[PATCH/RFC] dt-bindings: mtd: Remove Renesas FLCTL NAND controller support

[PATCH/RFC] dt-bindings: mtd: Remove Renesas FLCTL NAND controller support

[Geert Uytterhoeven]

The DT bindings for the Renesas FLCTL NAND controller document only support a
single SoC, namely the Renesas R-Mobile AP4 (SH7372).
Linux dropped support for this SoC in commit 59b89af1d5551c12 ("ARM:
shmobile: sh7372: Remove Legacy C SoC code") in v4.1.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
The FLCTL NAND controller (or an enhanced version) is also present on
SH-Mobile AG5 (sh73a0) and R-Mobile A1 (r8a7740), but the sole boards
supported upstream (KMC KZM-A9-GT resp. Atmark Techno Armadillo-800-EVA)
use eMMC NAND instead of raw NAND FLASH.

What's the policy w.r.t. stale DT bindings?
Should it be converted to json-schema instead?
drivers/mtd/nand/raw/sh_flctl.c still implements these bindings.
The driver cannot be removed, as it is also used on the non-DT
SH7723-based AP-325RXA platform.
---
 .../devicetree/bindings/mtd/flctl-nand.txt    | 49 -------------------
 1 file changed, 49 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/mtd/flctl-nand.txt

diff --git a/Documentation/devicetree/bindings/mtd/flctl-nand.txt b/Documentation/devicetree/bindings/mtd/flctl-nand.txt
deleted file mode 100644
index 427f46dc60add134..0000000000000000
--- a/Documentation/devicetree/bindings/mtd/flctl-nand.txt
+++ /dev/null
@@ -1,49 +0,0 @@
-FLCTL NAND controller
-
-Required properties:
-- compatible : "renesas,shmobile-flctl-sh7372"
-- reg : Address range of the FLCTL
-- interrupts : flste IRQ number
-- nand-bus-width : bus width to NAND chip
-
-Optional properties:
-- dmas: DMA specifier(s)
-- dma-names: name for each DMA specifier. Valid names are
-	     "data_tx", "data_rx", "ecc_tx", "ecc_rx"
-
-The DMA fields are not used yet in the driver but are listed here for
-completing the bindings.
-
-The device tree may optionally contain sub-nodes describing partitions of the
-address space. See partition.txt for more detail.
-
-Example:
-
-	flctl@e6a30000 {
-		#address-cells = <1>;
-		#size-cells = <1>;
-		compatible = "renesas,shmobile-flctl-sh7372";
-		reg = <0xe6a30000 0x100>;
-		interrupts = <0x0d80>;
-
-		nand-bus-width = <16>;
-
-		dmas = <&dmac 1 /* data_tx */
-			&dmac 2;> /* data_rx */
-		dma-names = "data_tx", "data_rx";
-
-		system@0 {
-			label = "system";
-			reg = <0x0 0x8000000>;
-		};
-
-		userdata@8000000 {
-			label = "userdata";
-			reg = <0x8000000 0x10000000>;
-		};
-
-		cache@18000000 {
-			label = "cache";
-			reg = <0x18000000 0x8000000>;
-		};
-	};
-- 
2.25.1

Re: [PATCH/RFC] dt-bindings: mtd: Remove Renesas FLCTL NAND controller support

[Rob Herring]

On Mon, May 09, 2022 at 02:27:52PM +0200, Geert Uytterhoeven wrote:
> The DT bindings for the Renesas FLCTL NAND controller document only support a
> single SoC, namely the Renesas R-Mobile AP4 (SH7372).
> Linux dropped support for this SoC in commit 59b89af1d5551c12 ("ARM:
> shmobile: sh7372: Remove Legacy C SoC code") in v4.1.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> The FLCTL NAND controller (or an enhanced version) is also present on
> SH-Mobile AG5 (sh73a0) and R-Mobile A1 (r8a7740), but the sole boards
> supported upstream (KMC KZM-A9-GT resp. Atmark Techno Armadillo-800-EVA)
> use eMMC NAND instead of raw NAND FLASH.
> 
> What's the policy w.r.t. stale DT bindings?
> Should it be converted to json-schema instead?

Wouldn't be high on my list.

> drivers/mtd/nand/raw/sh_flctl.c still implements these bindings.
> The driver cannot be removed, as it is also used on the non-DT
> SH7723-based AP-325RXA platform.

But you could remove the DT support in the driver? I'd just leave this 
as-is if you don't do that.

Rob