drivers/iio/adc/rn5t618-adc.c

Source file repositories/reference/linux-study-clean/drivers/iio/adc/rn5t618-adc.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/adc/rn5t618-adc.c
Extension
.c
Size
6452 bytes
Lines
260
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 rn5t618_adc_data {
	struct device *dev;
	struct rn5t618 *rn5t618;
	struct completion conv_completion;
	int irq;
};

enum rn5t618_channels {
	LIMMON = 0,
	VBAT,
	VADP,
	VUSB,
	VSYS,
	VTHM,
	AIN1,
	AIN0
};

static const struct u16_fract rn5t618_ratios[8] = {
	[LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */
	[VBAT] = {2, 1},
	[VADP] = {3, 1},
	[VUSB] = {3, 1},
	[VSYS] = {3, 1},
	[VTHM] = {1, 1},
	[AIN1] = {1, 1},
	[AIN0] = {1, 1},
};

static int rn5t618_read_adc_reg(struct rn5t618 *rn5t618, int reg, u16 *val)
{
	u8 data[2];
	int ret;

	ret = regmap_bulk_read(rn5t618->regmap, reg, data, sizeof(data));
	if (ret < 0)
		return ret;

	*val = (data[0] << 4) | (data[1] & 0xF);

	return 0;
}

static irqreturn_t rn5t618_adc_irq(int irq, void *data)
{
	struct rn5t618_adc_data *adc = data;
	unsigned int r = 0;
	int ret;

	/* clear low & high threshold irqs */
	regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC1, 0);
	regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC2, 0);

	ret = regmap_read(adc->rn5t618->regmap, RN5T618_IR_ADC3, &r);
	if (ret < 0)
		dev_err(adc->dev, "failed to read IRQ status: %d\n", ret);

	regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC3, 0);

	if (r & RN5T618_ADCEND_IRQ)
		complete(&adc->conv_completion);

	return IRQ_HANDLED;
}

static int rn5t618_adc_read(struct iio_dev *iio_dev,
			    const struct iio_chan_spec *chan,
			    int *val, int *val2, long mask)
{
	struct rn5t618_adc_data *adc = iio_priv(iio_dev);
	u16 raw;
	int ret;

	if (mask == IIO_CHAN_INFO_SCALE) {
		*val = RN5T618_REFERENCE_VOLT *
		       rn5t618_ratios[chan->channel].numerator;
		*val2 = rn5t618_ratios[chan->channel].denominator * 4095;

		return IIO_VAL_FRACTIONAL;
	}

	/* select channel */
	ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
				 RN5T618_ADCCNT3_CHANNEL_MASK,
				 chan->channel);
	if (ret < 0)
		return ret;

	ret = regmap_write(adc->rn5t618->regmap, RN5T618_EN_ADCIR3,
			   RN5T618_ADCEND_IRQ);

Annotation

Implementation Notes