dt_node_parent

src/drivers/dt/dt.c

@@ -59,11 +59,11 @@ int dt_check(void *mem, size_t size, size_t *offp)
     return 0;
 }
 
-int dt_parse(dt_node_t *node, int depth, size_t *offp, int (*cb_node)(void*, dt_node_t*), void *cbn_arg, int (*cb_prop)(void*, dt_node_t*, int, const char*, void*, size_t), void *cbp_arg)
+int dt_parse(dt_node_t *node, int depth, size_t *offp, int (*cb_node)(void*, dt_node_t*, int), void *cbn_arg, int (*cb_prop)(void*, dt_node_t*, int, const char*, void*, size_t), void *cbp_arg)
 {
     if(cb_node)
     {
-        int r = cb_node(cbn_arg, node);
+        int r = cb_node(cbn_arg, node, depth);
         if(r != 0) return r;
     }
     if(depth >= 0 || cb_prop)
@@ -198,7 +198,7 @@ typedef struct
     size_t size;
 } dt_arg_t;
 
-static int dt_cbn(void *a, dt_node_t *node)
+static int dt_cbn(void *a, dt_node_t *node, int depth)
 {
     if(a != node)
     {
@@ -430,7 +430,7 @@ int dt_print(dt_node_t *node, int argc, const char **argv)
 // ========== Legacy/Compat ==========
 
 int dt_check_32(void *mem, uint32_t size, uint32_t *offp) __asm__("_dt_check$32");
-int dt_parse_32(dt_node_t *node, int depth, uint32_t *offp, int (*cb_node)(void*, dt_node_t*), void *cbn_arg, int (*cb_prop)(void*, dt_node_t*, int, const char*, void*, uint32_t), void *cbp_arg) __asm__("_dt_parse$32");
+int dt_parse_32(dt_node_t *node, int depth, uint32_t *offp, int (*cb_node)(void*, dt_node_t*, int), void *cbn_arg, int (*cb_prop)(void*, dt_node_t*, int, const char*, void*, uint32_t), void *cbp_arg) __asm__("_dt_parse$32");
 void* dt_prop_32(dt_node_t *node, const char *key, uint32_t *lenp) __asm__("_dt_prop$32");
 
 int dt_check_32(void *mem, uint32_t size, uint32_t *offp)
@@ -453,7 +453,7 @@ static int dt_parse_32_cbp(void *a, dt_node_t *node, int depth, const char *key,
     return args->cb(args->arg, node, depth, key, val, (uint32_t)len);
 }
 
-int dt_parse_32(dt_node_t *node, int depth, uint32_t *offp, int (*cb_node)(void*, dt_node_t*), void *cbn_arg, int (*cb_prop)(void*, dt_node_t*, int, const char*, void*, uint32_t), void *cbp_arg)
+int dt_parse_32(dt_node_t *node, int depth, uint32_t *offp, int (*cb_node)(void*, dt_node_t*, int), void *cbn_arg, int (*cb_prop)(void*, dt_node_t*, int, const char*, void*, uint32_t), void *cbp_arg)
 {
     dt_parse_32_cbp_t cbp_arg_32 =
     {

src/drivers/dt/dt.h

@@ -1,7 +1,7 @@
 /*
  * pongoOS - https://checkra.in
  *
- * Copyright (C) 2019-2023 checkra1n team
+ * Copyright (C) 2019-2024 checkra1n team
  *
  * This file is part of pongoOS.
  *
@@ -49,7 +49,7 @@ typedef struct
 } dt_prop_t;
 
 extern int dt_check(void *mem, size_t size, size_t *offp) __asm__("_dt_check$64");
-extern int dt_parse(dt_node_t *node, int depth, size_t *offp, int (*cb_node)(void*, dt_node_t*), void *cbn_arg, int (*cb_prop)(void*, dt_node_t*, int, const char*, void*, size_t), void *cbp_arg) __asm__("_dt_parse$64");
+extern int dt_parse(dt_node_t *node, int depth, size_t *offp, int (*cb_node)(void*, dt_node_t*, int), void *cbn_arg, int (*cb_prop)(void*, dt_node_t*, int, const char*, void*, size_t), void *cbp_arg) __asm__("_dt_parse$64");
 extern dt_node_t* dt_find(dt_node_t *node, const char *name);
 extern void* dt_prop(dt_node_t *node, const char *key, size_t *lenp) __asm__("_dt_prop$64");
 extern int dt_print(dt_node_t *node, int argc, const char **argv);
@@ -65,6 +65,7 @@ struct memmap
 };
 
 extern dt_node_t* dt_node(dt_node_t *node, const char *name);
+extern dt_node_t* dt_node_parent(dt_node_t *node);
 extern dt_node_t* dt_get(const char *name);
 extern void* dt_node_prop(dt_node_t *node, const char *prop, size_t *size);
 extern void* dt_get_prop(const char *device, const char *prop, size_t *size) __asm__("_dt_get_prop$64");

src/drivers/dt/dt_get.c

@@ -1,7 +1,7 @@
 /*
  * pongoOS - https://checkra.in
  *
- * Copyright (C) 2019-2023 checkra1n team
+ * Copyright (C) 2019-2024 checkra1n team
  *
  * This file is part of pongoOS.
  *
@@ -41,6 +41,46 @@ dt_node_t* dt_node(dt_node_t *node, const char *name)
     return dev;
 }
 
+typedef struct
+{
+    dt_node_t *path[8];
+    dt_node_t *target;
+    dt_node_t *parent;
+} dt_node_parent_cb_t;
+
+static int dt_node_parent_cb(void *a, dt_node_t *node, int depth)
+{
+    dt_node_parent_cb_t *arg = a;
+    if(node == arg->target)
+    {
+        if(depth < 1)
+        {
+            panic("DeviceTree parent depth underflow: %d", depth);
+        }
+        arg->parent = arg->path[depth - 1];
+        return 1;
+    }
+    if(depth < 0 || depth >= 8)
+    {
+        panic("DeviceTree parent depth out of bunds: %d", depth);
+    }
+    arg->path[depth] = node;
+    return 0;
+}
+
+dt_node_t* dt_node_parent(dt_node_t *node)
+{
+    // Parsing the tree again just to find the parent node is really ugly and inefficient, but for now we're stuck with this.
+    // Ideally we'd parse the DeviceTree entirely into heap memory, so we can:
+    // a) traverse it faster and in either direction
+    // b) overwrite/relocate the original DeviceTree in memory (e.g. for loading a bigger kernel)
+    // The problem is that we currently allow clients to directly modify DeviceTree velues and we will need that
+    // in one form or another regardless, so we'd have to think about how to design such a writeback.
+    dt_node_parent_cb_t arg = { .target = node };
+    dt_parse(gDeviceTree, 0, NULL, &dt_node_parent_cb, &arg, NULL, NULL);
+    return arg.parent;
+}
+
 dt_node_t* dt_get(const char *name)
 {
     return dt_node(gDeviceTree, name);

src/drivers/hal/hal.c

@@ -36,7 +36,7 @@ struct hal_device* gRootDevice, * gDeviceTreeDevice;
 
 void hal_probe_hal_services(struct hal_device* device) ;
 
-static int hal_load_dtree_child_node(void* arg, dt_node_t* node) {
+static int hal_load_dtree_child_node(void* arg, dt_node_t* node, int depth) {
     struct hal_device* parentDevice = arg;
     if (parentDevice->node == node) return 0;