[src/trunk]: src/sys/dev/fdt The i2c-mux bindings specify that if the mux dev...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/d4da4f2ca4c7
branches:  trunk
changeset: 979427:d4da4f2ca4c7
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Mon Dec 28 15:08:06 2020 +0000

description:
The i2c-mux bindings specify that if the mux device has a child node named
"i2c-mux", then it is that node that is the parent of the i2c bus children.
This is to accommodate mux devices that may also have other kinds of child
nodes in addition to i2c bus child nodes.

diffstat:

 sys/dev/fdt/i2cmux_fdt.c |  31 +++++++++++++++++++++++++++----
 1 files changed, 27 insertions(+), 4 deletions(-)

diffs (76 lines):

diff -r 2bbe3a5dd3cf -r d4da4f2ca4c7 sys/dev/fdt/i2cmux_fdt.c
--- a/sys/dev/fdt/i2cmux_fdt.c  Mon Dec 28 14:28:54 2020 +0000
+++ b/sys/dev/fdt/i2cmux_fdt.c  Mon Dec 28 15:08:06 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: i2cmux_fdt.c,v 1.2 2020/12/23 16:04:42 thorpej Exp $   */
+/*     $NetBSD: i2cmux_fdt.c,v 1.3 2020/12/28 15:08:06 thorpej Exp $   */
 
 /*-
  * Copyright (c) 2020 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: i2cmux_fdt.c,v 1.2 2020/12/23 16:04:42 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: i2cmux_fdt.c,v 1.3 2020/12/28 15:08:06 thorpej Exp $");
 
 #include <sys/types.h>
 #include <sys/device.h>
@@ -94,6 +94,7 @@
 struct iicmux_softc {
        device_t                        sc_dev;
        int                             sc_phandle;
+       int                             sc_i2c_mux_phandle;
        const struct iicmux_config *    sc_config;
        i2c_tag_t                       sc_i2c_parent;
        struct iicmux_bus *             sc_busses;
@@ -317,10 +318,24 @@
 static int
 iicmux_count_children(struct iicmux_softc * const sc)
 {
+       char name[32];
        int child, count;
 
-       for (child = OF_child(sc->sc_phandle), count = 0; child;
+ restart:
+       for (child = OF_child(sc->sc_i2c_mux_phandle), count = 0; child;
             child = OF_peer(child)) {
+               if (OF_getprop(child, "name", name, sizeof(name)) <= 0) {
+                       continue;
+               }
+               if (strcmp(name, "i2c-mux") == 0) {
+                       /*
+                        * The node we encountered is the acutal parent
+                        * of the i2c bus children.  Stash its phandle
+                        * and restart the enumeration.
+                        */
+                       sc->sc_i2c_mux_phandle = child;
+                       goto restart;
+               }
                count++;
        }
 
@@ -394,6 +409,14 @@
        aprint_naive("\n");
        aprint_normal(": %s I2C mux\n", sc->sc_config->desc);
 
+       /*
+        * We start out assuming that the i2c bus nodes are children of
+        * our own node.  We'll adjust later if we encounter an "i2c-mux"
+        * node when counting our children.  If we encounter such a node,
+        * then it's that node that is the parent of the i2c bus children.
+        */
+       sc->sc_i2c_mux_phandle = sc->sc_phandle;
+
        sc->sc_i2c_parent = fdtbus_i2c_acquire(sc->sc_phandle, "i2c-parent");
        if (sc->sc_i2c_parent == NULL) {
                aprint_error_dev(sc->sc_dev, "unable to acquire i2c-parent\n");
@@ -409,7 +432,7 @@
            KM_SLEEP);
 
        int child, idx;
-       for (child = OF_child(sc->sc_phandle), idx = 0; child;
+       for (child = OF_child(sc->sc_i2c_mux_phandle), idx = 0; child;
             child = OF_peer(child), idx++) {
                KASSERT(idx < nchildren);
                iicmux_attach_bus(sc, child, idx);