drivers/input/touchscreen/mms114.c

Source file repositories/reference/linux-study-clean/drivers/input/touchscreen/mms114.c

File Facts

System
Linux kernel
Corpus path
drivers/input/touchscreen/mms114.c
Extension
.c
Size
17479 bytes
Lines
714
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 mms114_data {
	struct i2c_client	*client;
	struct input_dev	*input_dev;
	struct regulator	*core_reg;
	struct regulator	*io_reg;
	struct touchscreen_properties props;
	enum mms_type		type;
	unsigned int		contact_threshold;
	unsigned int		moving_threshold;

	u32 keycodes[MMS114_MAX_TOUCHKEYS];
	int num_keycodes;

	/* Use cache data for mode control register(write only) */
	u8			cache_mode_control;
};

struct mms114_touch {
	u8 id:4, reserved_bit4:1, type:2, pressed:1;
	u8 x_hi:4, y_hi:4;
	u8 x_lo;
	u8 y_lo;
	u8 width;
	u8 strength;
	u8 reserved[2];
} __packed;

static int __mms114_read_reg(struct mms114_data *data, unsigned int reg,
			     unsigned int len, u8 *val)
{
	struct i2c_client *client = data->client;
	struct i2c_msg xfer[2];
	u8 buf = reg & 0xff;
	int error;

	if (reg <= MMS114_MODE_CONTROL && reg + len > MMS114_MODE_CONTROL)
		BUG();

	/* Write register */
	xfer[0].addr = client->addr;
	xfer[0].flags = client->flags & I2C_M_TEN;
	xfer[0].len = 1;
	xfer[0].buf = &buf;

	/* Read data */
	xfer[1].addr = client->addr;
	xfer[1].flags = (client->flags & I2C_M_TEN) | I2C_M_RD;
	xfer[1].len = len;
	xfer[1].buf = val;

	error = i2c_transfer(client->adapter, xfer, 2);
	if (error != 2) {
		dev_err(&client->dev,
			"%s: i2c transfer failed (%d)\n", __func__, error);
		return error < 0 ? error : -EIO;
	}
	udelay(MMS114_I2C_DELAY);

	return 0;
}

static int mms114_read_reg(struct mms114_data *data, unsigned int reg)
{
	u8 val;
	int error;

	if (reg == MMS114_MODE_CONTROL)
		return data->cache_mode_control;

	error = __mms114_read_reg(data, reg, 1, &val);
	return error < 0 ? error : val;
}

static int mms114_write_reg(struct mms114_data *data, unsigned int reg,
			    unsigned int val)
{
	struct i2c_client *client = data->client;
	u8 buf[2];
	int error;

	buf[0] = reg & 0xff;
	buf[1] = val & 0xff;

	error = i2c_master_send(client, buf, 2);
	if (error != 2) {
		dev_err(&client->dev,
			"%s: i2c send failed (%d)\n", __func__, error);
		return error < 0 ? error : -EIO;
	}
	udelay(MMS114_I2C_DELAY);

Annotation

Implementation Notes