drivers/input/touchscreen/max11801_ts.c

Source file repositories/reference/linux-study-clean/drivers/input/touchscreen/max11801_ts.c

File Facts

System
Linux kernel
Corpus path
drivers/input/touchscreen/max11801_ts.c
Extension
.c
Size
6921 bytes
Lines
241
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 max11801_data {
	struct i2c_client		*client;
	struct input_dev		*input_dev;
};

static u8 read_register(struct i2c_client *client, int addr)
{
	/* XXX: The chip ignores LSB of register address */
	return i2c_smbus_read_byte_data(client, addr << 1);
}

static int max11801_write_reg(struct i2c_client *client, int addr, int data)
{
	/* XXX: The chip ignores LSB of register address */
	return i2c_smbus_write_byte_data(client, addr << 1, data);
}

static irqreturn_t max11801_ts_interrupt(int irq, void *dev_id)
{
	struct max11801_data *data = dev_id;
	struct i2c_client *client = data->client;
	int status, i, ret;
	u8 buf[XY_BUFSIZE];
	int x = -1;
	int y = -1;

	status = read_register(data->client, GENERNAL_STATUS_REG);

	if (status & (MAX11801_FIFO_INT | MAX11801_FIFO_OVERFLOW)) {
		status = read_register(data->client, GENERNAL_STATUS_REG);

		ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_CMD,
						    XY_BUFSIZE, buf);

		/*
		 * We should get 4 bytes buffer that contains X,Y
		 * and event tag
		 */
		if (ret < XY_BUFSIZE)
			goto out;

		for (i = 0; i < XY_BUFSIZE; i += XY_BUFSIZE / 2) {
			if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_X_TAG)
				x = (buf[i] << XY_BUF_OFFSET) +
				    (buf[i + 1] >> XY_BUF_OFFSET);
			else if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_Y_TAG)
				y = (buf[i] << XY_BUF_OFFSET) +
				    (buf[i + 1] >> XY_BUF_OFFSET);
		}

		if ((buf[1] & EVENT_TAG_MASK) != (buf[3] & EVENT_TAG_MASK))
			goto out;

		switch (buf[1] & EVENT_TAG_MASK) {
		case EVENT_INIT:
		case EVENT_MIDDLE:
			input_report_abs(data->input_dev, ABS_X, x);
			input_report_abs(data->input_dev, ABS_Y, y);
			input_event(data->input_dev, EV_KEY, BTN_TOUCH, 1);
			input_sync(data->input_dev);
			break;

		case EVENT_RELEASE:
			input_event(data->input_dev, EV_KEY, BTN_TOUCH, 0);
			input_sync(data->input_dev);
			break;

		case EVENT_FIFO_END:
			break;
		}
	}
out:
	return IRQ_HANDLED;
}

static void max11801_ts_phy_init(struct max11801_data *data)
{
	struct i2c_client *client = data->client;

	/* Average X,Y, take 16 samples, average eight media sample */
	max11801_write_reg(client, MESURE_AVER_CONF_REG, 0xff);
	/* X,Y panel setup time set to 20us */
	max11801_write_reg(client, PANEL_SETUPTIME_CONF_REG, 0x11);
	/* Rough pullup time (2uS), Fine pullup time (10us)  */
	max11801_write_reg(client, TOUCH_DETECT_PULLUP_CONF_REG, 0x10);
	/* Auto mode init period = 5ms , scan period = 5ms*/
	max11801_write_reg(client, AUTO_MODE_TIME_CONF_REG, 0xaa);
	/* Aperture X,Y set to +- 4LSB */
	max11801_write_reg(client, APERTURE_CONF_REG, 0x33);
	/* Enable Power, enable Automode, enable Aperture, enable Average X,Y */

Annotation

Implementation Notes