[PATCH v3 00/22] External ECC engines & Macronix support

[PATCH v3 00/22] External ECC engines & Macronix support

[Miquel Raynal]

Hello all,

~~~
Mark, I've added your Reviewed-by on all the SPI related patches, please
check and tell me if I made a mistake. In particular, I've added
something since v2: the spi-mxic.c driver now also depends on
MTD_NAND_ECC in order to avoid faulty situations where MTD/NAND=m and
SPI=y. Let me know if this does not work for you.
~~~

This series is now stable and brings support for external/modular ECC
engines, and let SPI controller using the ECC framework.

As a first example, Macronix ECC engine can be used as an
external engine (takes the data, proceeds to the calculations, writes
back the ECC bytes) or as a pipelined engine doing on-the-fly
calculations (which is very common in the raw NAND world).

In the device tree, the ECC engine should be described as a separated DT
node. Then:
* external case: the flash node should provide a nand-ecc-engine
  property pointing to the ECC engine node.
* pipelined case: the flash node should provide a nand-ecc-engine
  property pointing to the SPI controller, itself with another
  nand-ecc-engine property pointing at the ECC engine node.

This series comes with a bunch of improvements on the binding side as
well.

Cheers,
Miquèl

Changes in v3:
* Added Mark's R-by.
* Added a commit changing the initialization order between the dirmaps
  and the ECC engine so that the core might now if we are using a
  pipelined engine or not.
* Stopped creating additional dirmaps with ECC if the engine is not a
  pipelined engine.
* Solved the kernel test robot reports. In particular, I added a
  dependency on MTD_NAND_ECC to Macronix SPI controller driver.
* Added a patch to clean the NAND controller yaml file before moving
  some bits to nand-chip.yaml. This addresses the comments made by Rob
  about the useless allOf's.
* Used platform_get_irq_byname_optional() in order to avoid useless
  warnings when there is no IRQ.

Changes in v2:
* Fixed the bindings and added Rob's acks when relevant.
* Added locking in the ECC engine driver.
* Brought more changes in the core in order to bring the ECC information
  into the spi_mem_op structure with the idea of avoiding any races
  between parallel calls on the same engine.
* Reorganized the ECC driver entirely in order to have a per-engine mxic
  structure plus a per-NAND context. This lead to a number of changes
  internally which cannot all be listed.

Changes since the RFC:
* Rebased on top of v5.15-rc1.
* Fixed the dirmap configuration.
* Added the various tags received.
* Fixed the bindings as reported by the robots.
* Fixed the return value of the helper counting bitflips.
* Included a fix from Jaime Liao in the external pattern logic.
* Added the yaml conversion of Macronix SPI controller description.
* Added the yaml conversion of the SPI-NAND description.
* Created a nand-chip.yaml file to share properties between SPI-NAND and
  raw NAND.

Mason Yang (1):
  mtd: spinand: macronix: Use random program load

Miquel Raynal (21):
  dt-bindings: mtd: nand-controller: Fix the reg property description
  dt-bindings: mtd: nand-controller: Fix a comment in the examples
  dt-bindings: mtd: nand-controller: Harmonize the property types
  dt-bindings: mtd: nand-chip: Create a NAND chip description
  dt-bindings: mtd: spi-nand: Convert spi-nand description file to yaml
  dt-bindings: vendor-prefixes: Clarify Macronix prefix
  dt-bindings: spi: mxic: The interrupt property is not mandatory
  dt-bindings: spi: mxic: Convert to yaml
  dt-bindings: spi: mxic: Document the nand-ecc-engine property
  dt-bindings: mtd: Describe Macronix NAND ECC engine
  mtd: nand: ecc: Add infrastructure to support hardware engines
  mtd: nand: Add a new helper to retrieve the ECC context
  mtd: nand: mxic-ecc: Add Macronix external ECC engine support
  mtd: nand: mxic-ecc: Support SPI pipelined mode
  mtd: spinand: Delay a little bit dirmap creation
  mtd: spinand: Create direct mapping descriptors for ECC operations
  spi: mxic: Fix the transmit path
  spi: mxic: Create a helper to configure the controller before an
    operation
  spi: mxic: Create a helper to ease the start of an operation
  spi: mxic: Add support for direct mapping
  spi: mxic: Add support for pipelined ECC operations

 .../bindings/mtd/mxicy,nand-ecc-engine.yaml   |  77 ++
 .../devicetree/bindings/mtd/nand-chip.yaml    |  70 ++
 .../bindings/mtd/nand-controller.yaml         |  62 +-
 .../devicetree/bindings/mtd/spi-nand.txt      |   5 -
 .../devicetree/bindings/mtd/spi-nand.yaml     |  27 +
 .../bindings/spi/mxicy,mx25f0a-spi.yaml       |  66 ++
 .../devicetree/bindings/spi/spi-mxic.txt      |  34 -
 .../devicetree/bindings/vendor-prefixes.yaml  |   3 +
 drivers/mtd/nand/Kconfig                      |   6 +
 drivers/mtd/nand/Makefile                     |   1 +
 drivers/mtd/nand/core.c                       |  10 +-
 drivers/mtd/nand/ecc-mxic.c                   | 900 ++++++++++++++++++
 drivers/mtd/nand/ecc.c                        |  88 ++
 drivers/mtd/nand/spi/core.c                   |  51 +-
 drivers/mtd/nand/spi/macronix.c               |   2 +-
 drivers/spi/Kconfig                           |   2 +-
 drivers/spi/spi-mxic.c                        | 326 ++++++-
 include/linux/mtd/nand-ecc-mxic.h             |  49 +
 include/linux/mtd/nand.h                      |  33 +
 include/linux/mtd/spinand.h                   |   2 +
 include/linux/spi/spi-mem.h                   |   3 +
 21 files changed, 1656 insertions(+), 161 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mtd/mxicy,nand-ecc-engine.yaml
 create mode 100644 Documentation/devicetree/bindings/mtd/nand-chip.yaml
 delete mode 100644 Documentation/devicetree/bindings/mtd/spi-nand.txt
 create mode 100644 Documentation/devicetree/bindings/mtd/spi-nand.yaml
 create mode 100644 Documentation/devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml
 delete mode 100644 Documentation/devicetree/bindings/spi/spi-mxic.txt
 create mode 100644 drivers/mtd/nand/ecc-mxic.c
 create mode 100644 include/linux/mtd/nand-ecc-mxic.h

-- 
2.27.0

[PATCH v3 01/22] dt-bindings: mtd: nand-controller: Fix the reg property description

[Miquel Raynal]

The reg property of a NAND device always references the chip-select(s).
The ready/busy lines are described in the nand-rb property. I believe
this was a harmless copy/paste error during the conversion to yaml.

Fixes: 212e49693592 ("dt-bindings: mtd: Add YAML schemas for the generic NAND options")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/mtd/nand-controller.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mtd/nand-controller.yaml b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
index bd217e6f5018..811f03978fc6 100644
--- a/Documentation/devicetree/bindings/mtd/nand-controller.yaml
+++ b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
@@ -55,7 +55,7 @@ patternProperties:
     properties:
       reg:
         description:
-          Contains the native Ready/Busy IDs.
+          Contains the chip-select IDs.
 
       nand-ecc-engine:
         allOf:
-- 
2.27.0

[PATCH v3 02/22] dt-bindings: mtd: nand-controller: Fix a comment in the examples

[Miquel Raynal]

The controller properties should be in the controller 'parent' node,
while properties in the children nodes are specific to the NAND
*chip*. This error was already present during the yaml conversion.

Fixes: 2d472aba15ff ("mtd: nand: document the NAND controller/NAND chip DT representation")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/mtd/nand-controller.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mtd/nand-controller.yaml b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
index 811f03978fc6..5cd144a9ec99 100644
--- a/Documentation/devicetree/bindings/mtd/nand-controller.yaml
+++ b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
@@ -184,7 +184,7 @@ examples:
         nand-use-soft-ecc-engine;
         nand-ecc-algo = "bch";
 
-        /* controller specific properties */
+        /* NAND chip specific properties */
       };
 
       nand@1 {
-- 
2.27.0

[PATCH v3 03/22] dt-bindings: mtd: nand-controller: Harmonize the property types

[Miquel Raynal]

Harmonize the different properties in this file by:
* dropping the non-necessary allOf's
* always defining the keywords in the following order:
    - first: "type"/"$ref",
    - second: "description" (when relevant),
    - then the other generic keywords ("enum", "default", etc).

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 .../devicetree/bindings/mtd/nand-controller.yaml | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/mtd/nand-controller.yaml b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
index 5cd144a9ec99..7024ca24c2e2 100644
--- a/Documentation/devicetree/bindings/mtd/nand-controller.yaml
+++ b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
@@ -58,8 +58,7 @@ patternProperties:
           Contains the chip-select IDs.
 
       nand-ecc-engine:
-        allOf:
-          - $ref: /schemas/types.yaml#/definitions/phandle
+        $ref: /schemas/types.yaml#/definitions/phandle
         description: |
           A phandle on the hardware ECC engine if any. There are
           basically three possibilities:
@@ -79,25 +78,24 @@ patternProperties:
         description: Do not use any ECC correction.
 
       nand-ecc-placement:
-        allOf:
-          - $ref: /schemas/types.yaml#/definitions/string
-          - enum: [ oob, interleaved ]
+        $ref: /schemas/types.yaml#/definitions/string
         description:
           Location of the ECC bytes. This location is unknown by default
           but can be explicitly set to "oob", if all ECC bytes are
           known to be stored in the OOB area, or "interleaved" if ECC
           bytes will be interleaved with regular data in the main area.
+        enum: [ oob, interleaved ]
 
       nand-ecc-algo:
+        $ref: /schemas/types.yaml#/definitions/string
         description:
           Desired ECC algorithm.
-        $ref: /schemas/types.yaml#/definitions/string
         enum: [hamming, bch, rs]
 
       nand-bus-width:
+        $ref: /schemas/types.yaml#/definitions/uint32
         description:
           Bus width to the NAND chip
-        $ref: /schemas/types.yaml#/definitions/uint32
         enum: [8, 16]
         default: 8
 
@@ -113,15 +111,15 @@ patternProperties:
           build a volatile BBT in RAM.
 
       nand-ecc-strength:
+        $ref: /schemas/types.yaml#/definitions/uint32
         description:
           Maximum number of bits that can be corrected per ECC step.
-        $ref: /schemas/types.yaml#/definitions/uint32
         minimum: 1
 
       nand-ecc-step-size:
+        $ref: /schemas/types.yaml#/definitions/uint32
         description:
           Number of data bytes covered by a single ECC step.
-        $ref: /schemas/types.yaml#/definitions/uint32
         minimum: 1
 
       nand-ecc-maximize:
-- 
2.27.0

Re: [PATCH v3 03/22] dt-bindings: mtd: nand-controller: Harmonize the property types

[Rob Herring]

On Tue, Dec 07, 2021 at 10:34:03AM +0100, Miquel Raynal wrote:
> Harmonize the different properties in this file by:
> * dropping the non-necessary allOf's
> * always defining the keywords in the following order:
>     - first: "type"/"$ref",
>     - second: "description" (when relevant),

If we're going to muck with this, really I prefer description first or 
last and everything else together.

>     - then the other generic keywords ("enum", "default", etc).
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  .../devicetree/bindings/mtd/nand-controller.yaml | 16 +++++++---------
>  1 file changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/nand-controller.yaml b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
> index 5cd144a9ec99..7024ca24c2e2 100644
> --- a/Documentation/devicetree/bindings/mtd/nand-controller.yaml
> +++ b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
> @@ -58,8 +58,7 @@ patternProperties:
>            Contains the chip-select IDs.
>  
>        nand-ecc-engine:
> -        allOf:
> -          - $ref: /schemas/types.yaml#/definitions/phandle
> +        $ref: /schemas/types.yaml#/definitions/phandle
>          description: |
>            A phandle on the hardware ECC engine if any. There are
>            basically three possibilities:
> @@ -79,25 +78,24 @@ patternProperties:
>          description: Do not use any ECC correction.
>  
>        nand-ecc-placement:
> -        allOf:
> -          - $ref: /schemas/types.yaml#/definitions/string
> -          - enum: [ oob, interleaved ]
> +        $ref: /schemas/types.yaml#/definitions/string
>          description:
>            Location of the ECC bytes. This location is unknown by default
>            but can be explicitly set to "oob", if all ECC bytes are
>            known to be stored in the OOB area, or "interleaved" if ECC
>            bytes will be interleaved with regular data in the main area.
> +        enum: [ oob, interleaved ]
>  
>        nand-ecc-algo:
> +        $ref: /schemas/types.yaml#/definitions/string
>          description:
>            Desired ECC algorithm.
> -        $ref: /schemas/types.yaml#/definitions/string
>          enum: [hamming, bch, rs]
>  
>        nand-bus-width:
> +        $ref: /schemas/types.yaml#/definitions/uint32
>          description:
>            Bus width to the NAND chip
> -        $ref: /schemas/types.yaml#/definitions/uint32
>          enum: [8, 16]
>          default: 8
>  
> @@ -113,15 +111,15 @@ patternProperties:
>            build a volatile BBT in RAM.
>  
>        nand-ecc-strength:
> +        $ref: /schemas/types.yaml#/definitions/uint32
>          description:
>            Maximum number of bits that can be corrected per ECC step.
> -        $ref: /schemas/types.yaml#/definitions/uint32
>          minimum: 1
>  
>        nand-ecc-step-size:
> +        $ref: /schemas/types.yaml#/definitions/uint32
>          description:
>            Number of data bytes covered by a single ECC step.
> -        $ref: /schemas/types.yaml#/definitions/uint32
>          minimum: 1
>  
>        nand-ecc-maximize:
> -- 
> 2.27.0
> 
> 

Re: [PATCH v3 03/22] dt-bindings: mtd: nand-controller: Harmonize the property types

[Miquel Raynal]

Hi Rob,

robh@kernel.org wrote on Tue, 14 Dec 2021 11:45:25 -0600:

> On Tue, Dec 07, 2021 at 10:34:03AM +0100, Miquel Raynal wrote:
> > Harmonize the different properties in this file by:
> > * dropping the non-necessary allOf's
> > * always defining the keywords in the following order:
> >     - first: "type"/"$ref",
> >     - second: "description" (when relevant),  
> 
> If we're going to muck with this, really I prefer description first or 
> last and everything else together.

Ok, no problem.

This is just a patch cleaning things up before moving the properties
around anyway.

Can I add your Reviewed-by when sending the updated version? I would
like to merge the first halve of this series soon enough.

> 
> >     - then the other generic keywords ("enum", "default", etc).
> > 
> > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks,
Miquèl

[PATCH v3 04/22] dt-bindings: mtd: nand-chip: Create a NAND chip description

[Miquel Raynal]

Move the NAND chip description out of the NAND controller file. Indeed,
a subsequent part of the properties supported by a raw NAND chip are
also supported by SPI-NAND chips. So let's create a generic NAND chip
description which will be pulled by nand-controller.yaml and later by
spi-nand.yaml as well.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/mtd/nand-chip.yaml    | 70 +++++++++++++++++++
 .../bindings/mtd/nand-controller.yaml         | 50 +------------
 2 files changed, 72 insertions(+), 48 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mtd/nand-chip.yaml

diff --git a/Documentation/devicetree/bindings/mtd/nand-chip.yaml b/Documentation/devicetree/bindings/mtd/nand-chip.yaml
new file mode 100644
index 000000000000..2e91cf471f81
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/nand-chip.yaml
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/nand-chip.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NAND Chip and NAND Controller Generic Binding
+
+maintainers:
+  - Miquel Raynal <miquel.raynal@bootlin.com>
+
+description: |
+  This file covers the generic description of a NAND chip. It implies that the
+  bus interface should not be taken into account: both raw NAND devices and
+  SPI-NAND devices are concerned by this description.
+
+properties:
+  reg:
+    description:
+      Contains the chip-select IDs.
+
+  nand-ecc-engine:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: |
+      A phandle on the hardware ECC engine if any. There are
+      basically three possibilities:
+      1/ The ECC engine is part of the NAND controller, in this
+      case the phandle should reference the parent node.
+      2/ The ECC engine is part of the NAND part (on-die), in this
+      case the phandle should reference the node itself.
+      3/ The ECC engine is external, in this case the phandle should
+      reference the specific ECC engine node.
+
+  nand-use-soft-ecc-engine:
+    type: boolean
+    description: Use a software ECC engine.
+
+  nand-no-ecc-engine:
+    type: boolean
+    description: Do not use any ECC correction.
+
+  nand-ecc-algo:
+    $ref: /schemas/types.yaml#/definitions/string
+    description:
+      Desired ECC algorithm.
+    enum: [hamming, bch, rs]
+
+  nand-ecc-strength:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Maximum number of bits that can be corrected per ECC step.
+    minimum: 1
+
+  nand-ecc-step-size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Number of data bytes covered by a single ECC step.
+    minimum: 1
+
+  secure-regions:
+    $ref: /schemas/types.yaml#/definitions/uint64-matrix
+    description:
+      Regions in the NAND chip which are protected using a secure element
+      like Trustzone. This property contains the start address and size of
+      the secure regions present.
+
+required:
+  - reg
+
+additionalProperties: true
diff --git a/Documentation/devicetree/bindings/mtd/nand-controller.yaml b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
index 7024ca24c2e2..05229d2dbb07 100644
--- a/Documentation/devicetree/bindings/mtd/nand-controller.yaml
+++ b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
@@ -52,31 +52,13 @@ properties:
 patternProperties:
   "^nand@[a-f0-9]$":
     type: object
+    $ref: "nand-chip.yaml#"
+
     properties:
       reg:
         description:
           Contains the chip-select IDs.
 
-      nand-ecc-engine:
-        $ref: /schemas/types.yaml#/definitions/phandle
-        description: |
-          A phandle on the hardware ECC engine if any. There are
-          basically three possibilities:
-          1/ The ECC engine is part of the NAND controller, in this
-          case the phandle should reference the parent node.
-          2/ The ECC engine is part of the NAND part (on-die), in this
-          case the phandle should reference the node itself.
-          3/ The ECC engine is external, in this case the phandle should
-          reference the specific ECC engine node.
-
-      nand-use-soft-ecc-engine:
-        type: boolean
-        description: Use a software ECC engine.
-
-      nand-no-ecc-engine:
-        type: boolean
-        description: Do not use any ECC correction.
-
       nand-ecc-placement:
         $ref: /schemas/types.yaml#/definitions/string
         description:
@@ -86,12 +68,6 @@ patternProperties:
           bytes will be interleaved with regular data in the main area.
         enum: [ oob, interleaved ]
 
-      nand-ecc-algo:
-        $ref: /schemas/types.yaml#/definitions/string
-        description:
-          Desired ECC algorithm.
-        enum: [hamming, bch, rs]
-
       nand-bus-width:
         $ref: /schemas/types.yaml#/definitions/uint32
         description:
@@ -110,18 +86,6 @@ patternProperties:
           find Bad Block Markers (BBM). These markers will help to
           build a volatile BBT in RAM.
 
-      nand-ecc-strength:
-        $ref: /schemas/types.yaml#/definitions/uint32
-        description:
-          Maximum number of bits that can be corrected per ECC step.
-        minimum: 1
-
-      nand-ecc-step-size:
-        $ref: /schemas/types.yaml#/definitions/uint32
-        description:
-          Number of data bytes covered by a single ECC step.
-        minimum: 1
-
       nand-ecc-maximize:
         $ref: /schemas/types.yaml#/definitions/flag
         description:
@@ -152,13 +116,6 @@ patternProperties:
           Ready/Busy pins. Active state refers to the NAND ready state and
           should be set to GPIOD_ACTIVE_HIGH unless the signal is inverted.
 
-      secure-regions:
-        $ref: /schemas/types.yaml#/definitions/uint64-matrix
-        description:
-          Regions in the NAND chip which are protected using a secure element
-          like Trustzone. This property contains the start address and size of
-          the secure regions present.
-
     required:
       - reg
 
@@ -179,9 +136,6 @@ examples:
 
       nand@0 {
         reg = <0>; /* Native CS */
-        nand-use-soft-ecc-engine;
-        nand-ecc-algo = "bch";
-
         /* NAND chip specific properties */
       };
 
-- 
2.27.0

[PATCH v3 05/22] dt-bindings: mtd: spi-nand: Convert spi-nand description file to yaml

[Miquel Raynal]

Let's get rid of spi-nand.txt by converting it to yaml schema. While at
converting this file, let's actually pull all the generic properties
from nand-chip.yaml which might apply to a SPI-NAND chip.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/mtd/spi-nand.txt      |  5 ----
 .../devicetree/bindings/mtd/spi-nand.yaml     | 27 +++++++++++++++++++
 2 files changed, 27 insertions(+), 5 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/mtd/spi-nand.txt
 create mode 100644 Documentation/devicetree/bindings/mtd/spi-nand.yaml

diff --git a/Documentation/devicetree/bindings/mtd/spi-nand.txt b/Documentation/devicetree/bindings/mtd/spi-nand.txt
deleted file mode 100644
index 8b51f3b6d55c..000000000000
--- a/Documentation/devicetree/bindings/mtd/spi-nand.txt
+++ /dev/null
@@ -1,5 +0,0 @@
-SPI NAND flash
-
-Required properties:
-- compatible: should be "spi-nand"
-- reg: should encode the chip-select line used to access the NAND chip
diff --git a/Documentation/devicetree/bindings/mtd/spi-nand.yaml b/Documentation/devicetree/bindings/mtd/spi-nand.yaml
new file mode 100644
index 000000000000..19ac57dcffc3
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/spi-nand.yaml
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/spi-nand.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SPI-NAND flash device tree bindings
+
+maintainers:
+  - Miquel Raynal <miquel.raynal@bootlin.com>
+
+allOf:
+  - $ref: "nand-chip.yaml#"
+
+properties:
+  compatible:
+    const: spi-nand
+
+  reg:
+    maxItems: 1
+    description: Encode the chip-select line on the SPI bus
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
-- 
2.27.0

[PATCH v3 06/22] dt-bindings: vendor-prefixes: Clarify Macronix prefix

[Miquel Raynal]

When looking at compatible prefixes, Macronix is sometimes referred as
"mxicy":
- mxicy,mx25r1635f
- mxicy,mx25u6435f
- mxicy,mx25v8035f
- mxicy,mx25f0a-spi
and sometimes as "mxic":
- mxic,multi-itfc-v009-nand-controller
- mxic,enable-randomizer-otp

The oldest prefix that is also the one preferred by Macronix engineers
is "mxicy", so document the other one and mark it deprecated.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index a867f7102c35..93d65dc3746c 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -774,6 +774,9 @@ patternProperties:
     description: Mundo Reader S.L.
   "^murata,.*":
     description: Murata Manufacturing Co., Ltd.
+  "^mxic,.*":
+    description: Macronix International Co., Ltd.
+    deprecated: true
   "^mxicy,.*":
     description: Macronix International Co., Ltd.
   "^myir,.*":
-- 
2.27.0

[PATCH v3 07/22] dt-bindings: spi: mxic: The interrupt property is not mandatory

[Miquel Raynal]

The interrupt property is not mandatory at all, this property should not
be part of the required properties list, so move it into the optional
properties list.

Fixes: 326e5c8d4a87 ("dt-binding: spi: Document Macronix controller bindings")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 Documentation/devicetree/bindings/spi/spi-mxic.txt | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/spi/spi-mxic.txt b/Documentation/devicetree/bindings/spi/spi-mxic.txt
index 529f2dab2648..7bcbb229b78b 100644
--- a/Documentation/devicetree/bindings/spi/spi-mxic.txt
+++ b/Documentation/devicetree/bindings/spi/spi-mxic.txt
@@ -8,11 +8,13 @@ Required properties:
 - reg: should contain 2 entries, one for the registers and one for the direct
        mapping area
 - reg-names: should contain "regs" and "dirmap"
-- interrupts: interrupt line connected to the SPI controller
 - clock-names: should contain "ps_clk", "send_clk" and "send_dly_clk"
 - clocks: should contain 3 entries for the "ps_clk", "send_clk" and
 	  "send_dly_clk" clocks
 
+Optional properties:
+- interrupts: interrupt line connected to the SPI controller
+
 Example:
 
 	spi@43c30000 {
-- 
2.27.0

[PATCH v3 08/22] dt-bindings: spi: mxic: Convert to yaml

[Miquel Raynal]

Straightforward conversion from regular text to yaml schema of the
Macronix SPI controller DT bindings.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 .../bindings/spi/mxicy,mx25f0a-spi.yaml       | 60 +++++++++++++++++++
 .../devicetree/bindings/spi/spi-mxic.txt      | 36 -----------
 2 files changed, 60 insertions(+), 36 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml
 delete mode 100644 Documentation/devicetree/bindings/spi/spi-mxic.txt

diff --git a/Documentation/devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml b/Documentation/devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml
new file mode 100644
index 000000000000..f20d100b4a68
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/mxicy,mx25f0a-spi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Macronix SPI controller device tree bindings
+
+maintainers:
+  - Miquel Raynal <miquel.raynal@bootlin.com>
+
+allOf:
+  - $ref: "spi-controller.yaml#"
+
+properties:
+  compatible:
+    const: mxicy,mx25f0a-spi
+
+  reg:
+    minItems: 2
+    maxItems: 2
+
+  reg-names:
+    items:
+      - const: regs
+      - const: dirmap
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    minItems: 3
+    maxItems: 3
+
+  clock-names:
+    items:
+      - const: send_clk
+      - const: send_dly_clk
+      - const: ps_clk
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - clocks
+  - clock-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    spi@43c30000 {
+      compatible = "mxicy,mx25f0a-spi";
+      reg = <0x43c30000 0x10000>, <0xa0000000 0x20000000>;
+      reg-names = "regs", "dirmap";
+      clocks = <&clkwizard 0>, <&clkwizard 1>, <&clkc 18>;
+      clock-names = "send_clk", "send_dly_clk", "ps_clk";
+      #address-cells = <1>;
+      #size-cells = <0>;
+    };
diff --git a/Documentation/devicetree/bindings/spi/spi-mxic.txt b/Documentation/devicetree/bindings/spi/spi-mxic.txt
deleted file mode 100644
index 7bcbb229b78b..000000000000
--- a/Documentation/devicetree/bindings/spi/spi-mxic.txt
+++ /dev/null
@@ -1,36 +0,0 @@
-Macronix SPI controller Device Tree Bindings
---------------------------------------------
-
-Required properties:
-- compatible: should be "mxicy,mx25f0a-spi"
-- #address-cells: should be 1
-- #size-cells: should be 0
-- reg: should contain 2 entries, one for the registers and one for the direct
-       mapping area
-- reg-names: should contain "regs" and "dirmap"
-- clock-names: should contain "ps_clk", "send_clk" and "send_dly_clk"
-- clocks: should contain 3 entries for the "ps_clk", "send_clk" and
-	  "send_dly_clk" clocks
-
-Optional properties:
-- interrupts: interrupt line connected to the SPI controller
-
-Example:
-
-	spi@43c30000 {
-		compatible = "mxicy,mx25f0a-spi";
-		reg = <0x43c30000 0x10000>, <0xa0000000 0x20000000>;
-		reg-names = "regs", "dirmap";
-		clocks = <&clkwizard 0>, <&clkwizard 1>, <&clkc 18>;
-		clock-names = "send_clk", "send_dly_clk", "ps_clk";
-		#address-cells = <1>;
-		#size-cells = <0>;
-
-		flash@0 {
-			compatible = "jedec,spi-nor";
-			reg = <0>;
-			spi-max-frequency = <25000000>;
-			spi-tx-bus-width = <4>;
-			spi-rx-bus-width = <4>;
-		};
-	};
-- 
2.27.0

[PATCH v3 09/22] dt-bindings: spi: mxic: Document the nand-ecc-engine property

[Miquel Raynal]

This SPI controller supports interacting with an external ECC
engine. The nand-ecc-engine property already exist in the NAND world but
also applies to SPI controller nodes which have external correction
capabilities like Macronix's.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 .../devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml          | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml b/Documentation/devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml
index f20d100b4a68..4e8a73e00f22 100644
--- a/Documentation/devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml
+++ b/Documentation/devicetree/bindings/spi/mxicy,mx25f0a-spi.yaml
@@ -38,6 +38,12 @@ properties:
       - const: send_dly_clk
       - const: ps_clk
 
+  nand-ecc-engine:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/phandle
+    description: NAND ECC engine used by the SPI controller in order to perform
+      on-the-fly correction when using a SPI-NAND memory.
+
 required:
   - compatible
   - reg
-- 
2.27.0

[PATCH v3 10/22] dt-bindings: mtd: Describe Macronix NAND ECC engine

[Miquel Raynal]

Describe Macronix NAND ECC engine. This engine may be used as an
external engine or can be pipelined with either a raw NAND controller or
a SPI controller. Both hardware designs with a SPI controller are shown
in the examples.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/mtd/mxicy,nand-ecc-engine.yaml   | 77 +++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/mxicy,nand-ecc-engine.yaml

diff --git a/Documentation/devicetree/bindings/mtd/mxicy,nand-ecc-engine.yaml b/Documentation/devicetree/bindings/mtd/mxicy,nand-ecc-engine.yaml
new file mode 100644
index 000000000000..804479999ccb
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/mxicy,nand-ecc-engine.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/mxicy,nand-ecc-engine.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Macronix NAND ECC engine device tree bindings
+
+maintainers:
+  - Miquel Raynal <miquel.raynal@bootlin.com>
+
+properties:
+  compatible:
+    const: mxicy,nand-ecc-engine-rev3
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    /* External configuration */
+    spi_controller0: spi@43c30000 {
+        compatible = "mxicy,mx25f0a-spi";
+        reg = <0x43c30000 0x10000>, <0xa0000000 0x4000000>;
+        reg-names = "regs", "dirmap";
+        clocks = <&clkwizard 0>, <&clkwizard 1>, <&clkc 15>;
+        clock-names = "send_clk", "send_dly_clk", "ps_clk";
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        flash@0 {
+            compatible = "spi-nand";
+            reg = <0>;
+            nand-ecc-engine = <&ecc_engine0>;
+        };
+    };
+
+    ecc_engine0: ecc@43c40000 {
+        compatible = "mxicy,nand-ecc-engine-rev3";
+        reg = <0x43c40000 0x10000>;
+    };
+
+  - |
+    /* Pipelined configuration */
+    spi_controller1: spi@43c30000 {
+        compatible = "mxicy,mx25f0a-spi";
+        reg = <0x43c30000 0x10000>, <0xa0000000 0x4000000>;
+        reg-names = "regs", "dirmap";
+        clocks = <&clkwizard 0>, <&clkwizard 1>, <&clkc 15>;
+        clock-names = "send_clk", "send_dly_clk", "ps_clk";
+        #address-cells = <1>;
+        #size-cells = <0>;
+        nand-ecc-engine = <&ecc_engine1>;
+
+        flash@0 {
+            compatible = "spi-nand";
+            reg = <0>;
+            nand-ecc-engine = <&spi_controller1>;
+        };
+    };
+
+    ecc_engine1: ecc@43c40000 {
+        compatible = "mxicy,nand-ecc-engine-rev3";
+        reg = <0x43c40000 0x10000>;
+    };
-- 
2.27.0

[PATCH v3 11/22] mtd: spinand: macronix: Use random program load

[Miquel Raynal]

From: Mason Yang <masonccyang@mxic.com.tw>

Macronix SPI-NAND chips might benefit from an external ECC
engine. Such an engine might need to access random columns, thus needing
to use random commands (0x84 instead of 0x02).

Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/spi/macronix.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/spi/macronix.c b/drivers/mtd/nand/spi/macronix.c
index 3f31f1381a62..dce835132a1e 100644
--- a/drivers/mtd/nand/spi/macronix.c
+++ b/drivers/mtd/nand/spi/macronix.c
@@ -20,7 +20,7 @@ static SPINAND_OP_VARIANTS(read_cache_variants,
 
 static SPINAND_OP_VARIANTS(write_cache_variants,
 		SPINAND_PROG_LOAD_X4(true, 0, NULL, 0),
-		SPINAND_PROG_LOAD(true, 0, NULL, 0));
+		SPINAND_PROG_LOAD(false, 0, NULL, 0));
 
 static SPINAND_OP_VARIANTS(update_cache_variants,
 		SPINAND_PROG_LOAD_X4(false, 0, NULL, 0),
-- 
2.27.0

[PATCH v3 12/22] mtd: nand: ecc: Add infrastructure to support hardware engines

[Miquel Raynal]

Add the necessary helpers to register/unregister hardware ECC engines
that will be called from ECC engine drivers.

Also add helpers to get the right engine from the user
perspective. Keep a reference of the in use ECC engine in order to
prevent modules to be unloaded. Put the reference when the engine gets
retired.

A static list of hardware (only) ECC engines is setup to keep track of
the registered engines.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/core.c  | 10 +++--
 drivers/mtd/nand/ecc.c   | 88 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/nand.h | 28 +++++++++++++
 3 files changed, 123 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/core.c b/drivers/mtd/nand/core.c
index df9646685c91..5628bd410f7e 100644
--- a/drivers/mtd/nand/core.c
+++ b/drivers/mtd/nand/core.c
@@ -232,7 +232,9 @@ static int nanddev_get_ecc_engine(struct nand_device *nand)
 		nand->ecc.engine = nand_ecc_get_on_die_hw_engine(nand);
 		break;
 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
-		pr_err("On-host hardware ECC engines not supported yet\n");
+		nand->ecc.engine = nand_ecc_get_on_host_hw_engine(nand);
+		if (PTR_ERR(nand->ecc.engine) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
 		break;
 	default:
 		pr_err("Missing ECC engine type\n");
@@ -252,7 +254,7 @@ static int nanddev_put_ecc_engine(struct nand_device *nand)
 {
 	switch (nand->ecc.ctx.conf.engine_type) {
 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
-		pr_err("On-host hardware ECC engines not supported yet\n");
+		nand_ecc_put_on_host_hw_engine(nand);
 		break;
 	case NAND_ECC_ENGINE_TYPE_NONE:
 	case NAND_ECC_ENGINE_TYPE_SOFT:
@@ -297,7 +299,9 @@ int nanddev_ecc_engine_init(struct nand_device *nand)
 	/* Look for the ECC engine to use */
 	ret = nanddev_get_ecc_engine(nand);
 	if (ret) {
-		pr_err("No ECC engine found\n");
+		if (ret != -EPROBE_DEFER)
+			pr_err("No ECC engine found\n");
+
 		return ret;
 	}
 
diff --git a/drivers/mtd/nand/ecc.c b/drivers/mtd/nand/ecc.c
index 6c43dfda01d4..078f5ec38de3 100644
--- a/drivers/mtd/nand/ecc.c
+++ b/drivers/mtd/nand/ecc.c
@@ -96,6 +96,12 @@
 #include <linux/module.h>
 #include <linux/mtd/nand.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+
+static LIST_HEAD(on_host_hw_engines);
+static DEFINE_MUTEX(on_host_hw_engines_mutex);
 
 /**
  * nand_ecc_init_ctx - Init the ECC engine context
@@ -611,6 +617,88 @@ struct nand_ecc_engine *nand_ecc_get_on_die_hw_engine(struct nand_device *nand)
 }
 EXPORT_SYMBOL(nand_ecc_get_on_die_hw_engine);
 
+int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine)
+{
+	struct nand_ecc_engine *item;
+
+	if (!engine)
+		return -EINVAL;
+
+	/* Prevent multiple registrations of one engine */
+	list_for_each_entry(item, &on_host_hw_engines, node)
+		if (item == engine)
+			return 0;
+
+	mutex_lock(&on_host_hw_engines_mutex);
+	list_add_tail(&engine->node, &on_host_hw_engines);
+	mutex_unlock(&on_host_hw_engines_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(nand_ecc_register_on_host_hw_engine);
+
+int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine)
+{
+	if (!engine)
+		return -EINVAL;
+
+	mutex_lock(&on_host_hw_engines_mutex);
+	list_del(&engine->node);
+	mutex_unlock(&on_host_hw_engines_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(nand_ecc_unregister_on_host_hw_engine);
+
+static struct nand_ecc_engine *nand_ecc_match_on_host_hw_engine(struct device *dev)
+{
+	struct nand_ecc_engine *item;
+
+	list_for_each_entry(item, &on_host_hw_engines, node)
+		if (item->dev == dev)
+			return item;
+
+	return NULL;
+}
+
+struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand)
+{
+	struct nand_ecc_engine *engine = NULL;
+	struct device *dev = &nand->mtd.dev;
+	struct platform_device *pdev;
+	struct device_node *np;
+
+	if (list_empty(&on_host_hw_engines))
+		return NULL;
+
+	/* Check for an explicit nand-ecc-engine property */
+	np = of_parse_phandle(dev->of_node, "nand-ecc-engine", 0);
+	if (np) {
+		pdev = of_find_device_by_node(np);
+		if (!pdev)
+			return ERR_PTR(-EPROBE_DEFER);
+
+		engine = nand_ecc_match_on_host_hw_engine(&pdev->dev);
+		platform_device_put(pdev);
+		of_node_put(np);
+
+		if (!engine)
+			return ERR_PTR(-EPROBE_DEFER);
+	}
+
+	if (engine)
+		get_device(engine->dev);
+
+	return engine;
+}
+EXPORT_SYMBOL(nand_ecc_get_on_host_hw_engine);
+
+void nand_ecc_put_on_host_hw_engine(struct nand_device *nand)
+{
+	put_device(nand->ecc.engine->dev);
+}
+EXPORT_SYMBOL(nand_ecc_put_on_host_hw_engine);
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com>");
 MODULE_DESCRIPTION("Generic ECC engine");
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 32fc7edf65b3..4ddd20fe9c9e 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -263,12 +263,36 @@ struct nand_ecc_engine_ops {
 			     struct nand_page_io_req *req);
 };
 
+/**
+ * enum nand_ecc_engine_integration - How the NAND ECC engine is integrated
+ * @NAND_ECC_ENGINE_INTEGRATION_INVALID: Invalid value
+ * @NAND_ECC_ENGINE_INTEGRATION_PIPELINED: Pipelined engine, performs on-the-fly
+ *                                         correction, does not need to copy
+ *                                         data around
+ * @NAND_ECC_ENGINE_INTEGRATION_EXTERNAL: External engine, needs to bring the
+ *                                        data into its own area before use
+ */
+enum nand_ecc_engine_integration {
+	NAND_ECC_ENGINE_INTEGRATION_INVALID,
+	NAND_ECC_ENGINE_INTEGRATION_PIPELINED,
+	NAND_ECC_ENGINE_INTEGRATION_EXTERNAL,
+};
+
 /**
  * struct nand_ecc_engine - ECC engine abstraction for NAND devices
+ * @dev: Host device
+ * @node: Private field for registration time
  * @ops: ECC engine operations
+ * @integration: How the engine is integrated with the host
+ *               (only relevant on %NAND_ECC_ENGINE_TYPE_ON_HOST engines)
+ * @priv: Private data
  */
 struct nand_ecc_engine {
+	struct device *dev;
+	struct list_head node;
 	struct nand_ecc_engine_ops *ops;
+	enum nand_ecc_engine_integration integration;
+	void *priv;
 };
 
 void of_get_nand_ecc_user_config(struct nand_device *nand);
@@ -279,8 +303,12 @@ int nand_ecc_prepare_io_req(struct nand_device *nand,
 int nand_ecc_finish_io_req(struct nand_device *nand,
 			   struct nand_page_io_req *req);
 bool nand_ecc_is_strong_enough(struct nand_device *nand);
+int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine);
+int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine);
 struct nand_ecc_engine *nand_ecc_get_sw_engine(struct nand_device *nand);
 struct nand_ecc_engine *nand_ecc_get_on_die_hw_engine(struct nand_device *nand);
+struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand);
+void nand_ecc_put_on_host_hw_engine(struct nand_device *nand);
 
 #if IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING)
 struct nand_ecc_engine *nand_ecc_sw_hamming_get_engine(void);
-- 
2.27.0

[PATCH v3 13/22] mtd: nand: Add a new helper to retrieve the ECC context

[Miquel Raynal]

Introduce nand_to_ecc_ctx() which will allow to easily jump to the
private pointer of an ECC context given a NAND device. This is very
handy, from the prepare or finish ECC hook, to get the internal context
out of the NAND device object.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 include/linux/mtd/nand.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 4ddd20fe9c9e..b617efa0a881 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -990,6 +990,11 @@ int nanddev_markbad(struct nand_device *nand, const struct nand_pos *pos);
 int nanddev_ecc_engine_init(struct nand_device *nand);
 void nanddev_ecc_engine_cleanup(struct nand_device *nand);
 
+static inline void *nand_to_ecc_ctx(struct nand_device *nand)
+{
+	return nand->ecc.ctx.priv;
+}
+
 /* BBT related functions */
 enum nand_bbt_block_status {
 	NAND_BBT_BLOCK_STATUS_UNKNOWN,
-- 
2.27.0

[PATCH v3 14/22] mtd: nand: mxic-ecc: Add Macronix external ECC engine support

[Miquel Raynal]

Some SPI-NAND chips do not support on-die ECC. For these chips,
correction must apply on the SPI controller end. In order to avoid
doing all the calculations by software, Macronix provides a specific
engine that can offload the intensive work.

Add Macronix ECC engine support, this engine can work in conjunction
with a SPI controller and a raw NAND controller, it can be pipelined
or external and supports linear and syndrome layouts.

Right now the simplest configuration is supported: SPI controller
external and linear ECC engine.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/Kconfig    |   6 +
 drivers/mtd/nand/Makefile   |   1 +
 drivers/mtd/nand/ecc-mxic.c | 692 ++++++++++++++++++++++++++++++++++++
 3 files changed, 699 insertions(+)
 create mode 100644 drivers/mtd/nand/ecc-mxic.c

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index b40455234cbd..8431292ff49d 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -46,6 +46,12 @@ config MTD_NAND_ECC_SW_BCH
 	  ECC codes. They are used with NAND devices requiring more than 1 bit
 	  of error correction.
 
+config MTD_NAND_ECC_MXIC
+	bool "Macronix external hardware ECC engine"
+	select MTD_NAND_ECC
+	help
+	  This enables support for the hardware ECC engine from Macronix.
+
 endmenu
 
 endmenu
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 1c0b46960eb1..a4e6b7ae0614 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -10,3 +10,4 @@ obj-y	+= spi/
 nandcore-$(CONFIG_MTD_NAND_ECC) += ecc.o
 nandcore-$(CONFIG_MTD_NAND_ECC_SW_HAMMING) += ecc-sw-hamming.o
 nandcore-$(CONFIG_MTD_NAND_ECC_SW_BCH) += ecc-sw-bch.o
+nandcore-$(CONFIG_MTD_NAND_ECC_MXIC) += ecc-mxic.o
diff --git a/drivers/mtd/nand/ecc-mxic.c b/drivers/mtd/nand/ecc-mxic.c
new file mode 100644
index 000000000000..ea88a411ed70
--- /dev/null
+++ b/drivers/mtd/nand/ecc-mxic.c
@@ -0,0 +1,692 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Support for Macronix external hardware ECC engine for NAND devices, also
+ * called DPE for Data Processing Engine.
+ *
+ * Copyright © 2019 Macronix
+ * Author: Miquel Raynal <miquel.raynal@bootlin.com>
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/* DPE Configuration */
+#define DP_CONFIG 0x00
+#define   ECC_EN BIT(0)
+#define   ECC_TYP(idx) (((idx) << 3) & GENMASK(6, 3))
+/* DPE Interrupt Status */
+#define INTRPT_STS 0x04
+#define   TRANS_CMPLT BIT(0)
+#define   SDMA_MAIN BIT(1)
+#define   SDMA_SPARE BIT(2)
+#define   ECC_ERR BIT(3)
+#define   TO_SPARE BIT(4)
+#define   TO_MAIN BIT(5)
+/* DPE Interrupt Status Enable */
+#define INTRPT_STS_EN 0x08
+/* DPE Interrupt Signal Enable */
+#define INTRPT_SIG_EN 0x0C
+/* Host Controller Configuration */
+#define HC_CONFIG 0x10
+#define   MEM2MEM BIT(4) /* TRANS_TYP_IO in the spec */
+#define   ECC_PACKED 0 /* LAYOUT_TYP_INTEGRATED in the spec */
+#define   ECC_INTERLEAVED BIT(2) /* LAYOUT_TYP_DISTRIBUTED in the spec */
+#define   BURST_TYP_FIXED 0
+#define   BURST_TYP_INCREASING BIT(0)
+/* Host Controller Slave Address */
+#define HC_SLV_ADDR 0x14
+/* ECC Chunk Size */
+#define CHUNK_SIZE 0x20
+/* Main Data Size */
+#define MAIN_SIZE 0x24
+/* Spare Data Size */
+#define SPARE_SIZE 0x28
+#define   META_SZ(reg) ((reg) & GENMASK(7, 0))
+#define   PARITY_SZ(reg) (((reg) & GENMASK(15, 8)) >> 8)
+#define   RSV_SZ(reg) (((reg) & GENMASK(23, 16)) >> 16)
+#define   SPARE_SZ(reg) ((reg) >> 24)
+/* ECC Chunk Count */
+#define CHUNK_CNT 0x30
+/* SDMA Control */
+#define SDMA_CTRL 0x40
+#define   WRITE_NAND 0
+#define   READ_NAND BIT(1)
+#define   CONT_NAND BIT(29)
+#define   CONT_SYSM BIT(30) /* Continue System Memory? */
+#define   SDMA_STRT BIT(31)
+/* SDMA Address of Main Data */
+#define SDMA_MAIN_ADDR 0x44
+/* SDMA Address of Spare Data */
+#define SDMA_SPARE_ADDR 0x48
+/* DPE Version Number */
+#define DP_VER 0xD0
+#define   DP_VER_OFFSET 16
+
+/* Status bytes between each chunk of spare data */
+#define STAT_BYTES 4
+#define   NO_ERR 0x00
+#define   MAX_CORR_ERR 0x28
+#define   UNCORR_ERR 0xFE
+#define   ERASED_CHUNK 0xFF
+
+struct mxic_ecc_engine {
+	struct device *dev;
+	void __iomem *regs;
+	int irq;
+	struct completion complete;
+	struct nand_ecc_engine external_engine;
+	struct mutex lock;
+};
+
+struct mxic_ecc_ctx {
+	/* ECC machinery */
+	unsigned int data_step_sz;
+	unsigned int oob_step_sz;
+	unsigned int parity_sz;
+	unsigned int meta_sz;
+	u8 *status;
+	int steps;
+
+	/* DMA boilerplate */
+	struct nand_ecc_req_tweak_ctx req_ctx;
+	u8 *oobwithstat;
+	struct scatterlist sg[2];
+	struct nand_page_io_req *req;
+};
+
+static struct mxic_ecc_engine *ext_ecc_eng_to_mxic(struct nand_ecc_engine *eng)
+{
+	return container_of(eng, struct mxic_ecc_engine, external_engine);
+}
+
+static struct mxic_ecc_engine *nand_to_mxic(struct nand_device *nand)
+{
+	struct nand_ecc_engine *eng = nand->ecc.engine;
+
+	return ext_ecc_eng_to_mxic(eng);
+}
+
+static int mxic_ecc_ooblayout_ecc(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *oobregion)
+{
+	struct nand_device *nand = mtd_to_nanddev(mtd);
+	struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand);
+
+	if (section < 0 || section >= ctx->steps)
+		return -ERANGE;
+
+	oobregion->offset = (section * ctx->oob_step_sz) + ctx->meta_sz;
+	oobregion->length = ctx->parity_sz;
+
+	return 0;
+}
+
+static int mxic_ecc_ooblayout_free(struct mtd_info *mtd, int section,
+				   struct mtd_oob_region *oobregion)
+{
+	struct nand_device *nand = mtd_to_nanddev(mtd);
+	struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand);
+
+	if (section < 0 || section >= ctx->steps)
+		return -ERANGE;
+
+	if (!section) {
+		oobregion->offset = 2;
+		oobregion->length = ctx->meta_sz - 2;
+	} else {
+		oobregion->offset = section * ctx->oob_step_sz;
+		oobregion->length = ctx->meta_sz;
+	}
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops mxic_ecc_ooblayout_ops = {
+	.ecc = mxic_ecc_ooblayout_ecc,
+	.free = mxic_ecc_ooblayout_free,
+};
+
+static void mxic_ecc_disable_engine(struct mxic_ecc_engine *mxic)
+{
+	u32 reg;
+
+	reg = readl(mxic->regs + DP_CONFIG);
+	reg &= ~ECC_EN;
+	writel(reg, mxic->regs + DP_CONFIG);
+}
+
+static void mxic_ecc_enable_engine(struct mxic_ecc_engine *mxic)
+{
+	u32 reg;
+
+	reg = readl(mxic->regs + DP_CONFIG);
+	reg |= ECC_EN;
+	writel(reg, mxic->regs + DP_CONFIG);
+}
+
+static void mxic_ecc_disable_int(struct mxic_ecc_engine *mxic)
+{
+	writel(0, mxic->regs + INTRPT_SIG_EN);
+}
+
+static void mxic_ecc_enable_int(struct mxic_ecc_engine *mxic)
+{
+	writel(TRANS_CMPLT, mxic->regs + INTRPT_SIG_EN);
+}
+
+static irqreturn_t mxic_ecc_isr(int irq, void *dev_id)
+{
+	struct mxic_ecc_engine *mxic = dev_id;
+	u32 sts;
+
+	sts = readl(mxic->regs + INTRPT_STS);
+	if (!sts)
+		return IRQ_NONE;
+
+	if (sts & TRANS_CMPLT)
+		complete(&mxic->complete);
+
+	writel(sts, mxic->regs + INTRPT_STS);
+
+	return IRQ_HANDLED;
+}
+
+static int mxic_ecc_init_ctx(struct nand_device *nand, struct device *dev)
+{
+	struct mxic_ecc_engine *mxic = nand_to_mxic(nand);
+	struct nand_ecc_props *conf = &nand->ecc.ctx.conf;
+	struct nand_ecc_props *reqs = &nand->ecc.requirements;
+	struct nand_ecc_props *user = &nand->ecc.user_conf;
+	struct mtd_info *mtd = nanddev_to_mtd(nand);
+	int step_size = 0, strength = 0, desired_correction = 0, steps, idx;
+	int possible_strength[] = {4, 8, 40, 48};
+	int spare_size[] = {32, 32, 96, 96};
+	struct mxic_ecc_ctx *ctx;
+	u32 spare_reg;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	nand->ecc.ctx.priv = ctx;
+
+	/* Only large page NAND chips may use BCH */
+	if (mtd->oobsize < 64) {
+		pr_err("BCH cannot be used with small page NAND chips\n");
+		return -EINVAL;
+	}
+
+	mtd_set_ooblayout(mtd, &mxic_ecc_ooblayout_ops);
+
+	/* Enable all status bits */
+	writel(TRANS_CMPLT | SDMA_MAIN | SDMA_SPARE | ECC_ERR |
+	       TO_SPARE | TO_MAIN, mxic->regs + INTRPT_STS_EN);
+
+	/* Configure the correction depending on the NAND device topology */
+	if (user->step_size && user->strength) {
+		step_size = user->step_size;
+		strength = user->strength;
+	} else if (reqs->step_size && reqs->strength) {
+		step_size = reqs->step_size;
+		strength = reqs->strength;
+	}
+
+	if (step_size && strength) {
+		steps = mtd->writesize / step_size;
+		desired_correction = steps * strength;
+	}
+
+	/* Step size is fixed to 1kiB, strength may vary (4 possible values) */
+	conf->step_size = SZ_1K;
+	steps = mtd->writesize / conf->step_size;
+
+	ctx->status = devm_kzalloc(dev, steps * sizeof(u8), GFP_KERNEL);
+	if (!ctx->status)
+		return -ENOMEM;
+
+	if (desired_correction) {
+		strength = desired_correction / steps;
+
+		for (idx = 0; idx < ARRAY_SIZE(possible_strength); idx++)
+			if (possible_strength[idx] >= strength)
+				break;
+
+		idx = min_t(unsigned int, idx,
+			    ARRAY_SIZE(possible_strength) - 1);
+	} else {
+		/* Missing data, maximize the correction */
+		idx = ARRAY_SIZE(possible_strength) - 1;
+	}
+
+	/* Tune the selected strength until it fits in the OOB area */
+	for (; idx >= 0; idx--) {
+		if (spare_size[idx] * steps <= mtd->oobsize)
+			break;
+	}
+
+	/* This engine cannot be used with this NAND device */
+	if (idx < 0)
+		return -EINVAL;
+
+	/* Configure the engine for the desired strength */
+	writel(ECC_TYP(idx), mxic->regs + DP_CONFIG);
+	conf->strength = possible_strength[idx];
+	spare_reg = readl(mxic->regs + SPARE_SIZE);
+
+	ctx->steps = steps;
+	ctx->data_step_sz = mtd->writesize / steps;
+	ctx->oob_step_sz = mtd->oobsize / steps;
+	ctx->parity_sz = PARITY_SZ(spare_reg);
+	ctx->meta_sz = META_SZ(spare_reg);
+
+	/* Ensure buffers will contain enough bytes to store the STAT_BYTES */
+	ctx->req_ctx.oob_buffer_size = nanddev_per_page_oobsize(nand) +
+					(ctx->steps * STAT_BYTES);
+	ret = nand_ecc_init_req_tweaking(&ctx->req_ctx, nand);
+	if (ret)
+		return ret;
+
+	ctx->oobwithstat = kmalloc(mtd->oobsize + (ctx->steps * STAT_BYTES),
+				   GFP_KERNEL);
+	if (!ctx->oobwithstat) {
+		ret = -ENOMEM;
+		goto cleanup_req_tweak;
+	}
+
+	sg_init_table(ctx->sg, 2);
+
+	/* Configuration dump and sanity checks */
+	dev_err(dev, "DPE version number: %d\n",
+		readl(mxic->regs + DP_VER) >> DP_VER_OFFSET);
+	dev_err(dev, "Chunk size: %d\n", readl(mxic->regs + CHUNK_SIZE));
+	dev_err(dev, "Main size: %d\n", readl(mxic->regs + MAIN_SIZE));
+	dev_err(dev, "Spare size: %d\n", SPARE_SZ(spare_reg));
+	dev_err(dev, "Rsv size: %ld\n", RSV_SZ(spare_reg));
+	dev_err(dev, "Parity size: %d\n", ctx->parity_sz);
+	dev_err(dev, "Meta size: %d\n", ctx->meta_sz);
+
+	if ((ctx->meta_sz + ctx->parity_sz + RSV_SZ(spare_reg)) !=
+	    SPARE_SZ(spare_reg)) {
+		dev_err(dev, "Wrong OOB configuration: %d + %d + %ld != %d\n",
+			ctx->meta_sz, ctx->parity_sz, RSV_SZ(spare_reg),
+			SPARE_SZ(spare_reg));
+		ret = -EINVAL;
+		goto free_oobwithstat;
+	}
+
+	if (ctx->oob_step_sz != SPARE_SZ(spare_reg)) {
+		dev_err(dev, "Wrong OOB configuration: %d != %d\n",
+			ctx->oob_step_sz, SPARE_SZ(spare_reg));
+		ret = -EINVAL;
+		goto free_oobwithstat;
+	}
+
+	return 0;
+
+free_oobwithstat:
+	kfree(ctx->oobwithstat);
+cleanup_req_tweak:
+	nand_ecc_cleanup_req_tweaking(&ctx->req_ctx);
+
+	return ret;
+}
+
+static int mxic_ecc_init_ctx_external(struct nand_device *nand)
+{
+	struct mxic_ecc_engine *mxic = nand_to_mxic(nand);
+	struct device *dev = nand->ecc.engine->dev;
+	int ret;
+
+	dev_info(dev, "Macronix ECC engine in external mode\n");
+
+	ret = mxic_ecc_init_ctx(nand, dev);
+	if (ret)
+		return ret;
+
+	/* Trigger each step manually */
+	writel(1, mxic->regs + CHUNK_CNT);
+	writel(BURST_TYP_INCREASING | ECC_PACKED | MEM2MEM,
+	       mxic->regs + HC_CONFIG);
+
+	return 0;
+}
+
+static void mxic_ecc_cleanup_ctx(struct nand_device *nand)
+{
+	struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand);
+
+	if (ctx) {
+		nand_ecc_cleanup_req_tweaking(&ctx->req_ctx);
+		kfree(ctx->oobwithstat);
+	}
+}
+
+static int mxic_ecc_data_xfer_wait_for_completion(struct mxic_ecc_engine *mxic)
+{
+	u32 val;
+	int ret;
+
+	if (mxic->irq) {
+		reinit_completion(&mxic->complete);
+		mxic_ecc_enable_int(mxic);
+		ret = wait_for_completion_timeout(&mxic->complete,
+						  msecs_to_jiffies(1000));
+		mxic_ecc_disable_int(mxic);
+	} else {
+		ret = readl_poll_timeout(mxic->regs + INTRPT_STS, val,
+					 val & TRANS_CMPLT, 10, USEC_PER_SEC);
+		writel(val, mxic->regs + INTRPT_STS);
+	}
+
+	if (ret) {
+		dev_err(mxic->dev, "Timeout on data xfer completion (sts 0x%08x)\n", val);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int mxic_ecc_process_data(struct mxic_ecc_engine *mxic,
+				 unsigned int direction)
+{
+	unsigned int dir = (direction == NAND_PAGE_READ) ?
+			   READ_NAND : WRITE_NAND;
+	int ret;
+
+	mxic_ecc_enable_engine(mxic);
+
+	/* Trigger processing */
+	writel(SDMA_STRT | dir, mxic->regs + SDMA_CTRL);
+
+	/* Wait for completion */
+	ret = mxic_ecc_data_xfer_wait_for_completion(mxic);
+
+	mxic_ecc_disable_engine(mxic);
+
+	return ret;
+}
+
+static void mxic_ecc_extract_status_bytes(struct mxic_ecc_ctx *ctx)
+{
+	u8 *buf = ctx->oobwithstat;
+	int next_stat_pos;
+	int step;
+
+	/* Extract the ECC status */
+	for (step = 0; step < ctx->steps; step++) {
+		next_stat_pos = ctx->oob_step_sz +
+				((STAT_BYTES + ctx->oob_step_sz) * step);
+
+		ctx->status[step] = buf[next_stat_pos];
+	}
+}
+
+static void mxic_ecc_reconstruct_oobbuf(struct mxic_ecc_ctx *ctx,
+					u8 *dst, const u8 *src)
+{
+	int step;
+
+	/* Reconstruct the OOB buffer linearly (without the ECC status bytes) */
+	for (step = 0; step < ctx->steps; step++)
+		memcpy(dst + (step * ctx->oob_step_sz),
+		       src + (step * (ctx->oob_step_sz + STAT_BYTES)),
+		       ctx->oob_step_sz);
+}
+
+static void mxic_ecc_add_room_in_oobbuf(struct mxic_ecc_ctx *ctx,
+					u8 *dst, const u8 *src)
+{
+	int step;
+
+	/* Add some space in the OOB buffer for the status bytes */
+	for (step = 0; step < ctx->steps; step++)
+		memcpy(dst + (step * (ctx->oob_step_sz + STAT_BYTES)),
+		       src + (step * ctx->oob_step_sz),
+		       ctx->oob_step_sz);
+}
+
+static int mxic_ecc_count_biterrs(struct mxic_ecc_engine *mxic,
+				  struct nand_device *nand)
+{
+	struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand);
+	struct mtd_info *mtd = nanddev_to_mtd(nand);
+	struct device *dev = mxic->dev;
+	unsigned int max_bf = 0;
+	bool failure = false;
+	int step;
+
+	for (step = 0; step < ctx->steps; step++) {
+		u8 stat = ctx->status[step];
+
+		if (stat == NO_ERR) {
+			dev_dbg(dev, "ECC step %d: no error\n", step);
+		} else if (stat == ERASED_CHUNK) {
+			dev_dbg(dev, "ECC step %d: erased\n", step);
+		} else if (stat == UNCORR_ERR || stat > MAX_CORR_ERR) {
+			dev_dbg(dev, "ECC step %d: uncorrectable\n", step);
+			mtd->ecc_stats.failed++;
+			failure = true;
+		} else {
+			dev_dbg(dev, "ECC step %d: %d bits corrected\n",
+				step, stat);
+			max_bf = max_t(unsigned int, max_bf, stat);
+			mtd->ecc_stats.corrected += stat;
+		}
+	}
+
+	return failure ? -EBADMSG : max_bf;
+}
+
+/* External ECC engine helpers */
+static int mxic_ecc_prepare_io_req_external(struct nand_device *nand,
+					    struct nand_page_io_req *req)
+{
+	struct mxic_ecc_engine *mxic = nand_to_mxic(nand);
+	struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand);
+	struct mtd_info *mtd = nanddev_to_mtd(nand);
+	int offset, nents, step, ret;
+
+	if (req->mode == MTD_OPS_RAW)
+		return 0;
+
+	nand_ecc_tweak_req(&ctx->req_ctx, req);
+	ctx->req = req;
+
+	if (req->type == NAND_PAGE_READ)
+		return 0;
+
+	mxic_ecc_add_room_in_oobbuf(ctx, ctx->oobwithstat,
+				    ctx->req->oobbuf.out);
+
+	sg_set_buf(&ctx->sg[0], req->databuf.out, req->datalen);
+	sg_set_buf(&ctx->sg[1], ctx->oobwithstat,
+		   req->ooblen + (ctx->steps * STAT_BYTES));
+
+	nents = dma_map_sg(mxic->dev, ctx->sg, 2, DMA_BIDIRECTIONAL);
+	if (!nents)
+		return -EINVAL;
+
+	mutex_lock(&mxic->lock);
+
+	for (step = 0; step < ctx->steps; step++) {
+		writel(sg_dma_address(&ctx->sg[0]) + (step * ctx->data_step_sz),
+		       mxic->regs + SDMA_MAIN_ADDR);
+		writel(sg_dma_address(&ctx->sg[1]) + (step * (ctx->oob_step_sz + STAT_BYTES)),
+		       mxic->regs + SDMA_SPARE_ADDR);
+		ret = mxic_ecc_process_data(mxic, ctx->req->type);
+		if (ret)
+			break;
+	}
+
+	mutex_unlock(&mxic->lock);
+
+	dma_unmap_sg(mxic->dev, ctx->sg, 2, DMA_BIDIRECTIONAL);
+
+	/* Retrieve the calculated ECC bytes */
+	for (step = 0; step < ctx->steps; step++) {
+		offset = ctx->meta_sz + (step * ctx->oob_step_sz);
+		mtd_ooblayout_get_eccbytes(mtd,
+					   (u8 *)ctx->req->oobbuf.out + offset,
+					   ctx->oobwithstat + (step * STAT_BYTES),
+					   step * ctx->parity_sz,
+					   ctx->parity_sz);
+	}
+
+	return ret;
+}
+
+static int mxic_ecc_finish_io_req_external(struct nand_device *nand,
+					   struct nand_page_io_req *req)
+{
+	struct mxic_ecc_engine *mxic = nand_to_mxic(nand);
+	struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand);
+	int nents, step, ret;
+
+	if (req->mode == MTD_OPS_RAW)
+		return 0;
+
+	if (req->type == NAND_PAGE_WRITE) {
+		nand_ecc_restore_req(&ctx->req_ctx, req);
+		return 0;
+	}
+
+	/* Copy the OOB buffer and add room for the ECC engine status bytes */
+	mxic_ecc_add_room_in_oobbuf(ctx, ctx->oobwithstat, ctx->req->oobbuf.in);
+
+	sg_set_buf(&ctx->sg[0], req->databuf.in, req->datalen);
+	sg_set_buf(&ctx->sg[1], ctx->oobwithstat,
+		   req->ooblen + (ctx->steps * STAT_BYTES));
+	nents = dma_map_sg(mxic->dev, ctx->sg, 2, DMA_BIDIRECTIONAL);
+	if (!nents)
+		return -EINVAL;
+
+	mutex_lock(&mxic->lock);
+
+	for (step = 0; step < ctx->steps; step++) {
+		writel(sg_dma_address(&ctx->sg[0]) + (step * ctx->data_step_sz),
+		       mxic->regs + SDMA_MAIN_ADDR);
+		writel(sg_dma_address(&ctx->sg[1]) + (step * (ctx->oob_step_sz + STAT_BYTES)),
+		       mxic->regs + SDMA_SPARE_ADDR);
+		ret = mxic_ecc_process_data(mxic, ctx->req->type);
+		if (ret)
+			break;
+	}
+
+	mutex_unlock(&mxic->lock);
+
+	dma_unmap_sg(mxic->dev, ctx->sg, 2, DMA_BIDIRECTIONAL);
+
+	/* Extract the status bytes and reconstruct the buffer */
+	mxic_ecc_extract_status_bytes(ctx);
+	mxic_ecc_reconstruct_oobbuf(ctx, ctx->req->oobbuf.in, ctx->oobwithstat);
+
+	nand_ecc_restore_req(&ctx->req_ctx, req);
+
+	return mxic_ecc_count_biterrs(mxic, nand);
+}
+
+static struct nand_ecc_engine_ops mxic_ecc_engine_external_ops = {
+	.init_ctx = mxic_ecc_init_ctx_external,
+	.cleanup_ctx = mxic_ecc_cleanup_ctx,
+	.prepare_io_req = mxic_ecc_prepare_io_req_external,
+	.finish_io_req = mxic_ecc_finish_io_req_external,
+};
+
+static int mxic_ecc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mxic_ecc_engine *mxic;
+	int ret;
+
+	mxic = devm_kzalloc(&pdev->dev, sizeof(*mxic), GFP_KERNEL);
+	if (!mxic)
+		return -ENOMEM;
+
+	mxic->dev = &pdev->dev;
+
+	/*
+	 * Both memory regions for the ECC engine itself and the AXI slave
+	 * address are mandatory.
+	 */
+	mxic->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mxic->regs)) {
+		dev_err(&pdev->dev, "Missing memory region\n");
+		return PTR_ERR(mxic->regs);
+	}
+
+	mxic_ecc_disable_engine(mxic);
+	mxic_ecc_disable_int(mxic);
+
+	/* IRQ is optional yet much more efficient */
+	mxic->irq = platform_get_irq_byname_optional(pdev, "ecc-engine");
+	if (mxic->irq > 0) {
+		ret = devm_request_irq(&pdev->dev, mxic->irq, mxic_ecc_isr, 0,
+				       "mxic-ecc", mxic);
+		if (ret)
+			return ret;
+	} else {
+		dev_info(dev, "Invalid or missing IRQ, fallback to polling\n");
+		mxic->irq = 0;
+	}
+
+	mutex_init(&mxic->lock);
+
+	/*
+	 * In external mode, the device is the ECC engine. In pipelined mode,
+	 * the device is the host controller. The device is used to match the
+	 * right ECC engine based on the DT properties.
+	 */
+	mxic->external_engine.dev = &pdev->dev;
+	mxic->external_engine.integration = NAND_ECC_ENGINE_INTEGRATION_EXTERNAL;
+	mxic->external_engine.ops = &mxic_ecc_engine_external_ops;
+
+	nand_ecc_register_on_host_hw_engine(&mxic->external_engine);
+
+	platform_set_drvdata(pdev, mxic);
+
+	return 0;
+}
+
+static int mxic_ecc_remove(struct platform_device *pdev)
+{
+	struct mxic_ecc_engine *mxic = platform_get_drvdata(pdev);
+
+	nand_ecc_unregister_on_host_hw_engine(&mxic->external_engine);
+
+	return 0;
+}
+
+static const struct of_device_id mxic_ecc_of_ids[] = {
+	{
+		.compatible = "mxicy,nand-ecc-engine-rev3",
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, mxic_ecc_of_ids);
+
+static struct platform_driver mxic_ecc_driver = {
+	.driver	= {
+		.name = "mxic-nand-ecc-engine",
+		.of_match_table = mxic_ecc_of_ids,
+	},
+	.probe = mxic_ecc_probe,
+	.remove	= mxic_ecc_remove,
+};
+module_platform_driver(mxic_ecc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com>");
+MODULE_DESCRIPTION("Macronix NAND hardware ECC controller");
-- 
2.27.0

[PATCH v3 15/22] mtd: nand: mxic-ecc: Support SPI pipelined mode

[Miquel Raynal]

Introduce the support for another possible configuration: the ECC
engine may work as DMA master (pipelined) and move itself the data
to/from the NAND chip into the buffer, applying the necessary
corrections/computations on the fly.

This driver offers an ECC engine implementation that must be
instatiated from a SPI controller driver.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/ecc-mxic.c       | 210 +++++++++++++++++++++++++++++-
 include/linux/mtd/nand-ecc-mxic.h |  49 +++++++
 2 files changed, 258 insertions(+), 1 deletion(-)
 create mode 100644 include/linux/mtd/nand-ecc-mxic.h

diff --git a/drivers/mtd/nand/ecc-mxic.c b/drivers/mtd/nand/ecc-mxic.c
index ea88a411ed70..8eacddfa8ac6 100644
--- a/drivers/mtd/nand/ecc-mxic.c
+++ b/drivers/mtd/nand/ecc-mxic.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
+#include <linux/mtd/nand-ecc-mxic.h>
 #include <linux/mutex.h>
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
@@ -40,7 +41,9 @@
 #define INTRPT_SIG_EN 0x0C
 /* Host Controller Configuration */
 #define HC_CONFIG 0x10
+#define   DEV2MEM 0 /* TRANS_TYP_DMA in the spec */
 #define   MEM2MEM BIT(4) /* TRANS_TYP_IO in the spec */
+#define   MAPPING BIT(5) /* TRANS_TYP_MAPPING in the spec */
 #define   ECC_PACKED 0 /* LAYOUT_TYP_INTEGRATED in the spec */
 #define   ECC_INTERLEAVED BIT(2) /* LAYOUT_TYP_DISTRIBUTED in the spec */
 #define   BURST_TYP_FIXED 0
@@ -87,6 +90,7 @@ struct mxic_ecc_engine {
 	int irq;
 	struct completion complete;
 	struct nand_ecc_engine external_engine;
+	struct nand_ecc_engine pipelined_engine;
 	struct mutex lock;
 };
 
@@ -104,6 +108,7 @@ struct mxic_ecc_ctx {
 	u8 *oobwithstat;
 	struct scatterlist sg[2];
 	struct nand_page_io_req *req;
+	unsigned int pageoffs;
 };
 
 static struct mxic_ecc_engine *ext_ecc_eng_to_mxic(struct nand_ecc_engine *eng)
@@ -111,11 +116,19 @@ static struct mxic_ecc_engine *ext_ecc_eng_to_mxic(struct nand_ecc_engine *eng)
 	return container_of(eng, struct mxic_ecc_engine, external_engine);
 }
 
+static struct mxic_ecc_engine *pip_ecc_eng_to_mxic(struct nand_ecc_engine *eng)
+{
+	return container_of(eng, struct mxic_ecc_engine, pipelined_engine);
+}
+
 static struct mxic_ecc_engine *nand_to_mxic(struct nand_device *nand)
 {
 	struct nand_ecc_engine *eng = nand->ecc.engine;
 
-	return ext_ecc_eng_to_mxic(eng);
+	if (eng->integration == NAND_ECC_ENGINE_INTEGRATION_EXTERNAL)
+		return ext_ecc_eng_to_mxic(eng);
+	else
+		return pip_ecc_eng_to_mxic(eng);
 }
 
 static int mxic_ecc_ooblayout_ecc(struct mtd_info *mtd, int section,
@@ -203,6 +216,31 @@ static irqreturn_t mxic_ecc_isr(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static struct device *mxic_ecc_get_engine_dev(struct device *dev)
+{
+	struct platform_device *eccpdev;
+	struct device_node *np;
+
+	/*
+	 * If the device node contains this property, it means the device does
+	 * not represent the actual ECC engine.
+	 */
+	np = of_parse_phandle(dev->of_node, "nand-ecc-engine", 0);
+	if (!np)
+		return dev;
+
+	eccpdev = of_find_device_by_node(np);
+	if (!eccpdev) {
+		of_node_put(np);
+		return NULL;
+	}
+
+	platform_device_put(eccpdev);
+	of_node_put(np);
+
+	return &eccpdev->dev;
+}
+
 static int mxic_ecc_init_ctx(struct nand_device *nand, struct device *dev)
 {
 	struct mxic_ecc_engine *mxic = nand_to_mxic(nand);
@@ -364,6 +402,42 @@ static int mxic_ecc_init_ctx_external(struct nand_device *nand)
 	return 0;
 }
 
+static int mxic_ecc_init_ctx_pipelined(struct nand_device *nand)
+{
+	struct mxic_ecc_engine *mxic = nand_to_mxic(nand);
+	struct mxic_ecc_ctx *ctx;
+	struct device *dev;
+	int ret;
+
+	/*
+	 * In the case of a pipelined engine, the device registering the ECC
+	 * engine is not the actual ECC engine device but the host controller.
+	 */
+	dev = mxic_ecc_get_engine_dev(nand->ecc.engine->dev);
+	if (!dev)
+		return -EINVAL;
+
+	dev_info(dev, "Macronix ECC engine in pipelined/mapping mode\n");
+
+	ret = mxic_ecc_init_ctx(nand, dev);
+	if (ret)
+		return ret;
+
+	ctx = nand_to_ecc_ctx(nand);
+
+	/* All steps should be handled in one go directly by the internal DMA */
+	writel(ctx->steps, mxic->regs + CHUNK_CNT);
+
+	/*
+	 * Interleaved ECC scheme cannot be used otherwise factory bad block
+	 * markers would be lost. A packed layout is mandatory.
+	 */
+	writel(BURST_TYP_INCREASING | ECC_PACKED | MAPPING,
+	       mxic->regs + HC_CONFIG);
+
+	return 0;
+}
+
 static void mxic_ecc_cleanup_ctx(struct nand_device *nand)
 {
 	struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand);
@@ -419,6 +493,18 @@ static int mxic_ecc_process_data(struct mxic_ecc_engine *mxic,
 	return ret;
 }
 
+int mxic_ecc_process_data_pipelined(struct nand_ecc_engine *eng,
+				    unsigned int direction, dma_addr_t dirmap)
+{
+	struct mxic_ecc_engine *mxic = pip_ecc_eng_to_mxic(eng);
+
+	if (dirmap)
+		writel(dirmap, mxic->regs + HC_SLV_ADDR);
+
+	return mxic_ecc_process_data(mxic, direction);
+}
+EXPORT_SYMBOL_GPL(mxic_ecc_process_data_pipelined);
+
 static void mxic_ecc_extract_status_bytes(struct mxic_ecc_ctx *ctx)
 {
 	u8 *buf = ctx->oobwithstat;
@@ -598,6 +684,65 @@ static int mxic_ecc_finish_io_req_external(struct nand_device *nand,
 	return mxic_ecc_count_biterrs(mxic, nand);
 }
 
+/* Pipelined ECC engine helpers */
+static int mxic_ecc_prepare_io_req_pipelined(struct nand_device *nand,
+					     struct nand_page_io_req *req)
+{
+	struct mxic_ecc_engine *mxic = nand_to_mxic(nand);
+	struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand);
+	int nents;
+
+	if (req->mode == MTD_OPS_RAW)
+		return 0;
+
+	nand_ecc_tweak_req(&ctx->req_ctx, req);
+	ctx->req = req;
+
+	/* Copy the OOB buffer and add room for the ECC engine status bytes */
+	mxic_ecc_add_room_in_oobbuf(ctx, ctx->oobwithstat, ctx->req->oobbuf.in);
+
+	sg_set_buf(&ctx->sg[0], req->databuf.in, req->datalen);
+	sg_set_buf(&ctx->sg[1], ctx->oobwithstat,
+		   req->ooblen + (ctx->steps * STAT_BYTES));
+
+	nents = dma_map_sg(mxic->dev, ctx->sg, 2, DMA_BIDIRECTIONAL);
+	if (!nents)
+		return -EINVAL;
+
+	mutex_lock(&mxic->lock);
+
+	writel(sg_dma_address(&ctx->sg[0]), mxic->regs + SDMA_MAIN_ADDR);
+	writel(sg_dma_address(&ctx->sg[1]), mxic->regs + SDMA_SPARE_ADDR);
+
+	return 0;
+}
+
+static int mxic_ecc_finish_io_req_pipelined(struct nand_device *nand,
+					    struct nand_page_io_req *req)
+{
+	struct mxic_ecc_engine *mxic = nand_to_mxic(nand);
+	struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand);
+	int ret = 0;
+
+	if (req->mode == MTD_OPS_RAW)
+		return 0;
+
+	mutex_unlock(&mxic->lock);
+
+	dma_unmap_sg(mxic->dev, ctx->sg, 2, DMA_BIDIRECTIONAL);
+
+	if (req->type == NAND_PAGE_READ) {
+		mxic_ecc_extract_status_bytes(ctx);
+		mxic_ecc_reconstruct_oobbuf(ctx, ctx->req->oobbuf.in,
+					    ctx->oobwithstat);
+		ret = mxic_ecc_count_biterrs(mxic, nand);
+	}
+
+	nand_ecc_restore_req(&ctx->req_ctx, req);
+
+	return ret;
+}
+
 static struct nand_ecc_engine_ops mxic_ecc_engine_external_ops = {
 	.init_ctx = mxic_ecc_init_ctx_external,
 	.cleanup_ctx = mxic_ecc_cleanup_ctx,
@@ -605,6 +750,69 @@ static struct nand_ecc_engine_ops mxic_ecc_engine_external_ops = {
 	.finish_io_req = mxic_ecc_finish_io_req_external,
 };
 
+static struct nand_ecc_engine_ops mxic_ecc_engine_pipelined_ops = {
+	.init_ctx = mxic_ecc_init_ctx_pipelined,
+	.cleanup_ctx = mxic_ecc_cleanup_ctx,
+	.prepare_io_req = mxic_ecc_prepare_io_req_pipelined,
+	.finish_io_req = mxic_ecc_finish_io_req_pipelined,
+};
+
+struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void)
+{
+	return &mxic_ecc_engine_pipelined_ops;
+}
+EXPORT_SYMBOL_GPL(mxic_ecc_get_pipelined_ops);
+
+static struct platform_device *
+mxic_ecc_get_pdev(struct platform_device *spi_pdev)
+{
+	struct platform_device *eng_pdev;
+	struct device_node *np;
+
+	/* Retrieve the nand-ecc-engine phandle */
+	np = of_parse_phandle(spi_pdev->dev.of_node, "nand-ecc-engine", 0);
+	if (!np)
+		return NULL;
+
+	/* Jump to the engine's device node */
+	eng_pdev = of_find_device_by_node(np);
+	of_node_put(np);
+
+	return eng_pdev;
+}
+
+void mxic_ecc_put_pipelined_engine(struct nand_ecc_engine *eng)
+{
+	struct mxic_ecc_engine *mxic = pip_ecc_eng_to_mxic(eng);
+
+	platform_device_put(to_platform_device(mxic->dev));
+}
+EXPORT_SYMBOL_GPL(mxic_ecc_put_pipelined_engine);
+
+struct nand_ecc_engine *
+mxic_ecc_get_pipelined_engine(struct platform_device *spi_pdev)
+{
+	struct platform_device *eng_pdev;
+	struct mxic_ecc_engine *mxic;
+
+	eng_pdev = mxic_ecc_get_pdev(spi_pdev);
+	if (!eng_pdev)
+		return ERR_PTR(-ENODEV);
+
+	mxic = platform_get_drvdata(eng_pdev);
+	if (!mxic) {
+		platform_device_put(eng_pdev);
+		return ERR_PTR(-EPROBE_DEFER);
+	}
+
+	return &mxic->pipelined_engine;
+}
+EXPORT_SYMBOL_GPL(mxic_ecc_get_pipelined_engine);
+
+/*
+ * Only the external ECC engine is exported as the pipelined is SoC specific, so
+ * it is registered directly by the drivers that wrap it.
+ */
 static int mxic_ecc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
diff --git a/include/linux/mtd/nand-ecc-mxic.h b/include/linux/mtd/nand-ecc-mxic.h
new file mode 100644
index 000000000000..f3aa1ac82aed
--- /dev/null
+++ b/include/linux/mtd/nand-ecc-mxic.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright © 2019 Macronix
+ * Author: Miquèl Raynal <miquel.raynal@bootlin.com>
+ *
+ * Header for the Macronix external ECC engine.
+ */
+
+#ifndef __MTD_NAND_ECC_MXIC_H__
+#define __MTD_NAND_ECC_MXIC_H__
+
+#include <linux/platform_device.h>
+#include <linux/device.h>
+
+struct mxic_ecc_engine;
+
+#if IS_ENABLED(CONFIG_MTD_NAND_ECC_MXIC)
+
+struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void);
+struct nand_ecc_engine *mxic_ecc_get_pipelined_engine(struct platform_device *spi_pdev);
+void mxic_ecc_put_pipelined_engine(struct nand_ecc_engine *eng);
+int mxic_ecc_process_data_pipelined(struct nand_ecc_engine *eng,
+				    unsigned int direction, dma_addr_t dirmap);
+
+#else /* !CONFIG_MTD_NAND_ECC_MXIC */
+
+static inline struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void)
+{
+	return NULL;
+}
+
+static inline struct nand_ecc_engine *
+mxic_ecc_get_pipelined_engine(struct platform_device *spi_pdev)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline void mxic_ecc_put_pipelined_engine(struct nand_ecc_engine *eng) {}
+
+static inline int mxic_ecc_process_data_pipelined(struct nand_ecc_engine *eng,
+						  unsigned int direction,
+						  dma_addr_t dirmap)
+{
+	return -EOPNOTSUPP;
+}
+
+#endif /* CONFIG_MTD_NAND_ECC_MXIC */
+
+#endif /* __MTD_NAND_ECC_MXIC_H__ */
-- 
2.27.0

[PATCH v3 16/22] mtd: spinand: Delay a little bit dirmap creation

[Miquel Raynal]

As we will soon tweak the dirmap creation to act a little bit
differently depending on the picked ECC engine, we need to initialize
dirmaps after ECC engines. This should not have any effect as dirmaps
are not yet used at this point.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/spi/core.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 7027c09925e2..715cad26fdef 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1209,14 +1209,6 @@ static int spinand_init(struct spinand_device *spinand)
 	if (ret)
 		goto err_free_bufs;
 
-	ret = spinand_create_dirmaps(spinand);
-	if (ret) {
-		dev_err(dev,
-			"Failed to create direct mappings for read/write operations (err = %d)\n",
-			ret);
-		goto err_manuf_cleanup;
-	}
-
 	ret = nanddev_init(nand, &spinand_ops, THIS_MODULE);
 	if (ret)
 		goto err_manuf_cleanup;
@@ -1251,6 +1243,14 @@ static int spinand_init(struct spinand_device *spinand)
 	mtd->ecc_strength = nanddev_get_ecc_conf(nand)->strength;
 	mtd->ecc_step_size = nanddev_get_ecc_conf(nand)->step_size;
 
+	ret = spinand_create_dirmaps(spinand);
+	if (ret) {
+		dev_err(dev,
+			"Failed to create direct mappings for read/write operations (err = %d)\n",
+			ret);
+		goto err_cleanup_ecc_engine;
+	}
+
 	return 0;
 
 err_cleanup_ecc_engine:
-- 
2.27.0

[PATCH v3 17/22] mtd: spinand: Create direct mapping descriptors for ECC operations

[Miquel Raynal]

In order for pipelined ECC engines to be able to enable/disable the ECC
engine only when needed and avoid races when future parallel-operations
will be supported, we need to provide the information about the use of
the ECC engine in the direct mapping hooks. As direct mapping
configurations are meant to be static, it is best to create two new
mappings: one for regular 'raw' accesses and one for accesses involving
correction. It is up to the driver to use or not the new ECC enable
boolean contained in the spi-mem operation.

As dirmaps are not free (they consume a few pages of MMIO address space)
and because these extra entries are only meant to be used by pipelined
engines, let's limit their use to this specific type of engine and save
a bit of memory with all the other setups.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mtd/nand/spi/core.c | 35 +++++++++++++++++++++++++++++++++--
 include/linux/mtd/spinand.h |  2 ++
 include/linux/spi/spi-mem.h |  3 +++
 3 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 715cad26fdef..eb999e47e978 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -381,7 +381,10 @@ static int spinand_read_from_cache_op(struct spinand_device *spinand,
 		}
 	}
 
-	rdesc = spinand->dirmaps[req->pos.plane].rdesc;
+	if (req->mode == MTD_OPS_RAW)
+		rdesc = spinand->dirmaps[req->pos.plane].rdesc;
+	else
+		rdesc = spinand->dirmaps[req->pos.plane].rdesc_ecc;
 
 	while (nbytes) {
 		ret = spi_mem_dirmap_read(rdesc, column, nbytes, buf);
@@ -452,7 +455,10 @@ static int spinand_write_to_cache_op(struct spinand_device *spinand,
 			       req->ooblen);
 	}
 
-	wdesc = spinand->dirmaps[req->pos.plane].wdesc;
+	if (req->mode == MTD_OPS_RAW)
+		wdesc = spinand->dirmaps[req->pos.plane].wdesc;
+	else
+		wdesc = spinand->dirmaps[req->pos.plane].wdesc_ecc;
 
 	while (nbytes) {
 		ret = spi_mem_dirmap_write(wdesc, column, nbytes, buf);
@@ -866,6 +872,31 @@ static int spinand_create_dirmap(struct spinand_device *spinand,
 
 	spinand->dirmaps[plane].rdesc = desc;
 
+	if (nand->ecc.engine->integration != NAND_ECC_ENGINE_INTEGRATION_PIPELINED) {
+		spinand->dirmaps[plane].wdesc_ecc = spinand->dirmaps[plane].wdesc;
+		spinand->dirmaps[plane].rdesc_ecc = spinand->dirmaps[plane].rdesc;
+
+		return 0;
+	}
+
+	info.op_tmpl = *spinand->op_templates.update_cache;
+	info.op_tmpl.ecc_en = true;
+	desc = devm_spi_mem_dirmap_create(&spinand->spimem->spi->dev,
+					  spinand->spimem, &info);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	spinand->dirmaps[plane].wdesc_ecc = desc;
+
+	info.op_tmpl = *spinand->op_templates.read_cache;
+	info.op_tmpl.ecc_en = true;
+	desc = devm_spi_mem_dirmap_create(&spinand->spimem->spi->dev,
+					  spinand->spimem, &info);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	spinand->dirmaps[plane].rdesc_ecc = desc;
+
 	return 0;
 }
 
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 6988956b8492..3aa28240a77f 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -389,6 +389,8 @@ struct spinand_info {
 struct spinand_dirmap {
 	struct spi_mem_dirmap_desc *wdesc;
 	struct spi_mem_dirmap_desc *rdesc;
+	struct spi_mem_dirmap_desc *wdesc_ecc;
+	struct spi_mem_dirmap_desc *rdesc_ecc;
 };
 
 /**
diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
index 85e2ff7b840d..3be594be24c0 100644
--- a/include/linux/spi/spi-mem.h
+++ b/include/linux/spi/spi-mem.h
@@ -94,6 +94,7 @@ enum spi_mem_data_dir {
  *		 operation does not involve transferring data
  * @data.buf.in: input buffer (must be DMA-able)
  * @data.buf.out: output buffer (must be DMA-able)
+ * @ecc_en: error correction is required
  */
 struct spi_mem_op {
 	struct {
@@ -126,6 +127,8 @@ struct spi_mem_op {
 			const void *out;
 		} buf;
 	} data;
+
+	bool ecc_en;
 };
 
 #define SPI_MEM_OP(__cmd, __addr, __dummy, __data)		\
-- 
2.27.0

Re: [PATCH v3 17/22] mtd: spinand: Create direct mapping descriptors for ECC operations

[Boris Brezillon]

On Tue,  7 Dec 2021 10:34:17 +0100
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

>  /**
> diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
> index 85e2ff7b840d..3be594be24c0 100644
> --- a/include/linux/spi/spi-mem.h
> +++ b/include/linux/spi/spi-mem.h
> @@ -94,6 +94,7 @@ enum spi_mem_data_dir {
>   *		 operation does not involve transferring data
>   * @data.buf.in: input buffer (must be DMA-able)
>   * @data.buf.out: output buffer (must be DMA-able)
> + * @ecc_en: error correction is required
>   */
>  struct spi_mem_op {
>  	struct {
> @@ -126,6 +127,8 @@ struct spi_mem_op {
>  			const void *out;
>  		} buf;
>  	} data;
> +
> +	bool ecc_en;
>  };

I really think this should be in it's own commit. And you need to make
sure all existing drivers reject operation that have ecc_en set to
true (that shouldn't be too complicated since most of them use generic
helpers to do the check).

Re: [PATCH v3 17/22] mtd: spinand: Create direct mapping descriptors for ECC operations

[Miquel Raynal]

Hi Boris,

boris.brezillon@collabora.com wrote on Tue, 7 Dec 2021 10:46:27 +0100:

> On Tue,  7 Dec 2021 10:34:17 +0100
> Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> 
> >  /**
> > diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
> > index 85e2ff7b840d..3be594be24c0 100644
> > --- a/include/linux/spi/spi-mem.h
> > +++ b/include/linux/spi/spi-mem.h
> > @@ -94,6 +94,7 @@ enum spi_mem_data_dir {
> >   *		 operation does not involve transferring data
> >   * @data.buf.in: input buffer (must be DMA-able)
> >   * @data.buf.out: output buffer (must be DMA-able)
> > + * @ecc_en: error correction is required
> >   */
> >  struct spi_mem_op {
> >  	struct {
> > @@ -126,6 +127,8 @@ struct spi_mem_op {
> >  			const void *out;
> >  		} buf;
> >  	} data;
> > +
> > +	bool ecc_en;
> >  };  
> 
> I really think this should be in it's own commit.

Oh crap, I forgot about that.

> And you need to make
> sure all existing drivers reject operation that have ecc_en set to
> true (that shouldn't be too complicated since most of them use generic
> helpers to do the check).

Yes, I can add this check as well.

I will propose a first patch creating a spi-mem helper to do generic
checks, given a number of additional parameters (dtr, ecc). The current
helpers will call this generic function depending on what they check
(support for dtr or not). Then I will export this generic helper and
let the drivers use it directly if needed, in order to avoid the
explosion of helpers in the core to check all the possible combinations.

I'll certainly propose a v4 just with these patches and then apply them
within the v3 if everyone agrees with the rest.

Thanks,
Miquèl

[PATCH v3 18/22] spi: mxic: Fix the transmit path

[Miquel Raynal]

By working with external hardware ECC engines, we figured out that
Under certain circumstances, it is needed for the SPI controller to
check INT_TX_EMPTY and INT_RX_NOT_EMPTY in both receive and transmit
path (not only in the receive path). The delay penalty being
negligible, move this code in the common path.

Fixes: b942d80b0a39 ("spi: Add MXIC controller driver")
Cc: stable@vger.kernel.org
Suggested-by: Mason Yang <masonccyang@mxic.com.tw>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Zhengxun Li <zhengxunli@mxic.com.tw>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-mxic.c | 28 ++++++++++++----------------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 45889947afed..03fce4493aa7 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -304,25 +304,21 @@ static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
 
 		writel(data, mxic->regs + TXD(nbytes % 4));
 
+		ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+					 sts & INT_TX_EMPTY, 0, USEC_PER_SEC);
+		if (ret)
+			return ret;
+
+		ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+					 sts & INT_RX_NOT_EMPTY, 0,
+					 USEC_PER_SEC);
+		if (ret)
+			return ret;
+
+		data = readl(mxic->regs + RXD);
 		if (rxbuf) {
-			ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
-						 sts & INT_TX_EMPTY, 0,
-						 USEC_PER_SEC);
-			if (ret)
-				return ret;
-
-			ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
-						 sts & INT_RX_NOT_EMPTY, 0,
-						 USEC_PER_SEC);
-			if (ret)
-				return ret;
-
-			data = readl(mxic->regs + RXD);
 			data >>= (8 * (4 - nbytes));
 			memcpy(rxbuf + pos, &data, nbytes);
-			WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY);
-		} else {
-			readl(mxic->regs + RXD);
 		}
 		WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY);
 
-- 
2.27.0

[PATCH v3 19/22] spi: mxic: Create a helper to configure the controller before an operation

[Miquel Raynal]

Create the mxic_spi_set_hc_cfg() helper to configure the HC_CFG
register. This helper will soon be used by the dirmap implementation and
having this code factorized out earlier will clarify this addition.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-mxic.c | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 03fce4493aa7..068543c40ce7 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -280,6 +280,22 @@ static void mxic_spi_hw_init(struct mxic_spi *mxic)
 	       mxic->regs + HC_CFG);
 }
 
+static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
+{
+	int nio = 1;
+
+	if (spi->mode & (SPI_TX_OCTAL | SPI_RX_OCTAL))
+		nio = 8;
+	else if (spi->mode & (SPI_TX_QUAD | SPI_RX_QUAD))
+		nio = 4;
+	else if (spi->mode & (SPI_TX_DUAL | SPI_RX_DUAL))
+		nio = 2;
+
+	return flags | HC_CFG_NIO(nio) |
+	       HC_CFG_TYPE(spi->chip_select, HC_CFG_TYPE_SPI_NOR) |
+	       HC_CFG_SLV_ACT(spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1);
+}
+
 static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
 			      void *rxbuf, unsigned int len)
 {
@@ -357,7 +373,7 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 				const struct spi_mem_op *op)
 {
 	struct mxic_spi *mxic = spi_master_get_devdata(mem->spi->master);
-	int nio = 1, i, ret;
+	int i, ret;
 	u32 ss_ctrl;
 	u8 addr[8], cmd[2];
 
@@ -365,18 +381,9 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 	if (ret)
 		return ret;
 
-	if (mem->spi->mode & (SPI_TX_OCTAL | SPI_RX_OCTAL))
-		nio = 8;
-	else if (mem->spi->mode & (SPI_TX_QUAD | SPI_RX_QUAD))
-		nio = 4;
-	else if (mem->spi->mode & (SPI_TX_DUAL | SPI_RX_DUAL))
-		nio = 2;
-
-	writel(HC_CFG_NIO(nio) |
-	       HC_CFG_TYPE(mem->spi->chip_select, HC_CFG_TYPE_SPI_NOR) |
-	       HC_CFG_SLV_ACT(mem->spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1) |
-	       HC_CFG_MAN_CS_EN,
+	writel(mxic_spi_prep_hc_cfg(mem->spi, HC_CFG_MAN_CS_EN),
 	       mxic->regs + HC_CFG);
+
 	writel(HC_EN_BIT, mxic->regs + HC_EN);
 
 	ss_ctrl = OP_CMD_BYTES(op->cmd.nbytes) |
-- 
2.27.0

[PATCH v3 20/22] spi: mxic: Create a helper to ease the start of an operation

[Miquel Raynal]

Create the mxic_spi_mem_prep_op_cfg() helper to provide the content to
write to the register controlling the next IO command. This helper will
soon be used by the dirmap implementation and having this code
factorized out earlier will clarify this addition.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-mxic.c | 53 +++++++++++++++++++++++-------------------
 1 file changed, 29 insertions(+), 24 deletions(-)

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 068543c40ce7..3c4e64cbe812 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -296,6 +296,33 @@ static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
 	       HC_CFG_SLV_ACT(spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1);
 }
 
+static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op)
+{
+	u32 cfg = OP_CMD_BYTES(op->cmd.nbytes) |
+		  OP_CMD_BUSW(fls(op->cmd.buswidth) - 1) |
+		  (op->cmd.dtr ? OP_CMD_DDR : 0);
+
+	if (op->addr.nbytes)
+		cfg |= OP_ADDR_BYTES(op->addr.nbytes) |
+		       OP_ADDR_BUSW(fls(op->addr.buswidth) - 1) |
+		       (op->addr.dtr ? OP_ADDR_DDR : 0);
+
+	if (op->dummy.nbytes)
+		cfg |= OP_DUMMY_CYC(op->dummy.nbytes);
+
+	if (op->data.nbytes) {
+		cfg |= OP_DATA_BUSW(fls(op->data.buswidth) - 1) |
+		       (op->data.dtr ? OP_DATA_DDR : 0);
+		if (op->data.dir == SPI_MEM_DATA_IN) {
+			cfg |= OP_READ;
+			if (op->data.dtr)
+				cfg |= OP_DQS_EN;
+		}
+	}
+
+	return cfg;
+}
+
 static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
 			      void *rxbuf, unsigned int len)
 {
@@ -374,7 +401,6 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 {
 	struct mxic_spi *mxic = spi_master_get_devdata(mem->spi->master);
 	int i, ret;
-	u32 ss_ctrl;
 	u8 addr[8], cmd[2];
 
 	ret = mxic_spi_set_freq(mxic, mem->spi->max_speed_hz);
@@ -386,29 +412,8 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 
 	writel(HC_EN_BIT, mxic->regs + HC_EN);
 
-	ss_ctrl = OP_CMD_BYTES(op->cmd.nbytes) |
-		  OP_CMD_BUSW(fls(op->cmd.buswidth) - 1) |
-		  (op->cmd.dtr ? OP_CMD_DDR : 0);
-
-	if (op->addr.nbytes)
-		ss_ctrl |= OP_ADDR_BYTES(op->addr.nbytes) |
-			   OP_ADDR_BUSW(fls(op->addr.buswidth) - 1) |
-			   (op->addr.dtr ? OP_ADDR_DDR : 0);
-
-	if (op->dummy.nbytes)
-		ss_ctrl |= OP_DUMMY_CYC(op->dummy.nbytes);
-
-	if (op->data.nbytes) {
-		ss_ctrl |= OP_DATA_BUSW(fls(op->data.buswidth) - 1) |
-			   (op->data.dtr ? OP_DATA_DDR : 0);
-		if (op->data.dir == SPI_MEM_DATA_IN) {
-			ss_ctrl |= OP_READ;
-			if (op->data.dtr)
-				ss_ctrl |= OP_DQS_EN;
-		}
-	}
-
-	writel(ss_ctrl, mxic->regs + SS_CTRL(mem->spi->chip_select));
+	writel(mxic_spi_mem_prep_op_cfg(op),
+	       mxic->regs + SS_CTRL(mem->spi->chip_select));
 
 	writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
 	       mxic->regs + HC_CFG);
-- 
2.27.0

[PATCH v3 21/22] spi: mxic: Add support for direct mapping

[Miquel Raynal]

Implement the ->dirmap_create() and ->dirmap_read/write() hooks to
provide a fast path for read and write accesses.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Zhengxun Li <zhengxunli@mxic.com.tw>
Reviewed-by: Zhengxun Li <zhengxunli@mxic.com.tw>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-mxic.c | 112 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 109 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 3c4e64cbe812..485a7f2afb44 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -172,6 +172,11 @@ struct mxic_spi {
 	struct clk *send_dly_clk;
 	void __iomem *regs;
 	u32 cur_speed_hz;
+	struct {
+		void __iomem *map;
+		dma_addr_t dma;
+		size_t size;
+	} linear;
 };
 
 static int mxic_spi_clk_enable(struct mxic_spi *mxic)
@@ -296,7 +301,8 @@ static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
 	       HC_CFG_SLV_ACT(spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1);
 }
 
-static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op)
+static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op,
+				    unsigned int data_len)
 {
 	u32 cfg = OP_CMD_BYTES(op->cmd.nbytes) |
 		  OP_CMD_BUSW(fls(op->cmd.buswidth) - 1) |
@@ -310,7 +316,8 @@ static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op)
 	if (op->dummy.nbytes)
 		cfg |= OP_DUMMY_CYC(op->dummy.nbytes);
 
-	if (op->data.nbytes) {
+	/* Direct mapping data.nbytes field is not populated */
+	if (data_len) {
 		cfg |= OP_DATA_BUSW(fls(op->data.buswidth) - 1) |
 		       (op->data.dtr ? OP_DATA_DDR : 0);
 		if (op->data.dir == SPI_MEM_DATA_IN) {
@@ -371,6 +378,77 @@ static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
 	return 0;
 }
 
+static ssize_t mxic_spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
+					u64 offs, size_t len, void *buf)
+{
+	struct mxic_spi *mxic = spi_master_get_devdata(desc->mem->spi->master);
+	int ret;
+	u32 sts;
+
+	if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
+		return -EINVAL;
+
+	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);
+
+	writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
+	       mxic->regs + LRD_CFG);
+	writel(desc->info.offset + offs, mxic->regs + LRD_ADDR);
+	len = min_t(size_t, len, mxic->linear.size);
+	writel(len, mxic->regs + LRD_RANGE);
+	writel(LMODE_CMD0(desc->info.op_tmpl.cmd.opcode) |
+	       LMODE_SLV_ACT(desc->mem->spi->chip_select) |
+	       LMODE_EN,
+	       mxic->regs + LRD_CTRL);
+
+	memcpy_fromio(buf, mxic->linear.map, len);
+
+	writel(INT_LRD_DIS, mxic->regs + INT_STS);
+	writel(0, mxic->regs + LRD_CTRL);
+
+	ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+				 sts & INT_LRD_DIS, 0, USEC_PER_SEC);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+static ssize_t mxic_spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
+					 u64 offs, size_t len,
+					 const void *buf)
+{
+	struct mxic_spi *mxic = spi_master_get_devdata(desc->mem->spi->master);
+	u32 sts;
+	int ret;
+
+	if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
+		return -EINVAL;
+
+	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);
+
+	writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
+	       mxic->regs + LWR_CFG);
+	writel(desc->info.offset + offs, mxic->regs + LWR_ADDR);
+	len = min_t(size_t, len, mxic->linear.size);
+	writel(len, mxic->regs + LWR_RANGE);
+	writel(LMODE_CMD0(desc->info.op_tmpl.cmd.opcode) |
+	       LMODE_SLV_ACT(desc->mem->spi->chip_select) |
+	       LMODE_EN,
+	       mxic->regs + LWR_CTRL);
+
+	memcpy_toio(mxic->linear.map, buf, len);
+
+	writel(INT_LWR_DIS, mxic->regs + INT_STS);
+	writel(0, mxic->regs + LWR_CTRL);
+
+	ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+				 sts & INT_LWR_DIS, 0, USEC_PER_SEC);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
 static bool mxic_spi_mem_supports_op(struct spi_mem *mem,
 				     const struct spi_mem_op *op)
 {
@@ -396,6 +474,22 @@ static bool mxic_spi_mem_supports_op(struct spi_mem *mem,
 		return spi_mem_dtr_supports_op(mem, op);
 }
 
+static int mxic_spi_mem_dirmap_create(struct spi_mem_dirmap_desc *desc)
+{
+	struct mxic_spi *mxic = spi_master_get_devdata(desc->mem->spi->master);
+
+	if (!mxic->linear.map)
+		return -EINVAL;
+
+	if (desc->info.offset + desc->info.length > U32_MAX)
+		return -EINVAL;
+
+	if (!mxic_spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
 static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 				const struct spi_mem_op *op)
 {
@@ -412,7 +506,7 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 
 	writel(HC_EN_BIT, mxic->regs + HC_EN);
 
-	writel(mxic_spi_mem_prep_op_cfg(op),
+	writel(mxic_spi_mem_prep_op_cfg(op, op->data.nbytes),
 	       mxic->regs + SS_CTRL(mem->spi->chip_select));
 
 	writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
@@ -454,6 +548,9 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 static const struct spi_controller_mem_ops mxic_spi_mem_ops = {
 	.supports_op = mxic_spi_mem_supports_op,
 	.exec_op = mxic_spi_mem_exec_op,
+	.dirmap_create = mxic_spi_mem_dirmap_create,
+	.dirmap_read = mxic_spi_mem_dirmap_read,
+	.dirmap_write = mxic_spi_mem_dirmap_write,
 };
 
 static void mxic_spi_set_cs(struct spi_device *spi, bool lvl)
@@ -583,6 +680,15 @@ static int mxic_spi_probe(struct platform_device *pdev)
 	if (IS_ERR(mxic->regs))
 		return PTR_ERR(mxic->regs);
 
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirmap");
+	mxic->linear.map = devm_ioremap_resource(&pdev->dev, res);
+	if (!IS_ERR(mxic->linear.map)) {
+		mxic->linear.dma = res->start;
+		mxic->linear.size = resource_size(res);
+	} else {
+		mxic->linear.map = NULL;
+	}
+
 	pm_runtime_enable(&pdev->dev);
 	master->auto_runtime_pm = true;
 
-- 
2.27.0

[PATCH v3 22/22] spi: mxic: Add support for pipelined ECC operations

[Miquel Raynal]

Some SPI-NAND chips do not have a proper on-die ECC engine providing
error correction/detection. This is particularly an issue on embedded
devices with limited resources because all the computations must
happen in software, unless an external hardware engine is provided.

These external engines are new and can be of two categories: external
or pipelined. Macronix is providing both, the former being already
supported. The second, however, is very SoC implementation dependent
and must be instantiated by the SPI host controller directly.

An entire subsystem has been contributed to support these engines which
makes the insertion into another subsystem such as SPI quite
straightforward without the need for a lot of specific functions.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/Kconfig    |   2 +-
 drivers/spi/spi-mxic.c | 112 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 111 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 83e352b0c8f9..bff75629e872 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -856,7 +856,7 @@ config SPI_SYNQUACER
 
 config SPI_MXIC
 	tristate "Macronix MX25F0A SPI controller"
-	depends on SPI_MASTER
+	depends on SPI_MASTER && MTD_NAND_ECC
 	help
 	  This selects the Macronix MX25F0A SPI controller driver.
 
diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 485a7f2afb44..a180165281e5 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -12,6 +12,8 @@
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand-ecc-mxic.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/spi/spi.h>
@@ -167,6 +169,7 @@
 #define HW_TEST(x)		(0xe0 + ((x) * 4))
 
 struct mxic_spi {
+	struct device *dev;
 	struct clk *ps_clk;
 	struct clk *send_clk;
 	struct clk *send_dly_clk;
@@ -177,6 +180,12 @@ struct mxic_spi {
 		dma_addr_t dma;
 		size_t size;
 	} linear;
+
+	struct {
+		bool use_pipelined_conf;
+		struct nand_ecc_engine *pipelined_engine;
+		void *ctx;
+	} ecc;
 };
 
 static int mxic_spi_clk_enable(struct mxic_spi *mxic)
@@ -400,7 +409,15 @@ static ssize_t mxic_spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
 	       LMODE_EN,
 	       mxic->regs + LRD_CTRL);
 
-	memcpy_fromio(buf, mxic->linear.map, len);
+	if (mxic->ecc.use_pipelined_conf && desc->info.op_tmpl.ecc_en) {
+		ret = mxic_ecc_process_data_pipelined(mxic->ecc.pipelined_engine,
+						      NAND_PAGE_READ,
+						      mxic->linear.dma + offs);
+		if (ret)
+			return ret;
+	} else {
+		memcpy_fromio(buf, mxic->linear.map, len);
+	}
 
 	writel(INT_LRD_DIS, mxic->regs + INT_STS);
 	writel(0, mxic->regs + LRD_CTRL);
@@ -436,7 +453,15 @@ static ssize_t mxic_spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
 	       LMODE_EN,
 	       mxic->regs + LWR_CTRL);
 
-	memcpy_toio(mxic->linear.map, buf, len);
+	if (mxic->ecc.use_pipelined_conf && desc->info.op_tmpl.ecc_en) {
+		ret = mxic_ecc_process_data_pipelined(mxic->ecc.pipelined_engine,
+						      NAND_PAGE_WRITE,
+						      mxic->linear.dma + offs);
+		if (ret)
+			return ret;
+	} else {
+		memcpy_toio(mxic->linear.map, buf, len);
+	}
 
 	writel(INT_LWR_DIS, mxic->regs + INT_STS);
 	writel(0, mxic->regs + LWR_CTRL);
@@ -615,6 +640,80 @@ static int mxic_spi_transfer_one(struct spi_master *master,
 	return 0;
 }
 
+/* ECC wrapper */
+static int mxic_spi_mem_ecc_init_ctx(struct nand_device *nand)
+{
+	struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
+	struct mxic_spi *mxic = nand->ecc.engine->priv;
+
+	mxic->ecc.use_pipelined_conf = true;
+
+	return ops->init_ctx(nand);
+}
+
+static void mxic_spi_mem_ecc_cleanup_ctx(struct nand_device *nand)
+{
+	struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
+	struct mxic_spi *mxic = nand->ecc.engine->priv;
+
+	mxic->ecc.use_pipelined_conf = false;
+
+	ops->cleanup_ctx(nand);
+}
+
+static int mxic_spi_mem_ecc_prepare_io_req(struct nand_device *nand,
+					   struct nand_page_io_req *req)
+{
+	struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
+
+	return ops->prepare_io_req(nand, req);
+}
+
+static int mxic_spi_mem_ecc_finish_io_req(struct nand_device *nand,
+					  struct nand_page_io_req *req)
+{
+	struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
+
+	return ops->finish_io_req(nand, req);
+}
+
+static struct nand_ecc_engine_ops mxic_spi_mem_ecc_engine_pipelined_ops = {
+	.init_ctx = mxic_spi_mem_ecc_init_ctx,
+	.cleanup_ctx = mxic_spi_mem_ecc_cleanup_ctx,
+	.prepare_io_req = mxic_spi_mem_ecc_prepare_io_req,
+	.finish_io_req = mxic_spi_mem_ecc_finish_io_req,
+};
+
+static void mxic_spi_mem_ecc_remove(struct mxic_spi *mxic)
+{
+	if (mxic->ecc.pipelined_engine) {
+		mxic_ecc_put_pipelined_engine(mxic->ecc.pipelined_engine);
+		nand_ecc_unregister_on_host_hw_engine(mxic->ecc.pipelined_engine);
+	}
+}
+
+static int mxic_spi_mem_ecc_probe(struct platform_device *pdev,
+				  struct mxic_spi *mxic)
+{
+	struct nand_ecc_engine *eng;
+
+	if (!mxic_ecc_get_pipelined_ops())
+		return -EOPNOTSUPP;
+
+	eng = mxic_ecc_get_pipelined_engine(pdev);
+	if (IS_ERR(eng))
+		return PTR_ERR(eng);
+
+	eng->dev = &pdev->dev;
+	eng->integration = NAND_ECC_ENGINE_INTEGRATION_PIPELINED;
+	eng->ops = &mxic_spi_mem_ecc_engine_pipelined_ops;
+	eng->priv = mxic;
+	mxic->ecc.pipelined_engine = eng;
+	nand_ecc_register_on_host_hw_engine(eng);
+
+	return 0;
+}
+
 static int __maybe_unused mxic_spi_runtime_suspend(struct device *dev)
 {
 	struct spi_master *master = dev_get_drvdata(dev);
@@ -660,6 +759,7 @@ static int mxic_spi_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, master);
 
 	mxic = spi_master_get_devdata(master);
+	mxic->dev = &pdev->dev;
 
 	master->dev.of_node = pdev->dev.of_node;
 
@@ -705,6 +805,12 @@ static int mxic_spi_probe(struct platform_device *pdev)
 
 	mxic_spi_hw_init(mxic);
 
+	ret = mxic_spi_mem_ecc_probe(pdev, mxic);
+	if (ret == -EPROBE_DEFER) {
+		pm_runtime_disable(&pdev->dev);
+		return ret;
+	}
+
 	ret = spi_register_master(master);
 	if (ret) {
 		dev_err(&pdev->dev, "spi_register_master failed\n");
@@ -717,8 +823,10 @@ static int mxic_spi_probe(struct platform_device *pdev)
 static int mxic_spi_remove(struct platform_device *pdev)
 {
 	struct spi_master *master = platform_get_drvdata(pdev);
+	struct mxic_spi *mxic = spi_master_get_devdata(master);
 
 	pm_runtime_disable(&pdev->dev);
+	mxic_spi_mem_ecc_remove(mxic);
 	spi_unregister_master(master);
 
 	return 0;
-- 
2.27.0