[PATCH 7/9] Input: pixcir_i2c_ts: Implement Type B Multi Touch reporting

[Roger Quadros]

Some pixcir controllers e.g. tangoC family report finger IDs with
the co-ordinates and are more suitable for Type-B MT protocol.

Signed-off-by: Roger Quadros <rogerq@xxxxxx>
Acked-by: Mugunthan V N <mugunthanvnm@xxxxxx>
---
 drivers/input/touchscreen/pixcir_i2c_ts.c | 202 +++++++++++++++++++++++-------
 1 file changed, 155 insertions(+), 47 deletions(-)

diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c b/drivers/input/touchscreen/pixcir_i2c_ts.c
index ff68246..9e14415 100644
--- a/drivers/input/touchscreen/pixcir_i2c_ts.c
+++ b/drivers/input/touchscreen/pixcir_i2c_ts.c
@@ -23,84 +23,173 @@
 #include <linux/slab.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
+#include <linux/input/mt.h>
 #include <linux/input/pixcir_ts.h>
 #include <linux/gpio.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/of_device.h>
 
+#define MAX_FINGERS	5	/* Maximum supported by the driver */
+
 struct pixcir_i2c_ts_data {
 	struct i2c_client *client;
 	struct input_dev *input;
 	const struct pixcir_ts_platform_data *pdata;
 	bool exiting;
+	u8 max_fingers;		/* Maximum supported by the chip */
 };
 
-static void pixcir_ts_poscheck(struct pixcir_i2c_ts_data *data)
+static void pixcir_ts_typea_report(struct pixcir_i2c_ts_data *tsdata)
 {
-	struct pixcir_i2c_ts_data *tsdata = data;
+	const struct pixcir_ts_platform_data *pdata = tsdata->pdata;
 	u8 rdbuf[10], wrbuf[1] = { 0 };
 	u8 touch;
 	int ret;
 
-	ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
-	if (ret != sizeof(wrbuf)) {
-		dev_err(&tsdata->client->dev,
-			"%s: i2c_master_send failed(), ret=%d\n",
-			__func__, ret);
-		return;
-	}
+	while (!tsdata->exiting) {
 
-	ret = i2c_master_recv(tsdata->client, rdbuf, sizeof(rdbuf));
-	if (ret != sizeof(rdbuf)) {
-		dev_err(&tsdata->client->dev,
-			"%s: i2c_master_recv failed(), ret=%d\n",
-			__func__, ret);
-		return;
-	}
+		ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
+		if (ret != sizeof(wrbuf)) {
+			dev_err(&tsdata->client->dev,
+				 "%s: i2c_master_send failed(), ret=%d\n",
+				 __func__, ret);
+			return;
+		}
+
+		ret = i2c_master_recv(tsdata->client, rdbuf, sizeof(rdbuf));
+		if (ret != sizeof(rdbuf)) {
+			dev_err(&tsdata->client->dev,
+				 "%s: i2c_master_recv failed(), ret=%d\n",
+				 __func__, ret);
+			return;
+		}
 
-	touch = rdbuf[0];
-	if (touch) {
-		u16 posx1 = (rdbuf[3] << 8) | rdbuf[2];
-		u16 posy1 = (rdbuf[5] << 8) | rdbuf[4];
-		u16 posx2 = (rdbuf[7] << 8) | rdbuf[6];
-		u16 posy2 = (rdbuf[9] << 8) | rdbuf[8];
-
-		input_report_key(tsdata->input, BTN_TOUCH, 1);
-		input_report_abs(tsdata->input, ABS_X, posx1);
-		input_report_abs(tsdata->input, ABS_Y, posy1);
-
-		input_report_abs(tsdata->input, ABS_MT_POSITION_X, posx1);
-		input_report_abs(tsdata->input, ABS_MT_POSITION_Y, posy1);
-		input_mt_sync(tsdata->input);
-
-		if (touch == 2) {
-			input_report_abs(tsdata->input,
-					 ABS_MT_POSITION_X, posx2);
-			input_report_abs(tsdata->input,
-					 ABS_MT_POSITION_Y, posy2);
+		touch = rdbuf[0];
+		if (touch) {
+			u16 posx1 = (rdbuf[3] << 8) | rdbuf[2];
+			u16 posy1 = (rdbuf[5] << 8) | rdbuf[4];
+			u16 posx2 = (rdbuf[7] << 8) | rdbuf[6];
+			u16 posy2 = (rdbuf[9] << 8) | rdbuf[8];
+
+			input_report_key(tsdata->input, BTN_TOUCH, 1);
+			input_report_abs(tsdata->input, ABS_X, posx1);
+			input_report_abs(tsdata->input, ABS_Y, posy1);
+
+			input_report_abs(tsdata->input, ABS_MT_POSITION_X,
+									posx1);
+			input_report_abs(tsdata->input, ABS_MT_POSITION_Y,
+									posy1);
 			input_mt_sync(tsdata->input);
+
+			if (touch == 2) {
+				input_report_abs(tsdata->input,
+						ABS_MT_POSITION_X, posx2);
+				input_report_abs(tsdata->input,
+						ABS_MT_POSITION_Y, posy2);
+				input_mt_sync(tsdata->input);
+			}
+		} else {
+			input_report_key(tsdata->input, BTN_TOUCH, 0);
 		}
-	} else {
-		input_report_key(tsdata->input, BTN_TOUCH, 0);
-	}
 
-	input_sync(tsdata->input);
+		input_sync(tsdata->input);
+
+		if (gpio_get_value(pdata->gpio_attb))
+			break;
+
+		msleep(20);
+	}
 }
 
-static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
+static void pixcir_ts_typeb_report(struct pixcir_i2c_ts_data *ts)
 {
-	struct pixcir_i2c_ts_data *tsdata = dev_id;
-	const struct pixcir_ts_platform_data *pdata = tsdata->pdata;
+	const struct pixcir_ts_platform_data *pdata = ts->pdata;
+	struct device *dev = &ts->client->dev;
+	u8 rdbuf[32], wrbuf[1] = { 0 };
+	u8 *bufptr;
+	u8 num_fingers;
+	u8 unreliable;
+	int ret, i;
+
+	while (!ts->exiting) {
+
+		ret = i2c_master_send(ts->client, wrbuf, sizeof(wrbuf));
+		if (ret != sizeof(wrbuf)) {
+			dev_err(dev, "%s: i2c_master_send failed(), ret=%d\n",
+				 __func__, ret);
+			return;
+		}
 
-	while (!tsdata->exiting) {
-		pixcir_ts_poscheck(tsdata);
+		ret = i2c_master_recv(ts->client, rdbuf, sizeof(rdbuf));
+		if (ret != sizeof(rdbuf)) {
+			dev_err(dev, "%s: i2c_master_recv failed(), ret=%d\n",
+				 __func__, ret);
+			return;
+		}
+
+		unreliable = rdbuf[0] & 0xe0;
+
+		if (unreliable)
+			goto next;	/* ignore unreliable data */
+
+		num_fingers = rdbuf[0] & 0x7;
+		bufptr = &rdbuf[2];
 
+		if (num_fingers > ts->max_fingers) {
+			num_fingers = ts->max_fingers;
+			dev_dbg(dev, "limiting num_fingers to %d\n",
+								num_fingers);
+		}
+
+		for (i = 0; i < num_fingers; i++) {
+			u8 id;
+			unsigned int x, y;
+			int slot;
+
+			id = bufptr[4];
+			slot = input_mt_get_slot_by_key(ts->input, id);
+			if (slot < 0) {
+				dev_dbg(dev, "no free slot for id 0x%x\n", id);
+				continue;
+			}
+
+
+			x = bufptr[1] << 8 | bufptr[0];
+			y = bufptr[3] << 8 | bufptr[2];
+
+			input_mt_slot(ts->input, slot);
+			input_mt_report_slot_state(ts->input,
+							MT_TOOL_FINGER, true);
+
+			input_event(ts->input, EV_ABS, ABS_MT_POSITION_X, x);
+			input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y, y);
+
+			bufptr = &bufptr[5];
+			dev_dbg(dev, "%d: id 0x%x slot %d, x %d, y %d\n",
+							i, id, slot, x, y);
+		}
+
+		/* One frame is complete so sync it */
+		input_mt_sync_frame(ts->input);
+		input_sync(ts->input);
+
+next:
 		if (gpio_get_value(pdata->gpio_attb))
 			break;
 
-		msleep(20);
+		usleep_range(2000, 5000);
 	}
+}
+
+static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
+{
+	struct pixcir_i2c_ts_data *tsdata = dev_id;
+
+	if (tsdata->input->mt)
+		pixcir_ts_typeb_report(tsdata);
+	else
+		pixcir_ts_typea_report(tsdata);
 
 	return IRQ_HANDLED;
 }
@@ -376,9 +465,9 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
 	input->open = pixcir_input_open;
 	input->close = pixcir_input_close;
 
-	__set_bit(EV_KEY, input->evbit);
 	__set_bit(EV_ABS, input->evbit);
 	__set_bit(BTN_TOUCH, input->keybit);
+
 	input_set_abs_params(input, ABS_X,
 					0, pdata->x_size - 1, 0, 0);
 	input_set_abs_params(input, ABS_Y,
@@ -388,6 +477,25 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
 	input_set_abs_params(input, ABS_MT_POSITION_Y,
 					0, pdata->y_size - 1, 0, 0);
 
+	/* Type-B Multi-Touch support */
+	if (pdata->chip.num_report_ids) {
+		const struct pixcir_i2c_chip_data *chip = &pdata->chip;
+
+		tsdata->max_fingers = chip->num_report_ids;
+		if (tsdata->max_fingers > MAX_FINGERS) {
+			dev_info(dev, "Limiting maximum fingers to %d\n",
+								MAX_FINGERS);
+			tsdata->max_fingers = MAX_FINGERS;
+		}
+
+		error = input_mt_init_slots(input, tsdata->max_fingers,
+					INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+		if (error) {
+			dev_err(dev, "Error initializing Multi-Touch slots\n");
+			return error;
+		}
+	}
+
 	input_set_drvdata(input, tsdata);
 
 	error = devm_gpio_request_one(dev, pdata->gpio_attb,
-- 
1.8.3.2

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