drivers/hwmon/adm1177.c

Source file repositories/reference/linux-study-clean/drivers/hwmon/adm1177.c

File Facts

System
Linux kernel
Corpus path
drivers/hwmon/adm1177.c
Extension
.c
Size
6216 bytes
Lines
274
Domain
Driver Families
Bucket
drivers/hwmon
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 adm1177_state {
	struct i2c_client	*client;
	u32			r_sense_uohm;
	u64			alert_threshold_ua;
	bool			vrange_high;
};

static int adm1177_read_raw(struct adm1177_state *st, u8 num, u8 *data)
{
	return i2c_master_recv(st->client, data, num);
}

static int adm1177_write_cmd(struct adm1177_state *st, u8 cmd)
{
	return i2c_smbus_write_byte(st->client, cmd);
}

static int adm1177_write_alert_thr(struct adm1177_state *st,
				   u64 alert_threshold_ua)
{
	u64 val;
	int ret;

	val = 0xFFULL * alert_threshold_ua * st->r_sense_uohm;
	val = div_u64(val, 105840000U);
	val = div_u64(val, 1000U);
	if (val > 0xFF)
		val = 0xFF;

	ret = i2c_smbus_write_byte_data(st->client, ADM1177_REG_ALERT_TH,
					val);
	if (ret)
		return ret;

	st->alert_threshold_ua = alert_threshold_ua;
	return 0;
}

static int adm1177_read(struct device *dev, enum hwmon_sensor_types type,
			u32 attr, int channel, long *val)
{
	struct adm1177_state *st = dev_get_drvdata(dev);
	u8 data[3];
	long dummy;
	int ret;

	switch (type) {
	case hwmon_curr:
		switch (attr) {
		case hwmon_curr_input:
			ret = adm1177_read_raw(st, 3, data);
			if (ret < 0)
				return ret;
			dummy = (data[1] << 4) | (data[2] & 0xF);
			/*
			 * convert to milliamperes
			 * ((105.84mV / 4096) x raw) / senseResistor(ohm)
			 */
			*val = div_u64((105840000ull * dummy),
				       4096 * st->r_sense_uohm);
			return 0;
		case hwmon_curr_max:
			*val = div_u64(st->alert_threshold_ua, 1000);
			return 0;
		default:
			return -EOPNOTSUPP;
		}
	case hwmon_in:
		ret = adm1177_read_raw(st, 3, data);
		if (ret < 0)
			return ret;
		dummy = (data[0] << 4) | (data[2] >> 4);
		/*
		 * convert to millivolts based on resistor devision
		 * (V_fullscale / 4096) * raw
		 */
		if (st->vrange_high)
			dummy *= 26350;
		else
			dummy *= 6650;

		*val = DIV_ROUND_CLOSEST(dummy, 4096);
		return 0;
	default:
		return -EOPNOTSUPP;
	}
}

static int adm1177_write(struct device *dev, enum hwmon_sensor_types type,
			 u32 attr, int channel, long val)

Annotation

Implementation Notes