@@ -21,6 +21,7 @@
*
*/
+#include <libfdt.h>
#include "hw/arm/sysbus-fdt.h"
#include "qemu/error-report.h"
#include "sysemu/device_tree.h"
@@ -56,6 +57,125 @@ typedef struct NodeCreationPair {
int (*add_fdt_node_fn)(SysBusDevice *sbdev, void *opaque);
} NodeCreationPair;
+/* helpers */
+
+typedef struct HostProperty {
+ const char *name;
+ bool optional;
+} HostProperty;
+
+/**
+ * inherit_properties
+ *
+ * copies properties listed in an array from host device tree to
+ * guest device tree. If a non optional property is not found, the
+ * function self-asserts. An optional property is ignored if not found
+ * in the host device tree.
+ * @props: array of HostProperty to copy
+ * @nb_props: number of properties in the array
+ * @host_dt: host device tree blob
+ * @guest_dt: guest device tree blob
+ * @node_path: host dt node path where the property is supposed to be
+ found
+ * @nodename: guest node name the properties should be added to
+ */
+static void inherit_properties(HostProperty *props, int nb_props,
+ void *host_fdt, void *guest_fdt,
+ char *node_path, char *nodename)
+{
+ int i, prop_len;
+ const void *r;
+ Error *err = NULL;
+
+ for (i = 0; i < nb_props; i++) {
+ r = qemu_fdt_getprop(host_fdt, node_path,
+ props[i].name,
+ &prop_len,
+ props[i].optional ? &err : &error_fatal);
+ if (r) {
+ qemu_fdt_setprop(guest_fdt, nodename,
+ props[i].name, r, prop_len);
+ } else {
+ if (prop_len != -FDT_ERR_NOTFOUND) {
+ /* optional property not returned although property exists */
+ error_report_err(err);
+ } else {
+ error_free(err);
+ }
+ }
+ }
+}
+
+/* clock properties whose values are copied/pasted from host */
+static HostProperty clock_inherited_properties[] = {
+ {"compatible", false},
+ {"#clock-cells", false},
+ {"clock-frequency", true},
+ {"clock-output-names", true},
+};
+
+/**
+ * fdt_build_clock_node
+ *
+ * Build a guest clock node, used as a dependency from a passthrough'ed
+ * device. Most information are retrieved from the host clock node.
+ * Also check the host clock is a fixed one.
+ *
+ * @host_fdt: host device tree blob from which info are retrieved
+ * @guest_fdt: guest device tree blob where the clock node is added
+ * @host_phandle: phandle of the clock in host device tree
+ * @guest_phandle: phandle to assign to the guest node
+ */
+void fdt_build_clock_node(void *host_fdt, void *guest_fdt,
+ uint32_t host_phandle,
+ uint32_t guest_phandle);
+void fdt_build_clock_node(void *host_fdt, void *guest_fdt,
+ uint32_t host_phandle,
+ uint32_t guest_phandle)
+{
+ char *node_path = NULL;
+ char *nodename;
+ const void *r;
+ int ret, node_offset, prop_len, path_len = 16;
+
+ node_offset = fdt_node_offset_by_phandle(host_fdt, host_phandle);
+ if (node_offset <= 0) {
+ error_setg(&error_fatal,
+ "not able to locate clock handle %d in host device tree",
+ host_phandle);
+ }
+ node_path = g_malloc(path_len);
+ while ((ret = fdt_get_path(host_fdt, node_offset, node_path, path_len))
+ == -FDT_ERR_NOSPACE) {
+ path_len += 16;
+ node_path = g_realloc(node_path, path_len);
+ }
+ if (ret < 0) {
+ error_setg(&error_fatal,
+ "not able to retrieve node path for clock handle %d",
+ host_phandle);
+ }
+
+ r = qemu_fdt_getprop(host_fdt, node_path, "compatible", &prop_len,
+ &error_fatal);
+ if (strcmp(r, "fixed-clock")) {
+ error_setg(&error_fatal,
+ "clock handle %d is not a fixed clock", host_phandle);
+ }
+
+ nodename = strrchr(node_path, '/');
+ qemu_fdt_add_subnode(guest_fdt, nodename);
+
+ inherit_properties(clock_inherited_properties,
+ ARRAY_SIZE(clock_inherited_properties),
+ host_fdt, guest_fdt,
+ node_path, nodename);
+
+ qemu_fdt_setprop_cell(guest_fdt, nodename, "phandle", guest_phandle);
+
+ g_free(node_path);
+}
+
/* Device Specific Code */
/**
Some passthrough'ed devices depend on clock nodes. Those need to be generated in the guest device tree. This patch introduces some helpers to build a clock node from information retrieved in the host device tree. - inherit_properties copies properties from a host device tree node to a guest device tree node - fdt_build_clock_node builds a guest clock node and checks the host fellow clock is a fixed one. fdt_build_clock_node will become static as soon as it gets used. A dummy pre-declaration is needed for compilation of this patch. Signed-off-by: Eric Auger <eric.auger@linaro.org> --- v1 -> v2: - inherit properties now outputs an error message in case qemu_fdt_getprop fails for an existing optional property - no hardcoded fixed buffer length - fdt_build_clock_node becomes void and auto-asserts on error - use boolean values when defining the clock properties RFC -> v1: - use the new proto of qemu_fdt_getprop - remove newline in error_report - fix some style issues --- hw/arm/sysbus-fdt.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) -- 1.9.1