dt/bindings: memory: Add bindings for TI GPMC driver
GPMC stands for General Purpose Memory Controller and it is
present on many Texas Instruments SoCs.
It supports a number of Asynchronous and Synchronous interfaces
and has various settings to configure the bus interface.
The DT bindings define all the various GPMC settings.
As the GPMC supports multiple devices on the bus, each
device is represented as a child and the respective
GPMC settings are situated there. (see ti,gpmc-child.yaml)
These binding docs are picked up from the Linux kernel.
Signed-off-by: Roger Quadros <rogerq@kernel.org>
diff --git a/doc/device-tree-bindings/memory/ti,gpmc.yaml b/doc/device-tree-bindings/memory/ti,gpmc.yaml
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+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/ti,gpmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Texas Instruments GPMC Memory Controller device-tree bindings
+
+maintainers:
+ - Tony Lindgren <tony@atomide.com>
+ - Roger Quadros <rogerq@kernel.org>
+
+description:
+ The GPMC is a unified memory controller dedicated for interfacing
+ with external memory devices like
+ - Asynchronous SRAM-like memories and ASICs
+ - Asynchronous, synchronous, and page mode burst NOR flash
+ - NAND flash
+ - Pseudo-SRAM devices
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - ti,am3352-gpmc
+ - ti,am64-gpmc
+ - ti,omap2420-gpmc
+ - ti,omap2430-gpmc
+ - ti,omap3430-gpmc
+ - ti,omap4430-gpmc
+
+ reg:
+ minItems: 1
+ maxItems: 2
+
+ reg-names:
+ items:
+ - const: cfg
+ - const: data
+
+ interrupts:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+ description: |
+ Functional clock. Used for bus timing calculations and
+ GPMC configuration.
+
+ clock-names:
+ items:
+ - const: fck
+
+ power-domains:
+ maxItems: 1
+
+ dmas:
+ items:
+ - description: DMA channel for GPMC NAND prefetch
+
+ dma-names:
+ items:
+ - const: rxtx
+
+ "#address-cells": true
+
+ "#size-cells": true
+
+ gpmc,num-cs:
+ description: maximum number of supported chip-select lines.
+ $ref: /schemas/types.yaml#/definitions/uint32
+
+ gpmc,num-waitpins:
+ description: maximum number of supported wait pins.
+ $ref: /schemas/types.yaml#/definitions/uint32
+
+ ranges:
+ minItems: 1
+ description: |
+ Must be set up to reflect the memory layout with four
+ integer values for each chip-select line in use,
+ <cs-number> 0 <physical address of mapping> <size>
+ items:
+ - description: NAND bank 0
+ - description: NOR/SRAM bank 0
+ - description: NOR/SRAM bank 1
+
+ '#interrupt-cells':
+ const: 2
+
+ interrupt-controller:
+ description: |
+ The GPMC driver implements and interrupt controller for
+ the NAND events "fifoevent" and "termcount" plus the
+ rising/falling edges on the GPMC_WAIT pins.
+ The interrupt number mapping is as follows
+ 0 - NAND_fifoevent
+ 1 - NAND_termcount
+ 2 - GPMC_WAIT0 pin edge
+ 3 - GPMC_WAIT1 pin edge, and so on.
+
+ '#gpio-cells':
+ const: 2
+
+ gpio-controller:
+ description: |
+ The GPMC driver implements a GPIO controller for the
+ GPMC WAIT pins that can be used as general purpose inputs.
+ 0 maps to GPMC_WAIT0 pin.
+
+ ti,hwmods:
+ description:
+ Name of the HWMOD associated with GPMC. This is for legacy
+ omap2/3 platforms only.
+ $ref: /schemas/types.yaml#/definitions/string
+ deprecated: true
+
+ ti,no-idle-on-init:
+ description:
+ Prevent idling the module at init. This is for legacy omap2/3
+ platforms only.
+ type: boolean
+ deprecated: true
+
+patternProperties:
+ "@[0-7],[a-f0-9]+$":
+ type: object
+ description: |
+ The child device node represents the device connected to the GPMC
+ bus. The device can be a NAND chip, SRAM device, NOR device
+ or an ASIC.
+ $ref: "ti,gpmc-child.yaml"
+
+
+required:
+ - compatible
+ - reg
+ - gpmc,num-cs
+ - gpmc,num-waitpins
+ - "#address-cells"
+ - "#size-cells"
+
+allOf:
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: ti,am64-gpmc
+ then:
+ required:
+ - reg-names
+ - power-domains
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/gpio/gpio.h>
+
+ gpmc: memory-controller@50000000 {
+ compatible = "ti,am3352-gpmc";
+ reg = <0x50000000 0x2000>;
+ interrupts = <100>;
+ clocks = <&l3s_clkctrl>;
+ clock-names = "fck";
+ dmas = <&edma 52 0>;
+ dma-names = "rxtx";
+ gpmc,num-cs = <8>;
+ gpmc,num-waitpins = <2>;
+ #address-cells = <2>;
+ #size-cells = <1>;
+ ranges = <0 0 0x08000000 0x10000000>; /* CS0 @addr 0x8000000, size 0x10000000 */
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ gpio-controller;
+ #gpio-cells = <2>;
+
+ nand@0,0 {
+ compatible = "ti,omap2-nand";
+ reg = <0 0 4>;
+ interrupt-parent = <&gpmc>;
+ interrupts = <0 IRQ_TYPE_NONE>, /* fifoevent */
+ <1 IRQ_TYPE_NONE>; /* termcount */
+ ti,nand-xfer-type = "prefetch-dma";
+ ti,nand-ecc-opt = "bch16";
+ ti,elm-id = <&elm>;
+ rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 pin */
+ };
+ };