Re: [PATCH v3] ASoC: dt-bindings: davinci-mcasp: convert McASP bindings to yaml schema

From: Péter Ujfalusi
Date: Mon Nov 29 2021 - 01:59:10 EST




On 26/11/2021 07:02, Jayesh Choudhary wrote:
> Convert the bindings for McASP controllers for TI SOCs
> from txt to YAML schema.

Can you CC the sound/soc/ti/ maintainer next time, I have found this
patch in my Spam folder...

> Adds additional properties 'clocks', 'clock-names', 'power-domains',
> '#sound-dai-cells',

> 'num-serializer'

Which use was removed by 1427e660b49e87cd842dba94158b0fc73030c17e

> and 'port'

And what this "port" is?

> which were not there in the txt file.

Most likely for a reason?

> Adds 'dmas' and 'dma-names' in the example which were not there in
> the txt file.
> Changes 'interrupts' and 'interrupt-names' from optional to
> required properties.

My biggest problem with the davinci-mcasp-audio.txt is that it was done
in a wrong way and it just documented the pdata parameters as DT binding.
If we convert it to yaml, this is going to be 'written in stone'.

>
> Signed-off-by: Jayesh Choudhary <j-choudhary@xxxxxx>
> ---
> Changelog:
> v3:
> - removes maxItems from 'clock-names'
>
> v2:
> - changes the commit message
> - modifies the properties 'clocks', 'clock-names', 'dma-names',
> 'dmas', 'interrupts' and 'interrupt-names' according to the
> arm SOCs
> - adds 'port' and 'num-serializer' as node properties
>
> .../bindings/sound/davinci-mcasp-audio.txt | 86 ---------
> .../bindings/sound/davinci-mcasp-audio.yaml | 178 ++++++++++++++++++
> 2 files changed, 178 insertions(+), 86 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/sound/davinci-mcasp-audio.txt
> create mode 100644 Documentation/devicetree/bindings/sound/davinci-mcasp-audio.yaml
>
> diff --git a/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.txt b/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.txt
> deleted file mode 100644
> index bd863bd69501..000000000000
> --- a/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.txt
> +++ /dev/null
> @@ -1,86 +0,0 @@
> -Texas Instruments McASP controller
> -
> -Required properties:
> -- compatible :
> - "ti,dm646x-mcasp-audio" : for DM646x platforms
> - "ti,da830-mcasp-audio" : for both DA830 & DA850 platforms
> - "ti,am33xx-mcasp-audio" : for AM33xx platforms (AM33xx, AM43xx, TI81xx)
> - "ti,dra7-mcasp-audio" : for DRA7xx platforms
> - "ti,omap4-mcasp-audio" : for OMAP4
> -
> -- reg : Should contain reg specifiers for the entries in the reg-names property.
> -- reg-names : Should contain:
> - * "mpu" for the main registers (required). For compatibility with
> - existing software, it is recommended this is the first entry.
> - * "dat" for separate data port register access (optional).
> -- op-mode : I2S/DIT ops mode. 0 for I2S mode. 1 for DIT mode used for S/PDIF,
> - IEC60958-1, and AES-3 formats.
> -- tdm-slots : Slots for TDM operation. Indicates number of channels transmitted
> - or received over one serializer.
> -- serial-dir : A list of serializer configuration. Each entry is a number
> - indication for serializer pin direction.
> - (0 - INACTIVE, 1 - TX, 2 - RX)
> -- dmas: two element list of DMA controller phandles and DMA request line
> - ordered pairs.
> -- dma-names: identifier string for each DMA request line in the dmas property.
> - These strings correspond 1:1 with the ordered pairs in dmas. The dma
> - identifiers must be "rx" and "tx".
> -
> -Optional properties:
> -
> -- ti,hwmods : Must be "mcasp<n>", n is controller instance starting 0
> -- tx-num-evt : FIFO levels.
> -- rx-num-evt : FIFO levels.
> -- dismod : Specify the drive on TX pin during inactive slots
> - 0 : 3-state
> - 2 : logic low
> - 3 : logic high
> - Defaults to 'logic low' when the property is not present
> -- sram-size-playback : size of sram to be allocated during playback
> -- sram-size-capture : size of sram to be allocated during capture
> -- interrupts : Interrupt numbers for McASP
> -- interrupt-names : Known interrupt names are "tx" and "rx"
> -- pinctrl-0: Should specify pin control group used for this controller.
> -- pinctrl-names: Should contain only one value - "default", for more details
> - please refer to pinctrl-bindings.txt
> -- fck_parent : Should contain a valid clock name which will be used as parent
> - for the McASP fck
> -- auxclk-fs-ratio: When McASP is bus master indicates the ratio between AUCLK
> - and FS rate if applicable:
> - AUCLK rate = auxclk-fs-ratio * FS rate
> -
> -Optional GPIO support:
> -If any McASP pin need to be used as GPIO then the McASP node must have:
> -...
> - gpio-controller
> - #gpio-cells = <2>;
> -...
> -
> -When requesting a GPIO, the first parameter is the PIN index in McASP_P*
> -registers.
> -For example to request the AXR2 pin of mcasp8:
> -function-gpios = <&mcasp8 2 0>;
> -
> -Or to request the ACLKR pin of mcasp8:
> -function-gpios = <&mcasp8 29 0>;
> -
> -For generic gpio information, please refer to bindings/gpio/gpio.txt
> -
> -Example:
> -
> -mcasp0: mcasp0@1d00000 {
> - compatible = "ti,da830-mcasp-audio";
> - reg = <0x100000 0x3000>;
> - reg-names "mpu";
> - interrupts = <82>, <83>;
> - interrupt-names = "tx", "rx";
> - op-mode = <0>; /* MCASP_IIS_MODE */
> - tdm-slots = <2>;
> - serial-dir = <
> - 0 0 0 0 /* 0: INACTIVE, 1: TX, 2: RX */
> - 0 0 0 0
> - 0 0 0 1
> - 2 0 0 0 >;
> - tx-num-evt = <1>;
> - rx-num-evt = <1>;
> -};
> diff --git a/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.yaml b/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.yaml
> new file mode 100644
> index 000000000000..c4d3f56470bf
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/davinci-mcasp-audio.yaml
> @@ -0,0 +1,178 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/sound/davinci-mcasp-audio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: McASP Controller for TI SoCs
> +
> +maintainers:
> + - Jayesh Choudhary <j-choudhary@xxxxxx>
> +
> +properties:
> + compatible:
> + enum:
> + - ti,dm646x-mcasp-audio
> + - ti,da830-mcasp-audio
> + - ti,am33xx-mcasp-audio
> + - ti,dra7-mcasp-audio
> + - ti,omap4-mcasp-audio
> +
> + reg:
> + minItems: 1
> + items:
> + - description: main registers
> + - description: data port register
> +
> + reg-names:
> + minItems: 1
> + items:
> + - const: mpu
> + - const: dat
> +
> + op-mode:
> + description: I2S - 0 or DIT - 1 mode
> + enum:
> + - 0
> + - 1
> +
> + tdm-slots:

description?

> + maxItems: 1
> +
> + serial-dir:
> + description:
> + A list of serializer configuration
> + Entry is indication for serializer pin direction
> + 0 - Inactive, 1 - TX, 2 - RX

You should mention that _all_ AXR pins should be present in the array,
even if they are no in use.

> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + minItems: 1
> + maxItems: 16

a McASP could have up to 25 AXR pins...

> + items:
> + minimum: 0
> + maximum: 2
> + default: 0
> +
> + dmas:
> + minItems: 1
> + items:
> + - description: transmission DMA channel
> + - description: reception DMA channel
> +
> + dma-names:
> + minItems: 1
> + items:
> + - const: tx
> + - const: rx
> +
> + ti,hwmods:
> + $ref: /schemas/types.yaml#/definitions/string
> + description: Name of hwmod associated with McASP
> + maxItems: 1
> + deprecated: true
> +
> + tx-num-evt:

description?

> + maxItems: 1
> +
> + rx-num-evt:

description?

> + maxItems: 1
> +
> + dismod:

description?

> + enum:
> + - 0
> + - 2
> + - 3
> + default: 2
> +
> + sram-size-playback:
> + maxItems: 1

should be dropped, not used

> +
> + sram-size-capture:
> + maxItems: 1

not used, please drop

> +
> + interrupts:
> + minItems: 1
> + items:
> + - description: TX FIFO interrupt
> + - description: RX FIFO interrupt

The 'common' does not deserve a description?

> +
> + interrupt-names:
> + oneOf:
> + - minItems: 1
> + items:
> + - const: tx
> + - const: rx
> + - const: common
> +
> + fck_parent:
> + description: parent clock for McASP fck
> + maxItems: 1
> +
> + auxclk-fs-ratio:
> + description: ratio of AUCLK and FS if applicable
> + maxItems: 1
> +
> + gpio-controller: true
> +
> + "#gpio-cells":
> + const: 2
> +
> + function-gpios:
> + maxItems: 1

This is not McASP property, it was an example on how to use a pin as
GPIO from the outside...

> +
> + clocks:
> + minItems: 1
> + maxItems: 3
> +
> + clock-names:
> + minItems: 1
> + items:
> + - const: fck
> + - const: ahclkx
> + - const: ahclkr

I can not find any use in the code for ahclkx/r?

> +
> + power-domains:
> + maxItems: 1
> +
> + "#sound-dai-cells":
> + const: 0
> +
> + num-serializer:
> + maxItems: 1

Not used, the number of serializers is derived from the serial-dir array

> + port:
> + type: object
> +
> +required:
> + - compatible
> + - reg
> + - reg-names
> + - dmas
> + - dma-names
> + - interrupts
> + - interrupt-names
> + - serial-dir
> + - op-mode
> + - tdm-slots

The last three is not needed if the McASP is used only as GPIO.
The dmas and interrupts should not be needed in this case, but I think
it is not taken care of atm.

The tdm-slots is ignored for DIT mode

> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + mcasp0: mcasp0@1d00000 {
> + compatible = "ti,da830-mcasp-audio";
> + reg = <0x100000 0x3000>;
> + reg-names = "mpu";
> + interrupts = <82>, <83>;
> + interrupt-names = "tx", "rx";
> + op-mode = <0>; /* MCASP_IIS_MODE */
> + tdm-slots = <2>;
> + dmas = <&main_udmap 0xc400>, <&main_udmap 0x4400>;
> + dma-names = "tx", "rx";
> + serial-dir = <
> + 0 0 0 0 /* 0: INACTIVE, 1: TX, 2: RX */
> + 0 0 0 0
> + 0 0 0 1
> + 2 0 0 0 >;
> + tx-num-evt = <1>;
> + rx-num-evt = <1>;
> + };
>

--
Péter