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* [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
       [not found] <1444148837-10770-1-git-send-email-harvey.hunt@imgtec.com>
@ 2015-10-06 16:27 ` Harvey Hunt
  2015-10-06 16:27   ` Harvey Hunt
                     ` (2 more replies)
  0 siblings, 3 replies; 14+ messages in thread
From: Harvey Hunt @ 2015-10-06 16:27 UTC (permalink / raw)
  To: linux-mtd
  Cc: Alex Smith, Zubair Lutfullah Kakakhel, David Woodhouse,
	Brian Norris, Paul Burton, devicetree, linux-kernel, linux-mips,
	Alex Smith, Harvey Hunt

From: Alex Smith <alex.smith@imgtec.com>

Add device tree nodes for the NEMC and BCH to the JZ4780 device tree,
and make use of them in the Ci20 device tree to add a node for the
board's NAND.

Note that since the pinctrl driver is not yet upstream, this includes
neither pin configuration nor busy/write-protect GPIO pins for the
NAND. Use of the NAND relies on the boot loader to have left the pins
configured in a usable state, which should be the case when booted
from the NAND.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mtd@lists.infradead.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Alex Smith <alex@alex-smith.me.uk>
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
---
v6 -> v7:
 - Add nand-ecc-mode to DT.
 - Add nand-on-flash-bbt to DT.

v4 -> v5:
 - New patch adding DT nodes for the NAND so that the driver can be
   tested.

 arch/mips/boot/dts/ingenic/ci20.dts    | 54 ++++++++++++++++++++++++++++++++++
 arch/mips/boot/dts/ingenic/jz4780.dtsi | 26 ++++++++++++++++
 2 files changed, 80 insertions(+)

diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
index 9fcb9e7..453f1d3 100644
--- a/arch/mips/boot/dts/ingenic/ci20.dts
+++ b/arch/mips/boot/dts/ingenic/ci20.dts
@@ -42,3 +42,57 @@
 &uart4 {
 	status = "okay";
 };
+
+&nemc {
+	status = "okay";
+
+	nand: nand@1 {
+		compatible = "ingenic,jz4780-nand";
+		reg = <1 0 0x1000000>;
+
+		ingenic,nemc-tAS = <10>;
+		ingenic,nemc-tAH = <5>;
+		ingenic,nemc-tBP = <10>;
+		ingenic,nemc-tAW = <15>;
+		ingenic,nemc-tSTRV = <100>;
+
+		ingenic,bch-controller = <&bch>;
+		ingenic,ecc-size = <1024>;
+		ingenic,ecc-strength = <24>;
+
+		nand-ecc-mode = "hw";
+		nand-on-flash-bbt;
+
+		#address-cells = <2>;
+		#size-cells = <2>;
+
+		partition@0 {
+			label = "u-boot-spl";
+			reg = <0x0 0x0 0x0 0x800000>;
+		};
+
+		partition@0x800000 {
+			label = "u-boot";
+			reg = <0x0 0x800000 0x0 0x200000>;
+		};
+
+		partition@0xa00000 {
+			label = "u-boot-env";
+			reg = <0x0 0xa00000 0x0 0x200000>;
+		};
+
+		partition@0xc00000 {
+			label = "boot";
+			reg = <0x0 0xc00000 0x0 0x4000000>;
+		};
+
+		partition@0x8c00000 {
+			label = "system";
+			reg = <0x0 0x4c00000 0x1 0xfb400000>;
+		};
+	};
+};
+
+&bch {
+	status = "okay";
+};
diff --git a/arch/mips/boot/dts/ingenic/jz4780.dtsi b/arch/mips/boot/dts/ingenic/jz4780.dtsi
index 65389f6..b868b42 100644
--- a/arch/mips/boot/dts/ingenic/jz4780.dtsi
+++ b/arch/mips/boot/dts/ingenic/jz4780.dtsi
@@ -108,4 +108,30 @@
 
 		status = "disabled";
 	};
+
+	nemc: nemc@13410000 {
+		compatible = "ingenic,jz4780-nemc";
+		reg = <0x13410000 0x10000>;
+		#address-cells = <2>;
+		#size-cells = <1>;
+		ranges = <1 0 0x1b000000 0x1000000
+			  2 0 0x1a000000 0x1000000
+			  3 0 0x19000000 0x1000000
+			  4 0 0x18000000 0x1000000
+			  5 0 0x17000000 0x1000000
+			  6 0 0x16000000 0x1000000>;
+
+		clocks = <&cgu JZ4780_CLK_NEMC>;
+
+		status = "disabled";
+	};
+
+	bch: bch@134d0000 {
+		compatible = "ingenic,jz4780-bch";
+		reg = <0x134d0000 0x10000>;
+
+		clocks = <&cgu JZ4780_CLK_BCH>;
+
+		status = "disabled";
+	};
 };
-- 
2.6.0

^ permalink raw reply related	[flat|nested] 14+ messages in thread

* [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-06 16:27 ` [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes Harvey Hunt
@ 2015-10-06 16:27   ` Harvey Hunt
  2015-10-08 21:22   ` Ezequiel Garcia
  2015-10-15  8:47   ` James Hogan
  2 siblings, 0 replies; 14+ messages in thread
From: Harvey Hunt @ 2015-10-06 16:27 UTC (permalink / raw)
  To: linux-mtd
  Cc: Alex Smith, Zubair Lutfullah Kakakhel, David Woodhouse,
	Brian Norris, Paul Burton, devicetree, linux-kernel, linux-mips,
	Alex Smith, Harvey Hunt

From: Alex Smith <alex.smith@imgtec.com>

Add device tree nodes for the NEMC and BCH to the JZ4780 device tree,
and make use of them in the Ci20 device tree to add a node for the
board's NAND.

Note that since the pinctrl driver is not yet upstream, this includes
neither pin configuration nor busy/write-protect GPIO pins for the
NAND. Use of the NAND relies on the boot loader to have left the pins
configured in a usable state, which should be the case when booted
from the NAND.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mtd@lists.infradead.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Alex Smith <alex@alex-smith.me.uk>
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
---
v6 -> v7:
 - Add nand-ecc-mode to DT.
 - Add nand-on-flash-bbt to DT.

v4 -> v5:
 - New patch adding DT nodes for the NAND so that the driver can be
   tested.

 arch/mips/boot/dts/ingenic/ci20.dts    | 54 ++++++++++++++++++++++++++++++++++
 arch/mips/boot/dts/ingenic/jz4780.dtsi | 26 ++++++++++++++++
 2 files changed, 80 insertions(+)

diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
index 9fcb9e7..453f1d3 100644
--- a/arch/mips/boot/dts/ingenic/ci20.dts
+++ b/arch/mips/boot/dts/ingenic/ci20.dts
@@ -42,3 +42,57 @@
 &uart4 {
 	status = "okay";
 };
+
+&nemc {
+	status = "okay";
+
+	nand: nand@1 {
+		compatible = "ingenic,jz4780-nand";
+		reg = <1 0 0x1000000>;
+
+		ingenic,nemc-tAS = <10>;
+		ingenic,nemc-tAH = <5>;
+		ingenic,nemc-tBP = <10>;
+		ingenic,nemc-tAW = <15>;
+		ingenic,nemc-tSTRV = <100>;
+
+		ingenic,bch-controller = <&bch>;
+		ingenic,ecc-size = <1024>;
+		ingenic,ecc-strength = <24>;
+
+		nand-ecc-mode = "hw";
+		nand-on-flash-bbt;
+
+		#address-cells = <2>;
+		#size-cells = <2>;
+
+		partition@0 {
+			label = "u-boot-spl";
+			reg = <0x0 0x0 0x0 0x800000>;
+		};
+
+		partition@0x800000 {
+			label = "u-boot";
+			reg = <0x0 0x800000 0x0 0x200000>;
+		};
+
+		partition@0xa00000 {
+			label = "u-boot-env";
+			reg = <0x0 0xa00000 0x0 0x200000>;
+		};
+
+		partition@0xc00000 {
+			label = "boot";
+			reg = <0x0 0xc00000 0x0 0x4000000>;
+		};
+
+		partition@0x8c00000 {
+			label = "system";
+			reg = <0x0 0x4c00000 0x1 0xfb400000>;
+		};
+	};
+};
+
+&bch {
+	status = "okay";
+};
diff --git a/arch/mips/boot/dts/ingenic/jz4780.dtsi b/arch/mips/boot/dts/ingenic/jz4780.dtsi
index 65389f6..b868b42 100644
--- a/arch/mips/boot/dts/ingenic/jz4780.dtsi
+++ b/arch/mips/boot/dts/ingenic/jz4780.dtsi
@@ -108,4 +108,30 @@
 
 		status = "disabled";
 	};
+
+	nemc: nemc@13410000 {
+		compatible = "ingenic,jz4780-nemc";
+		reg = <0x13410000 0x10000>;
+		#address-cells = <2>;
+		#size-cells = <1>;
+		ranges = <1 0 0x1b000000 0x1000000
+			  2 0 0x1a000000 0x1000000
+			  3 0 0x19000000 0x1000000
+			  4 0 0x18000000 0x1000000
+			  5 0 0x17000000 0x1000000
+			  6 0 0x16000000 0x1000000>;
+
+		clocks = <&cgu JZ4780_CLK_NEMC>;
+
+		status = "disabled";
+	};
+
+	bch: bch@134d0000 {
+		compatible = "ingenic,jz4780-bch";
+		reg = <0x134d0000 0x10000>;
+
+		clocks = <&cgu JZ4780_CLK_BCH>;
+
+		status = "disabled";
+	};
 };
-- 
2.6.0

^ permalink raw reply related	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-06 16:27 ` [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes Harvey Hunt
  2015-10-06 16:27   ` Harvey Hunt
@ 2015-10-08 21:22   ` Ezequiel Garcia
  2015-10-14  9:15     ` Harvey Hunt
  2015-10-15  8:47   ` James Hogan
  2 siblings, 1 reply; 14+ messages in thread
From: Ezequiel Garcia @ 2015-10-08 21:22 UTC (permalink / raw)
  To: Harvey Hunt
  Cc: linux-mtd@lists.infradead.org, Alex Smith,
	Zubair Lutfullah Kakakhel, David Woodhouse, Brian Norris,
	Paul Burton, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mips, Alex Smith

On 6 October 2015 at 13:27, Harvey Hunt <harvey.hunt@imgtec.com> wrote:
> From: Alex Smith <alex.smith@imgtec.com>
>
> Add device tree nodes for the NEMC and BCH to the JZ4780 device tree,
> and make use of them in the Ci20 device tree to add a node for the
> board's NAND.
>
> Note that since the pinctrl driver is not yet upstream, this includes
> neither pin configuration nor busy/write-protect GPIO pins for the
> NAND. Use of the NAND relies on the boot loader to have left the pins
> configured in a usable state, which should be the case when booted
> from the NAND.
>
> Signed-off-by: Alex Smith <alex.smith@imgtec.com>
> Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Brian Norris <computersforpeace@gmail.com>
> Cc: Paul Burton <paul.burton@imgtec.com>
> Cc: linux-mtd@lists.infradead.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-mips@linux-mips.org
> Cc: Alex Smith <alex@alex-smith.me.uk>
> Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
> ---
> v6 -> v7:
>  - Add nand-ecc-mode to DT.
>  - Add nand-on-flash-bbt to DT.
>
> v4 -> v5:
>  - New patch adding DT nodes for the NAND so that the driver can be
>    tested.
>
>  arch/mips/boot/dts/ingenic/ci20.dts    | 54 ++++++++++++++++++++++++++++++++++
>  arch/mips/boot/dts/ingenic/jz4780.dtsi | 26 ++++++++++++++++
>  2 files changed, 80 insertions(+)
>
> diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
> index 9fcb9e7..453f1d3 100644
> --- a/arch/mips/boot/dts/ingenic/ci20.dts
> +++ b/arch/mips/boot/dts/ingenic/ci20.dts
> @@ -42,3 +42,57 @@
>  &uart4 {
>         status = "okay";
>  };
> +
> +&nemc {
> +       status = "okay";
> +
> +       nand: nand@1 {
> +               compatible = "ingenic,jz4780-nand";
> +               reg = <1 0 0x1000000>;
> +

Why is this in the ci20.dts instead of the SoC dtsi?

Seems at least compatible and reg is not board-specific.

Thanks,
-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar

^ permalink raw reply	[flat|nested] 14+ messages in thread

* RE: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-08 21:22   ` Ezequiel Garcia
@ 2015-10-14  9:15     ` Harvey Hunt
  0 siblings, 0 replies; 14+ messages in thread
From: Harvey Hunt @ 2015-10-14  9:15 UTC (permalink / raw)
  To: Ezequiel Garcia
  Cc: linux-mtd@lists.infradead.org, Alex Smith, Zubair Kakakhel,
	David Woodhouse, Brian Norris, Paul Burton,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mips@linux-mips.org, Alex Smith

On 8 October 2015 at 22:23, Ezequiel Garcia < ezequiel@vanguardiasur.com.ar> wrote:
>On 6 October 2015 at 13:27, Harvey Hunt <harvey.hunt@imgtec.com> wrote:
>> From: Alex Smith <alex.smith@imgtec.com>
>>
>> Add device tree nodes for the NEMC and BCH to the JZ4780 device tree,
>> and make use of them in the Ci20 device tree to add a node for the
>> board's NAND.
>>
>> Note that since the pinctrl driver is not yet upstream, this includes
>> neither pin configuration nor busy/write-protect GPIO pins for the
>> NAND. Use of the NAND relies on the boot loader to have left the pins
>> configured in a usable state, which should be the case when booted
>> from the NAND.
>>
>> Signed-off-by: Alex Smith <alex.smith@imgtec.com>
>> Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
>> Cc: David Woodhouse <dwmw2@infradead.org>
>> Cc: Brian Norris <computersforpeace@gmail.com>
>> Cc: Paul Burton <paul.burton@imgtec.com>
>> Cc: linux-mtd@lists.infradead.org
>> Cc: devicetree@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: linux-mips@linux-mips.org
>> Cc: Alex Smith <alex@alex-smith.me.uk>
>> Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
>> ---
>> v6 -> v7:
>>  - Add nand-ecc-mode to DT.
>>  - Add nand-on-flash-bbt to DT.
>>
>> v4 -> v5:
>>  - New patch adding DT nodes for the NAND so that the driver can be
>>    tested.
>>
>>  arch/mips/boot/dts/ingenic/ci20.dts    | 54 ++++++++++++++++++++++++++++++++++
>>  arch/mips/boot/dts/ingenic/jz4780.dtsi | 26 ++++++++++++++++
>>  2 files changed, 80 insertions(+)
>>
>> diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
>> index 9fcb9e7..453f1d3 100644
>> --- a/arch/mips/boot/dts/ingenic/ci20.dts
>> +++ b/arch/mips/boot/dts/ingenic/ci20.dts
>> @@ -42,3 +42,57 @@
>>  &uart4 {
>>         status = "okay";
>>  };
>> +
>> +&nemc {
>> +       status = "okay";
>> +
>> +       nand: nand@1 {
>> +               compatible = "ingenic,jz4780-nand";
>> +               reg = <1 0 0x1000000>;
>> +
>
>Why is this in the ci20.dts instead of the SoC dtsi?
>
>Seems at least compatible and reg is not board-specific.
>
>Thanks,
>-- 
>Ezequiel García, VanguardiaSur
>www.vanguardiasur.com.ar

Hi Ezequiel,

The number of NAND nodes under the NEMC node is board specific - some devices
could have 2 NAND banks and others could have none. Including the compatible
property in jz4780.dtsi would imply that all JZ4780 boards have at least one NAND bank.

The size in the reg property would be the same for all NAND devices (as it refers to the
NAND registers), however the bank number would be different, so that can also be seen
as board specific.

Thanks,

Harvey

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-06 16:27 ` [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes Harvey Hunt
  2015-10-06 16:27   ` Harvey Hunt
  2015-10-08 21:22   ` Ezequiel Garcia
@ 2015-10-15  8:47   ` James Hogan
  2015-10-15  8:47     ` James Hogan
  2015-10-16 10:11     ` Alex Smith
  2 siblings, 2 replies; 14+ messages in thread
From: James Hogan @ 2015-10-15  8:47 UTC (permalink / raw)
  To: Harvey Hunt
  Cc: linux-mtd, Alex Smith, Zubair Lutfullah Kakakhel, David Woodhouse,
	Brian Norris, Paul Burton, devicetree, linux-kernel, linux-mips,
	Alex Smith

[-- Attachment #1: Type: text/plain, Size: 4003 bytes --]

Hi Harvey,

On Tue, Oct 06, 2015 at 05:27:17PM +0100, Harvey Hunt wrote:
> From: Alex Smith <alex.smith@imgtec.com>
> 
> Add device tree nodes for the NEMC and BCH to the JZ4780 device tree,
> and make use of them in the Ci20 device tree to add a node for the
> board's NAND.
> 
> Note that since the pinctrl driver is not yet upstream, this includes
> neither pin configuration nor busy/write-protect GPIO pins for the
> NAND. Use of the NAND relies on the boot loader to have left the pins
> configured in a usable state, which should be the case when booted
> from the NAND.
> 
> Signed-off-by: Alex Smith <alex.smith@imgtec.com>
> Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Brian Norris <computersforpeace@gmail.com>
> Cc: Paul Burton <paul.burton@imgtec.com>
> Cc: linux-mtd@lists.infradead.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-mips@linux-mips.org
> Cc: Alex Smith <alex@alex-smith.me.uk>
> Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
> ---
> v6 -> v7:
>  - Add nand-ecc-mode to DT.
>  - Add nand-on-flash-bbt to DT.
> 
> v4 -> v5:
>  - New patch adding DT nodes for the NAND so that the driver can be
>    tested.
> 
>  arch/mips/boot/dts/ingenic/ci20.dts    | 54 ++++++++++++++++++++++++++++++++++
>  arch/mips/boot/dts/ingenic/jz4780.dtsi | 26 ++++++++++++++++
>  2 files changed, 80 insertions(+)
> 
> diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
> index 9fcb9e7..453f1d3 100644
> --- a/arch/mips/boot/dts/ingenic/ci20.dts
> +++ b/arch/mips/boot/dts/ingenic/ci20.dts
> @@ -42,3 +42,57 @@
>  &uart4 {
>  	status = "okay";
>  };
> +
> +&nemc {
> +	status = "okay";
> +
> +	nand: nand@1 {
> +		compatible = "ingenic,jz4780-nand";

Isn't the NAND a micron part? This doesn't seem right. Is the device
driver and binding already accepted upstream with that compatible
string?

Cheers
James

> +		reg = <1 0 0x1000000>;
> +
> +		ingenic,nemc-tAS = <10>;
> +		ingenic,nemc-tAH = <5>;
> +		ingenic,nemc-tBP = <10>;
> +		ingenic,nemc-tAW = <15>;
> +		ingenic,nemc-tSTRV = <100>;
> +
> +		ingenic,bch-controller = <&bch>;
> +		ingenic,ecc-size = <1024>;
> +		ingenic,ecc-strength = <24>;
> +
> +		nand-ecc-mode = "hw";
> +		nand-on-flash-bbt;
> +
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +
> +		partition@0 {
> +			label = "u-boot-spl";
> +			reg = <0x0 0x0 0x0 0x800000>;
> +		};
> +
> +		partition@0x800000 {
> +			label = "u-boot";
> +			reg = <0x0 0x800000 0x0 0x200000>;
> +		};
> +
> +		partition@0xa00000 {
> +			label = "u-boot-env";
> +			reg = <0x0 0xa00000 0x0 0x200000>;
> +		};
> +
> +		partition@0xc00000 {
> +			label = "boot";
> +			reg = <0x0 0xc00000 0x0 0x4000000>;
> +		};
> +
> +		partition@0x8c00000 {
> +			label = "system";
> +			reg = <0x0 0x4c00000 0x1 0xfb400000>;
> +		};
> +	};
> +};
> +
> +&bch {
> +	status = "okay";
> +};
> diff --git a/arch/mips/boot/dts/ingenic/jz4780.dtsi b/arch/mips/boot/dts/ingenic/jz4780.dtsi
> index 65389f6..b868b42 100644
> --- a/arch/mips/boot/dts/ingenic/jz4780.dtsi
> +++ b/arch/mips/boot/dts/ingenic/jz4780.dtsi
> @@ -108,4 +108,30 @@
>  
>  		status = "disabled";
>  	};
> +
> +	nemc: nemc@13410000 {
> +		compatible = "ingenic,jz4780-nemc";
> +		reg = <0x13410000 0x10000>;
> +		#address-cells = <2>;
> +		#size-cells = <1>;
> +		ranges = <1 0 0x1b000000 0x1000000
> +			  2 0 0x1a000000 0x1000000
> +			  3 0 0x19000000 0x1000000
> +			  4 0 0x18000000 0x1000000
> +			  5 0 0x17000000 0x1000000
> +			  6 0 0x16000000 0x1000000>;
> +
> +		clocks = <&cgu JZ4780_CLK_NEMC>;
> +
> +		status = "disabled";
> +	};
> +
> +	bch: bch@134d0000 {
> +		compatible = "ingenic,jz4780-bch";
> +		reg = <0x134d0000 0x10000>;
> +
> +		clocks = <&cgu JZ4780_CLK_BCH>;
> +
> +		status = "disabled";
> +	};
>  };
> -- 
> 2.6.0
> 
> 

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^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-15  8:47   ` James Hogan
@ 2015-10-15  8:47     ` James Hogan
  2015-10-16 10:11     ` Alex Smith
  1 sibling, 0 replies; 14+ messages in thread
From: James Hogan @ 2015-10-15  8:47 UTC (permalink / raw)
  To: Harvey Hunt
  Cc: linux-mtd, Alex Smith, Zubair Lutfullah Kakakhel, David Woodhouse,
	Brian Norris, Paul Burton, devicetree, linux-kernel, linux-mips,
	Alex Smith

[-- Attachment #1: Type: text/plain, Size: 4003 bytes --]

Hi Harvey,

On Tue, Oct 06, 2015 at 05:27:17PM +0100, Harvey Hunt wrote:
> From: Alex Smith <alex.smith@imgtec.com>
> 
> Add device tree nodes for the NEMC and BCH to the JZ4780 device tree,
> and make use of them in the Ci20 device tree to add a node for the
> board's NAND.
> 
> Note that since the pinctrl driver is not yet upstream, this includes
> neither pin configuration nor busy/write-protect GPIO pins for the
> NAND. Use of the NAND relies on the boot loader to have left the pins
> configured in a usable state, which should be the case when booted
> from the NAND.
> 
> Signed-off-by: Alex Smith <alex.smith@imgtec.com>
> Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Brian Norris <computersforpeace@gmail.com>
> Cc: Paul Burton <paul.burton@imgtec.com>
> Cc: linux-mtd@lists.infradead.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-mips@linux-mips.org
> Cc: Alex Smith <alex@alex-smith.me.uk>
> Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
> ---
> v6 -> v7:
>  - Add nand-ecc-mode to DT.
>  - Add nand-on-flash-bbt to DT.
> 
> v4 -> v5:
>  - New patch adding DT nodes for the NAND so that the driver can be
>    tested.
> 
>  arch/mips/boot/dts/ingenic/ci20.dts    | 54 ++++++++++++++++++++++++++++++++++
>  arch/mips/boot/dts/ingenic/jz4780.dtsi | 26 ++++++++++++++++
>  2 files changed, 80 insertions(+)
> 
> diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
> index 9fcb9e7..453f1d3 100644
> --- a/arch/mips/boot/dts/ingenic/ci20.dts
> +++ b/arch/mips/boot/dts/ingenic/ci20.dts
> @@ -42,3 +42,57 @@
>  &uart4 {
>  	status = "okay";
>  };
> +
> +&nemc {
> +	status = "okay";
> +
> +	nand: nand@1 {
> +		compatible = "ingenic,jz4780-nand";

Isn't the NAND a micron part? This doesn't seem right. Is the device
driver and binding already accepted upstream with that compatible
string?

Cheers
James

> +		reg = <1 0 0x1000000>;
> +
> +		ingenic,nemc-tAS = <10>;
> +		ingenic,nemc-tAH = <5>;
> +		ingenic,nemc-tBP = <10>;
> +		ingenic,nemc-tAW = <15>;
> +		ingenic,nemc-tSTRV = <100>;
> +
> +		ingenic,bch-controller = <&bch>;
> +		ingenic,ecc-size = <1024>;
> +		ingenic,ecc-strength = <24>;
> +
> +		nand-ecc-mode = "hw";
> +		nand-on-flash-bbt;
> +
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +
> +		partition@0 {
> +			label = "u-boot-spl";
> +			reg = <0x0 0x0 0x0 0x800000>;
> +		};
> +
> +		partition@0x800000 {
> +			label = "u-boot";
> +			reg = <0x0 0x800000 0x0 0x200000>;
> +		};
> +
> +		partition@0xa00000 {
> +			label = "u-boot-env";
> +			reg = <0x0 0xa00000 0x0 0x200000>;
> +		};
> +
> +		partition@0xc00000 {
> +			label = "boot";
> +			reg = <0x0 0xc00000 0x0 0x4000000>;
> +		};
> +
> +		partition@0x8c00000 {
> +			label = "system";
> +			reg = <0x0 0x4c00000 0x1 0xfb400000>;
> +		};
> +	};
> +};
> +
> +&bch {
> +	status = "okay";
> +};
> diff --git a/arch/mips/boot/dts/ingenic/jz4780.dtsi b/arch/mips/boot/dts/ingenic/jz4780.dtsi
> index 65389f6..b868b42 100644
> --- a/arch/mips/boot/dts/ingenic/jz4780.dtsi
> +++ b/arch/mips/boot/dts/ingenic/jz4780.dtsi
> @@ -108,4 +108,30 @@
>  
>  		status = "disabled";
>  	};
> +
> +	nemc: nemc@13410000 {
> +		compatible = "ingenic,jz4780-nemc";
> +		reg = <0x13410000 0x10000>;
> +		#address-cells = <2>;
> +		#size-cells = <1>;
> +		ranges = <1 0 0x1b000000 0x1000000
> +			  2 0 0x1a000000 0x1000000
> +			  3 0 0x19000000 0x1000000
> +			  4 0 0x18000000 0x1000000
> +			  5 0 0x17000000 0x1000000
> +			  6 0 0x16000000 0x1000000>;
> +
> +		clocks = <&cgu JZ4780_CLK_NEMC>;
> +
> +		status = "disabled";
> +	};
> +
> +	bch: bch@134d0000 {
> +		compatible = "ingenic,jz4780-bch";
> +		reg = <0x134d0000 0x10000>;
> +
> +		clocks = <&cgu JZ4780_CLK_BCH>;
> +
> +		status = "disabled";
> +	};
>  };
> -- 
> 2.6.0
> 
> 

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^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-15  8:47   ` James Hogan
  2015-10-15  8:47     ` James Hogan
@ 2015-10-16 10:11     ` Alex Smith
  2015-10-16 10:31       ` James Hogan
  1 sibling, 1 reply; 14+ messages in thread
From: Alex Smith @ 2015-10-16 10:11 UTC (permalink / raw)
  To: James Hogan
  Cc: Harvey Hunt, linux-mtd, Alex Smith, Zubair Lutfullah Kakakhel,
	David Woodhouse, Brian Norris, Paul Burton, devicetree,
	linux-kernel, linux-mips

Hi James,

On 15 October 2015 at 09:47, James Hogan <james.hogan@imgtec.com> wrote:
>> diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
>> index 9fcb9e7..453f1d3 100644
>> --- a/arch/mips/boot/dts/ingenic/ci20.dts
>> +++ b/arch/mips/boot/dts/ingenic/ci20.dts
>> @@ -42,3 +42,57 @@
>>  &uart4 {
>>       status = "okay";
>>  };
>> +
>> +&nemc {
>> +     status = "okay";
>> +
>> +     nand: nand@1 {
>> +             compatible = "ingenic,jz4780-nand";
>
> Isn't the NAND a micron part? This doesn't seem right. Is the device
> driver and binding already accepted upstream with that compatible
> string?

This is the compatible string for the JZ4780 NAND driver, this patch
is part of the series adding that. Detection of the NAND part is
handled by the MTD subsystem.

Thanks,
Alex

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-16 10:11     ` Alex Smith
@ 2015-10-16 10:31       ` James Hogan
  2015-10-16 10:31         ` James Hogan
  2015-10-16 10:48         ` Paul Burton
  0 siblings, 2 replies; 14+ messages in thread
From: James Hogan @ 2015-10-16 10:31 UTC (permalink / raw)
  To: Alex Smith
  Cc: Harvey Hunt, linux-mtd, Alex Smith, Zubair Lutfullah Kakakhel,
	David Woodhouse, Brian Norris, Paul Burton, devicetree,
	linux-kernel, linux-mips

[-- Attachment #1: Type: text/plain, Size: 1294 bytes --]

Hi Alex,

On Fri, Oct 16, 2015 at 11:11:29AM +0100, Alex Smith wrote:
> Hi James,
> 
> On 15 October 2015 at 09:47, James Hogan <james.hogan@imgtec.com> wrote:
> >> diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
> >> index 9fcb9e7..453f1d3 100644
> >> --- a/arch/mips/boot/dts/ingenic/ci20.dts
> >> +++ b/arch/mips/boot/dts/ingenic/ci20.dts
> >> @@ -42,3 +42,57 @@
> >>  &uart4 {
> >>       status = "okay";
> >>  };
> >> +
> >> +&nemc {
> >> +     status = "okay";
> >> +
> >> +     nand: nand@1 {
> >> +             compatible = "ingenic,jz4780-nand";
> >
> > Isn't the NAND a micron part? This doesn't seem right. Is the device
> > driver and binding already accepted upstream with that compatible
> > string?
> 
> This is the compatible string for the JZ4780 NAND driver, this patch
> is part of the series adding that. Detection of the NAND part is
> handled by the MTD subsystem.

Right (didn't spot that it was part of a series).

The node appears to describe the NAND interface itself, i.e. a part of
the SoC, so should be in the SoC dtsi file, with overrides in the board
file if necessary for it to work with a particular NAND part
(potentially utilising status="disabled"). Would you agree?

Cheers
James

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^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-16 10:31       ` James Hogan
@ 2015-10-16 10:31         ` James Hogan
  2015-10-16 10:48         ` Paul Burton
  1 sibling, 0 replies; 14+ messages in thread
From: James Hogan @ 2015-10-16 10:31 UTC (permalink / raw)
  To: Alex Smith
  Cc: Harvey Hunt, linux-mtd, Alex Smith, Zubair Lutfullah Kakakhel,
	David Woodhouse, Brian Norris, Paul Burton, devicetree,
	linux-kernel, linux-mips

[-- Attachment #1: Type: text/plain, Size: 1294 bytes --]

Hi Alex,

On Fri, Oct 16, 2015 at 11:11:29AM +0100, Alex Smith wrote:
> Hi James,
> 
> On 15 October 2015 at 09:47, James Hogan <james.hogan@imgtec.com> wrote:
> >> diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
> >> index 9fcb9e7..453f1d3 100644
> >> --- a/arch/mips/boot/dts/ingenic/ci20.dts
> >> +++ b/arch/mips/boot/dts/ingenic/ci20.dts
> >> @@ -42,3 +42,57 @@
> >>  &uart4 {
> >>       status = "okay";
> >>  };
> >> +
> >> +&nemc {
> >> +     status = "okay";
> >> +
> >> +     nand: nand@1 {
> >> +             compatible = "ingenic,jz4780-nand";
> >
> > Isn't the NAND a micron part? This doesn't seem right. Is the device
> > driver and binding already accepted upstream with that compatible
> > string?
> 
> This is the compatible string for the JZ4780 NAND driver, this patch
> is part of the series adding that. Detection of the NAND part is
> handled by the MTD subsystem.

Right (didn't spot that it was part of a series).

The node appears to describe the NAND interface itself, i.e. a part of
the SoC, so should be in the SoC dtsi file, with overrides in the board
file if necessary for it to work with a particular NAND part
(potentially utilising status="disabled"). Would you agree?

Cheers
James

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^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-16 10:31       ` James Hogan
  2015-10-16 10:31         ` James Hogan
@ 2015-10-16 10:48         ` Paul Burton
  2015-10-16 10:48           ` Paul Burton
  2015-11-04  7:51           ` Boris Brezillon
  1 sibling, 2 replies; 14+ messages in thread
From: Paul Burton @ 2015-10-16 10:48 UTC (permalink / raw)
  To: James Hogan
  Cc: Alex Smith, Harvey Hunt, linux-mtd, Alex Smith,
	Zubair Lutfullah Kakakhel, David Woodhouse, Brian Norris,
	devicetree, linux-kernel, linux-mips

On Fri, Oct 16, 2015 at 11:31:12AM +0100, James Hogan wrote:
> > >> +
> > >> +&nemc {
> > >> +     status = "okay";
> > >> +
> > >> +     nand: nand@1 {
> > >> +             compatible = "ingenic,jz4780-nand";
> > >
> > > Isn't the NAND a micron part? This doesn't seem right. Is the device
> > > driver and binding already accepted upstream with that compatible
> > > string?
> > 
> > This is the compatible string for the JZ4780 NAND driver, this patch
> > is part of the series adding that. Detection of the NAND part is
> > handled by the MTD subsystem.
> 
> Right (didn't spot that it was part of a series).
> 
> The node appears to describe the NAND interface itself, i.e. a part of
> the SoC, so should be in the SoC dtsi file, with overrides in the board
> file if necessary for it to work with a particular NAND part
> (potentially utilising status="disabled"). Would you agree?

Hi James,

The "nemc" node there is for the Nand & External Memory Controller which
is a hardware block inside the SoC. It has 6 banks (ie. 6 chip select
pins, each associated with a different address range, that connect to
different devices). NAND flash is one such possible device, but a board
could connect it to any of the 6 chip selects, or banks. To represent
that in the SoC dtsi you'd want to have 6 NAND nodes, each disabled by
default, which doesn't make a whole lot of sense to me. Other, non-NAND
devices can connect to the NEMC too - for example the ethernet
controller on the CI20 is connected to one bank.

The NAND device nodes are sort of a mix of describing the NAND flash
(ie. Micron part as you point out) and its connections & properties, the
way the NEMC should be used to interact with it alongside the BCH block,
and the configuration for the NEMC such as timing parameters.

I imagine the most semantically correct means of describing it would
probably be for the compatible string to reflect the Micron NAND part,
and the NEMC driver to pick up on the relevant properties of its child
nodes for configuring timings, whether the device is NAND etc. However
the handling of registering NAND devices with MTD would probably then
have to be part of the NEMC driver, which feels a bit off too.

Thanks,
    Paul

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-16 10:48         ` Paul Burton
@ 2015-10-16 10:48           ` Paul Burton
  2015-11-04  7:51           ` Boris Brezillon
  1 sibling, 0 replies; 14+ messages in thread
From: Paul Burton @ 2015-10-16 10:48 UTC (permalink / raw)
  To: James Hogan
  Cc: Alex Smith, Harvey Hunt, linux-mtd, Alex Smith,
	Zubair Lutfullah Kakakhel, David Woodhouse, Brian Norris,
	devicetree, linux-kernel, linux-mips

On Fri, Oct 16, 2015 at 11:31:12AM +0100, James Hogan wrote:
> > >> +
> > >> +&nemc {
> > >> +     status = "okay";
> > >> +
> > >> +     nand: nand@1 {
> > >> +             compatible = "ingenic,jz4780-nand";
> > >
> > > Isn't the NAND a micron part? This doesn't seem right. Is the device
> > > driver and binding already accepted upstream with that compatible
> > > string?
> > 
> > This is the compatible string for the JZ4780 NAND driver, this patch
> > is part of the series adding that. Detection of the NAND part is
> > handled by the MTD subsystem.
> 
> Right (didn't spot that it was part of a series).
> 
> The node appears to describe the NAND interface itself, i.e. a part of
> the SoC, so should be in the SoC dtsi file, with overrides in the board
> file if necessary for it to work with a particular NAND part
> (potentially utilising status="disabled"). Would you agree?

Hi James,

The "nemc" node there is for the Nand & External Memory Controller which
is a hardware block inside the SoC. It has 6 banks (ie. 6 chip select
pins, each associated with a different address range, that connect to
different devices). NAND flash is one such possible device, but a board
could connect it to any of the 6 chip selects, or banks. To represent
that in the SoC dtsi you'd want to have 6 NAND nodes, each disabled by
default, which doesn't make a whole lot of sense to me. Other, non-NAND
devices can connect to the NEMC too - for example the ethernet
controller on the CI20 is connected to one bank.

The NAND device nodes are sort of a mix of describing the NAND flash
(ie. Micron part as you point out) and its connections & properties, the
way the NEMC should be used to interact with it alongside the BCH block,
and the configuration for the NEMC such as timing parameters.

I imagine the most semantically correct means of describing it would
probably be for the compatible string to reflect the Micron NAND part,
and the NEMC driver to pick up on the relevant properties of its child
nodes for configuring timings, whether the device is NAND etc. However
the handling of registering NAND devices with MTD would probably then
have to be part of the NEMC driver, which feels a bit off too.

Thanks,
    Paul

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-10-16 10:48         ` Paul Burton
  2015-10-16 10:48           ` Paul Burton
@ 2015-11-04  7:51           ` Boris Brezillon
  2015-11-17 16:29             ` Harvey Hunt
  1 sibling, 1 reply; 14+ messages in thread
From: Boris Brezillon @ 2015-11-04  7:51 UTC (permalink / raw)
  To: Paul Burton, Harvey Hunt
  Cc: James Hogan, devicetree, Zubair Lutfullah Kakakhel, linux-mips,
	linux-kernel, Alex Smith, linux-mtd, Alex Smith, Brian Norris,
	David Woodhouse

Paul, Harvey,

On Fri, 16 Oct 2015 11:48:48 +0100
Paul Burton <paul.burton@imgtec.com> wrote:

> On Fri, Oct 16, 2015 at 11:31:12AM +0100, James Hogan wrote:
> > > >> +
> > > >> +&nemc {
> > > >> +     status = "okay";
> > > >> +
> > > >> +     nand: nand@1 {
> > > >> +             compatible = "ingenic,jz4780-nand";
> > > >
> > > > Isn't the NAND a micron part? This doesn't seem right. Is the device
> > > > driver and binding already accepted upstream with that compatible
> > > > string?
> > > 
> > > This is the compatible string for the JZ4780 NAND driver, this patch
> > > is part of the series adding that. Detection of the NAND part is
> > > handled by the MTD subsystem.
> > 
> > Right (didn't spot that it was part of a series).
> > 
> > The node appears to describe the NAND interface itself, i.e. a part of
> > the SoC, so should be in the SoC dtsi file, with overrides in the board
> > file if necessary for it to work with a particular NAND part
> > (potentially utilising status="disabled"). Would you agree?
> 
> Hi James,
> 
> The "nemc" node there is for the Nand & External Memory Controller which
> is a hardware block inside the SoC. It has 6 banks (ie. 6 chip select
> pins, each associated with a different address range, that connect to
> different devices). NAND flash is one such possible device, but a board
> could connect it to any of the 6 chip selects, or banks. To represent
> that in the SoC dtsi you'd want to have 6 NAND nodes, each disabled by
> default, which doesn't make a whole lot of sense to me. Other, non-NAND
> devices can connect to the NEMC too - for example the ethernet
> controller on the CI20 is connected to one bank.
> 
> The NAND device nodes are sort of a mix of describing the NAND flash
> (ie. Micron part as you point out) and its connections & properties, the
> way the NEMC should be used to interact with it alongside the BCH block,
> and the configuration for the NEMC such as timing parameters.
> 
> I imagine the most semantically correct means of describing it would
> probably be for the compatible string to reflect the Micron NAND part,
> and the NEMC driver to pick up on the relevant properties of its child
> nodes for configuring timings, whether the device is NAND etc. However
> the handling of registering NAND devices with MTD would probably then
> have to be part of the NEMC driver, which feels a bit off too.

Another solution would be to describe both the NAND controller and the
NAND chip in the DT (with the NAND chip being a chip of the NAND
controller).
Actually this is already what other binding are doing [1][2]. I know
those bindings are representing NAND controllers which can interface
with more than one NAND chip, but I think that even in the 1:1 case it
would make it clearer to represent both the NAND chip and the NAND
controller.

In your case this would give the following representation

+&nemc {
+	status = "okay";
+
+	nandc: nand-controller@1 {
+		compatible = "ingenic,jz4780-nand";
+		reg = <1 0 0x1000000>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ingenic,bch-controller = <&bch>;
+
+		nand@0 {
+			nand-ecc-mode = "hw";
+			nand-on-flash-bbt;
+			nand-ecc-size = <1024>;
+			nand-ecc-strength = <24>;
+
+			#address-cells = <2>;
+			#size-cells = <2>;
+
+			partition@0 {
+				label = "u-boot-spl";
+				reg = <0x0 0x0 0x0 0x800000>;
+			};
+			/* ... */
+
+		};
+	};
+};

Best Regards,

Boris

[1]http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt#L119
[2]http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/mtd/sunxi-nand.txt#L28

> 
> Thanks,
>     Paul
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-11-04  7:51           ` Boris Brezillon
@ 2015-11-17 16:29             ` Harvey Hunt
  2015-11-17 16:29               ` Harvey Hunt
  0 siblings, 1 reply; 14+ messages in thread
From: Harvey Hunt @ 2015-11-17 16:29 UTC (permalink / raw)
  To: Boris Brezillon, Paul Burton
  Cc: James Hogan, devicetree, Zubair Lutfullah Kakakhel, linux-mips,
	linux-kernel, Alex Smith, linux-mtd, Alex Smith, Brian Norris,
	David Woodhouse

Hi Boris,

On 04/11/15 07:51, Boris Brezillon wrote:
> Paul, Harvey,
>
> On Fri, 16 Oct 2015 11:48:48 +0100
> Paul Burton <paul.burton@imgtec.com> wrote:
>
>> On Fri, Oct 16, 2015 at 11:31:12AM +0100, James Hogan wrote:
>>>>>> +
>>>>>> +&nemc {
>>>>>> +     status = "okay";
>>>>>> +
>>>>>> +     nand: nand@1 {
>>>>>> +             compatible = "ingenic,jz4780-nand";
>>>>>
>>>>> Isn't the NAND a micron part? This doesn't seem right. Is the device
>>>>> driver and binding already accepted upstream with that compatible
>>>>> string?
>>>>
>>>> This is the compatible string for the JZ4780 NAND driver, this patch
>>>> is part of the series adding that. Detection of the NAND part is
>>>> handled by the MTD subsystem.
>>>
>>> Right (didn't spot that it was part of a series).
>>>
>>> The node appears to describe the NAND interface itself, i.e. a part of
>>> the SoC, so should be in the SoC dtsi file, with overrides in the board
>>> file if necessary for it to work with a particular NAND part
>>> (potentially utilising status="disabled"). Would you agree?
>>
>> Hi James,
>>
>> The "nemc" node there is for the Nand & External Memory Controller which
>> is a hardware block inside the SoC. It has 6 banks (ie. 6 chip select
>> pins, each associated with a different address range, that connect to
>> different devices). NAND flash is one such possible device, but a board
>> could connect it to any of the 6 chip selects, or banks. To represent
>> that in the SoC dtsi you'd want to have 6 NAND nodes, each disabled by
>> default, which doesn't make a whole lot of sense to me. Other, non-NAND
>> devices can connect to the NEMC too - for example the ethernet
>> controller on the CI20 is connected to one bank.
>>
>> The NAND device nodes are sort of a mix of describing the NAND flash
>> (ie. Micron part as you point out) and its connections & properties, the
>> way the NEMC should be used to interact with it alongside the BCH block,
>> and the configuration for the NEMC such as timing parameters.
>>
>> I imagine the most semantically correct means of describing it would
>> probably be for the compatible string to reflect the Micron NAND part,
>> and the NEMC driver to pick up on the relevant properties of its child
>> nodes for configuring timings, whether the device is NAND etc. However
>> the handling of registering NAND devices with MTD would probably then
>> have to be part of the NEMC driver, which feels a bit off too.
>
> Another solution would be to describe both the NAND controller and the
> NAND chip in the DT (with the NAND chip being a chip of the NAND
> controller).
> Actually this is already what other binding are doing [1][2]. I know
> those bindings are representing NAND controllers which can interface
> with more than one NAND chip, but I think that even in the 1:1 case it
> would make it clearer to represent both the NAND chip and the NAND
> controller.
>
> In your case this would give the following representation
>
> +&nemc {
> +	status = "okay";
> +
> +	nandc: nand-controller@1 {
> +		compatible = "ingenic,jz4780-nand";
> +		reg = <1 0 0x1000000>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		ingenic,bch-controller = <&bch>;
> +
> +		nand@0 {
> +			nand-ecc-mode = "hw";
> +			nand-on-flash-bbt;
> +			nand-ecc-size = <1024>;
> +			nand-ecc-strength = <24>;
> +
> +			#address-cells = <2>;
> +			#size-cells = <2>;
> +
> +			partition@0 {
> +				label = "u-boot-spl";
> +				reg = <0x0 0x0 0x0 0x800000>;
> +			};
> +			/* ... */
> +
> +		};
> +	};
> +};

I'll implement this in v8 - thanks for the example DT. :-)

> Best Regards,
>
> Boris
>
> [1]http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt#L119
> [2]http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/mtd/sunxi-nand.txt#L28
>
>>
>> Thanks,
>>      Paul
>>
>> ______________________________________________________
>> Linux MTD discussion mailing list
>> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>
>
>

Best regards,

Harvey Hunt

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes
  2015-11-17 16:29             ` Harvey Hunt
@ 2015-11-17 16:29               ` Harvey Hunt
  0 siblings, 0 replies; 14+ messages in thread
From: Harvey Hunt @ 2015-11-17 16:29 UTC (permalink / raw)
  To: Boris Brezillon, Paul Burton
  Cc: James Hogan, devicetree, Zubair Lutfullah Kakakhel, linux-mips,
	linux-kernel, Alex Smith, linux-mtd, Alex Smith, Brian Norris,
	David Woodhouse

Hi Boris,

On 04/11/15 07:51, Boris Brezillon wrote:
> Paul, Harvey,
>
> On Fri, 16 Oct 2015 11:48:48 +0100
> Paul Burton <paul.burton@imgtec.com> wrote:
>
>> On Fri, Oct 16, 2015 at 11:31:12AM +0100, James Hogan wrote:
>>>>>> +
>>>>>> +&nemc {
>>>>>> +     status = "okay";
>>>>>> +
>>>>>> +     nand: nand@1 {
>>>>>> +             compatible = "ingenic,jz4780-nand";
>>>>>
>>>>> Isn't the NAND a micron part? This doesn't seem right. Is the device
>>>>> driver and binding already accepted upstream with that compatible
>>>>> string?
>>>>
>>>> This is the compatible string for the JZ4780 NAND driver, this patch
>>>> is part of the series adding that. Detection of the NAND part is
>>>> handled by the MTD subsystem.
>>>
>>> Right (didn't spot that it was part of a series).
>>>
>>> The node appears to describe the NAND interface itself, i.e. a part of
>>> the SoC, so should be in the SoC dtsi file, with overrides in the board
>>> file if necessary for it to work with a particular NAND part
>>> (potentially utilising status="disabled"). Would you agree?
>>
>> Hi James,
>>
>> The "nemc" node there is for the Nand & External Memory Controller which
>> is a hardware block inside the SoC. It has 6 banks (ie. 6 chip select
>> pins, each associated with a different address range, that connect to
>> different devices). NAND flash is one such possible device, but a board
>> could connect it to any of the 6 chip selects, or banks. To represent
>> that in the SoC dtsi you'd want to have 6 NAND nodes, each disabled by
>> default, which doesn't make a whole lot of sense to me. Other, non-NAND
>> devices can connect to the NEMC too - for example the ethernet
>> controller on the CI20 is connected to one bank.
>>
>> The NAND device nodes are sort of a mix of describing the NAND flash
>> (ie. Micron part as you point out) and its connections & properties, the
>> way the NEMC should be used to interact with it alongside the BCH block,
>> and the configuration for the NEMC such as timing parameters.
>>
>> I imagine the most semantically correct means of describing it would
>> probably be for the compatible string to reflect the Micron NAND part,
>> and the NEMC driver to pick up on the relevant properties of its child
>> nodes for configuring timings, whether the device is NAND etc. However
>> the handling of registering NAND devices with MTD would probably then
>> have to be part of the NEMC driver, which feels a bit off too.
>
> Another solution would be to describe both the NAND controller and the
> NAND chip in the DT (with the NAND chip being a chip of the NAND
> controller).
> Actually this is already what other binding are doing [1][2]. I know
> those bindings are representing NAND controllers which can interface
> with more than one NAND chip, but I think that even in the 1:1 case it
> would make it clearer to represent both the NAND chip and the NAND
> controller.
>
> In your case this would give the following representation
>
> +&nemc {
> +	status = "okay";
> +
> +	nandc: nand-controller@1 {
> +		compatible = "ingenic,jz4780-nand";
> +		reg = <1 0 0x1000000>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		ingenic,bch-controller = <&bch>;
> +
> +		nand@0 {
> +			nand-ecc-mode = "hw";
> +			nand-on-flash-bbt;
> +			nand-ecc-size = <1024>;
> +			nand-ecc-strength = <24>;
> +
> +			#address-cells = <2>;
> +			#size-cells = <2>;
> +
> +			partition@0 {
> +				label = "u-boot-spl";
> +				reg = <0x0 0x0 0x0 0x800000>;
> +			};
> +			/* ... */
> +
> +		};
> +	};
> +};

I'll implement this in v8 - thanks for the example DT. :-)

> Best Regards,
>
> Boris
>
> [1]http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt#L119
> [2]http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/mtd/sunxi-nand.txt#L28
>
>>
>> Thanks,
>>      Paul
>>
>> ______________________________________________________
>> Linux MTD discussion mailing list
>> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>
>
>

Best regards,

Harvey Hunt

^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2015-11-17 16:29 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
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2015-10-06 16:27 ` [PATCH v7,3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes Harvey Hunt
2015-10-06 16:27   ` Harvey Hunt
2015-10-08 21:22   ` Ezequiel Garcia
2015-10-14  9:15     ` Harvey Hunt
2015-10-15  8:47   ` James Hogan
2015-10-15  8:47     ` James Hogan
2015-10-16 10:11     ` Alex Smith
2015-10-16 10:31       ` James Hogan
2015-10-16 10:31         ` James Hogan
2015-10-16 10:48         ` Paul Burton
2015-10-16 10:48           ` Paul Burton
2015-11-04  7:51           ` Boris Brezillon
2015-11-17 16:29             ` Harvey Hunt
2015-11-17 16:29               ` Harvey Hunt

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