Commit ae6b18e6 authored by Vincent Knecht's avatar Vincent Knecht Committed by Dmitry Torokhov
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Input: msg2638 - add support for msg2138 



msg2138 only supports 2 fingers presses, and needs different processing
since second finger press is encoded as a delta position wrt. first one
and the packet/touch_event structs are not the same as msg2638.

Add support for it by implementing distinct structs and irq handler.

Signed-off-by: default avatarVincent Knecht <vincent.knecht@mailoo.org>
Link: https://lore.kernel.org/r/20221110171952.34207-4-vincent.knecht@mailoo.org


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 14ce9e4c

drivers/input/touchscreen/msg2638.c

+93 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 


#define MODE_DATA_RAW			0x5A



#define MSG2138_MAX_FINGERS		2

#define MSG2638_MAX_FINGERS		5



#define CHIP_ON_DELAY_MS		15
@@ -38,6 +39,18 @@ struct msg_chip_data { 
	unsigned int max_fingers;

};



struct msg2138_packet {

	u8	xy_hi; /* higher bits of x and y coordinates */

	u8	x_low;

	u8	y_low;

};



struct msg2138_touch_event {

	u8	magic;

	struct	msg2138_packet pkt[MSG2138_MAX_FINGERS];

	u8	checksum;

};



struct msg2638_packet {

	u8	xy_hi; /* higher bits of x and y coordinates */

	u8	x_low;
@@ -72,6 +85,80 @@ static u8 msg2638_checksum(u8 *data, u32 length) 
	return (u8)((-sum) & 0xFF);

}



static irqreturn_t msg2138_ts_irq_handler(int irq, void *msg2638_handler)

{

	struct msg2638_ts_data *msg2638 = msg2638_handler;

	struct i2c_client *client = msg2638->client;

	struct input_dev *input = msg2638->input_dev;

	struct msg2138_touch_event touch_event;

	u32 len = sizeof(touch_event);

	struct i2c_msg msg[] = {

		{

			.addr	= client->addr,

			.flags	= I2C_M_RD,

			.len	= sizeof(touch_event),

			.buf	= (u8 *)&touch_event,

		},

	};

	struct msg2138_packet *p0, *p1;

	u16 x, y, delta_x, delta_y;

	int ret;



	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));

	if (ret != ARRAY_SIZE(msg)) {

		dev_err(&client->dev,

			"Failed I2C transfer in irq handler: %d\n",

			ret < 0 ? ret : -EIO);

		goto out;

	}



	if (msg2638_checksum((u8 *)&touch_event, len - 1) !=

						touch_event.checksum) {

		dev_err(&client->dev, "Failed checksum!\n");

		goto out;

	}



	p0 = &touch_event.pkt[0];

	p1 = &touch_event.pkt[1];



	/* Ignore non-pressed finger data */

	if (p0->xy_hi == 0xFF && p0->x_low == 0xFF && p0->y_low == 0xFF)

		goto report;



	x = ((p0->xy_hi & 0xF0) << 4) | p0->x_low;

	y = ((p0->xy_hi & 0x0F) << 8) | p0->y_low;



	input_mt_slot(input, 0);

	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);

	touchscreen_report_pos(input, &msg2638->prop, x, y, true);



	/* Ignore non-pressed finger data */

	if (p1->xy_hi == 0xFF && p1->x_low == 0xFF && p1->y_low == 0xFF)

		goto report;



	/* Second finger is reported as a delta position */

	delta_x = ((p1->xy_hi & 0xF0) << 4) | p1->x_low;

	delta_y = ((p1->xy_hi & 0x0F) << 8) | p1->y_low;



	/* Ignore second finger if both deltas equal 0 */

	if (delta_x == 0 && delta_y == 0)

		goto report;



	x += delta_x;

	y += delta_y;



	input_mt_slot(input, 1);

	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);

	touchscreen_report_pos(input, &msg2638->prop, x, y, true);



report:

	input_mt_sync_frame(msg2638->input_dev);

	input_sync(msg2638->input_dev);



out:

	return IRQ_HANDLED;

}



static irqreturn_t msg2638_ts_irq_handler(int irq, void *msg2638_handler)

{

	struct msg2638_ts_data *msg2638 = msg2638_handler;
@@ -331,12 +418,18 @@ static int __maybe_unused msg2638_resume(struct device *dev) 


static SIMPLE_DEV_PM_OPS(msg2638_pm_ops, msg2638_suspend, msg2638_resume);



static const struct msg_chip_data msg2138_data = {

	.irq_handler = msg2138_ts_irq_handler,

	.max_fingers = MSG2138_MAX_FINGERS,

};



static const struct msg_chip_data msg2638_data = {

	.irq_handler = msg2638_ts_irq_handler,

	.max_fingers = MSG2638_MAX_FINGERS,

};



static const struct of_device_id msg2638_of_match[] = {

	{ .compatible = "mstar,msg2138", .data = &msg2138_data },

	{ .compatible = "mstar,msg2638", .data = &msg2638_data },

	{ }

};