ioc: kernel-driver: implement keyboard driver

ioc/kernel-driver/lw35ioc.c

@@ -6,6 +6,9 @@
 #include <linux/of_device.h>
 #include <linux/serdev.h>
 #include <linux/types.h>
+#include <linux/input.h>
+
+// #define ENABLE_DEBUG ENABLE_DEBUG
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Markus Koch");
@@ -22,18 +25,86 @@ static struct of_device_id lw35ioc_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, lw35ioc_dt_ids);
 
+/* Only used for initialization, not for actualy keycode mapping */
+static int keycode_map[] = {
+	KEY_A, KEY_B, KEY_C, KEY_D, KEY_E, KEY_F, KEY_G, KEY_H, KEY_I, KEY_J,
+	KEY_K, KEY_L, KEY_M, KEY_N, KEY_O, KEY_P, KEY_Q, KEY_R, KEY_S, KEY_T,
+	KEY_U, KEY_V, KEY_W, KEY_X, KEY_Y, KEY_Z,
+	KEY_0, KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, KEY_6, KEY_7, KEY_8, KEY_9,
+	KEY_F1, KEY_F2, KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7, KEY_F8, KEY_F9,
+	KEY_F10, KEY_F11, KEY_F12,
+	KEY_UP, KEY_DOWN, KEY_RIGHT, KEY_LEFT, KEY_PAGEUP, KEY_PAGEDOWN,
+	KEY_102ND, KEY_INSERT, KEY_HOME, KEY_END, KEY_PRINT,
+	KEY_CAPSLOCK, KEY_LEFTCTRL, KEY_LEFTSHIFT, KEY_LEFTALT, KEY_TAB,
+	KEY_MINUS, KEY_COMMA, KEY_SEMICOLON, KEY_RIGHTBRACE, KEY_LEFTBRACE,
+	KEY_GRAVE, KEY_SPACE, KEY_EQUAL, KEY_DOT, KEY_SLASH, KEY_APOSTROPHE,
+	KEY_BACKSLASH,
+	KEY_DELETE, KEY_ESC, KEY_ENTER, KEY_BACKSPACE,
+	KEY_SYSRQ
+};
+
+enum lw35ioc_state {SYNC, TYPE, KEYBOARD, PRINTER};
+
+struct lw35ioc_packet {
+	enum lw35ioc_state state;
+};
+
 struct lw35ioc_priv {
 	struct serdev_device *serdev;
+	struct input_dev *input_dev;
 	
-	// USER VARS HERE
+	struct lw35ioc_packet packet;
 };
 
 static int lw35ioc_receive_buf(struct serdev_device *serdev,
 			       const unsigned char *data,
 			       size_t count)
 {
-	dev_info(&serdev->dev, "RX: %c\n", data[0]);
+	struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev);
-	return 1; // TODO: return proper value
+	unsigned char c;
+	int ev;
+	int i;
+
+#ifdef ENABLE_DEBUG
+	dev_info(&serdev->dev, "IRQ.\n");
+#endif
+	for (i = 0; i < count; ++i) {
+		c = data[i];
+#ifdef ENABLE_DEBUG
+		dev_info(&serdev->dev, "  RX [%d]: %02x\n", priv->packet.state, c);
+#endif
+		switch (priv->packet.state) {
+		case SYNC:
+			if (c == 0xFF)
+				priv->packet.state = TYPE;
+			break;
+		case TYPE:
+			if (c == 0x55)
+				priv->packet.state = KEYBOARD;
+			else if (c == 0xAA)
+				priv->packet.state = PRINTER;
+			else
+				priv->packet.state = SYNC;
+			break;
+		case KEYBOARD:
+			if (c > 127) {
+				c -= 128;
+				ev = 1;
+			} else {
+				ev = 0;
+			}
+			input_report_key(priv->input_dev, c, ev);
+			input_sync(priv->input_dev);
+			priv->packet.state = SYNC;
+			break;
+		case PRINTER:
+			dev_info(&serdev->dev, "Printer not yet implemented.\n");
+			priv->packet.state = SYNC;
+			break;
+		}
+	}
+
+	return i;
 }
 
 static void lw35ioc_write_wakeup(struct serdev_device *serdev)
@@ -51,39 +122,70 @@ static int lw35ioc_probe(struct serdev_device *serdev)
 {
 	struct lw35ioc_priv *priv = NULL;
 	int ret;
+	int i;
 	u32 speed = 9600;
+	struct input_dev *input_dev;
 
 	printk(KERN_INFO "lw35ioc: probe\n");
 
 	priv = devm_kzalloc(&serdev->dev,
 			    sizeof(struct lw35ioc_priv),
 			    GFP_KERNEL);
-        if (!priv)
+	if (!priv) {
+		printk(KERN_ERR "lw35ioc: Not enough memory.\n");
 		return -ENOMEM;
+	}
 	priv->serdev = serdev;
+	priv->packet.state = SYNC;
 	serdev_device_set_drvdata(serdev, priv);
 	serdev_device_set_client_ops(serdev, &lw35ioc_serdev_ops);
 
+	input_dev = devm_input_allocate_device(&serdev->dev);
+	if (!input_dev) {
+		dev_err(&serdev->dev, "Unable to allocate input device.\n");
+		return -ENOMEM;
+	}
+	priv->input_dev = input_dev;
+	input_dev->name = "lw35ioc";
+	input_dev->phys = "lw35ioc/input1";
+	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
+	__set_bit(EV_KEY, input_dev->evbit);
+	__set_bit(EV_REP, input_dev->evbit);
+	for (i = 0; i < ARRAY_SIZE(keycode_map); i++)
+		__set_bit(keycode_map[i], input_dev->keybit);
+	ret = input_register_device(input_dev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to register input device.\n");
+		goto fail0;
+	}
+
 	ret = serdev_device_open(serdev);
 	if (ret) {
 		dev_err(&serdev->dev, "Unable to open device.\n");
-		goto fail0;
+		goto fail1;
 	}
 
 	speed = serdev_device_set_baudrate(serdev, speed);
 	dev_info(&serdev->dev, "Using baudrate: %u\n", speed);
 
-	dev_info(&serdev->dev, "Loaded driver\n");
+	dev_info(&serdev->dev, "Loaded driver.\n");
 
 	return 0;
 
+fail1:
+	input_unregister_device(input_dev);
 fail0:
+	devm_kfree(&serdev->dev, input_dev);
 	return ret;
 }
 
 static void lw35ioc_remove(struct serdev_device *serdev)
 {
 	struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev);
+
+	serdev_device_close(priv->serdev);
+	input_unregister_device(priv->input_dev);
+
 	dev_info(&serdev->dev, "remove\n");
 	return;
 }