[PATCH 1/3] dt-bindings: nvmem: convert U-Boot env to NVMEM layout

[PATCH 1/3] dt-bindings: nvmem: convert U-Boot env to NVMEM layout

[Rafał Miłecki]

From: Rafał Miłecki <rafal@milecki.pl>

Use "nvmem-layout" and drop unused "mac" label while at it.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 .../bindings/nvmem/layouts/nvmem-layout.yaml    |  1 +
 .../nvmem/{ => layouts}/u-boot,env.yaml         | 17 +++++++++++------
 2 files changed, 12 insertions(+), 6 deletions(-)
 rename Documentation/devicetree/bindings/nvmem/{ => layouts}/u-boot,env.yaml (87%)

diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
index 3b40f7880774..382507060651 100644
--- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
+++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
@@ -21,6 +21,7 @@ oneOf:
   - $ref: fixed-layout.yaml
   - $ref: kontron,sl28-vpd.yaml
   - $ref: onie,tlv-layout.yaml
+  - $ref: u-boot,env.yaml
 
 properties:
   compatible: true
diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml
similarity index 87%
rename from Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
rename to Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml
index 36d97fb87865..ebe3b71ba155 100644
--- a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
+++ b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
 %YAML 1.2
 ---
-$id: http://devicetree.org/schemas/nvmem/u-boot,env.yaml#
+$id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
 title: U-Boot environment variables
@@ -72,11 +72,14 @@ examples:
         };
 
         env: partition@40000 {
-            compatible = "u-boot,env";
             reg = <0x40000 0x10000>;
 
-            mac: ethaddr {
-                #nvmem-cell-cells = <1>;
+            nvmem-layout {
+                compatible = "u-boot,env";
+
+                ethaddr {
+                    #nvmem-cell-cells = <1>;
+                };
             };
         };
     };
@@ -92,9 +95,11 @@ examples:
             label = "u-boot";
 
             partition-u-boot-env {
-                compatible = "brcm,env";
+                nvmem-layout {
+                    compatible = "brcm,env";
 
-                ethaddr {
+                    ethaddr {
+                    };
                 };
             };
         };
-- 
2.35.3

[PATCH 2/3] nvmem: core: export nvmem device size

[Rafał Miłecki]

From: Michael Walle <michael@walle.cc>

Export the size of the nvmem device. NVMEM layout drivers might need it
and might not have access to the device which is registering the NVMEM
device.

Signed-off-by: Michael Walle <michael@walle.cc>
---
 drivers/nvmem/core.c           | 13 +++++++++++++
 include/linux/nvmem-consumer.h |  6 ++++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index a0c9153cda28..57ccd4422e01 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -2224,6 +2224,19 @@ const char *nvmem_dev_name(struct nvmem_device *nvmem)
 }
 EXPORT_SYMBOL_GPL(nvmem_dev_name);
 
+/**
+ * nvmem_device_size() - Get the size of a given nvmem device.
+ *
+ * @nvmem: nvmem device.
+ *
+ * Return: size of the nvmem device.
+ */
+size_t nvmem_device_size(struct nvmem_device *nvmem)
+{
+	return nvmem->size;
+}
+EXPORT_SYMBOL_GPL(nvmem_device_size);
+
 static int __init nvmem_init(void)
 {
 	return bus_register(&nvmem_bus_type);
diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
index fa030d93b768..3270ad81e140 100644
--- a/include/linux/nvmem-consumer.h
+++ b/include/linux/nvmem-consumer.h
@@ -77,6 +77,7 @@ ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
 			   struct nvmem_cell_info *info, void *buf);
 int nvmem_device_cell_write(struct nvmem_device *nvmem,
 			    struct nvmem_cell_info *info, void *buf);
+size_t nvmem_device_size(struct nvmem_device *nvmem);
 
 const char *nvmem_dev_name(struct nvmem_device *nvmem);
 
@@ -206,6 +207,11 @@ static inline int nvmem_device_write(struct nvmem_device *nvmem,
 	return -EOPNOTSUPP;
 }
 
+static inline size_t nvmem_device_size(struct nvmem_device *nvmem)
+{
+	return 0;
+}
+
 static inline const char *nvmem_dev_name(struct nvmem_device *nvmem)
 {
 	return NULL;
-- 
2.35.3

[PATCH WIP 3/3] nvmem: u-boot-env: convert to NVMEM layout

[Rafał Miłecki]

From: Rafał Miłecki <rafal@milecki.pl>

This avoids code duplication (NVMEM device access) and allows reusing
this on top of other NVMEM devices.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 drivers/mtd/mtdcore.c                    |   7 ++
 drivers/nvmem/Kconfig                    |  15 ++-
 drivers/nvmem/Makefile                   |   2 -
 drivers/nvmem/layouts/Kconfig            |  10 ++
 drivers/nvmem/layouts/Makefile           |   1 +
 drivers/nvmem/{ => layouts}/u-boot-env.c | 112 +++++++++--------------
 6 files changed, 68 insertions(+), 79 deletions(-)
 rename drivers/nvmem/{ => layouts}/u-boot-env.c (67%)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 3d781ffb8c32..5f96affdfb0f 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -556,6 +556,13 @@ static int mtd_nvmem_add(struct mtd_info *mtd)
 	config.ignore_wp = true;
 	config.priv = mtd;
 
+	if (IS_ENABLED(NVMEM_U_BOOT_ENV) &&
+	    (of_device_is_compatible(node, "u-boot,env") ||
+	     of_device_is_compatible(node, "brcm,env"))) {
+		/* FIXME */
+		pr_warn("Missing support for deprecated U-Boot env binding\n");
+	}
+
 	mtd->nvmem = nvmem_register(&config);
 	if (IS_ERR(mtd->nvmem)) {
 		/* Just ignore if there is no NVMEM support in the kernel */
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index da9befa3d6c4..ff99c284a582 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -347,18 +347,15 @@ config NVMEM_SUNXI_SID
 	  will be called nvmem_sunxi_sid.
 
 config NVMEM_U_BOOT_ENV
-	tristate "U-Boot environment variables support"
+	bool "U-Boot environment variables support"
 	depends on OF && MTD
-	select CRC32
-	select GENERIC_NET_UTILS
+	select NVMEM_LAYOUT_U_BOOT_ENV
 	help
-	  U-Boot stores its setup as environment variables. This driver adds
-	  support for verifying & exporting such data. It also exposes variables
-	  as NVMEM cells so they can be referenced by other drivers.
-
-	  Currently this drivers works only with env variables on top of MTD.
+	  This option enables support for the old device tree binding describing
+	  U-Boot environment variables block on top of MTD partition.
 
-	  If compiled as module it will be called nvmem_u-boot-env.
+	  Those bindings have been deprecated in favor of using a proper NVMEM
+	  layout.
 
 config NVMEM_UNIPHIER_EFUSE
 	tristate "UniPhier SoCs eFuse support"
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index cc23ce4ffb1f..2558752fd9a3 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -69,8 +69,6 @@ obj-$(CONFIG_NVMEM_SUNPLUS_OCOTP)	+= nvmem_sunplus_ocotp.o
 nvmem_sunplus_ocotp-y			:= sunplus-ocotp.o
 obj-$(CONFIG_NVMEM_SUNXI_SID)		+= nvmem_sunxi_sid.o
 nvmem_sunxi_sid-y			:= sunxi_sid.o
-obj-$(CONFIG_NVMEM_U_BOOT_ENV)		+= nvmem_u-boot-env.o
-nvmem_u-boot-env-y			:= u-boot-env.o
 obj-$(CONFIG_NVMEM_UNIPHIER_EFUSE)	+= nvmem-uniphier-efuse.o
 nvmem-uniphier-efuse-y			:= uniphier-efuse.o
 obj-$(CONFIG_NVMEM_VF610_OCOTP)		+= nvmem-vf610-ocotp.o
diff --git a/drivers/nvmem/layouts/Kconfig b/drivers/nvmem/layouts/Kconfig
index 7ff1ee1c1f05..f33999be787e 100644
--- a/drivers/nvmem/layouts/Kconfig
+++ b/drivers/nvmem/layouts/Kconfig
@@ -20,4 +20,14 @@ config NVMEM_LAYOUT_ONIE_TLV
 
 	  If unsure, say N.
 
+config NVMEM_LAYOUT_U_BOOT_ENV
+	tristate "U-Boot environment variables layout support"
+	depends on OF
+	select CRC32
+	select GENERIC_NET_UTILS
+	help
+	  U-Boot stores its setup as environment variables. This driver adds
+	  support for verifying & exporting such data. It also exposes variables
+	  as NVMEM cells so they can be referenced by other drivers.
+
 endmenu
diff --git a/drivers/nvmem/layouts/Makefile b/drivers/nvmem/layouts/Makefile
index 2974bd7d33ed..4940c9db0665 100644
--- a/drivers/nvmem/layouts/Makefile
+++ b/drivers/nvmem/layouts/Makefile
@@ -5,3 +5,4 @@
 
 obj-$(CONFIG_NVMEM_LAYOUT_SL28_VPD) += sl28vpd.o
 obj-$(CONFIG_NVMEM_LAYOUT_ONIE_TLV) += onie-tlv.o
+obj-$(CONFIG_NVMEM_LAYOUT_U_BOOT_ENV) += u-boot-env.o
diff --git a/drivers/nvmem/u-boot-env.c b/drivers/nvmem/layouts/u-boot-env.c
similarity index 67%
rename from drivers/nvmem/u-boot-env.c
rename to drivers/nvmem/layouts/u-boot-env.c
index ee9fd9989b6e..32eae6df8d96 100644
--- a/drivers/nvmem/u-boot-env.c
+++ b/drivers/nvmem/layouts/u-boot-env.c
@@ -8,11 +8,9 @@
 #include <linux/if_ether.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
-#include <linux/mtd/mtd.h>
 #include <linux/nvmem-consumer.h>
 #include <linux/nvmem-provider.h>
 #include <linux/of_device.h>
-#include <linux/platform_device.h>
 #include <linux/slab.h>
 
 enum u_boot_env_format {
@@ -25,7 +23,7 @@ struct u_boot_env {
 	struct device *dev;
 	enum u_boot_env_format format;
 
-	struct mtd_info *mtd;
+	struct nvmem_device *nvmem;
 
 	/* Cells */
 	struct nvmem_cell_info *cells;
@@ -50,28 +48,6 @@ struct u_boot_env_image_broadcom {
 	uint8_t data[0];
 } __packed;
 
-static int u_boot_env_read(void *context, unsigned int offset, void *val,
-			   size_t bytes)
-{
-	struct u_boot_env *priv = context;
-	struct device *dev = priv->dev;
-	size_t bytes_read;
-	int err;
-
-	err = mtd_read(priv->mtd, offset, bytes, &bytes_read, val);
-	if (err && !mtd_is_bitflip(err)) {
-		dev_err(dev, "Failed to read from mtd: %d\n", err);
-		return err;
-	}
-
-	if (bytes_read != bytes) {
-		dev_err(dev, "Failed to read %zu bytes\n", bytes);
-		return -EIO;
-	}
-
-	return 0;
-}
-
 static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, int index,
 						unsigned int offset, void *buf, size_t bytes)
 {
@@ -95,17 +71,25 @@ static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf,
 				size_t data_offset, size_t data_len)
 {
 	struct device *dev = priv->dev;
+	struct device_node *layout_np;
 	char *data = buf + data_offset;
 	char *var, *value, *eq;
+	int err = 0;
 	int idx;
 
+	layout_np = of_nvmem_layout_get_container(priv->nvmem);
+	if (!layout_np)
+		return -ENOENT;
+
 	priv->ncells = 0;
 	for (var = data; var < data + data_len && *var; var += strlen(var) + 1)
 		priv->ncells++;
 
 	priv->cells = devm_kcalloc(dev, priv->ncells, sizeof(*priv->cells), GFP_KERNEL);
-	if (!priv->cells)
-		return -ENOMEM;
+	if (!priv->cells) {
+		err = -ENOMEM;
+		goto err_of_node_put;
+	}
 
 	for (var = data, idx = 0;
 	     var < data + data_len && *var;
@@ -117,11 +101,13 @@ static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf,
 		value = eq + 1;
 
 		priv->cells[idx].name = devm_kstrdup(dev, var, GFP_KERNEL);
-		if (!priv->cells[idx].name)
-			return -ENOMEM;
+		if (!priv->cells[idx].name) {
+			err = -ENOMEM;
+			goto err_of_node_put;
+		}
 		priv->cells[idx].offset = data_offset + value - data;
 		priv->cells[idx].bytes = strlen(value);
-		priv->cells[idx].np = of_get_child_by_name(dev->of_node, priv->cells[idx].name);
+		priv->cells[idx].np = of_get_child_by_name(layout_np, priv->cells[idx].name);
 		if (!strcmp(var, "ethaddr")) {
 			priv->cells[idx].raw_len = strlen(value);
 			priv->cells[idx].bytes = ETH_ALEN;
@@ -132,7 +118,10 @@ static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf,
 	if (WARN_ON(idx != priv->ncells))
 		priv->ncells = idx;
 
-	return 0;
+err_of_node_put:
+	of_node_put(layout_np);
+
+	return err;
 }
 
 static int u_boot_env_parse(struct u_boot_env *priv)
@@ -143,21 +132,25 @@ static int u_boot_env_parse(struct u_boot_env *priv)
 	size_t crc32_offset;
 	size_t data_offset;
 	size_t data_len;
+	size_t env_size;
 	uint32_t crc32;
 	uint32_t calc;
-	size_t bytes;
+	ssize_t bytes;
 	uint8_t *buf;
 	int err;
 
-	buf = kcalloc(1, priv->mtd->size, GFP_KERNEL);
+	env_size = nvmem_device_size(priv->nvmem);
+
+	buf = kcalloc(1, env_size, GFP_KERNEL);
 	if (!buf) {
 		err = -ENOMEM;
 		goto err_out;
 	}
 
-	err = mtd_read(priv->mtd, 0, priv->mtd->size, &bytes, buf);
-	if ((err && !mtd_is_bitflip(err)) || bytes != priv->mtd->size) {
-		dev_err(dev, "Failed to read from mtd: %d\n", err);
+	bytes = nvmem_device_read(priv->nvmem, 0, env_size, buf);
+	if (bytes < 0 || bytes != env_size) {
+		dev_err(dev, "Failed to read from NVMEM device: %zd\n", bytes);
+		err = -EIO;
 		goto err_kfree;
 	}
 
@@ -179,8 +172,8 @@ static int u_boot_env_parse(struct u_boot_env *priv)
 		break;
 	}
 	crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset));
-	crc32_data_len = priv->mtd->size - crc32_data_offset;
-	data_len = priv->mtd->size - data_offset;
+	crc32_data_len = env_size - crc32_data_offset;
+	data_len = env_size - data_offset;
 
 	calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L;
 	if (calc != crc32) {
@@ -189,7 +182,7 @@ static int u_boot_env_parse(struct u_boot_env *priv)
 		goto err_kfree;
 	}
 
-	buf[priv->mtd->size - 1] = '\0';
+	buf[env_size - 1] = '\0';
 	err = u_boot_env_add_cells(priv, buf, data_offset, data_len);
 	if (err)
 		dev_err(dev, "Failed to add cells: %d\n", err);
@@ -200,14 +193,9 @@ static int u_boot_env_parse(struct u_boot_env *priv)
 	return err;
 }
 
-static int u_boot_env_probe(struct platform_device *pdev)
+static int u_boot_env_layout_add_cells(struct device *dev, struct nvmem_device *nvmem,
+				       struct nvmem_layout *layout)
 {
-	struct nvmem_config config = {
-		.name = "u-boot-env",
-		.reg_read = u_boot_env_read,
-	};
-	struct device *dev = &pdev->dev;
-	struct device_node *np = dev->of_node;
 	struct u_boot_env *priv;
 	int err;
 
@@ -216,28 +204,18 @@ static int u_boot_env_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	priv->dev = dev;
 
-	priv->format = (uintptr_t)of_device_get_match_data(dev);
+	priv->format = (uintptr_t)nvmem_layout_get_match_data(nvmem, layout);
 
-	priv->mtd = of_get_mtd_device_by_node(np);
-	if (IS_ERR(priv->mtd)) {
-		dev_err_probe(dev, PTR_ERR(priv->mtd), "Failed to get %pOF MTD\n", np);
-		return PTR_ERR(priv->mtd);
-	}
+	priv->nvmem = nvmem;
 
 	err = u_boot_env_parse(priv);
 	if (err)
 		return err;
 
-	config.dev = dev;
-	config.cells = priv->cells;
-	config.ncells = priv->ncells;
-	config.priv = priv;
-	config.size = priv->mtd->size;
-
-	return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
+	return 0;
 }
 
-static const struct of_device_id u_boot_env_of_match_table[] = {
+static const struct of_device_id u_boot_env_layout_of_match_table[] = {
 	{ .compatible = "u-boot,env", .data = (void *)U_BOOT_FORMAT_SINGLE, },
 	{ .compatible = "u-boot,env-redundant-bool", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
 	{ .compatible = "u-boot,env-redundant-count", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
@@ -245,15 +223,13 @@ static const struct of_device_id u_boot_env_of_match_table[] = {
 	{},
 };
 
-static struct platform_driver u_boot_env_driver = {
-	.probe = u_boot_env_probe,
-	.driver = {
-		.name = "u_boot_env",
-		.of_match_table = u_boot_env_of_match_table,
-	},
+static struct nvmem_layout u_boot_env_layout = {
+	.name = "u_boot_env",
+	.of_match_table = u_boot_env_layout_of_match_table,
+	.add_cells = u_boot_env_layout_add_cells,
 };
-module_platform_driver(u_boot_env_driver);
+module_nvmem_layout_driver(u_boot_env_layout);
 
 MODULE_AUTHOR("Rafał Miłecki");
 MODULE_LICENSE("GPL");
-MODULE_DEVICE_TABLE(of, u_boot_env_of_match_table);
+MODULE_DEVICE_TABLE(of, u_boot_env_layout_of_match_table);
-- 
2.35.3

Re: [PATCH 1/3] dt-bindings: nvmem: convert U-Boot env to NVMEM layout

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 2904 bytes --]

On Tue, Jul 18, 2023 at 06:06:50PM +0200, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> Use "nvmem-layout" and drop unused "mac" label while at it.

Stupid question perhaps, does the "old" way of doing this still work
after this series?

Thanks
Conor.

> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
>  .../bindings/nvmem/layouts/nvmem-layout.yaml    |  1 +
>  .../nvmem/{ => layouts}/u-boot,env.yaml         | 17 +++++++++++------
>  2 files changed, 12 insertions(+), 6 deletions(-)
>  rename Documentation/devicetree/bindings/nvmem/{ => layouts}/u-boot,env.yaml (87%)
> 
> diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> index 3b40f7880774..382507060651 100644
> --- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> @@ -21,6 +21,7 @@ oneOf:
>    - $ref: fixed-layout.yaml
>    - $ref: kontron,sl28-vpd.yaml
>    - $ref: onie,tlv-layout.yaml
> +  - $ref: u-boot,env.yaml
>  
>  properties:
>    compatible: true
> diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml
> similarity index 87%
> rename from Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
> rename to Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml
> index 36d97fb87865..ebe3b71ba155 100644
> --- a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml
> @@ -1,7 +1,7 @@
>  # SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>  %YAML 1.2
>  ---
> -$id: http://devicetree.org/schemas/nvmem/u-boot,env.yaml#
> +$id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml#
>  $schema: http://devicetree.org/meta-schemas/core.yaml#
>  
>  title: U-Boot environment variables
> @@ -72,11 +72,14 @@ examples:
>          };
>  
>          env: partition@40000 {
> -            compatible = "u-boot,env";
>              reg = <0x40000 0x10000>;
>  
> -            mac: ethaddr {
> -                #nvmem-cell-cells = <1>;
> +            nvmem-layout {
> +                compatible = "u-boot,env";
> +
> +                ethaddr {
> +                    #nvmem-cell-cells = <1>;
> +                };
>              };
>          };
>      };
> @@ -92,9 +95,11 @@ examples:
>              label = "u-boot";
>  
>              partition-u-boot-env {
> -                compatible = "brcm,env";
> +                nvmem-layout {
> +                    compatible = "brcm,env";
>  
> -                ethaddr {
> +                    ethaddr {
> +                    };
>                  };
>              };
>          };
> -- 
> 2.35.3
> 

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