w1: Add 1-Wire uclass

We might want to use 1-Wire devices connected on boards such as EEPROMs in
U-Boot.

Provide a framework to be able to do that.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
[eugen.hristev@microchip.com: reworked]
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 10d2990..fcfc120 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -93,6 +93,7 @@
 	UCLASS_VIDEO,		/* Video or LCD device */
 	UCLASS_VIDEO_BRIDGE,	/* Video bridge, e.g. DisplayPort to LVDS */
 	UCLASS_VIDEO_CONSOLE,	/* Text console driver for video device */
+	UCLASS_W1,		/* Dallas 1-Wire bus */
 	UCLASS_WDT,		/* Watchdot Timer driver */
 
 	UCLASS_COUNT,
diff --git a/include/w1.h b/include/w1.h
new file mode 100644
index 0000000..b36e0f8
--- /dev/null
+++ b/include/w1.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier:	GPL-2.0+
+ *
+ * Copyright (c) 2015 Free Electrons
+ * Copyright (c) 2015 NextThing Co
+ *
+ */
+
+#ifndef __W1_H
+#define __W1_H
+
+#include <dm.h>
+
+#define W1_FAMILY_DS24B33	0x23
+#define W1_FAMILY_DS2431	0x2d
+
+struct w1_device {
+	u64	id;
+};
+
+struct w1_ops {
+	u8	(*read_byte)(struct udevice *dev);
+	bool	(*reset)(struct udevice *dev);
+	u8	(*triplet)(struct udevice *dev, bool bdir);
+	void	(*write_byte)(struct udevice *dev, u8 byte);
+};
+
+int w1_get_bus(int busnum, struct udevice **busp);
+u8 w1_get_device_family(struct udevice *dev);
+
+int w1_read_buf(struct udevice *dev, u8 *buf, unsigned int count);
+int w1_read_byte(struct udevice *dev);
+int w1_reset_select(struct udevice *dev);
+int w1_write_buf(struct udevice *dev, u8 *buf, unsigned int count);
+int w1_write_byte(struct udevice *dev, u8 byte);
+
+#endif