[1/2] input: elants: support old touch report format

Commit Message

Michał Mirosław June 13, 2017, 3:29 p.m. UTC

Support "old" firmware / touchscreen without touch pressure reading.

Tested on Asus TF300T tablet.

Signed-off-by: Michał Mirosław <[e-mail]>
---
 drivers/input/touchscreen/elants_i2c.c | 57 ++++++++++++++++++++++++----------
 1 file changed, 41 insertions(+), 16 deletions(-)

Patch

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index 872750eeca932..6509407f53e49 100644
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -70,6 +70,7 @@ 
 #define CMD_HEADER_REK		0x66
 
 /* FW position data */
+#define PACKET_SIZE_OLD		40
 #define PACKET_SIZE		55
 #define MAX_CONTACT_NUM		10
 #define FW_POS_HEADER		0
@@ -82,7 +83,11 @@ 
 
 #define HEADER_REPORT_10_FINGER	0x62
 
-/* Header (4 bytes) plus 3 fill 10-finger packets */
+/* Power state */
+#define PWR_STATE_DEEP_SLEEP	0
+#define PWR_STATE_NORMAL	1
+
+/* Header (4 bytes) plus 3 full 10-finger packets */
 #define MAX_PACKET_SIZE		169
 
 #define BOOT_TIME_DELAY_MS	50
@@ -92,10 +97,21 @@ 
 #define E_ELAN_INFO_BC_VER	0x10
 #define E_ELAN_INFO_TEST_VER	0xE0
 #define E_ELAN_INFO_FW_ID	0xF0
+#define E_POWER_MODE		0x40
+#define E_POWER_STATE		0x50
+#define E_INFO_X_RES		0x60
+#define E_INFO_Y_RES		0x63
 #define E_INFO_OSR		0xD6
 #define E_INFO_PHY_SCAN		0xD7
 #define E_INFO_PHY_DRIVER	0xD8
 
+/* FW write command, 0x54 0x?? 0x0, 0x01 */
+#define E_POWER_MODE_BATTERY	0x40
+#define E_POWER_MODE_AC		0x41
+#define E_POWER_MODE_USB	0x42
+#define E_POWER_STATE_SLEEP	0x50
+#define E_POWER_STATE_RESUME	0x58
+
 #define MAX_RETRIES		3
 #define MAX_FW_UPDATE_RETRIES	30
 
@@ -235,8 +251,8 @@  static int elants_i2c_calibrate(struct elants_data *ts)
 {
 	struct i2c_client *client = ts->client;
 	int ret, error;
-	static const u8 w_flashkey[] = { 0x54, 0xC0, 0xE1, 0x5A };
-	static const u8 rek[] = { 0x54, 0x29, 0x00, 0x01 };
+	static const u8 w_flashkey[] = { CMD_HEADER_WRITE, 0xC0, 0xE1, 0x5A };
+	static const u8 rek[] = { CMD_HEADER_WRITE, 0x29, 0x00, 0x01 };
 	static const u8 rek_resp[] = { CMD_HEADER_REK, 0x66, 0x66, 0x66 };
 
 	disable_irq(client->irq);
@@ -781,7 +797,7 @@  static int elants_i2c_fw_update(struct elants_data *ts)
  * Event reporting.
  */
 
-static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
+static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf, unsigned report_len)
 {
 	struct input_dev *input = ts->input;
 	unsigned int n_fingers;
@@ -793,7 +809,8 @@  static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
 			buf[FW_POS_STATE];
 
 	dev_dbg(&ts->client->dev,
-		"n_fingers: %u, state: %04x\n",  n_fingers, finger_state);
+		"n_fingers: %u, state: %04x, report_len: %u\n",
+		n_fingers, finger_state, report_len);
 
 	for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
 		if (finger_state & 1) {
@@ -803,8 +820,16 @@  static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
 			pos = &buf[FW_POS_XY + i * 3];
 			x = (((u16)pos[0] & 0xf0) << 4) | pos[1];
 			y = (((u16)pos[0] & 0x0f) << 8) | pos[2];
-			p = buf[FW_POS_PRESSURE + i];
-			w = buf[FW_POS_WIDTH + i];
+			if (report_len == PACKET_SIZE_OLD) {
+				w = buf[FW_POS_WIDTH + i / 2];
+				w >>= 4 * (~i & 1);	// little-endian-nibbles
+				w |= w << 4;
+				w |= !w;
+				p = w;
+			} else {
+				p = buf[FW_POS_PRESSURE + i];
+				w = buf[FW_POS_WIDTH + i];
+			}
 
 			dev_dbg(&ts->client->dev, "i=%d x=%d y=%d p=%d w=%d\n",
 				i, x, y, p, w);
@@ -837,7 +862,7 @@  static u8 elants_i2c_calculate_checksum(u8 *buf)
 	return checksum;
 }
 
-static void elants_i2c_event(struct elants_data *ts, u8 *buf)
+static void elants_i2c_event(struct elants_data *ts, u8 *buf, unsigned report_len)
 {
 	u8 checksum = elants_i2c_calculate_checksum(buf);
 
@@ -851,7 +876,7 @@  static void elants_i2c_event(struct elants_data *ts, u8 *buf)
 			 "%s: unknown packet type: %02x\n",
 			 __func__, buf[FW_POS_HEADER]);
 	else
-		elants_i2c_mt_event(ts, buf);
+		elants_i2c_mt_event(ts, buf, report_len);
 }
 
 static irqreturn_t elants_i2c_irq(int irq, void *_dev)
@@ -909,7 +934,7 @@  static irqreturn_t elants_i2c_irq(int irq, void *_dev)
 			break;
 
 		case QUEUE_HEADER_SINGLE:
-			elants_i2c_event(ts, &ts->buf[HEADER_SIZE]);
+			elants_i2c_event(ts, &ts->buf[HEADER_SIZE], ts->buf[FW_HDR_LENGTH]);
 			break;
 
 		case QUEUE_HEADER_NORMAL:
@@ -922,17 +947,17 @@  static irqreturn_t elants_i2c_irq(int irq, void *_dev)
 			}
 
 			report_len = ts->buf[FW_HDR_LENGTH] / report_count;
-			if (report_len != PACKET_SIZE) {
+			if (report_len != PACKET_SIZE && report_len != PACKET_SIZE_OLD) {
 				dev_err(&client->dev,
-					"mismatching report length: %*ph\n",
+					"bad report length: %*ph\n",
 					HEADER_SIZE, ts->buf);
 				break;
 			}
 
 			for (i = 0; i < report_count; i++) {
 				u8 *buf = ts->buf + HEADER_SIZE +
-							i * PACKET_SIZE;
-				elants_i2c_event(ts, buf);
+						i * report_len;
+				elants_i2c_event(ts, buf, report_len);
 			}
 			break;
 
@@ -1313,7 +1338,7 @@  static int __maybe_unused elants_i2c_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct elants_data *ts = i2c_get_clientdata(client);
-	const u8 set_sleep_cmd[] = { 0x54, 0x50, 0x00, 0x01 };
+	const u8 set_sleep_cmd[] = { CMD_HEADER_WRITE, E_POWER_STATE_SLEEP, 0x00, 0x01 };
 	int retry_cnt;
 	int error;
 
@@ -1350,7 +1375,7 @@  static int __maybe_unused elants_i2c_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct elants_data *ts = i2c_get_clientdata(client);
-	const u8 set_active_cmd[] = { 0x54, 0x58, 0x00, 0x01 };
+	const u8 set_active_cmd[] = { CMD_HEADER_WRITE, E_POWER_STATE_RESUME, 0x00, 0x01 };
 	int retry_cnt;
 	int error;