Re: [PATCH v9 3/4] Documentation/dt: Add descriptions for loongson display controller
From: Sui Jingfeng
Date: Thu Feb 17 2022 - 06:21:45 EST
On 2022/2/17 18:57, Krzysztof Kozlowski wrote:
On 17/02/2022 11:55, Sui Jingfeng wrote:
From: suijingfeng <suijingfeng@xxxxxxxxxxx>
Add DT documentation for loongson display controller found in
LS2K1000, LS2K0500, LS7A1000 and LS7A2000.
v2: DT binding docs and includes should be a separate patch,
fix a warnning because of that.
Signed-off-by: suijingfeng <suijingfeng@xxxxxxxxxxx>
Signed-off-by: Sui Jingfeng <15330273260@xxxxxx>
---
.../loongson/loongson,display-controller.yaml | 114 ++++++++++++++++++
1 file changed, 114 insertions(+)
create mode 100644 Documentation/devicetree/bindings/display/loongson/loongson,display-controller.yaml
diff --git a/Documentation/devicetree/bindings/display/loongson/loongson,display-controller.yaml b/Documentation/devicetree/bindings/display/loongson/loongson,display-controller.yaml
new file mode 100644
index 000000000000..94229519022a
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/loongson/loongson,display-controller.yaml
@@ -0,0 +1,114 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/loongson,display-controller.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Loongson LS7A2000/LS7A1000/LS2K1000/LS2K0500 Display Controller Device Tree Bindings
+
+maintainers:
+ - Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
+
+description: |+
+
+ Loongson display controllers are simple which require scanout buffers
+ to be physically contiguous. LS2K1000/LS2K0500 is a SOC, only system
+ memory is available. LS7A1000/LS7A2000 is bridge chip which is equipped
+ with a dedicated video ram which is 64MB or more.
+
+ For LS7A1000, there are 4 dedicated GPIOs whose control register is
+ located at the DC register space. They are used to emulate two way i2c,
+ One for DVO0, another for DVO1.
+
+ LS2K1000 and LS2K0500 SoC grab i2c adapter from other module, either
+ general purpose GPIO emulated i2c or hardware i2c in the SoC.
+
+ LSDC has two display pipes, each way has a DVO interface which provide
+ RGB888 signals, vertical & horizontal synchronisations, data enable and
+ the pixel clock. LSDC has two CRTC, each CRTC is able to scanout from
+ 1920x1080 resolution at 60Hz. Each CRTC has two FB address registers.
+
+ LSDC's display pipeline have several components as below description,
+
+ The display controller in LS7A1000:
+ ___________________ _________
+ | -------| | |
+ | CRTC0 --> | DVO0 ----> Encoder0 ---> Connector0 ---> | Monotor |
+ | _ _ -------| ^ ^ |_________|
+ | | | | | -------| | |
+ | |_| |_| | i2c0 <--------+-------------+
+ | -------|
+ | DC IN LS7A1000 |
+ | _ _ -------|
+ | | | | | | i2c1 <--------+-------------+
+ | |_| |_| -------| | | _________
+ | -------| | | | |
+ | CRTC1 --> | DVO1 ----> Encoder1 ---> Connector1 ---> | Panel |
+ | -------| |_________|
+ |___________________|
+
+ Simple usage of LS7A1000 with LS3A4000 CPU:
+
+ +------+ +-----------------------------------+
+ | DDR4 | | +-------------------+ |
+ +------+ | | PCIe Root complex | LS7A1000 |
+ || MC0 | +--++---------++----+ |
+ +----------+ HT 3.0 | || || |
+ | LS3A4000 |<-------->| +---++---+ +--++--+ +---------+ +------+
+ | CPU |<-------->| | GC1000 | | LSDC |<-->| DDR3 MC |<->| VRAM |
+ +----------+ | +--------+ +-+--+-+ +---------+ +------+
+ || MC1 +---------------|--|----------------+
+ +------+ | |
+ | DDR4 | +-------+ DVO0 | | DVO1 +------+
+ +------+ VGA <--|ADV7125|<--------+ +-------->|TFP410|--> DVI/HDMI
+ +-------+ +------+
+
+ The display controller in LS2K1000/LS2K0500:
+ ___________________ _________
+ | -------| | |
+ | CRTC0 --> | DVO0 ----> Encoder0 ---> Connector0 ---> | Monotor |
+ | _ _ -------| ^ ^ |_________|
+ | | | | | | | |
+ | |_| |_| | +------+ |
+ | <---->| i2c0 |<---------+
+ | DC IN LS2K1000 | +------+
+ | _ _ | +------+
+ | | | | | <---->| i2c1 |----------+
+ | |_| |_| | +------+ | _________
+ | -------| | | | |
+ | CRTC1 --> | DVO1 ----> Encoder1 ---> Connector1 ---> | Panel |
+ | -------| |_________|
+ |___________________|
+
+properties:
+ compatible:
+ enum:
+ - loongson,ls7a2000-dc
+ - loongson,ls7a1000-dc
+ - loongson,ls2k1000-dc
+ - loongson,ls2k0500-dc
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ minItems: 1
No need for minItems, if you have maxItems:1.
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - interrupts
+
+additionalProperties: false
+
+examples:
+ - |
+ lsdc: display-controller@6,1 {
+ compatible = "loongson,ls7a1000-dc";
+ reg = <0x3100 0x0 0x0 0x0 0x0>;
+ interrupts = <28 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-parent = <&pic>;
+ };
I still do not think you actually tested it with dt_bindings_check...
Best regards,
Krzysztof
I'm hurry to fix a few error in the v8 of this patch set, to avoid
reviewers get angry about those mistake in my patch.
I come cross a few problems when running make dt_bindings_check,
i am confusing about that, writing DT discpription of PCI display
controller is not as easy as platform one. I will fix it at next version,
thanks you.