github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-24 15:12:13 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

dt-bindings: display: ti: Add schema for AM625 OLDI Transmitter

Browse Source 
The OLDI transmitters (TXes) do not have registers of their own, and are
dependent on the source video-ports (VPs) from the DSS to provide
configuration data. This hardware doesn't directly sit on the internal
bus of the SoC, but does so via the DSS. Hence, the OLDI TXes are
supposed to be child nodes under the DSS, and not independent devices.

Two of the OLDI TXes can function in tandem to output dual-link OLDI
output, or cloned single-link outputs. In these cases, one OLDI will be
the primary OLDI, and the other one, a companion. The following diagram
represents such a configuration.

+-----+-----+         +-------+
|     |     |         |       |
|     | VP1 +----+--->+ OLDI0 |  (Primary - may need companion)
|     |     |    |    |       |
| DSS +-----+    |    +-------+
|     |     |    |
|     | VP2 |    |    +-------+
|     |     |    |    |       |
+-----+-----+    +--->+ OLDI1 |  (Companion OLDI)
                      |       |
                      +-------+

The DSS in AM625 SoC has a configuration like the one above. The AM625
DSS VP1 (port@0) can connect and control 2 OLDI TXes, to use them in
dual-link or cloned single-link OLDI modes. It is only the VP1 that can
connect to either OLDI TXes for the AM625 DSS, and not the VP2.

Alternatively, on some future TI SoCs, along with the above
configuration, the OLDI TX can _also_ connect to separate video sources,
making them work entirely independent of each other. In this case,
neither of the OLDIs are "companion" or "secondary" OLDIs, and nor do
they require one. They both are independent and primary OLDIs. The
following diagram represents such a configuration.

+-----+-----+               +-------+
|     |     |               |       |
|     | VP1 +--+----------->+ OLDI0 |  (Primary - may need companion)
|     |     |  |            |       |
|     +-----+  |            +-------+
|     |     |  |
|     | VP2 |  |
|     |     |  |
| DSS +-----+  |   +---+    +-------+
|     |     |  +-->+ M |    |       |
|     | VP3 +----->+ U +--->+ OLDI1 |  (Companion or Primary)
|     |     |      | X |    |       |
|     +-----+      +---+    +-------+
|     |     |
|     | VP4 |
|     |     |
+-----+-----+

Note that depending on the mux configuration, the OLDIs can either be
working together in tandem - sourced by VP1, OR, they could be working
independently sourced by VP1 and VP3 respectively.
The idea is to support all the configurations with this OLDI TX schema.

The OLDI functionality is further supported by a system-control module,
which contains a few registers to control OLDI IO power and other
electrical characteristics of the IO lanes.

Add devicetree binding schema for the OLDI TXes to support various
configurations, and extend their support to the AM625 DSS.

Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com>
Signed-off-by: Aradhya Bhatia <aradhya.bhatia@linux.dev>
Reviewed-by: "Rob Herring (Arm)" <robh@kernel.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://lore.kernel.org/r/20250528122544.817829-3-aradhya.bhatia@linux.dev
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
This commit is contained in:
Aradhya Bhatia 2025-05-28 17:55:42 +05:30 committed by Tomi Valkeinen
parent adc8f6ff0e
commit 90090f49f1
3 changed files with 237 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

79
Documentation/devicetree/bindings/display/ti/ti,am625-oldi.yaml Normal file
View File

@ -0,0 +1,79 @@
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/display/ti/ti,am625-oldi.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Texas Instruments AM625 OLDI Transmitter
maintainers:
- Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
- Aradhya Bhatia <aradhya.bhatia@linux.dev>
description:
The AM625 TI Keystone OpenLDI transmitter (OLDI TX) supports serialized RGB
pixel data transmission between host and flat panel display over LVDS (Low
Voltage Differential Sampling) interface. The OLDI TX consists of 7-to-1 data
serializers, and 4-data and 1-clock LVDS outputs. It supports the LVDS output
formats "jeida-18", "jeida-24" and "vesa-18", and can accept 24-bit RGB or
padded and un-padded 18-bit RGB bus formats as input.
properties:
reg:
maxItems: 1
clocks:
maxItems: 1
description: serial clock input for the OLDI transmitters
clock-names:
const: serial
ti,companion-oldi:
$ref: /schemas/types.yaml#/definitions/phandle
description:
phandle to companion OLDI transmitter. This property is required for both
the OLDI TXes if they are expected to work either in dual-lvds mode or in
clone mode. This property should point to the other OLDI TX's phandle.
ti,secondary-oldi:
type: boolean
description:
Boolean property to mark the OLDI transmitter as the secondary one, when the
OLDI hardware is expected to run as a companion HW, in cases of dual-lvds
mode or clone mode. The primary OLDI hardware is responsible for all the
hardware configuration.
ti,oldi-io-ctrl:
$ref: /schemas/types.yaml#/definitions/phandle
description:
phandle to syscon device node mapping OLDI IO_CTRL registers found in the
control MMR region. These registers are required to toggle the I/O lane
power, and control its electrical characteristics.
ports:
$ref: /schemas/graph.yaml#/properties/ports
properties:
port@0:
$ref: /schemas/graph.yaml#/properties/port
description: Parallel RGB input port
port@1:
$ref: /schemas/graph.yaml#/properties/port
description: LVDS output port
required:
- port@0
- port@1
required:
- reg
- clocks
- clock-names
- ti,oldi-io-ctrl
- ports
additionalProperties: false
...

157
Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
View File

@ -100,6 +100,24 @@ properties:
For AM62A7 DSS, the port is tied off inside the SoC.
For AM62L DSS, the DSS DPI output port node from video port 1
or DSI Tx controller node connected to video port 1.
properties:
endpoint@0:
$ref: /schemas/graph.yaml#/properties/endpoint
description:
For AM625 DSS, VP Connection to OLDI0.
For AM65X DSS, OLDI output from the SoC.
endpoint@1:
$ref: /schemas/graph.yaml#/properties/endpoint
description:
For AM625 DSS, VP Connection to OLDI1.
anyOf:
- required:
- endpoint
- required:
- endpoint@0
- endpoint@1
port@1:
$ref: /schemas/graph.yaml#/properties/port
@ -121,6 +139,25 @@ properties:
Input memory (from main memory to dispc) bandwidth limit in
bytes per second
oldi-transmitters:
description:
Child node under the DSS, to describe all the OLDI transmitters connected
to the DSS videoports.
type: object
additionalProperties: false
properties:
"#address-cells":
const: 1
"#size-cells":
const: 0
patternProperties:
'^oldi@[0-1]$':
$ref: ti,am625-oldi.yaml#
description: OLDI transmitters connected to the DSS VPs
allOf:
- if:
properties:
@ -129,6 +166,7 @@ allOf:
const: ti,am62a7-dss
then:
properties:
oldi-transmitters: false
ports:
properties:
port@0: false
@ -143,6 +181,22 @@ allOf:
properties:
port@1: false
- if:
properties:
compatible:
contains:
enum:
- ti,am62l-dss
- ti,am65x-dss
then:
properties:
oldi-transmitters: false
ports:
properties:
port@0:
properties:
endpoint@1: false
required:
- compatible
- reg
@ -190,3 +244,106 @@ examples:
};
};
};
- |
#include <dt-bindings/interrupt-controller/arm-gic.h>
#include <dt-bindings/interrupt-controller/irq.h>
#include <dt-bindings/soc/ti,sci_pm_domain.h>
bus {
#address-cells = <2>;
#size-cells = <2>;
dss1: dss@30200000 {
compatible = "ti,am625-dss";
reg = <0x00 0x30200000 0x00 0x1000>, /* common */
<0x00 0x30202000 0x00 0x1000>, /* vidl1 */
<0x00 0x30206000 0x00 0x1000>, /* vid */
<0x00 0x30207000 0x00 0x1000>, /* ovr1 */
<0x00 0x30208000 0x00 0x1000>, /* ovr2 */
<0x00 0x3020a000 0x00 0x1000>, /* vp1 */
<0x00 0x3020b000 0x00 0x1000>, /* vp2 */
<0x00 0x30201000 0x00 0x1000>; /* common1 */
reg-names = "common", "vidl1", "vid",
"ovr1", "ovr2", "vp1", "vp2", "common1";
power-domains = <&k3_pds 186 TI_SCI_PD_EXCLUSIVE>;
clocks = <&k3_clks 186 6>,
<&vp1_clock>,
<&k3_clks 186 2>;
clock-names = "fck", "vp1", "vp2";
interrupts = <GIC_SPI 84 IRQ_TYPE_LEVEL_HIGH>;
oldi-transmitters {
#address-cells = <1>;
#size-cells = <0>;
oldi0: oldi@0 {
reg = <0>;
clocks = <&k3_clks 186 0>;
clock-names = "serial";
ti,companion-oldi = <&oldi1>;
ti,oldi-io-ctrl = <&dss_oldi_io_ctrl>;
ports {
#address-cells = <1>;
#size-cells = <0>;
port@0 {
reg = <0>;
oldi0_in: endpoint {
remote-endpoint = <&dpi0_out0>;
};
};
port@1 {
reg = <1>;
oldi0_out: endpoint {
remote-endpoint = <&panel_in0>;
};
};
};
};
oldi1: oldi@1 {
reg = <1>;
clocks = <&k3_clks 186 0>;
clock-names = "serial";
ti,secondary-oldi;
ti,companion-oldi = <&oldi0>;
ti,oldi-io-ctrl = <&dss_oldi_io_ctrl>;
ports {
#address-cells = <1>;
#size-cells = <0>;
port@0 {
reg = <0>;
oldi1_in: endpoint {
remote-endpoint = <&dpi0_out1>;
};
};
port@1 {
reg = <1>;
oldi1_out: endpoint {
remote-endpoint = <&panel_in1>;
};
};
};
};
};
ports {
#address-cells = <1>;
#size-cells = <0>;
port@0 {
#address-cells = <1>;
#size-cells = <0>;
reg = <0>;
dpi0_out0: endpoint@0 {
reg = <0>;
remote-endpoint = <&oldi0_in>;
};
dpi0_out1: endpoint@1 {
reg = <1>;
remote-endpoint = <&oldi1_in>;
};
};
port@1 {
reg = <1>;
dpi1_out: endpoint {
remote-endpoint = <&hdmi_bridge>;
};
};
};
};
};

1
MAINTAINERS
View File

@ -8230,6 +8230,7 @@ M: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
L: dri-devel@lists.freedesktop.org
S: Maintained
T: git https://gitlab.freedesktop.org/drm/misc/kernel.git
F: Documentation/devicetree/bindings/display/ti/ti,am625-oldi.yaml
F: Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
F: Documentation/devicetree/bindings/display/ti/ti,j721e-dss.yaml
F: Documentation/devicetree/bindings/display/ti/ti,k2g-dss.yaml