drivers/iio/magnetometer/mag3110.c

Source file repositories/reference/linux-study-clean/drivers/iio/magnetometer/mag3110.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/magnetometer/mag3110.c
Extension
.c
Size
15460 bytes
Lines
648
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 mag3110_data {
	struct i2c_client *client;
	struct mutex lock;
	u8 ctrl_reg1;
	int sleep_val;
	struct regulator *vdd_reg;
	struct regulator *vddio_reg;
	/* Ensure natural alignment of timestamp */
	struct {
		__be16 channels[3];
		u8 temperature;
		aligned_s64 ts;
	} scan;
};

static int mag3110_request(struct mag3110_data *data)
{
	int ret, tries = 150;

	if ((data->ctrl_reg1 & MAG3110_CTRL_AC) == 0) {
		/* trigger measurement */
		ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
			data->ctrl_reg1 | MAG3110_CTRL_TM);
		if (ret < 0)
			return ret;
	}

	while (tries-- > 0) {
		ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
		if (ret < 0)
			return ret;
		/* wait for data ready */
		if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
			break;

		if (data->sleep_val <= 20)
			usleep_range(data->sleep_val * 250, data->sleep_val * 500);
		else
			msleep(20);
	}

	if (tries < 0) {
		dev_err(&data->client->dev, "data not ready\n");
		return -EIO;
	}

	return 0;
}

static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
{
	int ret;

	guard(mutex)(&data->lock);
	ret = mag3110_request(data);
	if (ret < 0)
		return ret;
	return i2c_smbus_read_i2c_block_data(data->client, MAG3110_OUT_X,
					     3 * sizeof(__be16), (u8 *) buf);
}

static ssize_t mag3110_show_int_plus_micros(char *buf,
	const int (*vals)[2], int n)
{
	size_t len = 0;

	while (n-- > 0)
		len += scnprintf(buf + len, PAGE_SIZE - len,
			"%d.%06d ", vals[n][0], vals[n][1]);

	/* replace trailing space by newline */
	buf[len - 1] = '\n';

	return len;
}

static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
					int val, int val2)
{
	while (n-- > 0)
		if (val == vals[n][0] && val2 == vals[n][1])
			return n;

	return -EINVAL;
}

static const int mag3110_samp_freq[8][2] = {
	{80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
	{1, 250000}, {0, 625000}
};

Annotation

Implementation Notes