drivers/comedi/drivers/dt2815.c

Source file repositories/reference/linux-study-clean/drivers/comedi/drivers/dt2815.c

File Facts

System
Linux kernel
Corpus path
drivers/comedi/drivers/dt2815.c
Extension
.c
Size
6299 bytes
Lines
230
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 dt2815_private {
	const struct comedi_lrange *range_type_list[8];
	unsigned int ao_readback[8];
};

static int dt2815_ao_status(struct comedi_device *dev,
			    struct comedi_subdevice *s,
			    struct comedi_insn *insn,
			    unsigned long context)
{
	unsigned int status;

	status = inb(dev->iobase + DT2815_STATUS);
	if (status == context)
		return 0;
	return -EBUSY;
}

static int dt2815_ao_insn_read(struct comedi_device *dev,
			       struct comedi_subdevice *s,
			       struct comedi_insn *insn, unsigned int *data)
{
	struct dt2815_private *devpriv = dev->private;
	int i;
	int chan = CR_CHAN(insn->chanspec);

	for (i = 0; i < insn->n; i++)
		data[i] = devpriv->ao_readback[chan];

	return i;
}

static int dt2815_ao_insn(struct comedi_device *dev, struct comedi_subdevice *s,
			  struct comedi_insn *insn, unsigned int *data)
{
	struct dt2815_private *devpriv = dev->private;
	int i;
	int chan = CR_CHAN(insn->chanspec);
	unsigned int lo, hi;
	int ret;

	for (i = 0; i < insn->n; i++) {
		/* FIXME: lo bit 0 chooses voltage output or current output */
		lo = ((data[i] & 0x0f) << 4) | (chan << 1) | 0x01;
		hi = (data[i] & 0xff0) >> 4;

		ret = comedi_timeout(dev, s, insn, dt2815_ao_status, 0x00);
		if (ret)
			return ret;

		outb(lo, dev->iobase + DT2815_DATA);

		ret = comedi_timeout(dev, s, insn, dt2815_ao_status, 0x10);
		if (ret)
			return ret;

		outb(hi, dev->iobase + DT2815_DATA);

		devpriv->ao_readback[chan] = data[i];
	}
	return i;
}

/*
 * options[0]   Board base address
 * options[1]   IRQ (not applicable)
 * options[2]   Voltage unipolar/bipolar configuration
 *		0 == unipolar 5V  (0V -- +5V)
 *		1 == bipolar 5V  (-5V -- +5V)
 * options[3]   Current offset configuration
 *		0 == disabled  (0mA -- +32mAV)
 *		1 == enabled  (+4mA -- +20mAV)
 * options[4]   Firmware program configuration
 *		0 == program 1 (see manual table 5-4)
 *		1 == program 2 (see manual table 5-4)
 *		2 == program 3 (see manual table 5-4)
 *		3 == program 4 (see manual table 5-4)
 * options[5]   Analog output 0 range configuration
 *		0 == voltage
 *		1 == current
 * options[6]   Analog output 1 range configuration
 * ...
 * options[12]   Analog output 7 range configuration
 *		0 == voltage
 *		1 == current
 */

static int dt2815_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
	struct dt2815_private *devpriv;

Annotation

Implementation Notes