sync_serial.c

linux内核源码

		reg_sser_rw_tr_cfg tr_cfg = REG_RD(sser, port->regi_sser, rw_tr_cfg);
		reg_sser_rw_rec_cfg rec_cfg = REG_RD(sser, port->regi_sser, rw_rec_cfg);
		cfg.en = regk_sser_yes;
		tr_cfg.tr_en = port->output;
		rec_cfg.rec_en = port->input;
		REG_WR(sser, port->regi_sser, rw_cfg, cfg);
		REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
		REG_WR(sser, port->regi_sser, rw_rec_cfg, rec_cfg);
		port->started = 1;
	}

	if (file->f_flags & O_NONBLOCK)	{
		spin_lock_irqsave(&port->lock, flags);
		if (!port->tr_running) {
			if (!port->use_dma) {
				reg_sser_rw_intr_mask intr_mask;
				intr_mask = REG_RD(sser, port->regi_sser, rw_intr_mask);
				/* Start sender by writing data */
				send_word(port);
				/* and enable transmitter ready IRQ */
				intr_mask.trdy = 1;
				REG_WR(sser, port->regi_sser, rw_intr_mask, intr_mask);
			} else {
				start_dma(port, (unsigned char* volatile )port->outp, c);
			}
		}
		spin_unlock_irqrestore(&port->lock, flags);
		DEBUGWRITE(printk("w d%d c %lu NB\n",
				  port->port_nbr, count));
		return count;
	}

	/* Sleep until all sent */

	add_wait_queue(&port->out_wait_q, &wait);
	set_current_state(TASK_INTERRUPTIBLE);
	spin_lock_irqsave(&port->lock, flags);
	if (!port->tr_running) {
		if (!port->use_dma) {
			reg_sser_rw_intr_mask intr_mask;
			intr_mask = REG_RD(sser, port->regi_sser, rw_intr_mask);
			/* Start sender by writing data */
			send_word(port);
			/* and enable transmitter ready IRQ */
			intr_mask.trdy = 1;
			REG_WR(sser, port->regi_sser, rw_intr_mask, intr_mask);
		} else {
			start_dma(port, port->outp, c);
		}
	}
	spin_unlock_irqrestore(&port->lock, flags);
	schedule();
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&port->out_wait_q, &wait);
	if (signal_pending(current))
	{
		return -EINTR;
	}
	DEBUGWRITE(printk("w d%d c %lu\n", port->port_nbr, count));
	return count;
}

static ssize_t sync_serial_read(struct file * file, char * buf,
				size_t count, loff_t *ppos)
{
	int dev = iminor(file->f_path.dentry->d_inode);
	int avail;
	sync_port *port;
	unsigned char* start;
	unsigned char* end;
	unsigned long flags;

	if (dev < 0 || dev >= NUMBER_OF_PORTS || !ports[dev].enabled)
	{
		DEBUG(printk("Invalid minor %d\n", dev));
		return -ENODEV;
	}
	port = &ports[dev];

	DEBUGREAD(printk("R%d c %d ri %lu wi %lu /%lu\n", dev, count, port->readp - port->flip, port->writep - port->flip, port->in_buffer_size));

	if (!port->started)
	{
		reg_sser_rw_cfg cfg = REG_RD(sser, port->regi_sser, rw_cfg);
		reg_sser_rw_tr_cfg tr_cfg = REG_RD(sser, port->regi_sser, rw_tr_cfg);
		reg_sser_rw_rec_cfg rec_cfg = REG_RD(sser, port->regi_sser, rw_rec_cfg);
		cfg.en = regk_sser_yes;
		tr_cfg.tr_en = regk_sser_yes;
		rec_cfg.rec_en = regk_sser_yes;
		REG_WR(sser, port->regi_sser, rw_cfg, cfg);
		REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
		REG_WR(sser, port->regi_sser, rw_rec_cfg, rec_cfg);
		port->started = 1;
	}


	/* Calculate number of available bytes */
	/* Save pointers to avoid that they are modified by interrupt */
	spin_lock_irqsave(&port->lock, flags);
	start = (unsigned char*)port->readp; /* cast away volatile */
	end = (unsigned char*)port->writep;  /* cast away volatile */
	spin_unlock_irqrestore(&port->lock, flags);
	while ((start == end) && !port->full) /* No data */
	{
		if (file->f_flags & O_NONBLOCK)
		{
			return -EAGAIN;
		}

		interruptible_sleep_on(&port->in_wait_q);
		if (signal_pending(current))
		{
			return -EINTR;
		}
		spin_lock_irqsave(&port->lock, flags);
		start = (unsigned char*)port->readp; /* cast away volatile */
		end = (unsigned char*)port->writep;  /* cast away volatile */
		spin_unlock_irqrestore(&port->lock, flags);
	}

	/* Lazy read, never return wrapped data. */
	if (port->full)
		avail = port->in_buffer_size;
	else if (end > start)
		avail = end - start;
	else
		avail = port->flip + port->in_buffer_size - start;

	count = count > avail ? avail : count;
	if (copy_to_user(buf, start, count))
		return -EFAULT;
	/* Disable interrupts while updating readp */
	spin_lock_irqsave(&port->lock, flags);
	port->readp += count;
	if (port->readp >= port->flip + port->in_buffer_size) /* Wrap? */
		port->readp = port->flip;
	port->full = 0;
	spin_unlock_irqrestore(&port->lock, flags);
	DEBUGREAD(printk("r %d\n", count));
	return count;
}

static void send_word(sync_port* port)
{
	reg_sser_rw_tr_cfg tr_cfg = REG_RD(sser, port->regi_sser, rw_tr_cfg);
	reg_sser_rw_tr_data tr_data =  {0};

	switch(tr_cfg.sample_size)
	{
	 case 8:
		 port->out_count--;
		 tr_data.data = *port->outp++;
		 REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
		 if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
			 port->outp = port->out_buffer;
		 break;
	 case 12:
	 {
		int data = (*port->outp++) << 8;
		data |= *port->outp++;
		port->out_count-=2;
		tr_data.data = data;
		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
		if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
			port->outp = port->out_buffer;
	}
	break;
	case 16:
		port->out_count-=2;
		tr_data.data = *(unsigned short *)port->outp;
		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
		port->outp+=2;
		if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
			port->outp = port->out_buffer;
		break;
	case 24:
		port->out_count-=3;
		tr_data.data = *(unsigned short *)port->outp;
		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
		port->outp+=2;
		tr_data.data = *port->outp++;
		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
		if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
			port->outp = port->out_buffer;
		break;
	case 32:
		port->out_count-=4;
		tr_data.data = *(unsigned short *)port->outp;
		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
		port->outp+=2;
		tr_data.data = *(unsigned short *)port->outp;
		REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
		port->outp+=2;
		if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
			port->outp = port->out_buffer;
		break;
	}
}


static void start_dma(struct sync_port* port, const char* data, int count)
{
	port->tr_running = 1;
	port->out_descr.buf = (char*)virt_to_phys((char*)data);
	port->out_descr.after = port->out_descr.buf + count;
	port->out_descr.eol = port->out_descr.intr = 1;

	port->out_context.saved_data = (dma_descr_data*)virt_to_phys(&port->out_descr);
	port->out_context.saved_data_buf = port->out_descr.buf;

	DMA_START_CONTEXT(port->regi_dmaout, virt_to_phys((char*)&port->out_context));
	DEBUGTXINT(printk("dma %08lX c %d\n", (unsigned long)data, count));
}

static void start_dma_in(sync_port* port)
{
	int i;
	char* buf;
	port->writep = port->flip;

	if (port->writep > port->flip + port->in_buffer_size)
	{
		panic("Offset too large in sync serial driver\n");
		return;
	}
	buf = (char*)virt_to_phys(port->in_buffer);
	for (i = 0; i < NUM_IN_DESCR; i++) {
		port->in_descr[i].buf = buf;
		port->in_descr[i].after = buf + port->inbufchunk;
		port->in_descr[i].intr = 1;
		port->in_descr[i].next = (dma_descr_data*)virt_to_phys(&port->in_descr[i+1]);
		port->in_descr[i].buf = buf;
		buf += port->inbufchunk;
	}
	/* Link the last descriptor to the first */
	port->in_descr[i-1].next = (dma_descr_data*)virt_to_phys(&port->in_descr[0]);
	port->in_descr[i-1].eol = regk_sser_yes;
	port->next_rx_desc = &port->in_descr[0];
	port->prev_rx_desc = &port->in_descr[NUM_IN_DESCR - 1];
	port->in_context.saved_data = (dma_descr_data*)virt_to_phys(&port->in_descr[0]);
	port->in_context.saved_data_buf = port->in_descr[0].buf;
	DMA_START_CONTEXT(port->regi_dmain, virt_to_phys(&port->in_context));
}

#ifdef SYNC_SER_DMA
static irqreturn_t tr_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	reg_dma_r_masked_intr masked;
	reg_dma_rw_ack_intr ack_intr = {.data = regk_dma_yes};
	int i;
	struct dma_descr_data *descr;
	unsigned int sentl;
	int found = 0;

	for (i = 0; i < NUMBER_OF_PORTS; i++)
	{
		sync_port *port = &ports[i];
		if (!port->enabled  || !port->use_dma )
			continue;

		masked = REG_RD(dma, port->regi_dmaout, r_masked_intr);

		if (masked.data) /* IRQ active for the port? */
		{
			found = 1;
			/* Clear IRQ */
			REG_WR(dma, port->regi_dmaout, rw_ack_intr, ack_intr);
			descr = &port->out_descr;
			sentl = descr->after - descr->buf;
			port->out_count -= sentl;
			port->outp += sentl;
			if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
				port->outp = port->out_buffer;
			if (port->out_count)  {
				int c;
				c = port->out_buffer + OUT_BUFFER_SIZE - port->outp;
				if (c > port->out_count)
					c = port->out_count;
				DEBUGTXINT(printk("tx_int DMAWRITE %i %i\n", sentl, c));
				start_dma(port, port->outp, c);
			} else  {
				DEBUGTXINT(printk("tx_int DMA stop %i\n", sentl));
				port->tr_running = 0;
			}
			wake_up_interruptible(&port->out_wait_q); /* wake up the waiting process */
		}
	}
	return IRQ_RETVAL(found);
} /* tr_interrupt */

static irqreturn_t rx_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	reg_dma_r_masked_intr masked;
	reg_dma_rw_ack_intr ack_intr = {.data = regk_dma_yes};

	int i;
	int found = 0;

	for (i = 0; i < NUMBER_OF_PORTS; i++)
	{
		sync_port *port = &ports[i];

		if (!port->enabled || !port->use_dma )
			continue;

		masked = REG_RD(dma, port->regi_dmain, r_masked_intr);

		if (masked.data) /* Descriptor interrupt */
		{
			found = 1;
			while (REG_RD(dma, port->regi_dmain, rw_data) !=
			       virt_to_phys(port->next_rx_desc)) {

				if (port->writep + port->inbufchunk > port->flip + port->in_buffer_size) {
					int first_size = port->flip + port->in_buffer_size - port->writep;
					memcpy((char*)port->writep, phys_to_virt((unsigned)port->next_rx_desc->buf), first_size);
					memcpy(port->flip, phys_to_virt((unsigned)port->next_rx_desc->buf+first_size), port->inbufchunk - first_size);
					port->writep = port->flip + port->inbufchunk - first_size;
				} else {
					memcpy((char*)port->writep,
					       phys_to_virt((unsigned)port->next_rx_desc->buf),
					       port->inbufchunk);
					port->writep += port->inbufchunk;
					if (port->writep >= port->flip + port->in_buffer_size)
						port->writep = port->flip;
				}
                                if (port->writep == port->readp)
                                {
				  port->full = 1;
                                }

				port->next_rx_desc->eol = 0;
				port->prev_rx_desc->eol = 1;
				port->prev_rx_desc = phys_to_virt((unsigned)port->next_rx_desc);
				port->next_rx_desc = phys_to_virt((unsigned)port->next_rx_desc->next);
				wake_up_interruptible(&port->in_wait_q); /* wake up the waiting process */
				DMA_CONTINUE(port->regi_dmain);
				REG_WR(dma, port->regi_dmain, rw_ack_intr, ack_intr);

			}
		}
	}
	return IRQ_RETVAL(found);
} /* rx_interrupt */
#endif /* SYNC_SER_DMA */

#ifdef SYNC_SER_MANUAL
static irqreturn_t manual_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	int i;
	int found = 0;
	reg_sser_r_masked_intr masked;

	for (i = 0; i < NUMBER_OF_PORTS; i++)
	{
		sync_port* port = &ports[i];

		if (!port->enabled || port->use_dma)
		{
			continue;
		}

		masked = REG_RD(sser, port->regi_sser, r_masked_intr);
		if (masked.rdav)	/* Data received? */
		{
			reg_sser_rw_rec_cfg rec_cfg = REG_RD(sser, port->regi_sser, rw_rec_cfg);
			reg_sser_r_rec_data data = REG_RD(sser, port->regi_sser, r_rec_data);
			found = 1;
			/* Read data */
			switch(rec_cfg.sample_size)
			{
			case 8:
				*port->writep++ = data.data & 0xff;
				break;
			case 12:
				*port->writep = (data.data & 0x0ff0) >> 4;
				*(port->writep + 1) = data.data & 0x0f;
				port->writep+=2;
				break;
			case 16:
				*(unsigned short*)port->writep = data.data;
				port->writep+=2;
				break;
			case 24:
				*(unsigned int*)port->writep = data.data;
				port->writep+=3;
				break;
			case 32:
				*(unsigned int*)port->writep = data.data;
				port->writep+=4;
				break;
			}

			if (port->writep >= port->flip + port->in_buffer_size) /* Wrap? */
				port->writep = port->flip;
			if (port->writep == port->readp) {
				/* receive buffer overrun, discard oldest data
				 */
				port->readp++;
				if (port->readp >= port->flip + port->in_buffer_size) /* Wrap? */
					port->readp = port->flip;
			}
			if (sync_data_avail(port) >= port->inbufchunk)
				wake_up_interruptible(&port->in_wait_q); /* Wake up application */
		}

		if (masked.trdy) /* Transmitter ready? */
		{
			found = 1;
			if (port->out_count > 0) /* More data to send */
				send_word(port);
			else /* transmission finished */
			{
				reg_sser_rw_intr_mask intr_mask;
				intr_mask = REG_RD(sser, port->regi_sser, rw_intr_mask);
				intr_mask.trdy = 0;
				REG_WR(sser, port->regi_sser, rw_intr_mask, intr_mask);
				wake_up_interruptible(&port->out_wait_q); /* Wake up application */
			}
		}
	}
	return IRQ_RETVAL(found);
}
#endif

module_init(etrax_sync_serial_init);