Input: elan_i2c - add support for high resolution reports

Newer controllers (identified as "pattern" version 2) send higher
resolution reports, with 16-bit X and Y coordinates (previous generations
used 12-bit values). These new high resolution reports use report ID of
0x60.

SMbus controllers use the same buffer size for both the new and old
reports, and because of that high resolution reports no longer carry
area of contact data with SMbus.

Signed-off-by: Jingle Wu <jingle.wu@emc.com.tw>
Link: https://lore.kernel.org/r/20200710054116.5529-1-jingle.wu@emc.com.tw
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 79 insertions, 47 deletions

diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c
index 3230aaf63dab..f10635a0b189 100644
--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -50,12 +50,14 @@
 #define ETP_MAX_FINGERS		5
 #define ETP_FINGER_DATA_LEN	5
 #define ETP_REPORT_ID		0x5D
+#define ETP_REPORT_ID2		0x60	/* High precision report */
 #define ETP_TP_REPORT_ID	0x5E
 #define ETP_REPORT_ID_OFFSET	2
 #define ETP_TOUCH_INFO_OFFSET	3
 #define ETP_FINGER_DATA_OFFSET	4
 #define ETP_HOVER_INFO_OFFSET	30
-#define ETP_MAX_REPORT_LEN	34
+#define ETP_MK_DATA_OFFSET	33	/* For high precision reports */
+#define ETP_MAX_REPORT_LEN	39
 
 /* The main device structure */
 struct elan_tp_data {
@@ -85,6 +87,8 @@ struct elan_tp_data {
 	u8			sm_version;
 	u8			iap_version;
 	u16			fw_checksum;
+	unsigned int		report_features;
+	unsigned int		report_len;
 	int			pressure_adjustment;
 	u8			mode;
 	u16			ic_type;
@@ -359,6 +363,12 @@ static int elan_query_device_info(struct elan_tp_data *data)
 	if (error)
 		return error;
 
+	error = data->ops->get_report_features(data->client, data->pattern,
+					       &data->report_features,
+					       &data->report_len);
+	if (error)
+		return error;
+
 	error = elan_get_fwinfo(data->ic_type, data->iap_version,
 				&data->fw_validpage_count,
 				&data->fw_signature_address,
@@ -371,16 +381,21 @@ static int elan_query_device_info(struct elan_tp_data *data)
 	return 0;
 }
 
-static unsigned int elan_convert_resolution(u8 val)
+static unsigned int elan_convert_resolution(u8 val, u8 pattern)
 {
 	/*
-	 * (value from firmware) * 10 + 790 = dpi
-	 *
+	 * pattern <= 0x01:
+	 *	(value from firmware) * 10 + 790 = dpi
+	 * else
+	 *	((value from firmware) + 3) * 100 = dpi
+	 */
+	int res = pattern <= 0x01 ?
+		(int)(char)val * 10 + 790 : ((int)(char)val + 3) * 100;
+	/*
 	 * We also have to convert dpi to dots/mm (*10/254 to avoid floating
 	 * point).
 	 */
-
-	return ((int)(char)val * 10 + 790) * 10 / 254;
+	return res * 10 / 254;
 }
 
 static int elan_query_device_parameters(struct elan_tp_data *data)
@@ -429,8 +444,8 @@ static int elan_query_device_parameters(struct elan_tp_data *data)
 		if (error)
 			return error;
 
-		data->x_res = elan_convert_resolution(hw_x_res);
-		data->y_res = elan_convert_resolution(hw_y_res);
+		data->x_res = elan_convert_resolution(hw_x_res, data->pattern);
+		data->y_res = elan_convert_resolution(hw_y_res, data->pattern);
 	} else {
 		data->x_res = (data->max_x + 1) / x_mm;
 		data->y_res = (data->max_y + 1) / y_mm;
@@ -908,24 +923,22 @@ static const struct attribute_group *elan_sysfs_groups[] = {
  * Elan isr functions
  ******************************************************************
  */
-static void elan_report_contact(struct elan_tp_data *data,
-				int contact_num, bool contact_valid,
-				u8 *finger_data)
+static void elan_report_contact(struct elan_tp_data *data, int contact_num,
+				bool contact_valid, bool high_precision,
+				u8 *packet, u8 *finger_data)
 {
 	struct input_dev *input = data->input;
 	unsigned int pos_x, pos_y;
-	unsigned int pressure, mk_x, mk_y;
-	unsigned int area_x, area_y, major, minor;
-	unsigned int scaled_pressure;
+	unsigned int pressure, scaled_pressure;
 
 	if (contact_valid) {
-		pos_x = ((finger_data[0] & 0xf0) << 4) |
-						finger_data[1];
-		pos_y = ((finger_data[0] & 0x0f) << 8) |
-						finger_data[2];
-		mk_x = (finger_data[3] & 0x0f);
-		mk_y = (finger_data[3] >> 4);
-		pressure = finger_data[4];
+		if (high_precision) {
+			pos_x = get_unaligned_be16(&finger_data[0]);
+			pos_y = get_unaligned_be16(&finger_data[2]);
+		} else {
+			pos_x = ((finger_data[0] & 0xf0) << 4) | finger_data[1];
+			pos_y = ((finger_data[0] & 0x0f) << 8) | finger_data[2];
+		}
 
 		if (pos_x > data->max_x || pos_y > data->max_y) {
 			dev_dbg(input->dev.parent,
@@ -935,18 +948,8 @@ static void elan_report_contact(struct elan_tp_data *data,
 			return;
 		}
 
-		/*
-		 * To avoid treating large finger as palm, let's reduce the
-		 * width x and y per trace.
-		 */
-		area_x = mk_x * (data->width_x - ETP_FWIDTH_REDUCE);
-		area_y = mk_y * (data->width_y - ETP_FWIDTH_REDUCE);
-
-		major = max(area_x, area_y);
-		minor = min(area_x, area_y);
-
+		pressure = finger_data[4];
 		scaled_pressure = pressure + data->pressure_adjustment;
-
 		if (scaled_pressure > ETP_MAX_PRESSURE)
 			scaled_pressure = ETP_MAX_PRESSURE;
 
@@ -955,16 +958,37 @@ static void elan_report_contact(struct elan_tp_data *data,
 		input_report_abs(input, ABS_MT_POSITION_X, pos_x);
 		input_report_abs(input, ABS_MT_POSITION_Y, data->max_y - pos_y);
 		input_report_abs(input, ABS_MT_PRESSURE, scaled_pressure);
-		input_report_abs(input, ABS_TOOL_WIDTH, mk_x);
-		input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
-		input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
+
+		if (data->report_features & ETP_FEATURE_REPORT_MK) {
+			unsigned int mk_x, mk_y, area_x, area_y;
+			u8 mk_data = high_precision ?
+				packet[ETP_MK_DATA_OFFSET + contact_num] :
+				finger_data[3];
+
+			mk_x = mk_data & 0x0f;
+			mk_y = mk_data >> 4;
+
+			/*
+			 * To avoid treating large finger as palm, let's reduce
+			 * the width x and y per trace.
+			 */
+			area_x = mk_x * (data->width_x - ETP_FWIDTH_REDUCE);
+			area_y = mk_y * (data->width_y - ETP_FWIDTH_REDUCE);
+
+			input_report_abs(input, ABS_TOOL_WIDTH, mk_x);
+			input_report_abs(input, ABS_MT_TOUCH_MAJOR,
+					 max(area_x, area_y));
+			input_report_abs(input, ABS_MT_TOUCH_MINOR,
+					 min(area_x, area_y));
+		}
 	} else {
 		input_mt_slot(input, contact_num);
 		input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
 	}
 }
 
-static void elan_report_absolute(struct elan_tp_data *data, u8 *packet)
+static void elan_report_absolute(struct elan_tp_data *data, u8 *packet,
+				 bool high_precision)
 {
 	struct input_dev *input = data->input;
 	u8 *finger_data = &packet[ETP_FINGER_DATA_OFFSET];
@@ -973,11 +997,12 @@ static void elan_report_absolute(struct elan_tp_data *data, u8 *packet)
 	u8 hover_info = packet[ETP_HOVER_INFO_OFFSET];
 	bool contact_valid, hover_event;
 
-	hover_event = hover_info & 0x40;
-	for (i = 0; i < ETP_MAX_FINGERS; i++) {
-		contact_valid = tp_info & (1U << (3 + i));
-		elan_report_contact(data, i, contact_valid, finger_data);
+	hover_event = hover_info & BIT(6);
 
+	for (i = 0; i < ETP_MAX_FINGERS; i++) {
+		contact_valid = tp_info & BIT(3 + i);
+		elan_report_contact(data, i, contact_valid, high_precision,
+				    packet, finger_data);
 		if (contact_valid)
 			finger_data += ETP_FINGER_DATA_LEN;
 	}
@@ -1034,7 +1059,7 @@ static irqreturn_t elan_isr(int irq, void *dev_id)
 		goto out;
 	}
 
-	error = data->ops->get_report(data->client, report);
+	error = data->ops->get_report(data->client, report, data->report_len);
 	if (error)
 		goto out;
 
@@ -1042,7 +1067,10 @@ static irqreturn_t elan_isr(int irq, void *dev_id)
 
 	switch (report[ETP_REPORT_ID_OFFSET]) {
 	case ETP_REPORT_ID:
-		elan_report_absolute(data, report);
+		elan_report_absolute(data, report, false);
+		break;
+	case ETP_REPORT_ID2:
+		elan_report_absolute(data, report, true);
 		break;
 	case ETP_TP_REPORT_ID:
 		elan_report_trackpoint(data, report);
@@ -1133,7 +1161,9 @@ static int elan_setup_input_device(struct elan_tp_data *data)
 	input_abs_set_res(input, ABS_X, data->x_res);
 	input_abs_set_res(input, ABS_Y, data->y_res);
 	input_set_abs_params(input, ABS_PRESSURE, 0, ETP_MAX_PRESSURE, 0, 0);
-	input_set_abs_params(input, ABS_TOOL_WIDTH, 0, ETP_FINGER_WIDTH, 0, 0);
+	if (data->report_features & ETP_FEATURE_REPORT_MK)
+		input_set_abs_params(input, ABS_TOOL_WIDTH,
+				     0, ETP_FINGER_WIDTH, 0, 0);
 	input_set_abs_params(input, ABS_DISTANCE, 0, 1, 0, 0);
 
 	/* And MT parameters */
@@ -1143,10 +1173,12 @@ static int elan_setup_input_device(struct elan_tp_data *data)
 	input_abs_set_res(input, ABS_MT_POSITION_Y, data->y_res);
 	input_set_abs_params(input, ABS_MT_PRESSURE, 0,
 			     ETP_MAX_PRESSURE, 0, 0);
-	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0,
-			     ETP_FINGER_WIDTH * max_width, 0, 0);
-	input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0,
-			     ETP_FINGER_WIDTH * min_width, 0, 0);
+	if (data->report_features & ETP_FEATURE_REPORT_MK) {
+		input_set_abs_params(input, ABS_MT_TOUCH_MAJOR,
+				     0, ETP_FINGER_WIDTH * max_width, 0, 0);
+		input_set_abs_params(input, ABS_MT_TOUCH_MINOR,
+				     0, ETP_FINGER_WIDTH * min_width, 0, 0);
+	}
 
 	data->input = input;