This series adds a proof of concept framework to implement schema checker
using a combined C and DTSS based approach. Several example bindings are
also implemented using C and DTSS[1].
Complex and generic bindings can be implemented directly in C and then
instantiated from simple device-specific bindings using DTS-like DTSS
language.
A quick description of C part:
A new check is registered in dtc checks framework to perform schema checking
of each node. Checking is done by searching specified schema set for matching
schemas (by compatible, device_type or absolute path) and applying matched
schemas to the node.
Schemas for complex generic bindings (such as interrupts, gpios, clocks, i2c,
mmio-bus, etc.) can be implemented directly in C and instantiated from DTSS
schemas of particular devices. An example C schema may look like:
static void generic_checkfn_xxx_yyy(const struct generic_schema *schema,
struct node *root, struct node *node,
struct node *params, bool required)
{
/*
* Get necessary schema arguments from DTSS schema by looking
* at properties of @params node.
*
* Check whether @node node matches the schema.
*
* The @required argument may be used to check whether some error
* conditions should be ignored (e.g. unspecified interrupt).
*/
}
GENERIC_SCHEMA("xxx-yyy", xxx_yyy);
A quick description of DTSS part:
* DTSS is a DTS-like language for specification of simple bindings, e.g.
bindings of particular devices. The basic syntax is very similar to DTS,
with main elements being nodes and properties. At root level a series of
nodes should be specified representing particular bindings:
/dtss-v1/;
binding1 {
/* Definition of binding 1 */
};
binding2 {
/* Definition of binding 2 */
};
* Matching key for each binding can be specified using /match/ keyword:
root-node {
/match/ path = "/";
};
wlf,wm8903 {
/match/ compatible = "wlf,wm8903";
};
pci-bus {
/match/ device_type = "memory";
};
Currently supported matches: path, compatible, device_type.
* Bindings can be specified either by listing properties they require
(or can use) directly or by instantiating generic C-based bindings.
binding {
required-property;
/optional/ optional-property;
/require/ required-generic-schema;
/use/ optional-generic-schema {
schema-argument = <1>;
};
};
Generic schemas are implemented in C, as described above, and can use
arguments specified in DTSS as properties. /require/ calls the schema with
required=true, while /use/ with required=false.
This is based on Stephen Warren's C based DT schema checker proof of
concept patch adding C-based validation[2].
TODO:
- specification of subnodes directly from DTSS,
- specification of simple property values from DTSS (cells, strings,
phandles),
- reporting of unrecognized properties,
- probably many more...
[1] Device Tree Schema Source
[2] http://thread.gmane.org/gmane.linux.ports.arm.kernel/275896
Tomasz Figa (5):
dtc: Add helpers for various message levels
dtc: livetree: Add more tree parsing helpers
Another try of DT schema checker using hybrid C and DTSS based
approach
Add sample C-based generic bindings
Add sample DTS and DTSS schema
Makefile | 2 +-
Makefile.dtc | 10 +-
checks.c | 15 +
dtc.c | 17 +-
dtc.h | 57 ++++
dtss-lexer.l | 291 +++++++++++++++++++
dtss-parser.y | 341 ++++++++++++++++++++++
livetree.c | 230 +++++++++++++++
sample.dts | 70 +++++
schema.dtss | 86 ++++++
schemas/clock/clock.c | 77 +++++
schemas/gpio/gpio.c | 93 ++++++
schemas/i2c/i2c.c | 42 +++
schemas/interrupt-controller/interrupts.c | 452 ++++++++++++++++++++++++++++++
schemas/mmio-bus.c | 97 +++++++
schemas/schema.c | 311 ++++++++++++++++++++
schemas/schema.h | 89 ++++++
srcpos.h | 2 +
treesource.c | 22 ++
19 files changed, 2300 insertions(+), 4 deletions(-)
create mode 100644 dtss-lexer.l
create mode 100644 dtss-parser.y
create mode 100644 sample.dts
create mode 100644 schema.dtss
create mode 100644 schemas/clock/clock.c
create mode 100644 schemas/gpio/gpio.c
create mode 100644 schemas/i2c/i2c.c
create mode 100644 schemas/interrupt-controller/interrupts.c
create mode 100644 schemas/mmio-bus.c
create mode 100644 schemas/schema.c
create mode 100644 schemas/schema.h
--
1.8.5.2
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