Re: [PATCH v4 07/10] dt-bindings: memory-controller: add STM32 FMC2 EBI controller documentation

From: Rob Herring
Date: Thu May 14 2020 - 11:07:38 EST


On Wed, May 06, 2020 at 11:11:16AM +0200, Christophe Kerello wrote:
> This patch adds the documentation of the device tree bindings for the STM32
> FMC2 EBI controller.
>
> Signed-off-by: Christophe Kerello <christophe.kerello@xxxxxx>
> ---
> Changes in v4:
> - fix filename: st,stm32-fmc2-ebi.yaml
>
> Changes in v3:
> - pattern name has been modified
> - vendor properties have been modified
> - s/_/-/
> - add unit suffix (-ns) on timing properties
>
> .../memory-controllers/st,stm32-fmc2-ebi.yaml | 261 +++++++++++++++++++++
> 1 file changed, 261 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/memory-controllers/st,stm32-fmc2-ebi.yaml
>
> diff --git a/Documentation/devicetree/bindings/memory-controllers/st,stm32-fmc2-ebi.yaml b/Documentation/devicetree/bindings/memory-controllers/st,stm32-fmc2-ebi.yaml
> new file mode 100644
> index 0000000..bf130c3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/memory-controllers/st,stm32-fmc2-ebi.yaml
> @@ -0,0 +1,261 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/memory-controllers/st,stm32-fmc2-ebi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: STMicroelectronics Flexible Memory Controller 2 (FMC2) Bindings
> +
> +description: |
> + The FMC2 functional block makes the interface with: synchronous and
> + asynchronous static devices (such as PSNOR, PSRAM or other memory-mapped
> + peripherals) and NAND flash memories.
> + Its main purposes are:
> + - to translate AXI transactions into the appropriate external device
> + protocol
> + - to meet the access time requirements of the external devices
> + All external devices share the addresses, data and control signals with the
> + controller. Each external device is accessed by means of a unique Chip
> + Select. The FMC2 performs only one access at a time to an external device.
> +
> +maintainers:
> + - Christophe Kerello <christophe.kerello@xxxxxx>
> +
> +properties:
> + compatible:
> + const: st,stm32mp1-fmc2-ebi
> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + maxItems: 1
> +
> + resets:
> + maxItems: 1
> +
> + "#address-cells":
> + const: 2
> +
> + "#size-cells":
> + const: 1
> +
> + ranges:
> + description: |
> + Reflects the memory layout with four integer values per bank. Format:
> + <bank-number> 0 <address of the bank> <size>
> +
> +patternProperties:
> + "^.*@[0-4],[a-f0-9]+$":
> + type: object
> +
> + properties:
> + reg:
> + description: Bank number, base address and size of the device.
> +
> + st,fmc2-ebi-cs-transaction-type:
> + description: |
> + Select one of the transactions type supported

Indent should be 2 more than 'description'.

> + 0: Asynchronous mode 1 SRAM/FRAM.
> + 1: Asynchronous mode 1 PSRAM.
> + 2: Asynchronous mode A SRAM/FRAM.
> + 3: Asynchronous mode A PSRAM.
> + 4: Asynchronous mode 2 NOR.
> + 5: Asynchronous mode B NOR.
> + 6: Asynchronous mode C NOR.
> + 7: Asynchronous mode D NOR.
> + 8: Synchronous read synchronous write PSRAM.
> + 9: Synchronous read asynchronous write PSRAM.
> + 10: Synchronous read synchronous write NOR.
> + 11: Synchronous read asynchronous write NOR.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 0
> + maximum: 11
> +
> + st,fmc2-ebi-cs-cclk-enable:
> + description: Continuous clock enable (first bank must be configured
> + in synchronous mode). The FMC_CLK is generated continuously
> + during asynchronous and synchronous access. By default, the
> + FMC_CLK is only generated during synchronous access.

Indent 2 more than 'description'. You can run this through yaml-format
in dtschema repo and it will re-flow everything for you.

With these fixed,

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>


> + $ref: /schemas/types.yaml#/definitions/flag
> +
> + st,fmc2-ebi-cs-mux-enable:
> + description: Address/Data multiplexed on databus (valid only with
> + NOR and PSRAM transactions type). By default, Address/Data
> + are not multiplexed.
> + $ref: /schemas/types.yaml#/definitions/flag
> +
> + st,fmc2-ebi-cs-buswidth:
> + description: Data bus width
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [ 8, 16 ]
> + default: 16
> +
> + st,fmc2-ebi-cs-waitpol-high:
> + description: Wait signal polarity (NWAIT signal active high).
> + By default, NWAIT is active low.
> + $ref: /schemas/types.yaml#/definitions/flag
> +
> + st,fmc2-ebi-cs-waitcfg-enable:
> + description: The NWAIT signal indicates wheither the data from the
> + device are valid or if a wait state must be inserted when
> + accessing the device in synchronous mode. By default, the
> + NWAIT signal is active one data cycle before wait state.
> + $ref: /schemas/types.yaml#/definitions/flag
> +
> + st,fmc2-ebi-cs-wait-enable:
> + description: The NWAIT signal is enabled (its level is taken into
> + account after the programmed latency period to insert wait
> + states if asserted). By default, the NWAIT signal is
> + disabled.
> + $ref: /schemas/types.yaml#/definitions/flag
> +
> + st,fmc2-ebi-cs-asyncwait-enable:
> + description: The NWAIT signal is taken into account during asynchronous
> + transactions. By default, the NWAIT signal is not taken
> + into account during asynchronous transactions.
> + $ref: /schemas/types.yaml#/definitions/flag
> +
> + st,fmc2-ebi-cs-cpsize:
> + description: CRAM page size. The controller splits the burst access
> + when the memory page is reached. By default, no burst
> + split when crossing page boundary.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [ 0, 128, 256, 512, 1024 ]
> + default: 0
> +
> + st,fmc2-ebi-cs-byte-lane-setup-ns:
> + description: This property configures the byte lane setup timing
> + defined in nanoseconds from NBLx low to Chip Select NEx
> + low.
> +
> + st,fmc2-ebi-cs-address-setup-ns:
> + description: This property defines the duration of the address setup
> + phase in nanoseconds used for asynchronous read/write
> + transactions.
> +
> + st,fmc2-ebi-cs-address-hold-ns:
> + description: This property defines the duration of the address hold
> + phase in nanoseconds used for asynchronous multiplexed
> + read/write transactions.
> +
> + st,fmc2-ebi-cs-data-setup-ns:
> + description: This property defines the duration of the data setup phase
> + in nanoseconds used for asynchronous read/write
> + transactions.
> +
> + st,fmc2-ebi-cs-bus-turnaround-ns:
> + description: This property defines the delay in nanoseconds between the
> + end of current read/write transaction and the next
> + transaction.
> +
> + st,fmc2-ebi-cs-data-hold-ns:
> + description: This property defines the duration of the data hold phase
> + in nanoseconds used for asynchronous read/write
> + transactions.
> +
> + st,fmc2-ebi-cs-clk-period-ns:
> + description: This property defines the FMC_CLK output signal period in
> + nanoseconds.
> +
> + st,fmc2-ebi-cs-data-latency-ns:
> + description: This property defines the data latency before reading or
> + writing the first data in nanoseconds.
> +
> + st,fmc2_ebi-cs-write-address-setup-ns:
> + description: This property defines the duration of the address setup
> + phase in nanoseconds used for asynchronous write
> + transactions.
> +
> + st,fmc2-ebi-cs-write-address-hold-ns:
> + description: This property defines the duration of the address hold
> + phase in nanoseconds used for asynchronous multiplexed
> + write transactions.
> +
> + st,fmc2-ebi-cs-write-data-setup-ns:
> + description: This property defines the duration of the data setup
> + phase in nanoseconds used for asynchronous write
> + transactions.
> +
> + st,fmc2-ebi-cs-write-bus-turnaround-ns:
> + description: This property defines the delay between the end of current
> + write transaction and the next transaction in nanoseconds.
> +
> + st,fmc2-ebi-cs-write-data-hold-ns:
> + description: This property defines the duration of the data hold phase
> + in nanoseconds used for asynchronous write transactions.
> +
> + st,fmc2-ebi-cs-max-low-pulse-ns:
> + description: This property defines the maximum chip select low pulse
> + duration in nanoseconds for synchronous transactions. When
> + this timing reaches 0, the controller splits the current
> + access, toggles NE to allow device refresh and restarts a
> + new access.
> +
> + required:
> + - reg
> +
> +required:
> + - "#address-cells"
> + - "#size-cells"
> + - compatible
> + - reg
> + - clocks
> + - ranges
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/clock/stm32mp1-clks.h>
> + #include <dt-bindings/reset/stm32mp1-resets.h>
> + memory-controller@58002000 {
> + #address-cells = <2>;
> + #size-cells = <1>;
> + compatible = "st,stm32mp1-fmc2-ebi";
> + reg = <0x58002000 0x1000>;
> + clocks = <&rcc FMC_K>;
> + resets = <&rcc FMC_R>;
> +
> + ranges = <0 0 0x60000000 0x04000000>, /* EBI CS 1 */
> + <1 0 0x64000000 0x04000000>, /* EBI CS 2 */
> + <2 0 0x68000000 0x04000000>, /* EBI CS 3 */
> + <3 0 0x6c000000 0x04000000>, /* EBI CS 4 */
> + <4 0 0x80000000 0x10000000>; /* NAND */
> +
> + psram@0,0 {
> + compatible = "mtd-ram";
> + reg = <0 0x00000000 0x100000>;
> + bank-width = <2>;
> +
> + st,fmc2-ebi-cs-transaction-type = <1>;
> + st,fmc2-ebi-cs-address-setup-ns = <60>;
> + st,fmc2-ebi-cs-data-setup-ns = <30>;
> + st,fmc2-ebi-cs-bus-turnaround-ns = <5>;
> + };
> +
> + nand-controller@4,0 {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + compatible = "st,stm32mp15-fmc2";
> + reg = <4 0x00000000 0x1000>,
> + <4 0x08010000 0x1000>,
> + <4 0x08020000 0x1000>,
> + <4 0x01000000 0x1000>,
> + <4 0x09010000 0x1000>,
> + <4 0x09020000 0x1000>;
> + interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>;
> + dmas = <&mdma1 20 0x2 0x12000a02 0x0 0x0>,
> + <&mdma1 20 0x2 0x12000a08 0x0 0x0>,
> + <&mdma1 21 0x2 0x12000a0a 0x0 0x0>;
> + dma-names = "tx", "rx", "ecc";
> +
> + nand@0 {
> + reg = <0>;
> + nand-on-flash-bbt;
> + #address-cells = <1>;
> + #size-cells = <1>;
> + };
> + };
> + };
> +
> +...
> --
> 1.9.1
>