static int das16_attach()

in drivers/das16.c [1015:1165]

• 121 lines of code
• 22 McCabe index (conditional complexity)

static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
	const struct das16_board *board = dev->board_ptr;
	struct das16_private_struct *devpriv;
	struct comedi_subdevice *s;
	unsigned int osc_base;
	unsigned int status;
	int ret;

	/*  check that clock setting is valid */
	if (it->options[3]) {
		if (it->options[3] != 1 && it->options[3] != 10) {
			dev_err(dev->class_dev,
				"Invalid option. Master clock must be set to 1 or 10 (MHz)\n");
			return -EINVAL;
		}
	}

	devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
	if (!devpriv)
		return -ENOMEM;
	devpriv->dev = dev;

	if (board->size < 0x400) {
		ret = comedi_request_region(dev, it->options[0], board->size);
		if (ret)
			return ret;
	} else {
		ret = comedi_request_region(dev, it->options[0], 0x10);
		if (ret)
			return ret;
		/* Request an additional region for the 8255 */
		ret = __comedi_request_region(dev, dev->iobase + 0x400,
					      board->size & 0x3ff);
		if (ret)
			return ret;
		devpriv->extra_iobase = dev->iobase + 0x400;
		devpriv->can_burst = 1;
	}

	/*  probe id bits to make sure they are consistent */
	if (das16_probe(dev, it))
		return -EINVAL;

	/*  get master clock speed */
	osc_base = I8254_OSC_BASE_1MHZ;
	if (devpriv->can_burst) {
		status = inb(dev->iobase + DAS1600_STATUS_REG);
		if (status & DAS1600_STATUS_CLK_10MHZ)
			osc_base = I8254_OSC_BASE_10MHZ;
	} else {
		if (it->options[3])
			osc_base = I8254_OSC_BASE_1MHZ / it->options[3];
	}

	dev->pacer = comedi_8254_init(dev->iobase + DAS16_TIMER_BASE_REG,
				      osc_base, I8254_IO8, 0);
	if (!dev->pacer)
		return -ENOMEM;

	das16_alloc_dma(dev, it->options[2]);

	ret = comedi_alloc_subdevices(dev, 4 + board->has_8255);
	if (ret)
		return ret;

	status = inb(dev->iobase + DAS16_STATUS_REG);

	/* Analog Input subdevice */
	s = &dev->subdevices[0];
	s->type		= COMEDI_SUBD_AI;
	s->subdev_flags	= SDF_READABLE;
	if (status & DAS16_STATUS_MUXBIT) {
		s->subdev_flags	|= SDF_GROUND;
		s->n_chan	= 16;
	} else {
		s->subdev_flags	|= SDF_DIFF;
		s->n_chan	= 8;
	}
	s->len_chanlist	= s->n_chan;
	s->maxdata	= board->ai_maxdata;
	s->range_table	= das16_ai_range(dev, s, it, board->ai_pg, status);
	s->insn_read	= das16_ai_insn_read;
	if (devpriv->dma) {
		dev->read_subdev = s;
		s->subdev_flags	|= SDF_CMD_READ;
		s->do_cmdtest	= das16_cmd_test;
		s->do_cmd	= das16_cmd_exec;
		s->cancel	= das16_cancel;
		s->munge	= das16_ai_munge;
	}

	/* Analog Output subdevice */
	s = &dev->subdevices[1];
	if (board->has_ao) {
		s->type		= COMEDI_SUBD_AO;
		s->subdev_flags	= SDF_WRITABLE;
		s->n_chan	= 2;
		s->maxdata	= 0x0fff;
		s->range_table	= das16_ao_range(dev, s, it);
		s->insn_write	= das16_ao_insn_write;

		ret = comedi_alloc_subdev_readback(s);
		if (ret)
			return ret;
	} else {
		s->type		= COMEDI_SUBD_UNUSED;
	}

	/* Digital Input subdevice */
	s = &dev->subdevices[2];
	s->type		= COMEDI_SUBD_DI;
	s->subdev_flags	= SDF_READABLE;
	s->n_chan	= 4;
	s->maxdata	= 1;
	s->range_table	= &range_digital;
	s->insn_bits	= das16_di_insn_bits;

	/* Digital Output subdevice */
	s = &dev->subdevices[3];
	s->type		= COMEDI_SUBD_DO;
	s->subdev_flags	= SDF_WRITABLE;
	s->n_chan	= 4;
	s->maxdata	= 1;
	s->range_table	= &range_digital;
	s->insn_bits	= das16_do_insn_bits;

	/* initialize digital output lines */
	outb(s->state, dev->iobase + DAS16_DIO_REG);

	/* 8255 Digital I/O subdevice */
	if (board->has_8255) {
		s = &dev->subdevices[4];
		ret = subdev_8255_init(dev, s, NULL, board->i8255_offset);
		if (ret)
			return ret;
	}

	das16_reset(dev);
	/* set the interrupt level */
	devpriv->ctrl_reg = DAS16_CTRL_IRQ(dev->irq);
	outb(devpriv->ctrl_reg, dev->iobase + DAS16_CTRL_REG);

	if (devpriv->can_burst) {
		outb(DAS1600_ENABLE_VAL, dev->iobase + DAS1600_ENABLE_REG);
		outb(0, dev->iobase + DAS1600_CONV_REG);
		outb(0, dev->iobase + DAS1600_BURST_REG);
	}

	return 0;
}