Eric Auger <eric.au...@linaro.org> writes:
> 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 from 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 a they get used
>
> Signed-off-by: Eric Auger <eric.au...@linaro.org>
> ---
> hw/arm/sysbus-fdt.c | 110
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 110 insertions(+)
>
> diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
> index 9d28797..22e5801 100644
> --- a/hw/arm/sysbus-fdt.c
> +++ b/hw/arm/sysbus-fdt.c
> @@ -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 +57,115 @@ typedef struct NodeCreationPair {
> int (*add_fdt_node_fn)(SysBusDevice *sbdev, void *opaque);
> } NodeCreationPair;
>
> +/* helpers */
> +
> +struct HostProperty {
> + const char *name;
> + bool optional;
> +};
> +
> +typedef struct HostProperty 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 exits. Not found optional ones are ignored.
> + * 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;
> +
> + for (i = 0; i < nb_props; i++) {
> + r = qemu_fdt_getprop_optional(host_fdt, node_path,
> + props[i].name,
> + props[i].optional,
> + &prop_len);
indentation?
> + if (r) {
> + qemu_fdt_setprop(guest_fdt, nodename,
> + props[i].name, r, prop_len);
> + }
> + }
> +}
> +
> +/* clock properties whose values are copied/pasted from host */
> +static HostProperty clock_inherited_properties[] = {
> + {"compatible", 0},
> + {"#clock-cells", 0},
> + {"clock-frequency", 1},
> + {"clock-output-names", 1},
> +};
> +
> +/**
> + * 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 fellow 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
> + */
> +int fdt_build_clock_node(void *host_fdt, void *guest_fdt,
> + uint32_t host_phandle,
> + uint32_t guest_phandle);
> +int fdt_build_clock_node(void *host_fdt, void *guest_fdt,
> + uint32_t host_phandle,
> + uint32_t guest_phandle)
I'm seeing double here ;-)
> +{
> + char node_path[256];
> + char *nodename;
> + const void *r;
> + int ret, prop_len;
> +
> + ret = fdt_node_offset_by_phandle(host_fdt, host_phandle);
> + if (ret <= 0) {
> + error_report("not able to locate clock handle %d in host device
> tree\n",
> + host_phandle);
> + goto out;
> + }
> + ret = fdt_get_path(host_fdt, ret, node_path, 256);
> + if (ret < 0) {
> + error_report("not able to retrieve node path for clock handle %d\n",
> + host_phandle);
> + goto out;
> + }
> +
> + r = qemu_fdt_getprop(host_fdt, node_path, "compatible", &prop_len);
> + if (strcmp(r, "fixed-clock")) {
> + error_report("clock handle %d is not a fixed clock\n", host_phandle);
> + ret = -1;
> + goto out;
> + }
> +
> + 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);
> +
> +out:
> + return ret;
> +}
> +
> /* Device Specific Code */
>
> /**
--
Alex Bennée
