drivers/iio/adc/viperboard_adc.c

Source file repositories/reference/linux-study-clean/drivers/iio/adc/viperboard_adc.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/adc/viperboard_adc.c
Extension
.c
Size
3483 bytes
Lines
151
Domain
Driver Families
Bucket
drivers/iio
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 vprbrd_adc_msg {
	u8 cmd;
	u8 chan;
	u8 val;
} __packed;

struct vprbrd_adc {
	struct vprbrd *vb;
};

#define VPRBRD_ADC_CHANNEL(_index) {			\
	.type = IIO_VOLTAGE,				\
	.indexed = 1,					\
	.channel = _index,				\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
}

static struct iio_chan_spec const vprbrd_adc_iio_channels[] = {
	VPRBRD_ADC_CHANNEL(0),
	VPRBRD_ADC_CHANNEL(1),
	VPRBRD_ADC_CHANNEL(2),
	VPRBRD_ADC_CHANNEL(3),
};

static int vprbrd_iio_read_raw(struct iio_dev *iio_dev,
				struct iio_chan_spec const *chan,
				int *val,
				int *val2,
				long info)
{
	int ret, error = 0;
	struct vprbrd_adc *adc = iio_priv(iio_dev);
	struct vprbrd *vb = adc->vb;
	struct vprbrd_adc_msg *admsg = (struct vprbrd_adc_msg *)vb->buf;

	switch (info) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&vb->lock);

		admsg->cmd = VPRBRD_ADC_CMD_GET;
		admsg->chan = chan->channel;
		admsg->val = 0x00;

		ret = usb_control_msg(vb->usb_dev,
			usb_sndctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
			VPRBRD_USB_TYPE_OUT, 0x0000, 0x0000, admsg,
			sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);
		if (ret != sizeof(struct vprbrd_adc_msg)) {
			mutex_unlock(&vb->lock);
			error = -EREMOTEIO;
			dev_err(&iio_dev->dev, "usb send error on adc read\n");
			goto error;
		}

		ret = usb_control_msg(vb->usb_dev,
			usb_rcvctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
			VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, admsg,
			sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);

		*val = admsg->val;

		mutex_unlock(&vb->lock);

		if (ret != sizeof(struct vprbrd_adc_msg)) {
			dev_err(&iio_dev->dev, "usb recv error on adc read\n");
			error = -EREMOTEIO;
		}

		if (error)
			goto error;

		return IIO_VAL_INT;
	default:
		error = -EINVAL;
		break;
	}
error:
	return error;
}

static const struct iio_info vprbrd_adc_iio_info = {
	.read_raw = &vprbrd_iio_read_raw,
};

static int vprbrd_adc_probe(struct platform_device *pdev)
{
	struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
	struct vprbrd_adc *adc;
	struct iio_dev *indio_dev;
	int ret;

Annotation

Implementation Notes