drivers/comedi/drivers/adq12b.c

Source file repositories/reference/linux-study-clean/drivers/comedi/drivers/adq12b.c

File Facts

System
Linux kernel
Corpus path
drivers/comedi/drivers/adq12b.c
Extension
.c
Size
6262 bytes
Lines
244
Domain
Driver Families
Bucket
drivers/comedi
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct adq12b_private {
	unsigned int last_ctreg;
};

static int adq12b_ai_eoc(struct comedi_device *dev,
			 struct comedi_subdevice *s,
			 struct comedi_insn *insn,
			 unsigned long context)
{
	unsigned char status;

	status = inb(dev->iobase + ADQ12B_STINR);
	if (status & ADQ12B_STINR_EOC)
		return 0;
	return -EBUSY;
}

static int adq12b_ai_insn_read(struct comedi_device *dev,
			       struct comedi_subdevice *s,
			       struct comedi_insn *insn,
			       unsigned int *data)
{
	struct adq12b_private *devpriv = dev->private;
	unsigned int chan = CR_CHAN(insn->chanspec);
	unsigned int range = CR_RANGE(insn->chanspec);
	unsigned int val;
	int ret;
	int i;

	/* change channel and range only if it is different from the previous */
	val = ADQ12B_CTREG_RANGE(range) | ADQ12B_CTREG_CHAN(chan);
	if (val != devpriv->last_ctreg) {
		outb(val, dev->iobase + ADQ12B_CTREG);
		devpriv->last_ctreg = val;
		usleep_range(50, 100);	/* wait for the mux to settle */
	}

	val = inb(dev->iobase + ADQ12B_ADLOW);	/* trigger A/D */

	for (i = 0; i < insn->n; i++) {
		ret = comedi_timeout(dev, s, insn, adq12b_ai_eoc, 0);
		if (ret)
			return ret;

		val = inb(dev->iobase + ADQ12B_ADHIG) << 8;
		val |= inb(dev->iobase + ADQ12B_ADLOW);	/* retriggers A/D */

		data[i] = val;
	}

	return insn->n;
}

static int adq12b_di_insn_bits(struct comedi_device *dev,
			       struct comedi_subdevice *s,
			       struct comedi_insn *insn, unsigned int *data)
{
	/* only bits 0-4 have information about digital inputs */
	data[1] = (inb(dev->iobase + ADQ12B_STINR) & ADQ12B_STINR_IN_MASK);

	return insn->n;
}

static int adq12b_do_insn_bits(struct comedi_device *dev,
			       struct comedi_subdevice *s,
			       struct comedi_insn *insn,
			       unsigned int *data)
{
	unsigned int mask;
	unsigned int chan;
	unsigned int val;

	mask = comedi_dio_update_state(s, data);
	if (mask) {
		for (chan = 0; chan < 8; chan++) {
			if ((mask >> chan) & 0x01) {
				val = (s->state >> chan) & 0x01;
				outb((val << 3) | chan,
				     dev->iobase + ADQ12B_OUTBR);
			}
		}
	}

	data[1] = s->state;

	return insn->n;
}

static int adq12b_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{

Annotation

Implementation Notes