| Message ID | 20210907113226.31876-6-rogerq@kernel.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | dt-bindings: memory-controllers: ti,gpmc: Convert to yaml | expand |
Hi Roger, rogerq@kernel.org wrote on Tue, 7 Sep 2021 14:32:23 +0300: > Convert gpmc-nand.txt to ti,gpmc-nand.yaml. > > Signed-off-by: Roger Quadros <rogerq@kernel.org> > --- > .../devicetree/bindings/mtd/gpmc-nand.txt | 147 ------------------ > .../devicetree/bindings/mtd/ti,gpmc-nand.yaml | 110 +++++++++++++ > 2 files changed, 110 insertions(+), 147 deletions(-) > delete mode 100644 Documentation/devicetree/bindings/mtd/gpmc-nand.txt > create mode 100644 Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml > > diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > deleted file mode 100644 > index 44919d48d241..000000000000 > --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > +++ /dev/null > @@ -1,147 +0,0 @@ > -Device tree bindings for GPMC connected NANDs > - > -GPMC connected NAND (found on OMAP boards) are represented as child nodes of > -the GPMC controller with a name of "nand". > - > -All timing relevant properties as well as generic gpmc child properties are > -explained in a separate documents - please refer to > -Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt > - > -For NAND specific properties such as ECC modes or bus width, please refer to > -Documentation/devicetree/bindings/mtd/nand-controller.yaml > - > - > -Required properties: > - > - - compatible: "ti,omap2-nand" > - - reg: range id (CS number), base offset and length of the > - NAND I/O space > - - interrupts: Two interrupt specifiers, one for fifoevent, one for termcount. > - > -Optional properties: > - > - - nand-bus-width: Set this numeric value to 16 if the hardware > - is wired that way. If not specified, a bus > - width of 8 is assumed. > - > - - ti,nand-ecc-opt: A string setting the ECC layout to use. One of: > - "sw" 1-bit Hamming ecc code via software > - "hw" <deprecated> use "ham1" instead > - "hw-romcode" <deprecated> use "ham1" instead > - "ham1" 1-bit Hamming ecc code > - "bch4" 4-bit BCH ecc code > - "bch8" 8-bit BCH ecc code > - "bch16" 16-bit BCH ECC code > - Refer below "How to select correct ECC scheme for your device ?" > - > - - ti,nand-xfer-type: A string setting the data transfer type. One of: > - > - "prefetch-polled" Prefetch polled mode (default) > - "polled" Polled mode, without prefetch > - "prefetch-dma" Prefetch enabled DMA mode > - "prefetch-irq" Prefetch enabled irq mode > - > - - elm_id: <deprecated> use "ti,elm-id" instead > - - ti,elm-id: Specifies phandle of the ELM devicetree node. > - ELM is an on-chip hardware engine on TI SoC which is used for > - locating ECC errors for BCHx algorithms. SoC devices which have > - ELM hardware engines should specify this device node in .dtsi > - Using ELM for ECC error correction frees some CPU cycles. > - - rb-gpios: GPIO specifier for the ready/busy# pin. > - > -For inline partition table parsing (optional): > - > - - #address-cells: should be set to 1 > - - #size-cells: should be set to 1 > - > -Example for an AM33xx board: > - > - gpmc: gpmc@50000000 { > - compatible = "ti,am3352-gpmc"; > - ti,hwmods = "gpmc"; > - reg = <0x50000000 0x36c>; > - interrupts = <100>; > - gpmc,num-cs = <8>; > - gpmc,num-waitpins = <2>; > - #address-cells = <2>; > - #size-cells = <1>; > - ranges = <0 0 0x08000000 0x1000000>; /* CS0 space, 16MB */ > - elm_id = <&elm>; > - interrupt-controller; > - #interrupt-cells = <2>; > - > - nand@0,0 { > - compatible = "ti,omap2-nand"; > - reg = <0 0 4>; /* CS0, offset 0, NAND I/O window 4 */ > - interrupt-parent = <&gpmc>; > - interrupts = <0 IRQ_TYPE_NONE>, <1 IRQ_TYPE NONE>; > - nand-bus-width = <16>; > - ti,nand-ecc-opt = "bch8"; > - ti,nand-xfer-type = "polled"; > - rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 */ > - > - gpmc,sync-clk-ps = <0>; > - gpmc,cs-on-ns = <0>; > - gpmc,cs-rd-off-ns = <44>; > - gpmc,cs-wr-off-ns = <44>; > - gpmc,adv-on-ns = <6>; > - gpmc,adv-rd-off-ns = <34>; > - gpmc,adv-wr-off-ns = <44>; > - gpmc,we-off-ns = <40>; > - gpmc,oe-off-ns = <54>; > - gpmc,access-ns = <64>; > - gpmc,rd-cycle-ns = <82>; > - gpmc,wr-cycle-ns = <82>; > - gpmc,wr-access-ns = <40>; > - gpmc,wr-data-mux-bus-ns = <0>; > - > - #address-cells = <1>; > - #size-cells = <1>; > - > - /* partitions go here */ > - }; > - }; > - > -How to select correct ECC scheme for your device ? > --------------------------------------------------- > -Higher ECC scheme usually means better protection against bit-flips and > -increased system lifetime. However, selection of ECC scheme is dependent > -on various other factors also like; > - > -(1) support of built in hardware engines. > - Some legacy OMAP SoC do not have ELM harware engine, so those SoC cannot > - support ecc-schemes with hardware error-correction (BCHx_HW). However > - such SoC can use ecc-schemes with software library for error-correction > - (BCHx_HW_DETECTION_SW). The error correction capability with software > - library remains equivalent to their hardware counter-part, but there is > - slight CPU penalty when too many bit-flips are detected during reads. > - > -(2) Device parameters like OOBSIZE. > - Other factor which governs the selection of ecc-scheme is oob-size. > - Higher ECC schemes require more OOB/Spare area to store ECC syndrome, > - so the device should have enough free bytes available its OOB/Spare > - area to accommodate ECC for entire page. In general following expression > - helps in determining if given device can accommodate ECC syndrome: > - "2 + (PAGESIZE / 512) * ECC_BYTES" >= OOBSIZE" > - where > - OOBSIZE number of bytes in OOB/spare area > - PAGESIZE number of bytes in main-area of device page > - ECC_BYTES number of ECC bytes generated to protect > - 512 bytes of data, which is: > - '3' for HAM1_xx ecc schemes > - '7' for BCH4_xx ecc schemes > - '14' for BCH8_xx ecc schemes > - '26' for BCH16_xx ecc schemes > - > - Example(a): For a device with PAGESIZE = 2048 and OOBSIZE = 64 and > - trying to use BCH16 (ECC_BYTES=26) ecc-scheme. > - Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B > - which is greater than capacity of NAND device (OOBSIZE=64) > - Hence, BCH16 cannot be supported on given device. But it can > - probably use lower ecc-schemes like BCH8. > - > - Example(b): For a device with PAGESIZE = 2048 and OOBSIZE = 128 and > - trying to use BCH16 (ECC_BYTES=26) ecc-scheme. > - Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B > - which can be accommodated in the OOB/Spare area of this device > - (OOBSIZE=128). So this device can use BCH16 ecc-scheme. > diff --git a/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml b/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml > new file mode 100644 > index 000000000000..db36f2e944ef > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml > @@ -0,0 +1,110 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/mtd/ti,gpmc-nand.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Texas Instruments GPMC NAND Flash controller. > + > +maintainers: > + - Tony Lindgren <tony@atomide.com> > + - Roger Quadros <rogerq@kernel.org> > + > +description: > + GPMC NAND controller/Flash is represented as a child of the > + GPMC controller node. > + > +properties: > + compatible: > + const: ti,omap2-nand > + > + reg: > + maxItems: 1 > + > + interrupts: > + items: > + - description: Interrupt for fifoevent > + - description: Interrupt for termcount > + > + "#address-cells": > + const: 1 > + > + "#size-cells": > + const: 1 > + > + ti,nand-ecc-opt: > + description: Desired ECC algorithm > + $ref: /schemas/types.yaml#/definitions/string > + enum: [sw, ham1, bch4, bch8, bch16] > + > + ti,nand-xfer-type: > + description: Data transfer method between controller and chip. > + $ref: /schemas/types.yaml#/definitions/string > + enum: [prefetch-polled, polled, prefetch-dma, prefetch-irq] > + default: prefetch-polled > + > + ti,elm-id: > + description: > + phandle to the ELM (Error Location Module). > + $ref: /schemas/types.yaml#/definitions/phandle Should perhaps keep the elm-id property documented but set to 'deprecated'. > + > + nand-bus-width: > + description: > + Bus width to the NAND chip > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [8, 16] > + default: 8 This is part of nand-controller.yaml binding and should not be there. > + > +allOf: > + - $ref: "../memory-controllers/ti,gpmc-child.yaml" Maybe you need to reference the nand controller bindings as well > + > +required: > + - compatible > + - reg > + - ti,nand-ecc-opt > + > +unevaluatedProperties: false > + > +examples: > + - | > + #include <dt-bindings/interrupt-controller/arm-gic.h> > + #include <dt-bindings/gpio/gpio.h> > + > + gpmc: memory-controller@50000000 { > + compatible = "ti,am3352-gpmc"; > + dmas = <&edma 52 0>; > + dma-names = "rxtx"; > + clocks = <&l3s_gclk>; > + clock-names = "fck"; > + reg = <0x50000000 0x2000>; > + interrupts = <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>; > + gpmc,num-cs = <7>; > + gpmc,num-waitpins = <2>; > + #address-cells = <2>; > + #size-cells = <1>; > + interrupt-controller; > + #interrupt-cells = <2>; > + gpio-controller; > + #gpio-cells = <2>; > + > + ranges = <0 0 0x08000000 0x01000000>; /* CS0 space. Min partition = 16MB */ > + nand@0,0 { > + compatible = "ti,omap2-nand"; > + reg = <0 0 4>; /* device IO registers */ > + 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>; > + #address-cells = <1>; > + #size-cells = <1>; > + > + /* NAND generic properties */ > + nand-bus-width = <8>; > + rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 */ > + > + /* GPMC properties*/ > + gpmc,device-width = <1>; > + }; > + }; Thanks, Miquèl
Hi Grygorii, > > > >> + > >> + nand-bus-width: > >> + description: > >> + Bus width to the NAND chip > >> + $ref: /schemas/types.yaml#/definitions/uint32 > >> + enum: [8, 16] > >> + default: 8 > > > > This is part of nand-controller.yaml binding and should not be there. > > > >> + > >> +allOf: > >> + - $ref: "../memory-controllers/ti,gpmc-child.yaml" > > > > Maybe you need to reference the nand controller bindings as well > > > > This will not work out of the box :( as nand-controller.yaml defines both > nand controller and nand memory. It potentially might work if it will be possible to split > nand memory definition (or nand memory properties) out of and-controller.yaml, similarly to > ti,gpmc-child.yaml from this series. What you think would be the issue? I am not opposed to split nand-controller.yaml into nand-controller.yaml and nand-chip.yaml if it simplifies the description of controllers but I don't get why it would be needed. In particular since we expect all drivers to support the nand-controller { controller-props; nand-chip { chip-props; } } organization which has been enforced since at least 2018. Having a controller vs. chip representation is fundamentally right. But here I see how "legacy" are these bindings with so much unneeded specific "ti," properties... On one side it would be good to verify that the driver supports this representation (which I believe is true) and on the other side maybe it's time to advertise "better" bindings as well. Thanks, Miquèl
On Tue, Sep 07, 2021 at 02:32:23PM +0300, Roger Quadros wrote: > Convert gpmc-nand.txt to ti,gpmc-nand.yaml. > > Signed-off-by: Roger Quadros <rogerq@kernel.org> > --- > .../devicetree/bindings/mtd/gpmc-nand.txt | 147 ------------------ > .../devicetree/bindings/mtd/ti,gpmc-nand.yaml | 110 +++++++++++++ > 2 files changed, 110 insertions(+), 147 deletions(-) > delete mode 100644 Documentation/devicetree/bindings/mtd/gpmc-nand.txt > create mode 100644 Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml > > diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > deleted file mode 100644 > index 44919d48d241..000000000000 > --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > +++ /dev/null > @@ -1,147 +0,0 @@ > -Device tree bindings for GPMC connected NANDs > - > -GPMC connected NAND (found on OMAP boards) are represented as child nodes of > -the GPMC controller with a name of "nand". > - > -All timing relevant properties as well as generic gpmc child properties are > -explained in a separate documents - please refer to > -Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt > - > -For NAND specific properties such as ECC modes or bus width, please refer to > -Documentation/devicetree/bindings/mtd/nand-controller.yaml > - > - > -Required properties: > - > - - compatible: "ti,omap2-nand" > - - reg: range id (CS number), base offset and length of the > - NAND I/O space > - - interrupts: Two interrupt specifiers, one for fifoevent, one for termcount. > - > -Optional properties: > - > - - nand-bus-width: Set this numeric value to 16 if the hardware > - is wired that way. If not specified, a bus > - width of 8 is assumed. > - > - - ti,nand-ecc-opt: A string setting the ECC layout to use. One of: > - "sw" 1-bit Hamming ecc code via software > - "hw" <deprecated> use "ham1" instead > - "hw-romcode" <deprecated> use "ham1" instead > - "ham1" 1-bit Hamming ecc code > - "bch4" 4-bit BCH ecc code > - "bch8" 8-bit BCH ecc code > - "bch16" 16-bit BCH ECC code > - Refer below "How to select correct ECC scheme for your device ?" > - > - - ti,nand-xfer-type: A string setting the data transfer type. One of: > - > - "prefetch-polled" Prefetch polled mode (default) > - "polled" Polled mode, without prefetch > - "prefetch-dma" Prefetch enabled DMA mode > - "prefetch-irq" Prefetch enabled irq mode > - > - - elm_id: <deprecated> use "ti,elm-id" instead > - - ti,elm-id: Specifies phandle of the ELM devicetree node. > - ELM is an on-chip hardware engine on TI SoC which is used for > - locating ECC errors for BCHx algorithms. SoC devices which have > - ELM hardware engines should specify this device node in .dtsi > - Using ELM for ECC error correction frees some CPU cycles. > - - rb-gpios: GPIO specifier for the ready/busy# pin. > - > -For inline partition table parsing (optional): > - > - - #address-cells: should be set to 1 > - - #size-cells: should be set to 1 > - > -Example for an AM33xx board: > - > - gpmc: gpmc@50000000 { > - compatible = "ti,am3352-gpmc"; > - ti,hwmods = "gpmc"; > - reg = <0x50000000 0x36c>; > - interrupts = <100>; > - gpmc,num-cs = <8>; > - gpmc,num-waitpins = <2>; > - #address-cells = <2>; > - #size-cells = <1>; > - ranges = <0 0 0x08000000 0x1000000>; /* CS0 space, 16MB */ > - elm_id = <&elm>; > - interrupt-controller; > - #interrupt-cells = <2>; > - > - nand@0,0 { > - compatible = "ti,omap2-nand"; > - reg = <0 0 4>; /* CS0, offset 0, NAND I/O window 4 */ > - interrupt-parent = <&gpmc>; > - interrupts = <0 IRQ_TYPE_NONE>, <1 IRQ_TYPE NONE>; > - nand-bus-width = <16>; > - ti,nand-ecc-opt = "bch8"; > - ti,nand-xfer-type = "polled"; > - rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 */ > - > - gpmc,sync-clk-ps = <0>; > - gpmc,cs-on-ns = <0>; > - gpmc,cs-rd-off-ns = <44>; > - gpmc,cs-wr-off-ns = <44>; > - gpmc,adv-on-ns = <6>; > - gpmc,adv-rd-off-ns = <34>; > - gpmc,adv-wr-off-ns = <44>; > - gpmc,we-off-ns = <40>; > - gpmc,oe-off-ns = <54>; > - gpmc,access-ns = <64>; > - gpmc,rd-cycle-ns = <82>; > - gpmc,wr-cycle-ns = <82>; > - gpmc,wr-access-ns = <40>; > - gpmc,wr-data-mux-bus-ns = <0>; > - > - #address-cells = <1>; > - #size-cells = <1>; > - > - /* partitions go here */ > - }; > - }; > - > -How to select correct ECC scheme for your device ? > --------------------------------------------------- > -Higher ECC scheme usually means better protection against bit-flips and > -increased system lifetime. However, selection of ECC scheme is dependent > -on various other factors also like; > - > -(1) support of built in hardware engines. > - Some legacy OMAP SoC do not have ELM harware engine, so those SoC cannot > - support ecc-schemes with hardware error-correction (BCHx_HW). However > - such SoC can use ecc-schemes with software library for error-correction > - (BCHx_HW_DETECTION_SW). The error correction capability with software > - library remains equivalent to their hardware counter-part, but there is > - slight CPU penalty when too many bit-flips are detected during reads. > - > -(2) Device parameters like OOBSIZE. > - Other factor which governs the selection of ecc-scheme is oob-size. > - Higher ECC schemes require more OOB/Spare area to store ECC syndrome, > - so the device should have enough free bytes available its OOB/Spare > - area to accommodate ECC for entire page. In general following expression > - helps in determining if given device can accommodate ECC syndrome: > - "2 + (PAGESIZE / 512) * ECC_BYTES" >= OOBSIZE" > - where > - OOBSIZE number of bytes in OOB/spare area > - PAGESIZE number of bytes in main-area of device page > - ECC_BYTES number of ECC bytes generated to protect > - 512 bytes of data, which is: > - '3' for HAM1_xx ecc schemes > - '7' for BCH4_xx ecc schemes > - '14' for BCH8_xx ecc schemes > - '26' for BCH16_xx ecc schemes > - > - Example(a): For a device with PAGESIZE = 2048 and OOBSIZE = 64 and > - trying to use BCH16 (ECC_BYTES=26) ecc-scheme. > - Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B > - which is greater than capacity of NAND device (OOBSIZE=64) > - Hence, BCH16 cannot be supported on given device. But it can > - probably use lower ecc-schemes like BCH8. > - > - Example(b): For a device with PAGESIZE = 2048 and OOBSIZE = 128 and > - trying to use BCH16 (ECC_BYTES=26) ecc-scheme. > - Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B > - which can be accommodated in the OOB/Spare area of this device > - (OOBSIZE=128). So this device can use BCH16 ecc-scheme. > diff --git a/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml b/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml > new file mode 100644 > index 000000000000..db36f2e944ef > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml > @@ -0,0 +1,110 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/mtd/ti,gpmc-nand.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Texas Instruments GPMC NAND Flash controller. > + > +maintainers: > + - Tony Lindgren <tony@atomide.com> > + - Roger Quadros <rogerq@kernel.org> > + > +description: > + GPMC NAND controller/Flash is represented as a child of the > + GPMC controller node. > + > +properties: > + compatible: > + const: ti,omap2-nand > + > + reg: > + maxItems: 1 > + > + interrupts: > + items: > + - description: Interrupt for fifoevent > + - description: Interrupt for termcount > + > + "#address-cells": > + const: 1 > + > + "#size-cells": > + const: 1 > + > + ti,nand-ecc-opt: > + description: Desired ECC algorithm > + $ref: /schemas/types.yaml#/definitions/string > + enum: [sw, ham1, bch4, bch8, bch16] > + > + ti,nand-xfer-type: > + description: Data transfer method between controller and chip. > + $ref: /schemas/types.yaml#/definitions/string > + enum: [prefetch-polled, polled, prefetch-dma, prefetch-irq] > + default: prefetch-polled > + > + ti,elm-id: > + description: > + phandle to the ELM (Error Location Module). > + $ref: /schemas/types.yaml#/definitions/phandle > + > + nand-bus-width: > + description: > + Bus width to the NAND chip > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [8, 16] > + default: 8 > + > +allOf: > + - $ref: "../memory-controllers/ti,gpmc-child.yaml" Use /schemas/... rather than '..' > + > +required: > + - compatible > + - reg > + - ti,nand-ecc-opt > + > +unevaluatedProperties: false This will throw errors if you have partition nodes. You need to reference the partitions schema. Or minimally restrict to nodes with: unevaluatedProperties: type: object > + > +examples: > + - | > + #include <dt-bindings/interrupt-controller/arm-gic.h> > + #include <dt-bindings/gpio/gpio.h> > + > + gpmc: memory-controller@50000000 { > + compatible = "ti,am3352-gpmc"; > + dmas = <&edma 52 0>; > + dma-names = "rxtx"; > + clocks = <&l3s_gclk>; > + clock-names = "fck"; > + reg = <0x50000000 0x2000>; > + interrupts = <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>; > + gpmc,num-cs = <7>; > + gpmc,num-waitpins = <2>; > + #address-cells = <2>; > + #size-cells = <1>; > + interrupt-controller; > + #interrupt-cells = <2>; > + gpio-controller; > + #gpio-cells = <2>; > + > + ranges = <0 0 0x08000000 0x01000000>; /* CS0 space. Min partition = 16MB */ > + nand@0,0 { > + compatible = "ti,omap2-nand"; > + reg = <0 0 4>; /* device IO registers */ > + 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>; > + #address-cells = <1>; > + #size-cells = <1>; > + > + /* NAND generic properties */ > + nand-bus-width = <8>; > + rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 */ > + > + /* GPMC properties*/ > + gpmc,device-width = <1>; > + }; > + }; > -- > 2.17.1 > >
On 08/09/2021 01:24, Rob Herring wrote: > On Tue, Sep 7, 2021 at 11:57 AM Roger Quadros <rogerq@kernel.org> wrote: >> >> Hi Miquel, >> >> On 07/09/2021 19:35, Miquel Raynal wrote: >>> Hi Grygorii, >>> >>>>> >>>>>> + >>>>>> + nand-bus-width: >>>>>> + description: >>>>>> + Bus width to the NAND chip >>>>>> + $ref: /schemas/types.yaml#/definitions/uint32 >>>>>> + enum: [8, 16] >>>>>> + default: 8 >>>>> >>>>> This is part of nand-controller.yaml binding and should not be there. >>>>> >>>>>> + >>>>>> +allOf: >>>>>> + - $ref: "../memory-controllers/ti,gpmc-child.yaml" >>>>> >>>>> Maybe you need to reference the nand controller bindings as well >>>>> >>>> >>>> This will not work out of the box :( as nand-controller.yaml defines both >>>> nand controller and nand memory. It potentially might work if it will be possible to split >>>> nand memory definition (or nand memory properties) out of and-controller.yaml, similarly to >>>> ti,gpmc-child.yaml from this series. >>> >>> What you think would be the issue? >> >> The issue is that dt_binding checks will fail if I reference nand-controller.yaml >> as we currently represent the controller as follows >> >> memory-controller { /* GPMC controller */ >> memory-controller-props; >> nand-chip { >> /* @chip select 0 */ >> nand-controller-props; >> memory-controller-timing-props; >> chip-props; >> } >> nand-chip { >> /* @chip select 1 */ >> nand-controller-props; >> memory-controller-timing-props; >> chip-props; >> } >> nor-chip { >> /* @chip select 2 */ >> memory-controller-timing-props; >> chip-props; >> } >> } >> >> The NAND controller IO registers are at different addresses for different >> chip select regions. Also, this is one way we can specify GPMC settings/timings >> for different chip selects. >> >>> >>> I am not opposed to split nand-controller.yaml into >>> nand-controller.yaml and nand-chip.yaml if it simplifies the >>> description of controllers but I don't get why it would be needed. In >>> particular since we expect all drivers to support the >>> >>> nand-controller { >>> controller-props; >>> nand-chip { >>> chip-props; >>> } >>> } >> >> Changing to this format will cause a lot of churn in DT files, which I'm not sure >> if it gives enough benefit. >> TI platforms will never have 2 NAND chips in the same chip select region. > > Probably best to just leave this alone. Unless this is getting used in > new chips? If so, I'd say it's a separate change. > >>> organization which has been enforced since at least 2018. Having a >>> controller vs. chip representation is fundamentally right. But here I >>> see how "legacy" are these bindings with so much unneeded specific "ti," >>> properties... On one side it would be good to verify that the driver >>> supports this representation (which I believe is true) and on the other >>> side maybe it's time to advertise "better" bindings as well. >> >> Yes, I'm OK to mark ti specific properties deprecated and use standard NAND chip >> bindings. > > I don't think it's really worth it to go half way using common > properties but not the common structure. I agree. We will be having new chips that will use this driver but we will migrate to new common structure when adding support for those chips. So I will leave this patch as it is for now. cheers, -roger
On Wed, Sep 8, 2021 at 6:14 AM Roger Quadros <rogerq@kernel.org> wrote: > > > > On 07/09/2021 20:01, Rob Herring wrote: > > On Tue, Sep 07, 2021 at 02:32:23PM +0300, Roger Quadros wrote: > >> Convert gpmc-nand.txt to ti,gpmc-nand.yaml. > >> > >> Signed-off-by: Roger Quadros <rogerq@kernel.org> > >> --- > >> .../devicetree/bindings/mtd/gpmc-nand.txt | 147 ------------------ > >> .../devicetree/bindings/mtd/ti,gpmc-nand.yaml | 110 +++++++++++++ > >> 2 files changed, 110 insertions(+), 147 deletions(-) > >> delete mode 100644 Documentation/devicetree/bindings/mtd/gpmc-nand.txt > >> create mode 100644 Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml > >> > >> diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > >> deleted file mode 100644 > >> index 44919d48d241..000000000000 > >> --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > >> +++ /dev/null > >> @@ -1,147 +0,0 @@ > >> -Device tree bindings for GPMC connected NANDs > >> - > >> -GPMC connected NAND (found on OMAP boards) are represented as child nodes of > >> -the GPMC controller with a name of "nand". > >> - > >> -All timing relevant properties as well as generic gpmc child properties are > >> -explained in a separate documents - please refer to > >> -Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt > >> - > >> -For NAND specific properties such as ECC modes or bus width, please refer to > >> -Documentation/devicetree/bindings/mtd/nand-controller.yaml > >> - > >> - > >> -Required properties: > >> - > >> - - compatible: "ti,omap2-nand" > >> - - reg: range id (CS number), base offset and length of the > >> - NAND I/O space > >> - - interrupts: Two interrupt specifiers, one for fifoevent, one for termcount. > >> - > >> -Optional properties: > >> - > >> - - nand-bus-width: Set this numeric value to 16 if the hardware > >> - is wired that way. If not specified, a bus > >> - width of 8 is assumed. > >> - > >> - - ti,nand-ecc-opt: A string setting the ECC layout to use. One of: > >> - "sw" 1-bit Hamming ecc code via software > >> - "hw" <deprecated> use "ham1" instead > >> - "hw-romcode" <deprecated> use "ham1" instead > >> - "ham1" 1-bit Hamming ecc code > >> - "bch4" 4-bit BCH ecc code > >> - "bch8" 8-bit BCH ecc code > >> - "bch16" 16-bit BCH ECC code > >> - Refer below "How to select correct ECC scheme for your device ?" > >> - > >> - - ti,nand-xfer-type: A string setting the data transfer type. One of: > >> - > >> - "prefetch-polled" Prefetch polled mode (default) > >> - "polled" Polled mode, without prefetch > >> - "prefetch-dma" Prefetch enabled DMA mode > >> - "prefetch-irq" Prefetch enabled irq mode > >> - > >> - - elm_id: <deprecated> use "ti,elm-id" instead > >> - - ti,elm-id: Specifies phandle of the ELM devicetree node. > >> - ELM is an on-chip hardware engine on TI SoC which is used for > >> - locating ECC errors for BCHx algorithms. SoC devices which have > >> - ELM hardware engines should specify this device node in .dtsi > >> - Using ELM for ECC error correction frees some CPU cycles. > >> - - rb-gpios: GPIO specifier for the ready/busy# pin. > >> - > >> -For inline partition table parsing (optional): > >> - > >> - - #address-cells: should be set to 1 > >> - - #size-cells: should be set to 1 > >> - > >> -Example for an AM33xx board: > >> - > >> - gpmc: gpmc@50000000 { > >> - compatible = "ti,am3352-gpmc"; > >> - ti,hwmods = "gpmc"; > >> - reg = <0x50000000 0x36c>; > >> - interrupts = <100>; > >> - gpmc,num-cs = <8>; > >> - gpmc,num-waitpins = <2>; > >> - #address-cells = <2>; > >> - #size-cells = <1>; > >> - ranges = <0 0 0x08000000 0x1000000>; /* CS0 space, 16MB */ > >> - elm_id = <&elm>; > >> - interrupt-controller; > >> - #interrupt-cells = <2>; > >> - > >> - nand@0,0 { > >> - compatible = "ti,omap2-nand"; > >> - reg = <0 0 4>; /* CS0, offset 0, NAND I/O window 4 */ > >> - interrupt-parent = <&gpmc>; > >> - interrupts = <0 IRQ_TYPE_NONE>, <1 IRQ_TYPE NONE>; > >> - nand-bus-width = <16>; > >> - ti,nand-ecc-opt = "bch8"; > >> - ti,nand-xfer-type = "polled"; > >> - rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 */ > >> - > >> - gpmc,sync-clk-ps = <0>; > >> - gpmc,cs-on-ns = <0>; > >> - gpmc,cs-rd-off-ns = <44>; > >> - gpmc,cs-wr-off-ns = <44>; > >> - gpmc,adv-on-ns = <6>; > >> - gpmc,adv-rd-off-ns = <34>; > >> - gpmc,adv-wr-off-ns = <44>; > >> - gpmc,we-off-ns = <40>; > >> - gpmc,oe-off-ns = <54>; > >> - gpmc,access-ns = <64>; > >> - gpmc,rd-cycle-ns = <82>; > >> - gpmc,wr-cycle-ns = <82>; > >> - gpmc,wr-access-ns = <40>; > >> - gpmc,wr-data-mux-bus-ns = <0>; > >> - > >> - #address-cells = <1>; > >> - #size-cells = <1>; > >> - > >> - /* partitions go here */ > >> - }; > >> - }; > >> - > >> -How to select correct ECC scheme for your device ? > >> --------------------------------------------------- > >> -Higher ECC scheme usually means better protection against bit-flips and > >> -increased system lifetime. However, selection of ECC scheme is dependent > >> -on various other factors also like; > >> - > >> -(1) support of built in hardware engines. > >> - Some legacy OMAP SoC do not have ELM harware engine, so those SoC cannot > >> - support ecc-schemes with hardware error-correction (BCHx_HW). However > >> - such SoC can use ecc-schemes with software library for error-correction > >> - (BCHx_HW_DETECTION_SW). The error correction capability with software > >> - library remains equivalent to their hardware counter-part, but there is > >> - slight CPU penalty when too many bit-flips are detected during reads. > >> - > >> -(2) Device parameters like OOBSIZE. > >> - Other factor which governs the selection of ecc-scheme is oob-size. > >> - Higher ECC schemes require more OOB/Spare area to store ECC syndrome, > >> - so the device should have enough free bytes available its OOB/Spare > >> - area to accommodate ECC for entire page. In general following expression > >> - helps in determining if given device can accommodate ECC syndrome: > >> - "2 + (PAGESIZE / 512) * ECC_BYTES" >= OOBSIZE" > >> - where > >> - OOBSIZE number of bytes in OOB/spare area > >> - PAGESIZE number of bytes in main-area of device page > >> - ECC_BYTES number of ECC bytes generated to protect > >> - 512 bytes of data, which is: > >> - '3' for HAM1_xx ecc schemes > >> - '7' for BCH4_xx ecc schemes > >> - '14' for BCH8_xx ecc schemes > >> - '26' for BCH16_xx ecc schemes > >> - > >> - Example(a): For a device with PAGESIZE = 2048 and OOBSIZE = 64 and > >> - trying to use BCH16 (ECC_BYTES=26) ecc-scheme. > >> - Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B > >> - which is greater than capacity of NAND device (OOBSIZE=64) > >> - Hence, BCH16 cannot be supported on given device. But it can > >> - probably use lower ecc-schemes like BCH8. > >> - > >> - Example(b): For a device with PAGESIZE = 2048 and OOBSIZE = 128 and > >> - trying to use BCH16 (ECC_BYTES=26) ecc-scheme. > >> - Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B > >> - which can be accommodated in the OOB/Spare area of this device > >> - (OOBSIZE=128). So this device can use BCH16 ecc-scheme. > >> diff --git a/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml b/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml > >> new file mode 100644 > >> index 000000000000..db36f2e944ef > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml > >> @@ -0,0 +1,110 @@ > >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > >> +%YAML 1.2 > >> +--- > >> +$id: http://devicetree.org/schemas/mtd/ti,gpmc-nand.yaml# > >> +$schema: http://devicetree.org/meta-schemas/core.yaml# > >> + > >> +title: Texas Instruments GPMC NAND Flash controller. > >> + > >> +maintainers: > >> + - Tony Lindgren <tony@atomide.com> > >> + - Roger Quadros <rogerq@kernel.org> > >> + > >> +description: > >> + GPMC NAND controller/Flash is represented as a child of the > >> + GPMC controller node. > >> + > >> +properties: > >> + compatible: > >> + const: ti,omap2-nand > >> + > >> + reg: > >> + maxItems: 1 > >> + > >> + interrupts: > >> + items: > >> + - description: Interrupt for fifoevent > >> + - description: Interrupt for termcount > >> + > >> + "#address-cells": > >> + const: 1 > >> + > >> + "#size-cells": > >> + const: 1 > >> + > >> + ti,nand-ecc-opt: > >> + description: Desired ECC algorithm > >> + $ref: /schemas/types.yaml#/definitions/string > >> + enum: [sw, ham1, bch4, bch8, bch16] > >> + > >> + ti,nand-xfer-type: > >> + description: Data transfer method between controller and chip. > >> + $ref: /schemas/types.yaml#/definitions/string > >> + enum: [prefetch-polled, polled, prefetch-dma, prefetch-irq] > >> + default: prefetch-polled > >> + > >> + ti,elm-id: > >> + description: > >> + phandle to the ELM (Error Location Module). > >> + $ref: /schemas/types.yaml#/definitions/phandle > >> + > >> + nand-bus-width: > >> + description: > >> + Bus width to the NAND chip > >> + $ref: /schemas/types.yaml#/definitions/uint32 > >> + enum: [8, 16] > >> + default: 8 > >> + > >> +allOf: > >> + - $ref: "../memory-controllers/ti,gpmc-child.yaml" > > > > Use /schemas/... rather than '..' > > ok. > > > > >> + > >> +required: > >> + - compatible > >> + - reg > >> + - ti,nand-ecc-opt > >> + > >> +unevaluatedProperties: false > > > > This will throw errors if you have partition nodes. You need to > > reference the partitions schema. > > I didn't get any errors with dtbs_check so far. But I will > try referencing the partition schema here. Not yet because 'unevaluatedProperties' isn't actually supported in the jsonschema package yet. It will be in the next release which I expect soonish. Rob
diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt deleted file mode 100644 index 44919d48d241..000000000000 --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt +++ /dev/null @@ -1,147 +0,0 @@ -Device tree bindings for GPMC connected NANDs - -GPMC connected NAND (found on OMAP boards) are represented as child nodes of -the GPMC controller with a name of "nand". - -All timing relevant properties as well as generic gpmc child properties are -explained in a separate documents - please refer to -Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt - -For NAND specific properties such as ECC modes or bus width, please refer to -Documentation/devicetree/bindings/mtd/nand-controller.yaml - - -Required properties: - - - compatible: "ti,omap2-nand" - - reg: range id (CS number), base offset and length of the - NAND I/O space - - interrupts: Two interrupt specifiers, one for fifoevent, one for termcount. - -Optional properties: - - - nand-bus-width: Set this numeric value to 16 if the hardware - is wired that way. If not specified, a bus - width of 8 is assumed. - - - ti,nand-ecc-opt: A string setting the ECC layout to use. One of: - "sw" 1-bit Hamming ecc code via software - "hw" <deprecated> use "ham1" instead - "hw-romcode" <deprecated> use "ham1" instead - "ham1" 1-bit Hamming ecc code - "bch4" 4-bit BCH ecc code - "bch8" 8-bit BCH ecc code - "bch16" 16-bit BCH ECC code - Refer below "How to select correct ECC scheme for your device ?" - - - ti,nand-xfer-type: A string setting the data transfer type. One of: - - "prefetch-polled" Prefetch polled mode (default) - "polled" Polled mode, without prefetch - "prefetch-dma" Prefetch enabled DMA mode - "prefetch-irq" Prefetch enabled irq mode - - - elm_id: <deprecated> use "ti,elm-id" instead - - ti,elm-id: Specifies phandle of the ELM devicetree node. - ELM is an on-chip hardware engine on TI SoC which is used for - locating ECC errors for BCHx algorithms. SoC devices which have - ELM hardware engines should specify this device node in .dtsi - Using ELM for ECC error correction frees some CPU cycles. - - rb-gpios: GPIO specifier for the ready/busy# pin. - -For inline partition table parsing (optional): - - - #address-cells: should be set to 1 - - #size-cells: should be set to 1 - -Example for an AM33xx board: - - gpmc: gpmc@50000000 { - compatible = "ti,am3352-gpmc"; - ti,hwmods = "gpmc"; - reg = <0x50000000 0x36c>; - interrupts = <100>; - gpmc,num-cs = <8>; - gpmc,num-waitpins = <2>; - #address-cells = <2>; - #size-cells = <1>; - ranges = <0 0 0x08000000 0x1000000>; /* CS0 space, 16MB */ - elm_id = <&elm>; - interrupt-controller; - #interrupt-cells = <2>; - - nand@0,0 { - compatible = "ti,omap2-nand"; - reg = <0 0 4>; /* CS0, offset 0, NAND I/O window 4 */ - interrupt-parent = <&gpmc>; - interrupts = <0 IRQ_TYPE_NONE>, <1 IRQ_TYPE NONE>; - nand-bus-width = <16>; - ti,nand-ecc-opt = "bch8"; - ti,nand-xfer-type = "polled"; - rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 */ - - gpmc,sync-clk-ps = <0>; - gpmc,cs-on-ns = <0>; - gpmc,cs-rd-off-ns = <44>; - gpmc,cs-wr-off-ns = <44>; - gpmc,adv-on-ns = <6>; - gpmc,adv-rd-off-ns = <34>; - gpmc,adv-wr-off-ns = <44>; - gpmc,we-off-ns = <40>; - gpmc,oe-off-ns = <54>; - gpmc,access-ns = <64>; - gpmc,rd-cycle-ns = <82>; - gpmc,wr-cycle-ns = <82>; - gpmc,wr-access-ns = <40>; - gpmc,wr-data-mux-bus-ns = <0>; - - #address-cells = <1>; - #size-cells = <1>; - - /* partitions go here */ - }; - }; - -How to select correct ECC scheme for your device ? --------------------------------------------------- -Higher ECC scheme usually means better protection against bit-flips and -increased system lifetime. However, selection of ECC scheme is dependent -on various other factors also like; - -(1) support of built in hardware engines. - Some legacy OMAP SoC do not have ELM harware engine, so those SoC cannot - support ecc-schemes with hardware error-correction (BCHx_HW). However - such SoC can use ecc-schemes with software library for error-correction - (BCHx_HW_DETECTION_SW). The error correction capability with software - library remains equivalent to their hardware counter-part, but there is - slight CPU penalty when too many bit-flips are detected during reads. - -(2) Device parameters like OOBSIZE. - Other factor which governs the selection of ecc-scheme is oob-size. - Higher ECC schemes require more OOB/Spare area to store ECC syndrome, - so the device should have enough free bytes available its OOB/Spare - area to accommodate ECC for entire page. In general following expression - helps in determining if given device can accommodate ECC syndrome: - "2 + (PAGESIZE / 512) * ECC_BYTES" >= OOBSIZE" - where - OOBSIZE number of bytes in OOB/spare area - PAGESIZE number of bytes in main-area of device page - ECC_BYTES number of ECC bytes generated to protect - 512 bytes of data, which is: - '3' for HAM1_xx ecc schemes - '7' for BCH4_xx ecc schemes - '14' for BCH8_xx ecc schemes - '26' for BCH16_xx ecc schemes - - Example(a): For a device with PAGESIZE = 2048 and OOBSIZE = 64 and - trying to use BCH16 (ECC_BYTES=26) ecc-scheme. - Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B - which is greater than capacity of NAND device (OOBSIZE=64) - Hence, BCH16 cannot be supported on given device. But it can - probably use lower ecc-schemes like BCH8. - - Example(b): For a device with PAGESIZE = 2048 and OOBSIZE = 128 and - trying to use BCH16 (ECC_BYTES=26) ecc-scheme. - Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B - which can be accommodated in the OOB/Spare area of this device - (OOBSIZE=128). So this device can use BCH16 ecc-scheme. diff --git a/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml b/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml new file mode 100644 index 000000000000..db36f2e944ef --- /dev/null +++ b/Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml @@ -0,0 +1,110 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/mtd/ti,gpmc-nand.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Texas Instruments GPMC NAND Flash controller. + +maintainers: + - Tony Lindgren <tony@atomide.com> + - Roger Quadros <rogerq@kernel.org> + +description: + GPMC NAND controller/Flash is represented as a child of the + GPMC controller node. + +properties: + compatible: + const: ti,omap2-nand + + reg: + maxItems: 1 + + interrupts: + items: + - description: Interrupt for fifoevent + - description: Interrupt for termcount + + "#address-cells": + const: 1 + + "#size-cells": + const: 1 + + ti,nand-ecc-opt: + description: Desired ECC algorithm + $ref: /schemas/types.yaml#/definitions/string + enum: [sw, ham1, bch4, bch8, bch16] + + ti,nand-xfer-type: + description: Data transfer method between controller and chip. + $ref: /schemas/types.yaml#/definitions/string + enum: [prefetch-polled, polled, prefetch-dma, prefetch-irq] + default: prefetch-polled + + ti,elm-id: + description: + phandle to the ELM (Error Location Module). + $ref: /schemas/types.yaml#/definitions/phandle + + nand-bus-width: + description: + Bus width to the NAND chip + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [8, 16] + default: 8 + +allOf: + - $ref: "../memory-controllers/ti,gpmc-child.yaml" + +required: + - compatible + - reg + - ti,nand-ecc-opt + +unevaluatedProperties: false + +examples: + - | + #include <dt-bindings/interrupt-controller/arm-gic.h> + #include <dt-bindings/gpio/gpio.h> + + gpmc: memory-controller@50000000 { + compatible = "ti,am3352-gpmc"; + dmas = <&edma 52 0>; + dma-names = "rxtx"; + clocks = <&l3s_gclk>; + clock-names = "fck"; + reg = <0x50000000 0x2000>; + interrupts = <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>; + gpmc,num-cs = <7>; + gpmc,num-waitpins = <2>; + #address-cells = <2>; + #size-cells = <1>; + interrupt-controller; + #interrupt-cells = <2>; + gpio-controller; + #gpio-cells = <2>; + + ranges = <0 0 0x08000000 0x01000000>; /* CS0 space. Min partition = 16MB */ + nand@0,0 { + compatible = "ti,omap2-nand"; + reg = <0 0 4>; /* device IO registers */ + 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>; + #address-cells = <1>; + #size-cells = <1>; + + /* NAND generic properties */ + nand-bus-width = <8>; + rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 */ + + /* GPMC properties*/ + gpmc,device-width = <1>; + }; + };
Convert gpmc-nand.txt to ti,gpmc-nand.yaml. Signed-off-by: Roger Quadros <rogerq@kernel.org> --- .../devicetree/bindings/mtd/gpmc-nand.txt | 147 ------------------ .../devicetree/bindings/mtd/ti,gpmc-nand.yaml | 110 +++++++++++++ 2 files changed, 110 insertions(+), 147 deletions(-) delete mode 100644 Documentation/devicetree/bindings/mtd/gpmc-nand.txt create mode 100644 Documentation/devicetree/bindings/mtd/ti,gpmc-nand.yaml