diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-06-10 05:30:17 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-06-10 05:30:17 -0300 |
commit | d635711daa98be86d4c7fd01499c34f566b54ccb (patch) | |
tree | aa5cc3760a27c3d57146498cb82fa549547de06c /drivers/staging/i4l/pcbit/layer2.c | |
parent | c91265cd0efb83778f015b4d4b1129bd2cfd075e (diff) |
Linux-libre 4.6.2-gnu
Diffstat (limited to 'drivers/staging/i4l/pcbit/layer2.c')
-rw-r--r-- | drivers/staging/i4l/pcbit/layer2.c | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/drivers/staging/i4l/pcbit/layer2.c b/drivers/staging/i4l/pcbit/layer2.c new file mode 100644 index 000000000..46e1240ae --- /dev/null +++ b/drivers/staging/i4l/pcbit/layer2.c @@ -0,0 +1,712 @@ +/* + * PCBIT-D low-layer interface + * + * Copyright (C) 1996 Universidade de Lisboa + * + * Written by Pedro Roque Marques (roque@di.fc.ul.pt) + * + * This software may be used and distributed according to the terms of + * the GNU General Public License, incorporated herein by reference. + */ + +/* + * 19991203 - Fernando Carvalho - takion@superbofh.org + * Hacked to compile with egcs and run with current version of isdn modules + */ + +/* + * Based on documentation provided by Inesc: + * - "Interface com bus do PC para o PCBIT e PCBIT-D", Inesc, Jan 93 + */ + +/* + * TODO: better handling of errors + * re-write/remove debug printks + */ + +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/workqueue.h> +#include <linux/mm.h> +#include <linux/skbuff.h> + +#include <linux/isdnif.h> + +#include <asm/io.h> + + +#include "pcbit.h" +#include "layer2.h" +#include "edss1.h" + +#undef DEBUG_FRAG + + +/* + * Prototypes + */ + +static void pcbit_transmit(struct pcbit_dev *dev); + +static void pcbit_recv_ack(struct pcbit_dev *dev, unsigned char ack); + +static void pcbit_l2_error(struct pcbit_dev *dev); +static void pcbit_l2_active_conf(struct pcbit_dev *dev, u_char info); +static void pcbit_l2_err_recover(unsigned long data); + +static void pcbit_firmware_bug(struct pcbit_dev *dev); + +static __inline__ void +pcbit_sched_delivery(struct pcbit_dev *dev) +{ + schedule_work(&dev->qdelivery); +} + + +/* + * Called from layer3 + */ + +int +pcbit_l2_write(struct pcbit_dev *dev, ulong msg, ushort refnum, + struct sk_buff *skb, unsigned short hdr_len) +{ + struct frame_buf *frame, + *ptr; + unsigned long flags; + + if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) { + dev_kfree_skb(skb); + return -1; + } + if ((frame = kmalloc(sizeof(struct frame_buf), + GFP_ATOMIC)) == NULL) { + dev_kfree_skb(skb); + return -1; + } + frame->msg = msg; + frame->refnum = refnum; + frame->copied = 0; + frame->hdr_len = hdr_len; + + if (skb) + frame->dt_len = skb->len - hdr_len; + else + frame->dt_len = 0; + + frame->skb = skb; + + frame->next = NULL; + + spin_lock_irqsave(&dev->lock, flags); + + if (dev->write_queue == NULL) { + dev->write_queue = frame; + spin_unlock_irqrestore(&dev->lock, flags); + pcbit_transmit(dev); + } else { + for (ptr = dev->write_queue; ptr->next; ptr = ptr->next); + ptr->next = frame; + + spin_unlock_irqrestore(&dev->lock, flags); + } + return 0; +} + +static __inline__ void +pcbit_tx_update(struct pcbit_dev *dev, ushort len) +{ + u_char info; + + dev->send_seq = (dev->send_seq + 1) % 8; + + dev->fsize[dev->send_seq] = len; + info = 0; + info |= dev->rcv_seq << 3; + info |= dev->send_seq; + + writeb(info, dev->sh_mem + BANK4); + +} + +/* + * called by interrupt service routine or by write_2 + */ + +static void +pcbit_transmit(struct pcbit_dev *dev) +{ + struct frame_buf *frame = NULL; + unsigned char unacked; + int flen; /* fragment frame length including all headers */ + int free; + int count, + cp_len; + unsigned long flags; + unsigned short tt; + + if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) + return; + + unacked = (dev->send_seq + (8 - dev->unack_seq)) & 0x07; + + spin_lock_irqsave(&dev->lock, flags); + + if (dev->free > 16 && dev->write_queue && unacked < 7) { + + if (!dev->w_busy) + dev->w_busy = 1; + else { + spin_unlock_irqrestore(&dev->lock, flags); + return; + } + + + frame = dev->write_queue; + free = dev->free; + + spin_unlock_irqrestore(&dev->lock, flags); + + if (frame->copied == 0) { + + /* Type 0 frame */ + + ulong msg; + + if (frame->skb) + flen = FRAME_HDR_LEN + PREHDR_LEN + frame->skb->len; + else + flen = FRAME_HDR_LEN + PREHDR_LEN; + + if (flen > free) + flen = free; + + msg = frame->msg; + + /* + * Board level 2 header + */ + + pcbit_writew(dev, flen - FRAME_HDR_LEN); + + pcbit_writeb(dev, GET_MSG_CPU(msg)); + + pcbit_writeb(dev, GET_MSG_PROC(msg)); + + /* TH */ + pcbit_writew(dev, frame->hdr_len + PREHDR_LEN); + + /* TD */ + pcbit_writew(dev, frame->dt_len); + + + /* + * Board level 3 fixed-header + */ + + /* LEN = TH */ + pcbit_writew(dev, frame->hdr_len + PREHDR_LEN); + + /* XX */ + pcbit_writew(dev, 0); + + /* C + S */ + pcbit_writeb(dev, GET_MSG_CMD(msg)); + pcbit_writeb(dev, GET_MSG_SCMD(msg)); + + /* NUM */ + pcbit_writew(dev, frame->refnum); + + count = FRAME_HDR_LEN + PREHDR_LEN; + } else { + /* Type 1 frame */ + + flen = 2 + (frame->skb->len - frame->copied); + + if (flen > free) + flen = free; + + /* TT */ + tt = ((ushort) (flen - 2)) | 0x8000U; /* Type 1 */ + pcbit_writew(dev, tt); + + count = 2; + } + + if (frame->skb) { + cp_len = frame->skb->len - frame->copied; + if (cp_len > flen - count) + cp_len = flen - count; + + memcpy_topcbit(dev, frame->skb->data + frame->copied, + cp_len); + frame->copied += cp_len; + } + /* bookkeeping */ + dev->free -= flen; + pcbit_tx_update(dev, flen); + + spin_lock_irqsave(&dev->lock, flags); + + if (frame->skb == NULL || frame->copied == frame->skb->len) { + + dev->write_queue = frame->next; + + if (frame->skb != NULL) { + /* free frame */ + dev_kfree_skb(frame->skb); + } + kfree(frame); + } + dev->w_busy = 0; + spin_unlock_irqrestore(&dev->lock, flags); + } else { + spin_unlock_irqrestore(&dev->lock, flags); +#ifdef DEBUG + printk(KERN_DEBUG "unacked %d free %d write_queue %s\n", + unacked, dev->free, dev->write_queue ? "not empty" : + "empty"); +#endif + } +} + + +/* + * deliver a queued frame to the upper layer + */ + +void +pcbit_deliver(struct work_struct *work) +{ + struct frame_buf *frame; + unsigned long flags, msg; + struct pcbit_dev *dev = + container_of(work, struct pcbit_dev, qdelivery); + + spin_lock_irqsave(&dev->lock, flags); + + while ((frame = dev->read_queue)) { + dev->read_queue = frame->next; + spin_unlock_irqrestore(&dev->lock, flags); + + msg = 0; + SET_MSG_CPU(msg, 0); + SET_MSG_PROC(msg, 0); + SET_MSG_CMD(msg, frame->skb->data[2]); + SET_MSG_SCMD(msg, frame->skb->data[3]); + + frame->refnum = *((ushort *)frame->skb->data + 4); + frame->msg = *((ulong *)&msg); + + skb_pull(frame->skb, 6); + + pcbit_l3_receive(dev, frame->msg, frame->skb, frame->hdr_len, + frame->refnum); + + kfree(frame); + + spin_lock_irqsave(&dev->lock, flags); + } + + spin_unlock_irqrestore(&dev->lock, flags); +} + +/* + * Reads BANK 2 & Reassembles + */ + +static void +pcbit_receive(struct pcbit_dev *dev) +{ + unsigned short tt; + u_char cpu, + proc; + struct frame_buf *frame = NULL; + unsigned long flags; + u_char type1; + + if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) + return; + + tt = pcbit_readw(dev); + + if ((tt & 0x7fffU) > 511) { + printk(KERN_INFO "pcbit: invalid frame length -> TT=%04x\n", + tt); + pcbit_l2_error(dev); + return; + } + if (!(tt & 0x8000U)) { /* Type 0 */ + type1 = 0; + + if (dev->read_frame) { + printk(KERN_DEBUG "pcbit_receive: Type 0 frame and read_frame != NULL\n"); + /* discard previous queued frame */ + kfree_skb(dev->read_frame->skb); + kfree(dev->read_frame); + dev->read_frame = NULL; + } + frame = kzalloc(sizeof(struct frame_buf), GFP_ATOMIC); + + if (frame == NULL) { + printk(KERN_WARNING "kmalloc failed\n"); + return; + } + + cpu = pcbit_readb(dev); + proc = pcbit_readb(dev); + + + if (cpu != 0x06 && cpu != 0x02) { + printk(KERN_DEBUG "pcbit: invalid cpu value\n"); + kfree(frame); + pcbit_l2_error(dev); + return; + } + /* + * we discard cpu & proc on receiving + * but we read it to update the pointer + */ + + frame->hdr_len = pcbit_readw(dev); + frame->dt_len = pcbit_readw(dev); + + /* + * 0 sized packet + * I don't know if they are an error or not... + * But they are very frequent + * Not documented + */ + + if (frame->hdr_len == 0) { + kfree(frame); +#ifdef DEBUG + printk(KERN_DEBUG "0 sized frame\n"); +#endif + pcbit_firmware_bug(dev); + return; + } + /* sanity check the length values */ + if (frame->hdr_len > 1024 || frame->dt_len > 2048) { +#ifdef DEBUG + printk(KERN_DEBUG "length problem: "); + printk(KERN_DEBUG "TH=%04x TD=%04x\n", + frame->hdr_len, + frame->dt_len); +#endif + pcbit_l2_error(dev); + kfree(frame); + return; + } + /* minimum frame read */ + + frame->skb = dev_alloc_skb(frame->hdr_len + frame->dt_len + + ((frame->hdr_len + 15) & ~15)); + + if (!frame->skb) { + printk(KERN_DEBUG "pcbit_receive: out of memory\n"); + kfree(frame); + return; + } + /* 16 byte alignment for IP */ + if (frame->dt_len) + skb_reserve(frame->skb, (frame->hdr_len + 15) & ~15); + + } else { + /* Type 1 */ + type1 = 1; + tt &= 0x7fffU; + + if (!(frame = dev->read_frame)) { + printk("Type 1 frame and no frame queued\n"); + /* usually after an error: toss frame */ + dev->readptr += tt; + if (dev->readptr > dev->sh_mem + BANK2 + BANKLEN) + dev->readptr -= BANKLEN; + return; + + } + } + + memcpy_frompcbit(dev, skb_put(frame->skb, tt), tt); + + frame->copied += tt; + spin_lock_irqsave(&dev->lock, flags); + if (frame->copied == frame->hdr_len + frame->dt_len) { + + if (type1) { + dev->read_frame = NULL; + } + if (dev->read_queue) { + struct frame_buf *ptr; + for (ptr = dev->read_queue; ptr->next; ptr = ptr->next); + ptr->next = frame; + } else + dev->read_queue = frame; + + } else { + dev->read_frame = frame; + } + spin_unlock_irqrestore(&dev->lock, flags); +} + +/* + * The board sends 0 sized frames + * They are TDATA_CONFs that get messed up somehow + * gotta send a fake acknowledgment to the upper layer somehow + */ + +static __inline__ void +pcbit_fake_conf(struct pcbit_dev *dev, struct pcbit_chan *chan) +{ + isdn_ctrl ictl; + + if (chan->queued) { + chan->queued--; + + ictl.driver = dev->id; + ictl.command = ISDN_STAT_BSENT; + ictl.arg = chan->id; + dev->dev_if->statcallb(&ictl); + } +} + +static void +pcbit_firmware_bug(struct pcbit_dev *dev) +{ + struct pcbit_chan *chan; + + chan = dev->b1; + + if (chan->fsm_state == ST_ACTIVE) { + pcbit_fake_conf(dev, chan); + } + chan = dev->b2; + + if (chan->fsm_state == ST_ACTIVE) { + pcbit_fake_conf(dev, chan); + } +} + +irqreturn_t +pcbit_irq_handler(int interrupt, void *devptr) +{ + struct pcbit_dev *dev; + u_char info, + ack_seq, + read_seq; + + dev = (struct pcbit_dev *) devptr; + + if (!dev) { + printk(KERN_WARNING "pcbit_irq_handler: wrong device\n"); + return IRQ_NONE; + } + if (dev->interrupt) { + printk(KERN_DEBUG "pcbit: reentering interrupt handler\n"); + return IRQ_HANDLED; + } + dev->interrupt = 1; + + info = readb(dev->sh_mem + BANK3); + + if (dev->l2_state == L2_STARTING || dev->l2_state == L2_ERROR) { + pcbit_l2_active_conf(dev, info); + dev->interrupt = 0; + return IRQ_HANDLED; + } + if (info & 0x40U) { /* E bit set */ +#ifdef DEBUG + printk(KERN_DEBUG "pcbit_irq_handler: E bit on\n"); +#endif + pcbit_l2_error(dev); + dev->interrupt = 0; + return IRQ_HANDLED; + } + if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) { + dev->interrupt = 0; + return IRQ_HANDLED; + } + ack_seq = (info >> 3) & 0x07U; + read_seq = (info & 0x07U); + + dev->interrupt = 0; + + if (read_seq != dev->rcv_seq) { + while (read_seq != dev->rcv_seq) { + pcbit_receive(dev); + dev->rcv_seq = (dev->rcv_seq + 1) % 8; + } + pcbit_sched_delivery(dev); + } + if (ack_seq != dev->unack_seq) { + pcbit_recv_ack(dev, ack_seq); + } + info = dev->rcv_seq << 3; + info |= dev->send_seq; + + writeb(info, dev->sh_mem + BANK4); + return IRQ_HANDLED; +} + + +static void +pcbit_l2_active_conf(struct pcbit_dev *dev, u_char info) +{ + u_char state; + + state = dev->l2_state; + +#ifdef DEBUG + printk(KERN_DEBUG "layer2_active_confirm\n"); +#endif + + + if (info & 0x80U) { + dev->rcv_seq = info & 0x07U; + dev->l2_state = L2_RUNNING; + } else + dev->l2_state = L2_DOWN; + + if (state == L2_STARTING) + wake_up_interruptible(&dev->set_running_wq); + + if (state == L2_ERROR && dev->l2_state == L2_RUNNING) { + pcbit_transmit(dev); + } +} + +static void +pcbit_l2_err_recover(unsigned long data) +{ + + struct pcbit_dev *dev; + struct frame_buf *frame; + + dev = (struct pcbit_dev *) data; + + del_timer(&dev->error_recover_timer); + if (dev->w_busy || dev->r_busy) { + init_timer(&dev->error_recover_timer); + dev->error_recover_timer.expires = jiffies + ERRTIME; + add_timer(&dev->error_recover_timer); + return; + } + dev->w_busy = dev->r_busy = 1; + + if (dev->read_frame) { + kfree_skb(dev->read_frame->skb); + kfree(dev->read_frame); + dev->read_frame = NULL; + } + if (dev->write_queue) { + frame = dev->write_queue; +#ifdef FREE_ON_ERROR + dev->write_queue = dev->write_queue->next; + + if (frame->skb) { + dev_kfree_skb(frame->skb); + } + kfree(frame); +#else + frame->copied = 0; +#endif + } + dev->rcv_seq = dev->send_seq = dev->unack_seq = 0; + dev->free = 511; + dev->l2_state = L2_ERROR; + + /* this is an hack... */ + pcbit_firmware_bug(dev); + + dev->writeptr = dev->sh_mem; + dev->readptr = dev->sh_mem + BANK2; + + writeb((0x80U | ((dev->rcv_seq & 0x07) << 3) | (dev->send_seq & 0x07)), + dev->sh_mem + BANK4); + dev->w_busy = dev->r_busy = 0; + +} + +static void +pcbit_l2_error(struct pcbit_dev *dev) +{ + if (dev->l2_state == L2_RUNNING) { + + printk(KERN_INFO "pcbit: layer 2 error\n"); + +#ifdef DEBUG + log_state(dev); +#endif + + dev->l2_state = L2_DOWN; + + init_timer(&dev->error_recover_timer); + dev->error_recover_timer.function = &pcbit_l2_err_recover; + dev->error_recover_timer.data = (ulong) dev; + dev->error_recover_timer.expires = jiffies + ERRTIME; + add_timer(&dev->error_recover_timer); + } +} + +/* + * Description: + * if board acks frames + * update dev->free + * call pcbit_transmit to write possible queued frames + */ + +static void +pcbit_recv_ack(struct pcbit_dev *dev, unsigned char ack) +{ + int i, + count; + int unacked; + + unacked = (dev->send_seq + (8 - dev->unack_seq)) & 0x07; + + /* dev->unack_seq < ack <= dev->send_seq; */ + + if (unacked) { + + if (dev->send_seq > dev->unack_seq) { + if (ack <= dev->unack_seq || ack > dev->send_seq) { + printk(KERN_DEBUG + "layer 2 ack unacceptable - dev %d", + dev->id); + + pcbit_l2_error(dev); + } else if (ack > dev->send_seq && ack <= dev->unack_seq) { + printk(KERN_DEBUG + "layer 2 ack unacceptable - dev %d", + dev->id); + pcbit_l2_error(dev); + } + } + /* ack is acceptable */ + + + i = dev->unack_seq; + + do { + dev->unack_seq = i = (i + 1) % 8; + dev->free += dev->fsize[i]; + } while (i != ack); + + count = 0; + while (count < 7 && dev->write_queue) { + u8 lsend_seq = dev->send_seq; + + pcbit_transmit(dev); + + if (dev->send_seq == lsend_seq) + break; + count++; + } + } else + printk(KERN_DEBUG "recv_ack: unacked = 0\n"); +} |