drivers/input/misc/bma150.c

Source file repositories/reference/linux-study-clean/drivers/input/misc/bma150.c

File Facts

System
Linux kernel
Corpus path
drivers/input/misc/bma150.c
Extension
.c
Size
13682 bytes
Lines
563
Domain
Driver Families
Bucket
drivers/input
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 bma150_data {
	struct i2c_client *client;
	struct input_dev *input;
	u8 mode;
};

/*
 * The settings for the given range, bandwidth and interrupt features
 * are stated and verified by Bosch Sensortec where they are configured
 * to provide a generic sensitivity performance.
 */
static const struct bma150_cfg default_cfg = {
	.any_motion_int = 1,
	.hg_int = 1,
	.lg_int = 1,
	.any_motion_dur = 0,
	.any_motion_thres = 0,
	.hg_hyst = 0,
	.hg_dur = 150,
	.hg_thres = 160,
	.lg_hyst = 0,
	.lg_dur = 150,
	.lg_thres = 20,
	.range = BMA150_RANGE_2G,
	.bandwidth = BMA150_BW_50HZ
};

static int bma150_write_byte(struct i2c_client *client, u8 reg, u8 val)
{
	s32 ret;

	/* As per specification, disable irq in between register writes */
	if (client->irq)
		disable_irq_nosync(client->irq);

	ret = i2c_smbus_write_byte_data(client, reg, val);

	if (client->irq)
		enable_irq(client->irq);

	return ret;
}

static int bma150_set_reg_bits(struct i2c_client *client,
					int val, int shift, u8 mask, u8 reg)
{
	int data;

	data = i2c_smbus_read_byte_data(client, reg);
	if (data < 0)
		return data;

	data = (data & ~mask) | ((val << shift) & mask);
	return bma150_write_byte(client, reg, data);
}

static int bma150_set_mode(struct bma150_data *bma150, u8 mode)
{
	int error;

	error = bma150_set_reg_bits(bma150->client, mode, BMA150_WAKE_UP_POS,
				BMA150_WAKE_UP_MSK, BMA150_WAKE_UP_REG);
	if (error)
		return error;

	error = bma150_set_reg_bits(bma150->client, mode, BMA150_SLEEP_POS,
				BMA150_SLEEP_MSK, BMA150_SLEEP_REG);
	if (error)
		return error;

	if (mode == BMA150_MODE_NORMAL)
		usleep_range(2000, 2100);

	bma150->mode = mode;
	return 0;
}

static int bma150_soft_reset(struct bma150_data *bma150)
{
	int error;

	error = bma150_set_reg_bits(bma150->client, 1, BMA150_SW_RES_POS,
				BMA150_SW_RES_MSK, BMA150_SW_RES_REG);
	if (error)
		return error;

	usleep_range(2000, 2100);
	return 0;
}

Annotation

Implementation Notes