Il 20/05/22 10:15, Krzysztof Kozlowski ha scritto:
On 19/05/2022 12:18, AngeloGioacchino Del Regno wrote:
Convert the mtk-gce documentation from freeform text format to a
json-schema.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
.../bindings/mailbox/mediatek,gce-mbox.yaml | 114 ++++++++++++++++++
.../devicetree/bindings/mailbox/mtk-gce.txt | 82 -------------
2 files changed, 114 insertions(+), 82 deletions(-)
create mode 100644 Documentation/devicetree/bindings/mailbox/mediatek,gce-mbox.yaml
delete mode 100644 Documentation/devicetree/bindings/mailbox/mtk-gce.txt
diff --git a/Documentation/devicetree/bindings/mailbox/mediatek,gce-mbox.yaml b/Documentation/devicetree/bindings/mailbox/mediatek,gce-mbox.yaml
new file mode 100644
index 000000000000..750391b4038c
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/mediatek,gce-mbox.yaml
@@ -0,0 +1,114 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/mediatek,gce-mbox.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek Global Command Engine (GCE) mailbox
+
+maintainers:
+ - Houlong Wei <houlong.wei@xxxxxxxxxxxx>
+
+description: |
+ The Global Command Engine (GCE) is used to help read/write registers
+ with critical time limitation, such as updating display configuration
+ during the vblank.
+ The GCE can be used to implement the Command Queue (CMDQ) driver.
Mention the headers in description.
Values for properties used by the GCE, such as sub-system IDs, thread
priority and event IDs are defined in 'dt-bindings/gce/<chip>-gce.h'.
Would that be enough, or should I list all of the headers?
+
+properties:
+ compatible:
+ enum:
+ - mediatek,mt6779-gce
+ - mediatek,mt8173-gce
+ - mediatek,mt8183-gce
+ - mediatek,mt8186-gce
+ - mediatek,mt8192-gce
+ - mediatek,mt8195-gce
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ items:
+ - const: gce
+
+ '#mbox-cells':
+ description: |
+ The first cell describes the mailbox channel, which is the GCE Thread ID;
+ The second cell describes the priority of the GCE thread.
+ const: 2
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - clocks
+ - clock-names
+ - '#mbox-cells'
+
+additionalProperties: false
+
+allOf:
+ - if:
+ properties:
+ compatible:
+ enum:
+ - mediatek,mt8195-gce
+ then:
+ properties:
+ clocks:
+ maxItems: 2
Are you sure this works on mt8195-gce?
Thanks for that, I've just rechecked the driver and.. no, that won't
work for MT8195: it's just one clock there (like the others) and the
clock names aren't even enforced, as the driver is always taking the
clock at index 0.
I got confused because the driver uses a slightly different kind of
logic when probing on SoCs with multiple mailboxes, specifically:
- For single mailbox, having a clock with name "gce" is enforced
as it's grabbing it with devm_clk_get(dev, clk_name), where the
clock name is declared in a string called "clk_name";
- For multiple mailboxes, it's looking for an of_alias, declared
in an array of strings called "clk_names" and getting the clock
with of_clk_get(node, 0).
So there comes my confusion, recapping:
static const char * const clk_name = "gce";
<- this is a clock name
static const char * const clk_names[] = { "gce0", "gce1" }; <- OF alias names
At this point, I think that the best idea would be to fix this issue
first... luckily there's no MT8195 devicetree upstream yet, so I would
technically not be breaking any ABI by changing it to be the same as
the others.
Easier explanation: plan is to change the driver such that we won't
need anything different from the others in this schema.
New version coming soon, then....
Regards,
Angelo
