* [v5 2/2] dt-bindings: mtd: Add Cadence NAND controller driver
[not found] <20190725145804.8886-1-piotrs@cadence.com>
@ 2019-07-25 14:59 ` Piotr Sroka
2019-08-16 21:31 ` Rob Herring
2019-08-30 9:46 ` Miquel Raynal
0 siblings, 2 replies; 6+ messages in thread
From: Piotr Sroka @ 2019-07-25 14:59 UTC (permalink / raw)
To: linux-kernel
Cc: David Woodhouse, BrianNorris, Boris Brezillon, Marek Vasut,
Richard Weinberger, Rob Herring, Mark Rutland, linux-mtd,
devicetree, Kazuhiro Kasai, Piotr Sroka
Document the bindings used by Cadence NAND controller driver
Signed-off-by: Piotr Sroka <piotrs@cadence.com>
---
Changes for v5:
- replace "_" by "-" in all properties
- change compatible name from cdns,hpnfc to cdns,hp-nfc
Changes for v4:
- add commit message
Changes for v3:
- add unit suffix for board_delay
- move child description to proper place
- remove prefix cadence_ for reg and sdma fields
Changes for v2:
- remove chip dependends parameters from dts bindings
- add names for register ranges in dts bindings
- add generic bindings to describe NAND chip representation
---
.../bindings/mtd/cadence-nand-controller.txt | 50 ++++++++++++++++++++++
1 file changed, 50 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
diff --git a/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
new file mode 100644
index 000000000000..423547a3f993
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
@@ -0,0 +1,50 @@
+* Cadence NAND controller
+
+Required properties:
+ - compatible : "cdns,hp-nfc"
+ - reg : Contains two entries, each of which is a tuple consisting of a
+ physical address and length. The first entry is the address and
+ length of the controller register set. The second entry is the
+ address and length of the Slave DMA data port.
+ - reg-names: should contain "reg" and "sdma"
+ - interrupts : The interrupt number.
+ - clocks: phandle of the controller core clock (nf_clk).
+
+Optional properties:
+ - dmas: shall reference DMA channel associated to the NAND controller
+ - cdns,board-delay-ps : Estimated Board delay. The value includes the total
+ round trip delay for the signals and is used for deciding on values
+ associated with data read capture. The example formula for SDR mode is
+ the following:
+ board delay = RE#PAD delay + PCB trace to device + PCB trace from device
+ + DQ PAD delay
+
+Child nodes represent the available NAND chips.
+
+Required properties of NAND chips:
+ - reg: shall contain the native Chip Select ids from 0 to max supported by
+ the cadence nand flash controller
+
+
+See Documentation/devicetree/bindings/mtd/nand.txt for more details on
+generic bindings.
+
+Example:
+
+nand_controller: nand-controller @60000000 {
+ compatible = "cdns,hp-nfc";
+ reg = <0x60000000 0x10000>, <0x80000000 0x10000>;
+ reg-names = "reg", "sdma";
+ clocks = <&nf_clk>;
+ cdns,board-delay-ps = <4830>;
+ interrupts = <2 0>;
+ nand@0 {
+ reg = <0>;
+ label = "nand-1";
+ };
+ nand@1 {
+ reg = <1>;
+ label = "nand-2";
+ };
+
+};
--
2.15.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [v5 2/2] dt-bindings: mtd: Add Cadence NAND controller driver
2019-07-25 14:59 ` [v5 2/2] dt-bindings: mtd: Add Cadence NAND controller driver Piotr Sroka
@ 2019-08-16 21:31 ` Rob Herring
2019-08-30 9:46 ` Miquel Raynal
1 sibling, 0 replies; 6+ messages in thread
From: Rob Herring @ 2019-08-16 21:31 UTC (permalink / raw)
To: Piotr Sroka
Cc: linux-kernel, David Woodhouse, BrianNorris, Boris Brezillon,
Marek Vasut, Richard Weinberger, Mark Rutland, linux-mtd,
devicetree, Kazuhiro Kasai
On Thu, Jul 25, 2019 at 03:59:55PM +0100, Piotr Sroka wrote:
> Document the bindings used by Cadence NAND controller driver
>
> Signed-off-by: Piotr Sroka <piotrs@cadence.com>
> ---
> Changes for v5:
> - replace "_" by "-" in all properties
> - change compatible name from cdns,hpnfc to cdns,hp-nfc
> Changes for v4:
> - add commit message
> Changes for v3:
> - add unit suffix for board_delay
> - move child description to proper place
> - remove prefix cadence_ for reg and sdma fields
> Changes for v2:
> - remove chip dependends parameters from dts bindings
> - add names for register ranges in dts bindings
> - add generic bindings to describe NAND chip representation
> ---
> .../bindings/mtd/cadence-nand-controller.txt | 50 ++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
>
> diff --git a/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
> new file mode 100644
> index 000000000000..423547a3f993
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
> @@ -0,0 +1,50 @@
> +* Cadence NAND controller
> +
> +Required properties:
> + - compatible : "cdns,hp-nfc"
> + - reg : Contains two entries, each of which is a tuple consisting of a
> + physical address and length. The first entry is the address and
> + length of the controller register set. The second entry is the
> + address and length of the Slave DMA data port.
> + - reg-names: should contain "reg" and "sdma"
> + - interrupts : The interrupt number.
> + - clocks: phandle of the controller core clock (nf_clk).
> +
> +Optional properties:
> + - dmas: shall reference DMA channel associated to the NAND controller
> + - cdns,board-delay-ps : Estimated Board delay. The value includes the total
> + round trip delay for the signals and is used for deciding on values
> + associated with data read capture. The example formula for SDR mode is
> + the following:
> + board delay = RE#PAD delay + PCB trace to device + PCB trace from device
> + + DQ PAD delay
> +
> +Child nodes represent the available NAND chips.
> +
> +Required properties of NAND chips:
> + - reg: shall contain the native Chip Select ids from 0 to max supported by
> + the cadence nand flash controller
> +
> +
> +See Documentation/devicetree/bindings/mtd/nand.txt for more details on
> +generic bindings.
> +
> +Example:
> +
> +nand_controller: nand-controller @60000000 {
space ^
> + compatible = "cdns,hp-nfc";
> + reg = <0x60000000 0x10000>, <0x80000000 0x10000>;
> + reg-names = "reg", "sdma";
> + clocks = <&nf_clk>;
> + cdns,board-delay-ps = <4830>;
> + interrupts = <2 0>;
You need #address-cells and #size-cells here.
With those fixes,
Reviewed-by: Rob Herring <robh@kernel.org>
> + nand@0 {
> + reg = <0>;
> + label = "nand-1";
> + };
> + nand@1 {
> + reg = <1>;
> + label = "nand-2";
> + };
> +
> +};
> --
> 2.15.0
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [v5 2/2] dt-bindings: mtd: Add Cadence NAND controller driver
2019-07-25 14:59 ` [v5 2/2] dt-bindings: mtd: Add Cadence NAND controller driver Piotr Sroka
2019-08-16 21:31 ` Rob Herring
@ 2019-08-30 9:46 ` Miquel Raynal
2019-09-11 15:04 ` Piotr Sroka
1 sibling, 1 reply; 6+ messages in thread
From: Miquel Raynal @ 2019-08-30 9:46 UTC (permalink / raw)
To: Piotr Sroka
Cc: linux-kernel, Mark Rutland, devicetree, Boris Brezillon,
Richard Weinberger, Marek Vasut, Rob Herring, linux-mtd,
BrianNorris, David Woodhouse, Kazuhiro Kasai
Hi Piotr,
Piotr Sroka <piotrs@cadence.com> wrote on Thu, 25 Jul 2019 15:59:55
+0100:
> Document the bindings used by Cadence NAND controller driver
>
> Signed-off-by: Piotr Sroka <piotrs@cadence.com>
> ---
> Changes for v5:
> - replace "_" by "-" in all properties
> - change compatible name from cdns,hpnfc to cdns,hp-nfc
> Changes for v4:
> - add commit message
> Changes for v3:
> - add unit suffix for board_delay
> - move child description to proper place
> - remove prefix cadence_ for reg and sdma fields
> Changes for v2:
> - remove chip dependends parameters from dts bindings
> - add names for register ranges in dts bindings
> - add generic bindings to describe NAND chip representation
> ---
> .../bindings/mtd/cadence-nand-controller.txt | 50 ++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
>
> diff --git a/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
> new file mode 100644
> index 000000000000..423547a3f993
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
> @@ -0,0 +1,50 @@
> +* Cadence NAND controller
> +
> +Required properties:
> + - compatible : "cdns,hp-nfc"
> + - reg : Contains two entries, each of which is a tuple consisting of a
> + physical address and length. The first entry is the address and
> + length of the controller register set. The second entry is the
> + address and length of the Slave DMA data port.
> + - reg-names: should contain "reg" and "sdma"
> + - interrupts : The interrupt number.
> + - clocks: phandle of the controller core clock (nf_clk).
> +
> +Optional properties:
> + - dmas: shall reference DMA channel associated to the NAND controller
> + - cdns,board-delay-ps : Estimated Board delay. The value includes the total
> + round trip delay for the signals and is used for deciding on values
> + associated with data read capture. The example formula for SDR mode is
> + the following:
> + board delay = RE#PAD delay + PCB trace to device + PCB trace from device
> + + DQ PAD delay
> +
> +Child nodes represent the available NAND chips.
> +
> +Required properties of NAND chips:
> + - reg: shall contain the native Chip Select ids from 0 to max supported by
> + the cadence nand flash controller
> +
> +
> +See Documentation/devicetree/bindings/mtd/nand.txt for more details on
> +generic bindings.
> +
> +Example:
> +
> +nand_controller: nand-controller @60000000 {
> + compatible = "cdns,hp-nfc";
> + reg = <0x60000000 0x10000>, <0x80000000 0x10000>;
> + reg-names = "reg", "sdma";
> + clocks = <&nf_clk>;
> + cdns,board-delay-ps = <4830>;
Are you sure you want to export this to the user? Not sure it is easily
understandable and tunable... I'm not against but I would have troubles
tuning it myself, unless using the documented value. Maybe you should
explain more how to derive it?
The rest looks fine, let's see if Rob agrees. Maybe he will request a
yaml schema; in this case you can check sunxi NAND bindings which
already have been converted.
> + interrupts = <2 0>;
> + nand@0 {
> + reg = <0>;
> + label = "nand-1";
> + };
> + nand@1 {
> + reg = <1>;
> + label = "nand-2";
> + };
> +
> +};
Thanks,
Miquèl
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [v5 2/2] dt-bindings: mtd: Add Cadence NAND controller driver
2019-08-30 9:46 ` Miquel Raynal
@ 2019-09-11 15:04 ` Piotr Sroka
2019-09-13 12:49 ` Miquel Raynal
0 siblings, 1 reply; 6+ messages in thread
From: Piotr Sroka @ 2019-09-11 15:04 UTC (permalink / raw)
To: Miquel Raynal
Cc: linux-kernel, Mark Rutland, devicetree, Boris Brezillon,
Richard Weinberger, Marek Vasut, Rob Herring, linux-mtd,
BrianNorris, David Woodhouse, Kazuhiro Kasai
Hi Miquel
The 08/30/2019 11:46, Miquel Raynal wrote:
>EXTERNAL MAIL
>
>
>Hi Piotr,
>
>Piotr Sroka <piotrs@cadence.com> wrote on Thu, 25 Jul 2019 15:59:55
>+0100:
>
>> Document the bindings used by Cadence NAND controller driver
>>
>> Signed-off-by: Piotr Sroka <piotrs@cadence.com>
>> ---
>> Changes for v5:
>> - replace "_" by "-" in all properties
>> - change compatible name from cdns,hpnfc to cdns,hp-nfc
>> Changes for v4:
>> - add commit message
>> Changes for v3:
>> - add unit suffix for board_delay
>> - move child description to proper place
>> - remove prefix cadence_ for reg and sdma fields
>> Changes for v2:
>> - remove chip dependends parameters from dts bindings
>> - add names for register ranges in dts bindings
>> - add generic bindings to describe NAND chip representation
>> ---
>> .../bindings/mtd/cadence-nand-controller.txt | 50 ++++++++++++++++++++++
>> 1 file changed, 50 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
>>
>> diff --git a/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
>> new file mode 100644
>> index 000000000000..423547a3f993
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
>> @@ -0,0 +1,50 @@
>> +* Cadence NAND controller
>> +
>> +Required properties:
>> + - compatible : "cdns,hp-nfc"
>> + - reg : Contains two entries, each of which is a tuple consisting of a
>> + physical address and length. The first entry is the address and
>> + length of the controller register set. The second entry is the
>> + address and length of the Slave DMA data port.
>> + - reg-names: should contain "reg" and "sdma"
>> + - interrupts : The interrupt number.
>> + - clocks: phandle of the controller core clock (nf_clk).
>> +
>> +Optional properties:
>> + - dmas: shall reference DMA channel associated to the NAND controller
>> + - cdns,board-delay-ps : Estimated Board delay. The value includes the total
>> + round trip delay for the signals and is used for deciding on values
>> + associated with data read capture. The example formula for SDR mode is
>> + the following:
>> + board delay = RE#PAD delay + PCB trace to device + PCB trace from device
>> + + DQ PAD delay
>> +
>> +Child nodes represent the available NAND chips.
>> +
>> +Required properties of NAND chips:
>> + - reg: shall contain the native Chip Select ids from 0 to max supported by
>> + the cadence nand flash controller
>> +
>> +
>> +See Documentation/devicetree/bindings/mtd/nand.txt for more details on
>> +generic bindings.
>> +
>> +Example:
>> +
>> +nand_controller: nand-controller @60000000 {
>> + compatible = "cdns,hp-nfc";
>> + reg = <0x60000000 0x10000>, <0x80000000 0x10000>;
>> + reg-names = "reg", "sdma";
>> + clocks = <&nf_clk>;
>> + cdns,board-delay-ps = <4830>;
>
>Are you sure you want to export this to the user? Not sure it is easily
>understandable and tunable... I'm not against but I would have troubles
>tuning it myself, unless using the documented value. Maybe you should
>explain more how to derive it?
I need to export this parameter somehow. The default value may not be
valid for other platforms.
This value depends on platform, and may be different on different SoCs.
So I think the DTS is the best place to put such configuration
parameter.
>
>The rest looks fine, let's see if Rob agrees. Maybe he will request a
>yaml schema; in this case you can check sunxi NAND bindings which
>already have been converted.
>
>> + interrupts = <2 0>;
>> + nand@0 {
>> + reg = <0>;
>> + label = "nand-1";
>> + };
>> + nand@1 {
>> + reg = <1>;
>> + label = "nand-2";
>> + };
>> +
>> +};
>
>Thanks,
>Miquèl
Thanks
Piotr
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [v5 2/2] dt-bindings: mtd: Add Cadence NAND controller driver
2019-09-11 15:04 ` Piotr Sroka
@ 2019-09-13 12:49 ` Miquel Raynal
2019-09-13 14:41 ` Piotr Sroka
0 siblings, 1 reply; 6+ messages in thread
From: Miquel Raynal @ 2019-09-13 12:49 UTC (permalink / raw)
To: Piotr Sroka
Cc: linux-kernel, Mark Rutland, devicetree, Boris Brezillon,
Richard Weinberger, Marek Vasut, Rob Herring, linux-mtd,
BrianNorris, David Woodhouse, Kazuhiro Kasai
Hi Piotr,
Piotr Sroka <piotrs@cadence.com> wrote on Wed, 11 Sep 2019 16:04:24
+0100:
> Hi Miquel
>
> The 08/30/2019 11:46, Miquel Raynal wrote:
> >EXTERNAL MAIL
> >
> >
> >Hi Piotr,
> >
> >Piotr Sroka <piotrs@cadence.com> wrote on Thu, 25 Jul 2019 15:59:55
> >+0100:
> >
> >> Document the bindings used by Cadence NAND controller driver
> >>
> >> Signed-off-by: Piotr Sroka <piotrs@cadence.com>
> >> ---
> >> Changes for v5:
> >> - replace "_" by "-" in all properties
> >> - change compatible name from cdns,hpnfc to cdns,hp-nfc
> >> Changes for v4:
> >> - add commit message
> >> Changes for v3:
> >> - add unit suffix for board_delay
> >> - move child description to proper place
> >> - remove prefix cadence_ for reg and sdma fields
> >> Changes for v2:
> >> - remove chip dependends parameters from dts bindings
> >> - add names for register ranges in dts bindings
> >> - add generic bindings to describe NAND chip representation
> >> ---
> >> .../bindings/mtd/cadence-nand-controller.txt | 50 ++++++++++++++++++++++
> >> 1 file changed, 50 insertions(+)
> >> create mode 100644 Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
> >>
> >> diff --git a/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
> >> new file mode 100644
> >> index 000000000000..423547a3f993
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
> >> @@ -0,0 +1,50 @@
> >> +* Cadence NAND controller
> >> +
> >> +Required properties:
> >> + - compatible : "cdns,hp-nfc"
> >> + - reg : Contains two entries, each of which is a tuple consisting of a
> >> + physical address and length. The first entry is the address and
> >> + length of the controller register set. The second entry is the
> >> + address and length of the Slave DMA data port.
> >> + - reg-names: should contain "reg" and "sdma"
> >> + - interrupts : The interrupt number.
> >> + - clocks: phandle of the controller core clock (nf_clk).
> >> +
> >> +Optional properties:
> >> + - dmas: shall reference DMA channel associated to the NAND controller
> >> + - cdns,board-delay-ps : Estimated Board delay. The value includes the total
> >> + round trip delay for the signals and is used for deciding on values
> >> + associated with data read capture. The example formula for SDR mode is
> >> + the following:
> >> + board delay = RE#PAD delay + PCB trace to device + PCB trace from device
> >> + + DQ PAD delay
> >> +
> >> +Child nodes represent the available NAND chips.
> >> +
> >> +Required properties of NAND chips:
> >> + - reg: shall contain the native Chip Select ids from 0 to max supported by
> >> + the cadence nand flash controller
> >> +
> >> +
> >> +See Documentation/devicetree/bindings/mtd/nand.txt for more details on
> >> +generic bindings.
> >> +
> >> +Example:
> >> +
> >> +nand_controller: nand-controller @60000000 {
> >> + compatible = "cdns,hp-nfc";
> >> + reg = <0x60000000 0x10000>, <0x80000000 0x10000>;
> >> + reg-names = "reg", "sdma";
> >> + clocks = <&nf_clk>;
> >> + cdns,board-delay-ps = <4830>;
> >
> >Are you sure you want to export this to the user? Not sure it is easily
> >understandable and tunable... I'm not against but I would have troubles
> >tuning it myself, unless using the documented value. Maybe you should
> >explain more how to derive it?
> I need to export this parameter somehow. The default value may not be
> valid for other platforms. This value depends on platform, and may be different on different SoCs. So I think the DTS is the best place to put such configuration
> parameter.
What about a different compatible if it depends on the SoC?
This way you can retrieve a different driver data structure and avoid
the pain for the user.
Thanks,
Miquèl
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [v5 2/2] dt-bindings: mtd: Add Cadence NAND controller driver
2019-09-13 12:49 ` Miquel Raynal
@ 2019-09-13 14:41 ` Piotr Sroka
0 siblings, 0 replies; 6+ messages in thread
From: Piotr Sroka @ 2019-09-13 14:41 UTC (permalink / raw)
To: Miquel Raynal
Cc: linux-kernel, Mark Rutland, devicetree, Boris Brezillon,
Richard Weinberger, Marek Vasut, Rob Herring, linux-mtd,
BrianNorris, David Woodhouse, Kazuhiro Kasai
The 09/13/2019 14:49, Miquel Raynal wrote:
>EXTERNAL MAIL
>
>
>Hi Piotr,
>
>Piotr Sroka <piotrs@cadence.com> wrote on Wed, 11 Sep 2019 16:04:24
>+0100:
>
>> Hi Miquel
>>
>> The 08/30/2019 11:46, Miquel Raynal wrote:
>> >EXTERNAL MAIL
>> >
>> >
>> >Hi Piotr,
>> >
>> >Piotr Sroka <piotrs@cadence.com> wrote on Thu, 25 Jul 2019 15:59:55
>> >+0100:
>> >
>> >> Document the bindings used by Cadence NAND controller driver
>> >>
>> >> Signed-off-by: Piotr Sroka <piotrs@cadence.com>
>> >> ---
>> >> Changes for v5:
>> >> - replace "_" by "-" in all properties
>> >> - change compatible name from cdns,hpnfc to cdns,hp-nfc
>> >> Changes for v4:
>> >> - add commit message
>> >> Changes for v3:
>> >> - add unit suffix for board_delay
>> >> - move child description to proper place
>> >> - remove prefix cadence_ for reg and sdma fields
>> >> Changes for v2:
>> >> - remove chip dependends parameters from dts bindings
>> >> - add names for register ranges in dts bindings
>> >> - add generic bindings to describe NAND chip representation
>> >> ---
>> >> .../bindings/mtd/cadence-nand-controller.txt | 50 ++++++++++++++++++++++
>> >> 1 file changed, 50 insertions(+)
>> >> create mode 100644 Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
>> >>
>> >> diff --git a/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
>> >> new file mode 100644
>> >> index 000000000000..423547a3f993
>> >> --- /dev/null
>> >> +++ b/Documentation/devicetree/bindings/mtd/cadence-nand-controller.txt
>> >> @@ -0,0 +1,50 @@
>> >> +* Cadence NAND controller
>> >> +
>> >> +Required properties:
>> >> + - compatible : "cdns,hp-nfc"
>> >> + - reg : Contains two entries, each of which is a tuple consisting of a
>> >> + physical address and length. The first entry is the address and
>> >> + length of the controller register set. The second entry is the
>> >> + address and length of the Slave DMA data port.
>> >> + - reg-names: should contain "reg" and "sdma"
>> >> + - interrupts : The interrupt number.
>> >> + - clocks: phandle of the controller core clock (nf_clk).
>> >> +
>> >> +Optional properties:
>> >> + - dmas: shall reference DMA channel associated to the NAND controller
>> >> + - cdns,board-delay-ps : Estimated Board delay. The value includes the total
>> >> + round trip delay for the signals and is used for deciding on values
>> >> + associated with data read capture. The example formula for SDR mode is
>> >> + the following:
>> >> + board delay = RE#PAD delay + PCB trace to device + PCB trace from device
>> >> + + DQ PAD delay
>> >> +
>> >> +Child nodes represent the available NAND chips.
>> >> +
>> >> +Required properties of NAND chips:
>> >> + - reg: shall contain the native Chip Select ids from 0 to max supported by
>> >> + the cadence nand flash controller
>> >> +
>> >> +
>> >> +See Documentation/devicetree/bindings/mtd/nand.txt for more details on
>> >> +generic bindings.
>> >> +
>> >> +Example:
>> >> +
>> >> +nand_controller: nand-controller @60000000 {
>> >> + compatible = "cdns,hp-nfc";
>> >> + reg = <0x60000000 0x10000>, <0x80000000 0x10000>;
>> >> + reg-names = "reg", "sdma";
>> >> + clocks = <&nf_clk>;
>> >> + cdns,board-delay-ps = <4830>;
>> >
>> >Are you sure you want to export this to the user? Not sure it is easily
>> >understandable and tunable... I'm not against but I would have troubles
>> >tuning it myself, unless using the documented value. Maybe you should
>> >explain more how to derive it?
>> I need to export this parameter somehow. The default value may not be
>> valid for other platforms. This value depends on platform, and may be different on different SoCs. So I think the DTS is the best place to put such configuration
>> parameter.
>
>What about a different compatible if it depends on the SoC?
I considered it but this dealy consists of PADs delay and PCB trace
delay. PAD delays are SoC dependent. Unfortunatelly PCB delay not.
What can I do I can split it on two delays, PAD_delay and trace_delay.
Then handle PAD_delay by compatible and trace_delay by dts. But I am not
sure whether it changes anythig. Still a delay need to passed by dts.
>
>This way you can retrieve a different driver data structure and avoid
>the pain for the user.
>
>Thanks,
>Miquèl
Thanks
Piotr
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-09-13 14:41 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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[not found] <20190725145804.8886-1-piotrs@cadence.com>
2019-07-25 14:59 ` [v5 2/2] dt-bindings: mtd: Add Cadence NAND controller driver Piotr Sroka
2019-08-16 21:31 ` Rob Herring
2019-08-30 9:46 ` Miquel Raynal
2019-09-11 15:04 ` Piotr Sroka
2019-09-13 12:49 ` Miquel Raynal
2019-09-13 14:41 ` Piotr Sroka
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