From 83a1f53cfae1fb65bd85dfda3f5b0dd3774262e4 Mon Sep 17 00:00:00 2001
From: SuperTurboZ <42510238+SuperTurboZ@users.noreply.github.com>
Date: Thu, 8 Dec 2022 00:27:42 +0900
Subject: [PATCH] input: keyboard: fix key scan and support more events

---
 drivers/input/keyboard/brain-kbd-i2c.c | 74 +++++++++++++++++++++-----
 1 file changed, 61 insertions(+), 13 deletions(-)

diff --git a/drivers/input/keyboard/brain-kbd-i2c.c b/drivers/input/keyboard/brain-kbd-i2c.c
index e7cd36b6ec7d..4bd1d844337e 100644
--- a/drivers/input/keyboard/brain-kbd-i2c.c
+++ b/drivers/input/keyboard/brain-kbd-i2c.c
@@ -24,6 +24,16 @@
 
 #define BK_IS_PRESSED(val) ((~val & 0x40) >> 6)
 
+#define BK_IS_SWITCH(val) (((val)&0x80) != 0)
+#define BK_SW_CODE(val) (((val) >> 1) & 0x1F)
+#define BK_SWITCH_ON(val) (((val)&1) == 0)
+
+enum { BK_SW_LCD_TRANSFORMING_TO_TABLET = 3,
+       BK_SW_UNKNOWN4,
+       BK_SW_USB_VBUS,
+       BK_SW_LCD_FULLY_TRANSFORMED,
+       BK_SW_LCD_TRANSFORMING_TO_CLOSED };
+
 struct keymap_def {
 	u8 brain_keycode;
 	unsigned int kernel_keycode;
@@ -39,11 +49,41 @@ struct bk_i2c_data {
 
 	bool symbol;
 	u32 symbol_keycode;
+	bool closing;
 };
 
 static bool detect_key(struct bk_i2c_data *kbd, u8 keycode)
 {
 	int i;
+	if (BK_IS_SWITCH(keycode)) {
+		bool sw_on = BK_SWITCH_ON(keycode);
+		unsigned int sw_code;
+		switch (BK_SW_CODE(keycode)) {
+		case BK_SW_LCD_TRANSFORMING_TO_TABLET:
+			if (!sw_on) {
+				kbd->closing = false;
+			}
+			return true;
+		case BK_SW_LCD_TRANSFORMING_TO_CLOSED:
+			if (sw_on) {
+				kbd->closing = true;
+			}
+			return true;
+
+		case BK_SW_LCD_FULLY_TRANSFORMED:
+			sw_code = (kbd->closing) ? SW_LID : SW_TABLET_MODE;
+			input_report_switch(kbd->idev, sw_code, sw_on);
+			return true;
+
+		case BK_SW_USB_VBUS:
+			input_report_switch(kbd->idev, SW_DOCK, sw_on);
+			return true;
+		default:
+			dev_dbg(&kbd->cli->dev, "Unknown switch event %0x02X",
+				keycode);
+		}
+		return false;
+	}
 
 	if ((keycode & 0x3f) == (u8)(kbd->symbol_keycode)) {
 		if (BK_IS_PRESSED(keycode)) {
@@ -101,20 +141,23 @@ static irqreturn_t bk_i2c_irq_handler(int irq, void *devid)
 	n = raw >> 8;
 	k1 = raw & 0xff;
 
+	dev_dbg(&kbd->cli->dev, "N=%d, Raw key event: %02X\n", n, k1);
 	if (k1 == 0x00) {
 		dev_dbg(&kbd->cli->dev,
 			"interrupted but no key press was found\n");
 		goto err;
 	}
 
-	if (n == 1) {
-		if (detect_key(kbd, k1)) {
-			goto done;
-		} else {
-			dev_dbg(&kbd->cli->dev,
-				"unknown key was pressed: %02x\n", (k1 & 0x3f));
-			goto err;
-		}
+	if (n < 1) {
+		goto done;
+	}
+	if (!detect_key(kbd, k1)) {
+		dev_dbg(&kbd->cli->dev, "unknown key was pressed: %02x\n",
+			(k1 & 0x3f));
+		goto err;
+	}
+	if (n < 2) {
+		goto done;
 	}
 
 	raw = i2c_smbus_read_word_swapped(kbd->cli, BK_CMD_KEYCODE);
@@ -127,12 +170,13 @@ static irqreturn_t bk_i2c_irq_handler(int irq, void *devid)
 	k2 = (raw & 0xff00) >> 8;
 	k3 = raw & 0xff;
 
+	dev_dbg(&kbd->cli->dev, "Raw key event 2 and 3: %02X,%02X\n", k2, k3);
 	detect_key(kbd, k2);
 
-	if (n == 3) {
-		detect_key(kbd, k3);
+	if (n < 3) {
+		goto done;
 	}
-
+	detect_key(kbd, k3);
 done:
 	input_sync(kbd->idev);
 err:
@@ -155,8 +199,8 @@ static int bk_i2c_probe(struct i2c_client *cli, const struct i2c_device_id *id)
 		return -ENOMEM;
 	}
 
-	if (of_property_read_u32(cli->dev.of_node,
-			"symbol-keycode", &kbd->symbol_keycode)) {
+	if (of_property_read_u32(cli->dev.of_node, "symbol-keycode",
+				 &kbd->symbol_keycode)) {
 		kbd->symbol_keycode = 0x19;
 	}
 
@@ -254,6 +298,10 @@ static int bk_i2c_probe(struct i2c_client *cli, const struct i2c_device_id *id)
 		input_set_capability(kbd->idev, EV_KEY,
 				     kbd->km_symbol[i].kernel_keycode);
 	}
+	kbd->closing = false;
+	input_set_capability(kbd->idev, EV_SW, SW_LID);
+	input_set_capability(kbd->idev, EV_SW, SW_TABLET_MODE);
+	input_set_capability(kbd->idev, EV_SW, SW_DOCK);
 
 	err = input_register_device(kbd->idev);
 	if (err) {