Introduce the dt-bindings documentation for bcm2835 CCP2/CSI2 Unicam
camera interface. Also add a MAINTAINERS entry for it.
Signed-off-by: Dave Stevenson <[email protected]>
Signed-off-by: Naushir Patuck <[email protected]>
Signed-off-by: Jean-Michel Hautbois <[email protected]>
---
v4:
- make MAINTAINERS its own patch
- describe the reg and clocks correctly
- use a vendor entry for the number of data lanes
---
.../bindings/media/brcm,bcm2835-unicam.yaml | 110 ++++++++++++++++++
1 file changed, 110 insertions(+)
create mode 100644 Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
diff --git a/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
new file mode 100644
index 000000000000..0725a0267c60
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
@@ -0,0 +1,110 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/brcm,bcm2835-unicam.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom BCM283x Camera Interface (Unicam)
+
+maintainers:
+ - Raspberry Pi Kernel Maintenance <[email protected]>
+
+description: |-
+ The Unicam block on BCM283x SoCs is the receiver for either
+ CSI-2 or CCP2 data from image sensors or similar devices.
+
+ The main platform using this SoC is the Raspberry Pi family of boards.
+ On the Pi the VideoCore firmware can also control this hardware block,
+ and driving it from two different processors will cause issues.
+ To avoid this, the firmware checks the device tree configuration
+ during boot. If it finds device tree nodes starting by csi then
+ it will stop the firmware accessing the block, and it can then
+ safely be used via the device tree binding.
+
+properties:
+ compatible:
+ const: brcm,bcm2835-unicam
+
+ reg:
+ items:
+ - description: Unicam block.
+ - description: Clock Manager Image (CMI) block.
+
+ interrupts:
+ maxItems: 1
+
+ clocks:
+ items:
+ - description: Clock to drive the LP state machine of Unicam.
+ - description: Clock for the vpu (core clock).
+
+ clock-names:
+ items:
+ - const: lp
+ - const: vpu
+
+ power-domains:
+ items:
+ - description: Unicam power domain
+
+ brcm,num-data-lanes:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [ 2, 4 ]
+ description: Number of data lanes on the csi bus
+
+ port:
+ additionalProperties: false
+ $ref: /schemas/graph.yaml#/$defs/port-base
+
+ properties:
+ endpoint:
+ $ref: /schemas/media/video-interfaces.yaml#
+ unevaluatedProperties: false
+
+ properties:
+ data-lanes: true
+ link-frequencies: true
+
+ required:
+ - data-lanes
+ - link-frequencies
+
+ required:
+ - endpoint
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - clocks
+ - clock-names
+ - power-domains
+ - brcm,num-data-lanes
+ - port
+
+additionalProperties: False
+
+examples:
+ - |
+ #include <dt-bindings/clock/bcm2835.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/power/raspberrypi-power.h>
+ csi1: csi@7e801000 {
+ compatible = "brcm,bcm2835-unicam";
+ reg = <0x7e801000 0x800>,
+ <0x7e802004 0x4>;
+ interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&clocks BCM2835_CLOCK_CAM1>,
+ <&firmware_clocks 4>;
+ clock-names = "lp", "vpu";
+ power-domains = <&power RPI_POWER_DOMAIN_UNICAM1>;
+ brcm,num-data-lanes = <2>;
+ port {
+ csi1_ep: endpoint {
+ remote-endpoint = <&imx219_0>;
+ data-lanes = <1 2>;
+ link-frequencies = /bits/ 64 <456000000>;
+ };
+ };
+ };
+...
--
2.32.0
Hi Jean-Michel,
Thank you for the patch.
On Thu, Feb 03, 2022 at 06:50:00PM +0100, Jean-Michel Hautbois wrote:
> Introduce the dt-bindings documentation for bcm2835 CCP2/CSI2 Unicam
> camera interface. Also add a MAINTAINERS entry for it.
You can drop the last sentence now that the MAINTAINERS entry has been
moved out.
> Signed-off-by: Dave Stevenson <[email protected]>
> Signed-off-by: Naushir Patuck <[email protected]>
> Signed-off-by: Jean-Michel Hautbois <[email protected]>
>
> ---
> v4:
> - make MAINTAINERS its own patch
> - describe the reg and clocks correctly
> - use a vendor entry for the number of data lanes
> ---
> .../bindings/media/brcm,bcm2835-unicam.yaml | 110 ++++++++++++++++++
> 1 file changed, 110 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
>
> diff --git a/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> new file mode 100644
> index 000000000000..0725a0267c60
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> @@ -0,0 +1,110 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/brcm,bcm2835-unicam.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Broadcom BCM283x Camera Interface (Unicam)
> +
> +maintainers:
> + - Raspberry Pi Kernel Maintenance <[email protected]>
> +
> +description: |-
> + The Unicam block on BCM283x SoCs is the receiver for either
> + CSI-2 or CCP2 data from image sensors or similar devices.
> +
> + The main platform using this SoC is the Raspberry Pi family of boards.
> + On the Pi the VideoCore firmware can also control this hardware block,
> + and driving it from two different processors will cause issues.
> + To avoid this, the firmware checks the device tree configuration
> + during boot. If it finds device tree nodes starting by csi then
"[...] device tree nodes whose name starts with 'csi' then [...]"
> + it will stop the firmware accessing the block, and it can then
> + safely be used via the device tree binding.
> +
> +properties:
> + compatible:
> + const: brcm,bcm2835-unicam
> +
> + reg:
> + items:
> + - description: Unicam block.
> + - description: Clock Manager Image (CMI) block.
As Stefan pointed out, you need
reg-names:
items:
- const: main
- const: cmi
Alternatives for main could be core or unicam. Dave, do you have a
preference ?
> +
> + interrupts:
> + maxItems: 1
> +
> + clocks:
> + items:
> + - description: Clock to drive the LP state machine of Unicam.
> + - description: Clock for the vpu (core clock).
s/vpu/VPU/
> +
> + clock-names:
> + items:
> + - const: lp
> + - const: vpu
> +
> + power-domains:
> + items:
> + - description: Unicam power domain
> +
> + brcm,num-data-lanes:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [ 2, 4 ]
> + description: Number of data lanes on the csi bus
I'd write
description: |
Number of CSI-2 data lanes supported by this Unicam instance. The number
of data lanes actively used is specified with the data-lanes endpoint
property.
> +
> + port:
> + additionalProperties: false
Shouldn't this be unevaluatedProperties ?
I would also put it after the $ref line.
> + $ref: /schemas/graph.yaml#/$defs/port-base
> +
> + properties:
> + endpoint:
> + $ref: /schemas/media/video-interfaces.yaml#
> + unevaluatedProperties: false
> +
> + properties:
> + data-lanes: true
> + link-frequencies: true
link-frequencies is specified on the sensor side, not here. You can drop
it.
> +
> + required:
> + - data-lanes
> + - link-frequencies
> +
> + required:
> + - endpoint
> +
> +required:
> + - compatible
> + - reg
> + - interrupts
> + - clocks
> + - clock-names
> + - power-domains
> + - brcm,num-data-lanes
> + - port
> +
> +additionalProperties: False
> +
> +examples:
> + - |
> + #include <dt-bindings/clock/bcm2835.h>
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/power/raspberrypi-power.h>
> + csi1: csi@7e801000 {
> + compatible = "brcm,bcm2835-unicam";
> + reg = <0x7e801000 0x800>,
> + <0x7e802004 0x4>;
> + interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
> + clocks = <&clocks BCM2835_CLOCK_CAM1>,
> + <&firmware_clocks 4>;
> + clock-names = "lp", "vpu";
> + power-domains = <&power RPI_POWER_DOMAIN_UNICAM1>;
> + brcm,num-data-lanes = <2>;
> + port {
> + csi1_ep: endpoint {
Wrong indentation.
> + remote-endpoint = <&imx219_0>;
> + data-lanes = <1 2>;
> + link-frequencies = /bits/ 64 <456000000>;
Drop link-frequencies here too.
With these small issues fixed,
Reviewed-by: Laurent Pinchart <[email protected]>
> + };
> + };
> + };
> +...
--
Regards,
Laurent Pinchart
Hi Jean-Michel,
Am 03.02.22 um 18:50 schrieb Jean-Michel Hautbois:
> Introduce the dt-bindings documentation for bcm2835 CCP2/CSI2 Unicam
> camera interface. Also add a MAINTAINERS entry for it.
>
> Signed-off-by: Dave Stevenson <[email protected]>
> Signed-off-by: Naushir Patuck <[email protected]>
> Signed-off-by: Jean-Michel Hautbois <[email protected]>
>
> ---
> v4:
> - make MAINTAINERS its own patch
> - describe the reg and clocks correctly
> - use a vendor entry for the number of data lanes
> ---
> .../bindings/media/brcm,bcm2835-unicam.yaml | 110 ++++++++++++++++++
> 1 file changed, 110 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
>
> diff --git a/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> new file mode 100644
> index 000000000000..0725a0267c60
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> @@ -0,0 +1,110 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/brcm,bcm2835-unicam.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Broadcom BCM283x Camera Interface (Unicam)
> +
> +maintainers:
> + - Raspberry Pi Kernel Maintenance <[email protected]>
> +
> +description: |-
> + The Unicam block on BCM283x SoCs is the receiver for either
> + CSI-2 or CCP2 data from image sensors or similar devices.
> +
> + The main platform using this SoC is the Raspberry Pi family of boards.
> + On the Pi the VideoCore firmware can also control this hardware block,
> + and driving it from two different processors will cause issues.
> + To avoid this, the firmware checks the device tree configuration
> + during boot. If it finds device tree nodes starting by csi then
> + it will stop the firmware accessing the block, and it can then
> + safely be used via the device tree binding.
> +
> +properties:
> + compatible:
> + const: brcm,bcm2835-unicam
> +
> + reg:
> + items:
> + - description: Unicam block.
> + - description: Clock Manager Image (CMI) block.
thanks for describing the registers, but this is not what i meant with
adding "reg-names" in my last comment. Please look at the clocks below ...
> +
> + interrupts:
> + maxItems: 1
> +
> + clocks:
> + items:
> + - description: Clock to drive the LP state machine of Unicam.
> + - description: Clock for the vpu (core clock).
> +
> + clock-names:
> + items:
> + - const: lp
> + - const: vpu
> +
> +
Best regards
Am Donnerstag, 3. Februar 2022, 18:50:00 CET schrieb Jean-Michel Hautbois:
> Introduce the dt-bindings documentation for bcm2835 CCP2/CSI2 Unicam
> camera interface. Also add a MAINTAINERS entry for it.
>
> Signed-off-by: Dave Stevenson <[email protected]>
> Signed-off-by: Naushir Patuck <[email protected]>
> Signed-off-by: Jean-Michel Hautbois <[email protected]>
>
> ---
> v4:
> - make MAINTAINERS its own patch
> - describe the reg and clocks correctly
> - use a vendor entry for the number of data lanes
> ---
> .../bindings/media/brcm,bcm2835-unicam.yaml | 110 ++++++++++++++++++
> 1 file changed, 110 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
>
> diff --git
> a/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml new file
> mode 100644
> index 000000000000..0725a0267c60
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> @@ -0,0 +1,110 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/brcm,bcm2835-unicam.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Broadcom BCM283x Camera Interface (Unicam)
> +
> +maintainers:
> + - Raspberry Pi Kernel Maintenance <[email protected]>
> +
> +description: |-
> + The Unicam block on BCM283x SoCs is the receiver for either
> + CSI-2 or CCP2 data from image sensors or similar devices.
> +
> + The main platform using this SoC is the Raspberry Pi family of boards.
> + On the Pi the VideoCore firmware can also control this hardware block,
> + and driving it from two different processors will cause issues.
> + To avoid this, the firmware checks the device tree configuration
> + during boot. If it finds device tree nodes starting by csi then
> + it will stop the firmware accessing the block, and it can then
> + safely be used via the device tree binding.
> +
> +properties:
> + compatible:
> + const: brcm,bcm2835-unicam
> +
> + reg:
> + items:
> + - description: Unicam block.
> + - description: Clock Manager Image (CMI) block.
> +
> + interrupts:
> + maxItems: 1
> +
> + clocks:
> + items:
> + - description: Clock to drive the LP state machine of Unicam.
> + - description: Clock for the vpu (core clock).
> +
> + clock-names:
> + items:
> + - const: lp
> + - const: vpu
> +
> + power-domains:
> + items:
> + - description: Unicam power domain
> +
> + brcm,num-data-lanes:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [ 2, 4 ]
> + description: Number of data lanes on the csi bus
There is already data-lanes in Documentation/devicetree/bindings/media/video-
interfaces.yaml. AFAICS these two are identical. Can't the video-
interface.yaml be used for this? I'm no expert TBH.
Regards,
Alexander
Hi Alexander,
On Fri, Feb 04, 2022 at 09:50:06AM +0100, Alexander Stein wrote:
> Am Donnerstag, 3. Februar 2022, 18:50:00 CET schrieb Jean-Michel Hautbois:
> > Introduce the dt-bindings documentation for bcm2835 CCP2/CSI2 Unicam
> > camera interface. Also add a MAINTAINERS entry for it.
> >
> > Signed-off-by: Dave Stevenson <[email protected]>
> > Signed-off-by: Naushir Patuck <[email protected]>
> > Signed-off-by: Jean-Michel Hautbois <[email protected]>
> >
> > ---
> > v4:
> > - make MAINTAINERS its own patch
> > - describe the reg and clocks correctly
> > - use a vendor entry for the number of data lanes
> > ---
> > .../bindings/media/brcm,bcm2835-unicam.yaml | 110 ++++++++++++++++++
> > 1 file changed, 110 insertions(+)
> > create mode 100644
> > Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> > b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml new file
> > mode 100644
> > index 000000000000..0725a0267c60
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> > @@ -0,0 +1,110 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/brcm,bcm2835-unicam.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Broadcom BCM283x Camera Interface (Unicam)
> > +
> > +maintainers:
> > + - Raspberry Pi Kernel Maintenance <[email protected]>
> > +
> > +description: |-
> > + The Unicam block on BCM283x SoCs is the receiver for either
> > + CSI-2 or CCP2 data from image sensors or similar devices.
> > +
> > + The main platform using this SoC is the Raspberry Pi family of boards.
> > + On the Pi the VideoCore firmware can also control this hardware block,
> > + and driving it from two different processors will cause issues.
> > + To avoid this, the firmware checks the device tree configuration
> > + during boot. If it finds device tree nodes starting by csi then
> > + it will stop the firmware accessing the block, and it can then
> > + safely be used via the device tree binding.
> > +
> > +properties:
> > + compatible:
> > + const: brcm,bcm2835-unicam
> > +
> > + reg:
> > + items:
> > + - description: Unicam block.
> > + - description: Clock Manager Image (CMI) block.
> > +
> > + interrupts:
> > + maxItems: 1
> > +
> > + clocks:
> > + items:
> > + - description: Clock to drive the LP state machine of Unicam.
> > + - description: Clock for the vpu (core clock).
> > +
> > + clock-names:
> > + items:
> > + - const: lp
> > + - const: vpu
> > +
> > + power-domains:
> > + items:
> > + - description: Unicam power domain
> > +
> > + brcm,num-data-lanes:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + enum: [ 2, 4 ]
> > + description: Number of data lanes on the csi bus
>
> There is already data-lanes in Documentation/devicetree/bindings/media/video-
> interfaces.yaml. AFAICS these two are identical. Can't the video-
> interface.yaml be used for this? I'm no expert TBH.
This is the number of data lanes that the Unicam instance supports.
There are two Unicam instances, and they can have 2 or 4 data lanes
depending on the SoC. The data-lanes endpoint property indicates the
number of lanes used on a particular board.
--
Regards,
Laurent Pinchart
Hi Laurent,
Am Samstag, 5. Februar 2022, 03:22:51 CET schrieb Laurent Pinchart:
> Hi Alexander,
>
> On Fri, Feb 04, 2022 at 09:50:06AM +0100, Alexander Stein wrote:
> > Am Donnerstag, 3. Februar 2022, 18:50:00 CET schrieb Jean-Michel Hautbois:
> > > Introduce the dt-bindings documentation for bcm2835 CCP2/CSI2 Unicam
> > > camera interface. Also add a MAINTAINERS entry for it.
> > >
> > > Signed-off-by: Dave Stevenson <[email protected]>
> > > Signed-off-by: Naushir Patuck <[email protected]>
> > > Signed-off-by: Jean-Michel Hautbois
> > > <[email protected]>
> > >
> > > ---
> > > v4:
> > > - make MAINTAINERS its own patch
> > > - describe the reg and clocks correctly
> > > - use a vendor entry for the number of data lanes
> > > ---
> > >
> > > .../bindings/media/brcm,bcm2835-unicam.yaml | 110 ++++++++++++++++++
> > > 1 file changed, 110 insertions(+)
> > > create mode 100644
> > >
> > > Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> > >
> > > diff --git
> > > a/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> > > b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml new
> > > file
> > > mode 100644
> > > index 000000000000..0725a0267c60
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> > > @@ -0,0 +1,110 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/media/brcm,bcm2835-unicam.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Broadcom BCM283x Camera Interface (Unicam)
> > > +
> > > +maintainers:
> > > + - Raspberry Pi Kernel Maintenance <[email protected]>
> > > +
> > > +description: |-
> > > + The Unicam block on BCM283x SoCs is the receiver for either
> > > + CSI-2 or CCP2 data from image sensors or similar devices.
> > > +
> > > + The main platform using this SoC is the Raspberry Pi family of
> > > boards.
> > > + On the Pi the VideoCore firmware can also control this hardware
> > > block,
> > > + and driving it from two different processors will cause issues.
> > > + To avoid this, the firmware checks the device tree configuration
> > > + during boot. If it finds device tree nodes starting by csi then
> > > + it will stop the firmware accessing the block, and it can then
> > > + safely be used via the device tree binding.
> > > +
> > > +properties:
> > > + compatible:
> > > + const: brcm,bcm2835-unicam
> > > +
> > > + reg:
> > > + items:
> > > + - description: Unicam block.
> > > + - description: Clock Manager Image (CMI) block.
> > > +
> > > + interrupts:
> > > + maxItems: 1
> > > +
> > > + clocks:
> > > + items:
> > > + - description: Clock to drive the LP state machine of Unicam.
> > > + - description: Clock for the vpu (core clock).
> > > +
> > > + clock-names:
> > > + items:
> > > + - const: lp
> > > + - const: vpu
> > > +
> > > + power-domains:
> > > + items:
> > > + - description: Unicam power domain
> > > +
> > > + brcm,num-data-lanes:
> > > + $ref: /schemas/types.yaml#/definitions/uint32
> > > + enum: [ 2, 4 ]
> > > + description: Number of data lanes on the csi bus
> >
> > There is already data-lanes in
> > Documentation/devicetree/bindings/media/video- interfaces.yaml. AFAICS
> > these two are identical. Can't the video-
> > interface.yaml be used for this? I'm no expert TBH.
>
> This is the number of data lanes that the Unicam instance supports.
> There are two Unicam instances, and they can have 2 or 4 data lanes
> depending on the SoC. The data-lanes endpoint property indicates the
> number of lanes used on a particular board.
Thanks for the explanation. Isn't this something which could be derived from
the compatible, e.g. having 2 different ones for 2 and 4 lanes respectively?
See [1] for a similar situation in the SPI subsystem.
I don't have a strong opinion, just want to share my feedback.
Regards,
Alexander
[1] https://patchwork.kernel.org/project/spi-devel-general/patch/
[email protected]/#24641405