On Wed, Mar 23, 2016 at 07:40:19PM -0500, Rob Herring wrote:
> In preparation to support bus specific checks, add the necessary
> infrastructure to determine the bus type for nodes. Initially, PCI and
> simple bus are supported.
>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> David,
Sorry it's taken me a while to look at this. I've been a mixture of
busy and sick :/
> Hopefully this matches what you had in mind for bus checks.
It's getting there.
>
> Rob
>
> checks.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> dtc.h | 11 +++++++++
> 2 files changed, 90 insertions(+)
>
> diff --git a/checks.c b/checks.c
> index 386f956..48e926e 100644
> --- a/checks.c
> +++ b/checks.c
> @@ -527,6 +527,84 @@ static void fixup_path_references(struct check *c, struct node *dt,
> ERROR(path_references, NULL, NULL, fixup_path_references, NULL,
> &duplicate_node_names);
>
> +static bool is_pci_bridge(struct node *node)
> +{
> + struct property *prop;
> +
> + if (!node)
> + return false;
> +
> + prop = get_property(node, "device_type");
> + if (!prop)
> + return false;
> +
> + if (strcmp(prop->val.val, "pci") == 0)
> + return true;
> +
> + return false;
> +}
So, I don't love using device_type here, since that's generally
discouraged in modern flat trees, but I don't know of a better way to
detect a pci bridge, so I guess it's ok.
> +struct bus_type pci_bus_type = {
> + .expected_addr_cells = 3,
> + .expected_size_cells = 2,
I'm a bit torn here. Part of me wants to suggest a 'check_bridge'
function which handles this and can also make more subtle checks, but
then just the expected cells values will handle nearly all real cases
more succinctly.
> + .is_type = is_pci_bridge,
'is_type' isn't clear whether it's checking a bus bridge or a bus
device, so it needs a rename. 'bridge_is_type' maybe?
> +};
> +
> +static bool is_simple_bridge(struct node *node)
> +{
> + struct property *prop;
> + int len = 0;
> +
> + if (!node)
> + return false;
> +
> + /* root node is special case defaulting to simple-bus */
> + if (!node->parent)
> + return true;
> +
> + prop = get_property(node, "compatible");
> + if (!prop)
> + return false;
> +
> + do {
> + const char *str = prop->val.val;
> +
> + if (strcmp(str, "simple-bus") == 0)
> + return true;
> + len += strlen(str) + 1;
> + str += len;
> + } while (len < prop->val.len);
Definitely want a helper function in livetree.c to do this check for a
compatible value.
> + return false;
> +}
> +
> +struct bus_type simple_bus_type = {
> + .expected_addr_cells = -1, /* For don't care */
> + .expected_size_cells = -1,
> + .is_type = is_simple_bridge,
> +};
> +
> +struct bus_type *bus_types[] = {
> + &pci_bus_type,
> + &simple_bus_type,
> + NULL
> +};
> +
> +static void fixup_bus_type(struct check *c, struct node *dt,
> + struct node *node)
> +{
> + struct bus_type **bus;
> +
> + for (bus = bus_types; *bus != NULL; bus++) {
> + if (!(*bus)->is_type(node))
> + continue;
> +
> + node->bus_type = *bus;
> + break;
> + }
> +}
> +ERROR(bus_type, NULL, fixup_bus_type, NULL, NULL);
> +
> /*
> * Semantic checks
> */
> @@ -685,6 +763,7 @@ static struct check *check_table[] = {
>
> &explicit_phandles,
> &phandle_references, &path_references,
> + &bus_type,
>
> &address_cells_is_cell, &size_cells_is_cell, &interrupt_cells_is_cell,
> &device_type_is_string, &model_is_string, &status_is_string,
> diff --git a/dtc.h b/dtc.h
> index 56212c8..c1a1fe9 100644
> --- a/dtc.h
> +++ b/dtc.h
> @@ -132,6 +132,16 @@ struct label {
> struct label *next;
> };
>
> +struct check;
> +struct node;
> +
> +struct bus_type {
> + int expected_addr_cells;
> + int expected_size_cells;
> + bool (*is_type)(struct node *node);
> + void (*check_unit_addr)(struct check *c, struct node *dt, struct node *node);
> +};
> +
> struct property {
> bool deleted;
> char *name;
> @@ -158,6 +168,7 @@ struct node {
> int addr_cells, size_cells;
>
> struct label *labels;
> + struct bus_type *bus_type;
> };
>
> #define for_each_label_withdel(l0, l) \
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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