Add an I2C framework, so that nodes that need to use I2C but

are not children of the I2C controller are able to use it.

ok kettenis@

2 files changed, 61 insertions, 2 deletions

diff --git a/sys/dev/ofw/ofw_misc.c b/sys/dev/ofw/ofw_misc.c
index db1e54760af..b988d3b0789 100644
--- a/sys/dev/ofw/ofw_misc.c
+++ b/sys/dev/ofw/ofw_misc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ofw_misc.c,v 1.7 2019/09/04 11:25:54 kettenis Exp $	*/
+/*	$OpenBSD: ofw_misc.c,v 1.8 2019/09/07 13:27:23 patrick Exp $	*/
 /*
  * Copyright (c) 2017 Mark Kettenis
  *
@@ -198,3 +198,46 @@ phy_enable(int node, const char *name)
 
 	return phy_enable_idx(node, idx);
 }
+
+/*
+ * I2C support.
+ */
+
+LIST_HEAD(, i2c_bus) i2c_busses =
+	LIST_HEAD_INITIALIZER(i2c_bus);
+
+void
+i2c_register(struct i2c_bus *ib)
+{
+	ib->ib_phandle = OF_getpropint(ib->ib_node, "phandle", 0);
+	if (ib->ib_phandle == 0)
+		return;
+
+	LIST_INSERT_HEAD(&i2c_busses, ib, ib_list);
+}
+
+struct i2c_controller *
+i2c_bynode(int node)
+{
+	struct i2c_bus *ib;
+
+	LIST_FOREACH(ib, &i2c_busses, ib_list) {
+		if (ib->ib_node == node)
+			return ib->ib_ic;
+	}
+
+	return NULL;
+}
+
+struct i2c_controller *
+i2c_byphandle(uint32_t phandle)
+{
+	struct i2c_bus *ib;
+
+	LIST_FOREACH(ib, &i2c_busses, ib_list) {
+		if (ib->ib_phandle == phandle)
+			return ib->ib_ic;
+	}
+
+	return NULL;
+}
diff --git a/sys/dev/ofw/ofw_misc.h b/sys/dev/ofw/ofw_misc.h
index 6cff23281d0..c97e04f0b48 100644
--- a/sys/dev/ofw/ofw_misc.h
+++ b/sys/dev/ofw/ofw_misc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ofw_misc.h,v 1.4 2019/08/28 07:03:51 kettenis Exp $	*/
+/*	$OpenBSD: ofw_misc.h,v 1.5 2019/09/07 13:27:23 patrick Exp $	*/
 /*
  * Copyright (c) 2017 Mark Kettenis
  *
@@ -54,4 +54,20 @@ void	phy_register(struct phy_device *);
 int	phy_enable_idx(int, int);
 int	phy_enable(int, const char *);
 
+/* I2C support */
+
+struct i2c_controller;
+struct i2c_bus {
+	int			ib_node;
+	struct i2c_controller	*ib_ic;
+
+	LIST_ENTRY(i2c_bus) ib_list;
+	uint32_t ib_phandle;
+};
+
+void	i2c_register(struct i2c_bus *);
+
+struct i2c_controller *i2c_bynode(int);
+struct i2c_controller *i2c_byphandle(uint32_t);
+
 #endif /* _DEV_OFW_MISC_H_ */