { + head = tail; + break; + } + } + } + + dbg(DEBUG_INTR, "setting head to %u", head); + atomic_set(&inbuf->head, head); + } +} + + +/* == data output ========================================================== */ + +/* Encoding of a PPP packet into an octet stuffed HDLC frame + * with FCS, opening and closing flags. + * parameters: + * skb skb containing original packet (freed upon return) + * head number of headroom bytes to allocate in result skb + * tail number of tailroom bytes to allocate in result skb + * Return value: + * pointer to newly allocated skb containing the result frame + */ +static struct sk_buff *HDLC_Encode(struct sk_buff *skb, int head, int tail) +{ + struct sk_buff *hdlc_skb; + __u16 fcs; + unsigned char c; + unsigned char *cp; + int len; + unsigned int stuf_cnt; + + stuf_cnt = 0; + fcs = PPP_INITFCS; + cp = skb->data; + len = skb->len; + while (len--) { + if (muststuff(*cp)) + stuf_cnt++; + fcs = crc_ccitt_byte(fcs, *cp++); + } + fcs ^= 0xffff; /* complement */ + + /* size of new buffer: original size + number of stuffing bytes + * + 2 bytes FCS + 2 stuffing bytes for FCS (if needed) + 2 flag bytes + */ + hdlc_skb = dev_alloc_skb(skb->len + stuf_cnt + 6 + tail + head); + if (!hdlc_skb) { + err("unable to allocate memory for HDLC encoding!"); + dev_kfree_skb(skb); + return NULL; + } + skb_reserve(hdlc_skb, head); + + /* Copy acknowledge request into new skb */ + memcpy(hdlc_skb->head, skb->head, 2); + + /* Add flag sequence in front of everything.. */ + *(skb_put(hdlc_skb, 1)) = PPP_FLAG; + + /* Perform byte stuffing while copying data. */ + while (skb->len--) { + if (muststuff(*skb->data)) { + *(skb_put(hdlc_skb, 1)) = PPP_ESCAPE; + *(skb_put(hdlc_skb, 1)) = (*skb->data++) ^ PPP_TRANS; + } else + *(skb_put(hdlc_skb, 1)) = *skb->data++; + } + + /* Finally add FCS (byte stuffed) and flag sequence */ + c = (fcs & 0x00ff); /* least significant byte first */ + if (muststuff(c)) { + *(skb_put(hdlc_skb, 1)) = PPP_ESCAPE; + c ^= PPP_TRANS; + } + *(skb_put(hdlc_skb, 1)) = c; + + c = ((fcs >> 8) & 0x00ff); + if (muststuff(c)) { + *(skb_put(hdlc_skb, 1)) = PPP_ESCAPE; + c ^= PPP_TRANS; + } + *(skb_put(hdlc_skb, 1)) = c; + + *(skb_put(hdlc_skb, 1)) = PPP_FLAG; + + dev_kfree_skb(skb); + return hdlc_skb; +} + +/* Encoding of a raw packet into an octet stuffed bit inverted frame + * parameters: + * skb skb containing original packet (freed upon return) + * head number of headroom bytes to allocate in result skb + * tail number of tailroom bytes to allocate in result skb + * Return value: + * pointer to newly allocated skb containing the result frame + */ +static struct sk_buff *iraw_encode(struct sk_buff *skb, int head, int tail) +{ + struct sk_buff *iraw_skb; + unsigned char c; + unsigned char *cp; + int len; + + /* worst case: every byte must be stuffed */ + iraw_skb = dev_alloc_skb(2*skb->len + tail + head); + if (!iraw_skb) { + err("unable to allocate memory for HDLC encoding!"); + dev_kfree_skb(skb); + return NULL; + } + skb_reserve(iraw_skb, head); + + cp = skb->data; + len = skb->len; + while (len--) { + c = gigaset_invtab[*cp++]; + if (c == DLE_FLAG) + *(skb_put(iraw_skb, 1)) = c; + *(skb_put(iraw_skb, 1)) = c; + } + dev_kfree_skb(skb); + return iraw_skb; +} + +/* gigaset_send_skb + * called by common.c to queue an skb for sending + * and start transmission if necessary + * parameters: + * B Channel control structure + * skb + * Return value: + * number of bytes accepted for sending + * (skb->len if ok, 0 if out of buffer space) + * or error code (< 0, eg. -EINVAL) + */ +int gigaset_m10x_send_skb(struct bc_state *bcs, struct sk_buff *skb) +{ + unsigned len; + + IFNULLRETVAL(bcs, -EFAULT); + IFNULLRETVAL(skb, -EFAULT); + len = skb->len; + + if (bcs->proto2 == ISDN_PROTO_L2_HDLC) + skb = HDLC_Encode(skb, HW_HDR_LEN, 0); + else + skb = iraw_encode(skb, HW_HDR_LEN, 0); + if (!skb) + return -ENOMEM; + + skb_queue_tail(&bcs->squeue, skb); + tasklet_schedule(&bcs->cs->write_tasklet); + + return len; /* ok so far */ +} |