From 4a1a40233b4a9fc159a5c7a27dc34c5c7bc5be55 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Fri, 15 Dec 2023 11:15:28 +0000
Subject: nvmem: Move of_nvmem_layout_get_container() in another header

nvmem-consumer.h is included by consumer devices, extracting data from
NVMEM devices whereas nvmem-provider.h is included by devices providing
NVMEM content.

The only users of of_nvmem_layout_get_container() outside of the core
are layout drivers, so better move its prototype to nvmem-provider.h.

While we do so, we also move the kdoc associated with the function to
the header rather than the .c file.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/core.c | 8 --------
 1 file changed, 8 deletions(-)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 608b352a7d91..b5b6ec8e04bb 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -847,14 +847,6 @@ static int nvmem_add_cells_from_layout(struct nvmem_device *nvmem)
 }
 
 #if IS_ENABLED(CONFIG_OF)
-/**
- * of_nvmem_layout_get_container() - Get OF node to layout container.
- *
- * @nvmem: nvmem device.
- *
- * Return: a node pointer with refcount incremented or NULL if no
- * container exists. Use of_node_put() on it when done.
- */
 struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)
 {
 	return of_get_child_by_name(nvmem->dev.of_node, "nvmem-layout");
-- 
cgit v1.2.3-70-g09d2


From ec9c08a1cb8dc5e8e003f95f5f62de41dde235bb Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Fri, 15 Dec 2023 11:15:29 +0000
Subject: nvmem: Create a header for internal sharing

Before adding all the NVMEM layout bus infrastructure to the core, let's
move the main nvmem_device structure in an internal header, only
available to the core. This way all the additional code can be added in
a dedicated file in order to keep the current core file tidy.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/core.c      | 24 +-----------------------
 drivers/nvmem/internals.h | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 23 deletions(-)
 create mode 100644 drivers/nvmem/internals.h

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index b5b6ec8e04bb..b5e5ce67398f 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -19,29 +19,7 @@
 #include <linux/of.h>
 #include <linux/slab.h>
 
-struct nvmem_device {
-	struct module		*owner;
-	struct device		dev;
-	int			stride;
-	int			word_size;
-	int			id;
-	struct kref		refcnt;
-	size_t			size;
-	bool			read_only;
-	bool			root_only;
-	int			flags;
-	enum nvmem_type		type;
-	struct bin_attribute	eeprom;
-	struct device		*base_dev;
-	struct list_head	cells;
-	const struct nvmem_keepout *keepout;
-	unsigned int		nkeepout;
-	nvmem_reg_read_t	reg_read;
-	nvmem_reg_write_t	reg_write;
-	struct gpio_desc	*wp_gpio;
-	struct nvmem_layout	*layout;
-	void *priv;
-};
+#include "internals.h"
 
 #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
 
diff --git a/drivers/nvmem/internals.h b/drivers/nvmem/internals.h
new file mode 100644
index 000000000000..ce353831cd65
--- /dev/null
+++ b/drivers/nvmem/internals.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _LINUX_NVMEM_INTERNALS_H
+#define _LINUX_NVMEM_INTERNALS_H
+
+#include <linux/device.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/nvmem-provider.h>
+
+struct nvmem_device {
+	struct module		*owner;
+	struct device		dev;
+	struct list_head	node;
+	int			stride;
+	int			word_size;
+	int			id;
+	struct kref		refcnt;
+	size_t			size;
+	bool			read_only;
+	bool			root_only;
+	int			flags;
+	enum nvmem_type		type;
+	struct bin_attribute	eeprom;
+	struct device		*base_dev;
+	struct list_head	cells;
+	const struct nvmem_keepout *keepout;
+	unsigned int		nkeepout;
+	nvmem_reg_read_t	reg_read;
+	nvmem_reg_write_t	reg_write;
+	struct gpio_desc	*wp_gpio;
+	struct nvmem_layout	*layout;
+	void *priv;
+};
+
+#endif  /* ifndef _LINUX_NVMEM_INTERNALS_H */
-- 
cgit v1.2.3-70-g09d2


From 1b7c298a4ecbc28cc6ee94005734bff55eb83d22 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Fri, 15 Dec 2023 11:15:30 +0000
Subject: nvmem: Simplify the ->add_cells() hook

The layout entry is not used and will anyway be made useless by the new
layout bus infrastructure coming next, so drop it. While at it, clarify
the kdoc entry.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/core.c             | 2 +-
 drivers/nvmem/layouts/onie-tlv.c | 3 +--
 drivers/nvmem/layouts/sl28vpd.c  | 3 +--
 include/linux/nvmem-provider.h   | 8 +++-----
 4 files changed, 6 insertions(+), 10 deletions(-)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index b5e5ce67398f..f63db5e01fca 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -816,7 +816,7 @@ static int nvmem_add_cells_from_layout(struct nvmem_device *nvmem)
 	int ret;
 
 	if (layout && layout->add_cells) {
-		ret = layout->add_cells(&nvmem->dev, nvmem, layout);
+		ret = layout->add_cells(&nvmem->dev, nvmem);
 		if (ret)
 			return ret;
 	}
diff --git a/drivers/nvmem/layouts/onie-tlv.c b/drivers/nvmem/layouts/onie-tlv.c
index 59fc87ccfcff..defd42d4375c 100644
--- a/drivers/nvmem/layouts/onie-tlv.c
+++ b/drivers/nvmem/layouts/onie-tlv.c
@@ -182,8 +182,7 @@ static bool onie_tlv_crc_is_valid(struct device *dev, size_t table_len, u8 *tabl
 	return true;
 }
 
-static int onie_tlv_parse_table(struct device *dev, struct nvmem_device *nvmem,
-				struct nvmem_layout *layout)
+static int onie_tlv_parse_table(struct device *dev, struct nvmem_device *nvmem)
 {
 	struct onie_tlv_hdr hdr;
 	size_t table_len, data_len, hdr_len;
diff --git a/drivers/nvmem/layouts/sl28vpd.c b/drivers/nvmem/layouts/sl28vpd.c
index 05671371f631..26c7cf21b523 100644
--- a/drivers/nvmem/layouts/sl28vpd.c
+++ b/drivers/nvmem/layouts/sl28vpd.c
@@ -80,8 +80,7 @@ static int sl28vpd_v1_check_crc(struct device *dev, struct nvmem_device *nvmem)
 	return 0;
 }
 
-static int sl28vpd_add_cells(struct device *dev, struct nvmem_device *nvmem,
-			     struct nvmem_layout *layout)
+static int sl28vpd_add_cells(struct device *dev, struct nvmem_device *nvmem)
 {
 	const struct nvmem_cell_info *pinfo;
 	struct nvmem_cell_info info = {0};
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index e5de21516387..3939991b3c5f 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -156,9 +156,8 @@ struct nvmem_cell_table {
  *
  * @name:		Layout name.
  * @of_match_table:	Open firmware match table.
- * @add_cells:		Will be called if a nvmem device is found which
- *			has this layout. The function will add layout
- *			specific cells with nvmem_add_one_cell().
+ * @add_cells:		Called to populate the layout using
+ *			nvmem_add_one_cell().
  * @fixup_cell_info:	Will be called before a cell is added. Can be
  *			used to modify the nvmem_cell_info.
  * @owner:		Pointer to struct module.
@@ -172,8 +171,7 @@ struct nvmem_cell_table {
 struct nvmem_layout {
 	const char *name;
 	const struct of_device_id *of_match_table;
-	int (*add_cells)(struct device *dev, struct nvmem_device *nvmem,
-			 struct nvmem_layout *layout);
+	int (*add_cells)(struct device *dev, struct nvmem_device *nvmem);
 	void (*fixup_cell_info)(struct nvmem_device *nvmem,
 				struct nvmem_layout *layout,
 				struct nvmem_cell_info *cell);
-- 
cgit v1.2.3-70-g09d2


From 1172460e716784ac7e1049a537bdca8edbf97360 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Fri, 15 Dec 2023 11:15:31 +0000
Subject: nvmem: Move and rename ->fixup_cell_info()

This hook is meant to be used by any provider and instantiating a layout
just for this is useless. Let's instead move this hook to the nvmem
device and add it to the config structure to be easily shared by the
providers.

While at moving this hook, rename it ->fixup_dt_cell_info() to clarify
its main intended purpose.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/core.c           |  6 +++---
 drivers/nvmem/imx-ocotp.c      | 11 +++--------
 drivers/nvmem/internals.h      |  2 ++
 drivers/nvmem/mtk-efuse.c      | 11 +++--------
 include/linux/nvmem-provider.h |  9 ++++-----
 5 files changed, 15 insertions(+), 24 deletions(-)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index f63db5e01fca..a885713d6b4b 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -675,7 +675,6 @@ static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
 
 static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_node *np)
 {
-	struct nvmem_layout *layout = nvmem->layout;
 	struct device *dev = &nvmem->dev;
 	struct device_node *child;
 	const __be32 *addr;
@@ -705,8 +704,8 @@ static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_nod
 
 		info.np = of_node_get(child);
 
-		if (layout && layout->fixup_cell_info)
-			layout->fixup_cell_info(nvmem, layout, &info);
+		if (nvmem->fixup_dt_cell_info)
+			nvmem->fixup_dt_cell_info(nvmem, &info);
 
 		ret = nvmem_add_one_cell(nvmem, &info);
 		kfree(info.name);
@@ -895,6 +894,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 
 	kref_init(&nvmem->refcnt);
 	INIT_LIST_HEAD(&nvmem->cells);
+	nvmem->fixup_dt_cell_info = config->fixup_dt_cell_info;
 
 	nvmem->owner = config->owner;
 	if (!nvmem->owner && config->dev->driver)
diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c
index f1e202efaa49..79dd4fda0329 100644
--- a/drivers/nvmem/imx-ocotp.c
+++ b/drivers/nvmem/imx-ocotp.c
@@ -583,17 +583,12 @@ static const struct of_device_id imx_ocotp_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
 
-static void imx_ocotp_fixup_cell_info(struct nvmem_device *nvmem,
-				      struct nvmem_layout *layout,
-				      struct nvmem_cell_info *cell)
+static void imx_ocotp_fixup_dt_cell_info(struct nvmem_device *nvmem,
+					 struct nvmem_cell_info *cell)
 {
 	cell->read_post_process = imx_ocotp_cell_pp;
 }
 
-static struct nvmem_layout imx_ocotp_layout = {
-	.fixup_cell_info = imx_ocotp_fixup_cell_info,
-};
-
 static int imx_ocotp_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -619,7 +614,7 @@ static int imx_ocotp_probe(struct platform_device *pdev)
 	imx_ocotp_nvmem_config.size = 4 * priv->params->nregs;
 	imx_ocotp_nvmem_config.dev = dev;
 	imx_ocotp_nvmem_config.priv = priv;
-	imx_ocotp_nvmem_config.layout = &imx_ocotp_layout;
+	imx_ocotp_nvmem_config.fixup_dt_cell_info = &imx_ocotp_fixup_dt_cell_info;
 
 	priv->config = &imx_ocotp_nvmem_config;
 
diff --git a/drivers/nvmem/internals.h b/drivers/nvmem/internals.h
index ce353831cd65..893553fbdf51 100644
--- a/drivers/nvmem/internals.h
+++ b/drivers/nvmem/internals.h
@@ -23,6 +23,8 @@ struct nvmem_device {
 	struct bin_attribute	eeprom;
 	struct device		*base_dev;
 	struct list_head	cells;
+	void (*fixup_dt_cell_info)(struct nvmem_device *nvmem,
+				   struct nvmem_cell_info *cell);
 	const struct nvmem_keepout *keepout;
 	unsigned int		nkeepout;
 	nvmem_reg_read_t	reg_read;
diff --git a/drivers/nvmem/mtk-efuse.c b/drivers/nvmem/mtk-efuse.c
index 87c94686cfd2..84f05b40a411 100644
--- a/drivers/nvmem/mtk-efuse.c
+++ b/drivers/nvmem/mtk-efuse.c
@@ -45,9 +45,8 @@ static int mtk_efuse_gpu_speedbin_pp(void *context, const char *id, int index,
 	return 0;
 }
 
-static void mtk_efuse_fixup_cell_info(struct nvmem_device *nvmem,
-				      struct nvmem_layout *layout,
-				      struct nvmem_cell_info *cell)
+static void mtk_efuse_fixup_dt_cell_info(struct nvmem_device *nvmem,
+					 struct nvmem_cell_info *cell)
 {
 	size_t sz = strlen(cell->name);
 
@@ -61,10 +60,6 @@ static void mtk_efuse_fixup_cell_info(struct nvmem_device *nvmem,
 		cell->read_post_process = mtk_efuse_gpu_speedbin_pp;
 }
 
-static struct nvmem_layout mtk_efuse_layout = {
-	.fixup_cell_info = mtk_efuse_fixup_cell_info,
-};
-
 static int mtk_efuse_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -91,7 +86,7 @@ static int mtk_efuse_probe(struct platform_device *pdev)
 	econfig.priv = priv;
 	econfig.dev = dev;
 	if (pdata->uses_post_processing)
-		econfig.layout = &mtk_efuse_layout;
+		econfig.fixup_dt_cell_info = &mtk_efuse_fixup_dt_cell_info;
 	nvmem = devm_nvmem_register(dev, &econfig);
 
 	return PTR_ERR_OR_ZERO(nvmem);
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index 3939991b3c5f..36415a602d9e 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -83,6 +83,8 @@ struct nvmem_cell_info {
  * @cells:	Optional array of pre-defined NVMEM cells.
  * @ncells:	Number of elements in cells.
  * @add_legacy_fixed_of_cells:	Read fixed NVMEM cells from old OF syntax.
+ * @fixup_dt_cell_info: Will be called before a cell is added. Can be
+ *		used to modify the nvmem_cell_info.
  * @keepout:	Optional array of keepout ranges (sorted ascending by start).
  * @nkeepout:	Number of elements in the keepout array.
  * @type:	Type of the nvmem storage
@@ -113,6 +115,8 @@ struct nvmem_config {
 	const struct nvmem_cell_info	*cells;
 	int			ncells;
 	bool			add_legacy_fixed_of_cells;
+	void (*fixup_dt_cell_info)(struct nvmem_device *nvmem,
+				   struct nvmem_cell_info *cell);
 	const struct nvmem_keepout *keepout;
 	unsigned int		nkeepout;
 	enum nvmem_type		type;
@@ -158,8 +162,6 @@ struct nvmem_cell_table {
  * @of_match_table:	Open firmware match table.
  * @add_cells:		Called to populate the layout using
  *			nvmem_add_one_cell().
- * @fixup_cell_info:	Will be called before a cell is added. Can be
- *			used to modify the nvmem_cell_info.
  * @owner:		Pointer to struct module.
  * @node:		List node.
  *
@@ -172,9 +174,6 @@ struct nvmem_layout {
 	const char *name;
 	const struct of_device_id *of_match_table;
 	int (*add_cells)(struct device *dev, struct nvmem_device *nvmem);
-	void (*fixup_cell_info)(struct nvmem_device *nvmem,
-				struct nvmem_layout *layout,
-				struct nvmem_cell_info *cell);
 
 	/* private */
 	struct module *owner;
-- 
cgit v1.2.3-70-g09d2


From fc29fd821d9ac2ae3d32a722fac39ce874efb883 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Fri, 15 Dec 2023 11:15:32 +0000
Subject: nvmem: core: Rework layouts to become regular devices
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Current layout support was initially written without modules support in
mind. When the requirement for module support rose, the existing base
was improved to adopt modularization support, but kind of a design flaw
was introduced. With the existing implementation, when a storage device
registers into NVMEM, the core tries to hook a layout (if any) and
populates its cells immediately. This means, if the hardware description
expects a layout to be hooked up, but no driver was provided for that,
the storage medium will fail to probe and try later from
scratch. Even if we consider that the hardware description shall be
correct, we could still probe the storage device (especially if it
contains the rootfs).

One way to overcome this situation is to consider the layouts as
devices, and leverage the native notifier mechanism. When a new NVMEM
device is registered, we can populate its nvmem-layout child, if any,
and wait for the matching to be done in order to get the cells (the
waiting can be easily done with the NVMEM notifiers). If the layout
driver is compiled as a module, it should automatically be loaded. This
way, there is no strong order to enforce, any NVMEM device creation
or NVMEM layout driver insertion will be observed as a new event which
may lead to the creation of additional cells, without disturbing the
probes with costly (and sometimes endless) deferrals.

In order to achieve that goal we create a new bus for the nvmem-layouts
with minimal logic to match nvmem-layout devices with nvmem-layout
drivers. All this infrastructure code is created in the layouts.c file.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/Kconfig            |   1 +
 drivers/nvmem/Makefile           |   2 +
 drivers/nvmem/core.c             | 170 ++++++++++++---------------------
 drivers/nvmem/internals.h        |  21 ++++
 drivers/nvmem/layouts.c          | 201 +++++++++++++++++++++++++++++++++++++++
 drivers/nvmem/layouts/Kconfig    |   8 ++
 drivers/nvmem/layouts/onie-tlv.c |  24 ++++-
 drivers/nvmem/layouts/sl28vpd.c  |  24 ++++-
 include/linux/nvmem-provider.h   |  38 ++++----
 9 files changed, 354 insertions(+), 135 deletions(-)
 create mode 100644 drivers/nvmem/layouts.c

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 5bc9c4874fe3..283134498fbc 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 menuconfig NVMEM
 	bool "NVMEM Support"
+	imply NVMEM_LAYOUTS
 	help
 	  Support for NVMEM(Non Volatile Memory) devices like EEPROM, EFUSES...
 
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 423baf089515..cdd01fbf1313 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -5,6 +5,8 @@
 
 obj-$(CONFIG_NVMEM)		+= nvmem_core.o
 nvmem_core-y			:= core.o
+obj-$(CONFIG_NVMEM_LAYOUTS)	+= nvmem_layouts.o
+nvmem_layouts-y			:= layouts.o
 obj-y				+= layouts/
 
 # Devices
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index a885713d6b4b..4c2154ddf8a7 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -55,9 +55,6 @@ static LIST_HEAD(nvmem_lookup_list);
 
 static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
 
-static DEFINE_SPINLOCK(nvmem_layout_lock);
-static LIST_HEAD(nvmem_layouts);
-
 static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
 			    void *val, size_t bytes)
 {
@@ -740,97 +737,22 @@ static int nvmem_add_cells_from_fixed_layout(struct nvmem_device *nvmem)
 	return err;
 }
 
-int __nvmem_layout_register(struct nvmem_layout *layout, struct module *owner)
+int nvmem_layout_register(struct nvmem_layout *layout)
 {
-	layout->owner = owner;
-
-	spin_lock(&nvmem_layout_lock);
-	list_add(&layout->node, &nvmem_layouts);
-	spin_unlock(&nvmem_layout_lock);
-
-	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_LAYOUT_ADD, layout);
+	if (!layout->add_cells)
+		return -EINVAL;
 
-	return 0;
+	/* Populate the cells */
+	return layout->add_cells(&layout->nvmem->dev, layout->nvmem);
 }
-EXPORT_SYMBOL_GPL(__nvmem_layout_register);
+EXPORT_SYMBOL_GPL(nvmem_layout_register);
 
 void nvmem_layout_unregister(struct nvmem_layout *layout)
 {
-	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_LAYOUT_REMOVE, layout);
-
-	spin_lock(&nvmem_layout_lock);
-	list_del(&layout->node);
-	spin_unlock(&nvmem_layout_lock);
+	/* Keep the API even with an empty stub in case we need it later */
 }
 EXPORT_SYMBOL_GPL(nvmem_layout_unregister);
 
-static struct nvmem_layout *nvmem_layout_get(struct nvmem_device *nvmem)
-{
-	struct device_node *layout_np;
-	struct nvmem_layout *l, *layout = ERR_PTR(-EPROBE_DEFER);
-
-	layout_np = of_nvmem_layout_get_container(nvmem);
-	if (!layout_np)
-		return NULL;
-
-	/* Fixed layouts don't have a matching driver */
-	if (of_device_is_compatible(layout_np, "fixed-layout")) {
-		of_node_put(layout_np);
-		return NULL;
-	}
-
-	/*
-	 * In case the nvmem device was built-in while the layout was built as a
-	 * module, we shall manually request the layout driver loading otherwise
-	 * we'll never have any match.
-	 */
-	of_request_module(layout_np);
-
-	spin_lock(&nvmem_layout_lock);
-
-	list_for_each_entry(l, &nvmem_layouts, node) {
-		if (of_match_node(l->of_match_table, layout_np)) {
-			if (try_module_get(l->owner))
-				layout = l;
-
-			break;
-		}
-	}
-
-	spin_unlock(&nvmem_layout_lock);
-	of_node_put(layout_np);
-
-	return layout;
-}
-
-static void nvmem_layout_put(struct nvmem_layout *layout)
-{
-	if (layout)
-		module_put(layout->owner);
-}
-
-static int nvmem_add_cells_from_layout(struct nvmem_device *nvmem)
-{
-	struct nvmem_layout *layout = nvmem->layout;
-	int ret;
-
-	if (layout && layout->add_cells) {
-		ret = layout->add_cells(&nvmem->dev, nvmem);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
-}
-
-#if IS_ENABLED(CONFIG_OF)
-struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)
-{
-	return of_get_child_by_name(nvmem->dev.of_node, "nvmem-layout");
-}
-EXPORT_SYMBOL_GPL(of_nvmem_layout_get_container);
-#endif
-
 const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem,
 					struct nvmem_layout *layout)
 {
@@ -838,7 +760,7 @@ const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem,
 	const struct of_device_id *match;
 
 	layout_np = of_nvmem_layout_get_container(nvmem);
-	match = of_match_node(layout->of_match_table, layout_np);
+	match = of_match_node(layout->dev.driver->of_match_table, layout_np);
 
 	return match ? match->data : NULL;
 }
@@ -950,19 +872,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 			goto err_put_device;
 	}
 
-	/*
-	 * If the driver supplied a layout by config->layout, the module
-	 * pointer will be NULL and nvmem_layout_put() will be a noop.
-	 */
-	nvmem->layout = config->layout ?: nvmem_layout_get(nvmem);
-	if (IS_ERR(nvmem->layout)) {
-		rval = PTR_ERR(nvmem->layout);
-		nvmem->layout = NULL;
-
-		if (rval == -EPROBE_DEFER)
-			goto err_teardown_compat;
-	}
-
 	if (config->cells) {
 		rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
 		if (rval)
@@ -983,24 +892,24 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	if (rval)
 		goto err_remove_cells;
 
-	rval = nvmem_add_cells_from_layout(nvmem);
-	if (rval)
-		goto err_remove_cells;
-
 	dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
 
 	rval = device_add(&nvmem->dev);
 	if (rval)
 		goto err_remove_cells;
 
+	rval = nvmem_populate_layout(nvmem);
+	if (rval)
+		goto err_remove_dev;
+
 	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
 
 	return nvmem;
 
+err_remove_dev:
+	device_del(&nvmem->dev);
 err_remove_cells:
 	nvmem_device_remove_all_cells(nvmem);
-	nvmem_layout_put(nvmem->layout);
-err_teardown_compat:
 	if (config->compat)
 		nvmem_sysfs_remove_compat(nvmem, config);
 err_put_device:
@@ -1022,7 +931,7 @@ static void nvmem_device_release(struct kref *kref)
 		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
 
 	nvmem_device_remove_all_cells(nvmem);
-	nvmem_layout_put(nvmem->layout);
+	nvmem_destroy_layout(nvmem);
 	device_unregister(&nvmem->dev);
 }
 
@@ -1324,6 +1233,12 @@ nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
 	return cell;
 }
 
+static void nvmem_layout_module_put(struct nvmem_device *nvmem)
+{
+	if (nvmem->layout && nvmem->layout->dev.driver)
+		module_put(nvmem->layout->dev.driver->owner);
+}
+
 #if IS_ENABLED(CONFIG_OF)
 static struct nvmem_cell_entry *
 nvmem_find_cell_entry_by_node(struct nvmem_device *nvmem, struct device_node *np)
@@ -1342,6 +1257,18 @@ nvmem_find_cell_entry_by_node(struct nvmem_device *nvmem, struct device_node *np
 	return cell;
 }
 
+static int nvmem_layout_module_get_optional(struct nvmem_device *nvmem)
+{
+	if (!nvmem->layout)
+		return 0;
+
+	if (!nvmem->layout->dev.driver ||
+	    !try_module_get(nvmem->layout->dev.driver->owner))
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+
 /**
  * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
  *
@@ -1404,16 +1331,29 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
 		return ERR_CAST(nvmem);
 	}
 
+	ret = nvmem_layout_module_get_optional(nvmem);
+	if (ret) {
+		of_node_put(cell_np);
+		__nvmem_device_put(nvmem);
+		return ERR_PTR(ret);
+	}
+
 	cell_entry = nvmem_find_cell_entry_by_node(nvmem, cell_np);
 	of_node_put(cell_np);
 	if (!cell_entry) {
 		__nvmem_device_put(nvmem);
-		return ERR_PTR(-ENOENT);
+		nvmem_layout_module_put(nvmem);
+		if (nvmem->layout)
+			return ERR_PTR(-EPROBE_DEFER);
+		else
+			return ERR_PTR(-ENOENT);
 	}
 
 	cell = nvmem_create_cell(cell_entry, id, cell_index);
-	if (IS_ERR(cell))
+	if (IS_ERR(cell)) {
 		__nvmem_device_put(nvmem);
+		nvmem_layout_module_put(nvmem);
+	}
 
 	return cell;
 }
@@ -1527,6 +1467,7 @@ void nvmem_cell_put(struct nvmem_cell *cell)
 
 	kfree(cell);
 	__nvmem_device_put(nvmem);
+	nvmem_layout_module_put(nvmem);
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_put);
 
@@ -2104,11 +2045,22 @@ EXPORT_SYMBOL_GPL(nvmem_dev_name);
 
 static int __init nvmem_init(void)
 {
-	return bus_register(&nvmem_bus_type);
+	int ret;
+
+	ret = bus_register(&nvmem_bus_type);
+	if (ret)
+		return ret;
+
+	ret = nvmem_layout_bus_register();
+	if (ret)
+		bus_unregister(&nvmem_bus_type);
+
+	return ret;
 }
 
 static void __exit nvmem_exit(void)
 {
+	nvmem_layout_bus_unregister();
 	bus_unregister(&nvmem_bus_type);
 }
 
diff --git a/drivers/nvmem/internals.h b/drivers/nvmem/internals.h
index 893553fbdf51..4946456c76c7 100644
--- a/drivers/nvmem/internals.h
+++ b/drivers/nvmem/internals.h
@@ -34,4 +34,25 @@ struct nvmem_device {
 	void *priv;
 };
 
+#if IS_ENABLED(CONFIG_OF)
+int nvmem_layout_bus_register(void);
+void nvmem_layout_bus_unregister(void);
+int nvmem_populate_layout(struct nvmem_device *nvmem);
+void nvmem_destroy_layout(struct nvmem_device *nvmem);
+#else /* CONFIG_OF */
+static inline int nvmem_layout_bus_register(void)
+{
+	return 0;
+}
+
+static inline void nvmem_layout_bus_unregister(void) {}
+
+static inline int nvmem_populate_layout(struct nvmem_device *nvmem)
+{
+	return 0;
+}
+
+static inline void nvmem_destroy_layout(struct nvmem_device *nvmem) { }
+#endif /* CONFIG_OF */
+
 #endif  /* ifndef _LINUX_NVMEM_INTERNALS_H */
diff --git a/drivers/nvmem/layouts.c b/drivers/nvmem/layouts.c
new file mode 100644
index 000000000000..6a6aa58369ff
--- /dev/null
+++ b/drivers/nvmem/layouts.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVMEM layout bus handling
+ *
+ * Copyright (C) 2023 Bootlin
+ * Author: Miquel Raynal <miquel.raynal@bootlin.com
+ */
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+
+#include "internals.h"
+
+#define to_nvmem_layout_driver(drv) \
+	(container_of((drv), struct nvmem_layout_driver, driver))
+#define to_nvmem_layout_device(_dev) \
+	container_of((_dev), struct nvmem_layout, dev)
+
+static int nvmem_layout_bus_match(struct device *dev, struct device_driver *drv)
+{
+	return of_driver_match_device(dev, drv);
+}
+
+static int nvmem_layout_bus_probe(struct device *dev)
+{
+	struct nvmem_layout_driver *drv = to_nvmem_layout_driver(dev->driver);
+	struct nvmem_layout *layout = to_nvmem_layout_device(dev);
+
+	if (!drv->probe || !drv->remove)
+		return -EINVAL;
+
+	return drv->probe(layout);
+}
+
+static void nvmem_layout_bus_remove(struct device *dev)
+{
+	struct nvmem_layout_driver *drv = to_nvmem_layout_driver(dev->driver);
+	struct nvmem_layout *layout = to_nvmem_layout_device(dev);
+
+	return drv->remove(layout);
+}
+
+static struct bus_type nvmem_layout_bus_type = {
+	.name		= "nvmem-layout",
+	.match		= nvmem_layout_bus_match,
+	.probe		= nvmem_layout_bus_probe,
+	.remove		= nvmem_layout_bus_remove,
+};
+
+int nvmem_layout_driver_register(struct nvmem_layout_driver *drv)
+{
+	drv->driver.bus = &nvmem_layout_bus_type;
+
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(nvmem_layout_driver_register);
+
+void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv)
+{
+	driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(nvmem_layout_driver_unregister);
+
+static void nvmem_layout_release_device(struct device *dev)
+{
+	struct nvmem_layout *layout = to_nvmem_layout_device(dev);
+
+	of_node_put(layout->dev.of_node);
+	kfree(layout);
+}
+
+static int nvmem_layout_create_device(struct nvmem_device *nvmem,
+				      struct device_node *np)
+{
+	struct nvmem_layout *layout;
+	struct device *dev;
+	int ret;
+
+	layout = kzalloc(sizeof(*layout), GFP_KERNEL);
+	if (!layout)
+		return -ENOMEM;
+
+	/* Create a bidirectional link */
+	layout->nvmem = nvmem;
+	nvmem->layout = layout;
+
+	/* Device model registration */
+	dev = &layout->dev;
+	device_initialize(dev);
+	dev->parent = &nvmem->dev;
+	dev->bus = &nvmem_layout_bus_type;
+	dev->release = nvmem_layout_release_device;
+	dev->coherent_dma_mask = DMA_BIT_MASK(32);
+	dev->dma_mask = &dev->coherent_dma_mask;
+	device_set_node(dev, of_fwnode_handle(of_node_get(np)));
+	of_device_make_bus_id(dev);
+	of_msi_configure(dev, dev->of_node);
+
+	ret = device_add(dev);
+	if (ret) {
+		put_device(dev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_nvmem_layout_skip_table[] = {
+	{ .compatible = "fixed-layout", },
+	{}
+};
+
+static int nvmem_layout_bus_populate(struct nvmem_device *nvmem,
+				     struct device_node *layout_dn)
+{
+	int ret;
+
+	/* Make sure it has a compatible property */
+	if (!of_get_property(layout_dn, "compatible", NULL)) {
+		pr_debug("%s() - skipping %pOF, no compatible prop\n",
+			 __func__, layout_dn);
+		return 0;
+	}
+
+	/* Fixed layouts are parsed manually somewhere else for now */
+	if (of_match_node(of_nvmem_layout_skip_table, layout_dn)) {
+		pr_debug("%s() - skipping %pOF node\n", __func__, layout_dn);
+		return 0;
+	}
+
+	if (of_node_check_flag(layout_dn, OF_POPULATED_BUS)) {
+		pr_debug("%s() - skipping %pOF, already populated\n",
+			 __func__, layout_dn);
+
+		return 0;
+	}
+
+	/* NVMEM layout buses expect only a single device representing the layout */
+	ret = nvmem_layout_create_device(nvmem, layout_dn);
+	if (ret)
+		return ret;
+
+	of_node_set_flag(layout_dn, OF_POPULATED_BUS);
+
+	return 0;
+}
+
+struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)
+{
+	return of_get_child_by_name(nvmem->dev.of_node, "nvmem-layout");
+}
+EXPORT_SYMBOL_GPL(of_nvmem_layout_get_container);
+
+/*
+ * Returns the number of devices populated, 0 if the operation was not relevant
+ * for this nvmem device, an error code otherwise.
+ */
+int nvmem_populate_layout(struct nvmem_device *nvmem)
+{
+	struct device_node *layout_dn;
+	int ret;
+
+	layout_dn = of_nvmem_layout_get_container(nvmem);
+	if (!layout_dn)
+		return 0;
+
+	/* Populate the layout device */
+	device_links_supplier_sync_state_pause();
+	ret = nvmem_layout_bus_populate(nvmem, layout_dn);
+	device_links_supplier_sync_state_resume();
+
+	of_node_put(layout_dn);
+	return ret;
+}
+
+void nvmem_destroy_layout(struct nvmem_device *nvmem)
+{
+	struct device *dev;
+
+	if (!nvmem->layout)
+		return;
+
+	dev = &nvmem->layout->dev;
+	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
+	device_unregister(dev);
+}
+
+int nvmem_layout_bus_register(void)
+{
+	return bus_register(&nvmem_layout_bus_type);
+}
+
+void nvmem_layout_bus_unregister(void)
+{
+	bus_unregister(&nvmem_layout_bus_type);
+}
diff --git a/drivers/nvmem/layouts/Kconfig b/drivers/nvmem/layouts/Kconfig
index 7ff1ee1c1f05..9c6e672fc350 100644
--- a/drivers/nvmem/layouts/Kconfig
+++ b/drivers/nvmem/layouts/Kconfig
@@ -1,5 +1,11 @@
 # SPDX-License-Identifier: GPL-2.0
 
+config NVMEM_LAYOUTS
+	bool
+	depends on OF
+
+if NVMEM_LAYOUTS
+
 menu "Layout Types"
 
 config NVMEM_LAYOUT_SL28_VPD
@@ -21,3 +27,5 @@ config NVMEM_LAYOUT_ONIE_TLV
 	  If unsure, say N.
 
 endmenu
+
+endif
diff --git a/drivers/nvmem/layouts/onie-tlv.c b/drivers/nvmem/layouts/onie-tlv.c
index defd42d4375c..b24cc5dcc6ee 100644
--- a/drivers/nvmem/layouts/onie-tlv.c
+++ b/drivers/nvmem/layouts/onie-tlv.c
@@ -225,16 +225,32 @@ static int onie_tlv_parse_table(struct device *dev, struct nvmem_device *nvmem)
 	return 0;
 }
 
+static int onie_tlv_probe(struct nvmem_layout *layout)
+{
+	layout->add_cells = onie_tlv_parse_table;
+
+	return nvmem_layout_register(layout);
+}
+
+static void onie_tlv_remove(struct nvmem_layout *layout)
+{
+	nvmem_layout_unregister(layout);
+}
+
 static const struct of_device_id onie_tlv_of_match_table[] = {
 	{ .compatible = "onie,tlv-layout", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, onie_tlv_of_match_table);
 
-static struct nvmem_layout onie_tlv_layout = {
-	.name = "ONIE tlv layout",
-	.of_match_table = onie_tlv_of_match_table,
-	.add_cells = onie_tlv_parse_table,
+static struct nvmem_layout_driver onie_tlv_layout = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "onie-tlv-layout",
+		.of_match_table = onie_tlv_of_match_table,
+	},
+	.probe = onie_tlv_probe,
+	.remove = onie_tlv_remove,
 };
 module_nvmem_layout_driver(onie_tlv_layout);
 
diff --git a/drivers/nvmem/layouts/sl28vpd.c b/drivers/nvmem/layouts/sl28vpd.c
index 26c7cf21b523..b8ffae646cc2 100644
--- a/drivers/nvmem/layouts/sl28vpd.c
+++ b/drivers/nvmem/layouts/sl28vpd.c
@@ -134,16 +134,32 @@ static int sl28vpd_add_cells(struct device *dev, struct nvmem_device *nvmem)
 	return 0;
 }
 
+static int sl28vpd_probe(struct nvmem_layout *layout)
+{
+	layout->add_cells = sl28vpd_add_cells;
+
+	return nvmem_layout_register(layout);
+}
+
+static void sl28vpd_remove(struct nvmem_layout *layout)
+{
+	nvmem_layout_unregister(layout);
+}
+
 static const struct of_device_id sl28vpd_of_match_table[] = {
 	{ .compatible = "kontron,sl28-vpd" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, sl28vpd_of_match_table);
 
-static struct nvmem_layout sl28vpd_layout = {
-	.name = "sl28-vpd",
-	.of_match_table = sl28vpd_of_match_table,
-	.add_cells = sl28vpd_add_cells,
+static struct nvmem_layout_driver sl28vpd_layout = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "kontron-sl28vpd-layout",
+		.of_match_table = sl28vpd_of_match_table,
+	},
+	.probe = sl28vpd_probe,
+	.remove = sl28vpd_remove,
 };
 module_nvmem_layout_driver(sl28vpd_layout);
 
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index 36415a602d9e..6fe65b35ea97 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -9,6 +9,7 @@
 #ifndef _LINUX_NVMEM_PROVIDER_H
 #define _LINUX_NVMEM_PROVIDER_H
 
+#include <linux/device.h>
 #include <linux/device/driver.h>
 #include <linux/err.h>
 #include <linux/errno.h>
@@ -158,12 +159,11 @@ struct nvmem_cell_table {
 /**
  * struct nvmem_layout - NVMEM layout definitions
  *
- * @name:		Layout name.
- * @of_match_table:	Open firmware match table.
- * @add_cells:		Called to populate the layout using
- *			nvmem_add_one_cell().
- * @owner:		Pointer to struct module.
- * @node:		List node.
+ * @dev:		Device-model layout device.
+ * @nvmem:		The underlying NVMEM device
+ * @add_cells:		Will be called if a nvmem device is found which
+ *			has this layout. The function will add layout
+ *			specific cells with nvmem_add_one_cell().
  *
  * A nvmem device can hold a well defined structure which can just be
  * evaluated during runtime. For example a TLV list, or a list of "name=val"
@@ -171,13 +171,15 @@ struct nvmem_cell_table {
  * cells.
  */
 struct nvmem_layout {
-	const char *name;
-	const struct of_device_id *of_match_table;
+	struct device dev;
+	struct nvmem_device *nvmem;
 	int (*add_cells)(struct device *dev, struct nvmem_device *nvmem);
+};
 
-	/* private */
-	struct module *owner;
-	struct list_head node;
+struct nvmem_layout_driver {
+	struct device_driver driver;
+	int (*probe)(struct nvmem_layout *layout);
+	void (*remove)(struct nvmem_layout *layout);
 };
 
 #if IS_ENABLED(CONFIG_NVMEM)
@@ -194,11 +196,15 @@ void nvmem_del_cell_table(struct nvmem_cell_table *table);
 int nvmem_add_one_cell(struct nvmem_device *nvmem,
 		       const struct nvmem_cell_info *info);
 
-int __nvmem_layout_register(struct nvmem_layout *layout, struct module *owner);
-#define nvmem_layout_register(layout) \
-	__nvmem_layout_register(layout, THIS_MODULE)
+int nvmem_layout_register(struct nvmem_layout *layout);
 void nvmem_layout_unregister(struct nvmem_layout *layout);
 
+int nvmem_layout_driver_register(struct nvmem_layout_driver *drv);
+void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv);
+#define module_nvmem_layout_driver(__nvmem_layout_driver)		\
+	module_driver(__nvmem_layout_driver, nvmem_layout_driver_register, \
+		      nvmem_layout_driver_unregister)
+
 const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem,
 					struct nvmem_layout *layout);
 
@@ -262,8 +268,4 @@ static inline struct device_node *of_nvmem_layout_get_container(struct nvmem_dev
 
 #endif /* CONFIG_NVMEM && CONFIG_OF */
 
-#define module_nvmem_layout_driver(__layout_driver)		\
-	module_driver(__layout_driver, nvmem_layout_register,	\
-		      nvmem_layout_unregister)
-
 #endif  /* ifndef _LINUX_NVMEM_PROVIDER_H */
-- 
cgit v1.2.3-70-g09d2


From 0331c611949fffdf486652450901a4dc52bc5cca Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Fri, 15 Dec 2023 11:15:34 +0000
Subject: nvmem: core: Expose cells through sysfs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The binary content of nvmem devices is available to the user so in the
easiest cases, finding the content of a cell is rather easy as it is
just a matter of looking at a known and fixed offset. However, nvmem
layouts have been recently introduced to cope with more advanced
situations, where the offset and size of the cells is not known in
advance or is dynamic. When using layouts, more advanced parsers are
used by the kernel in order to give direct access to the content of each
cell, regardless of its position/size in the underlying
device. Unfortunately, these information are not accessible by users,
unless by fully re-implementing the parser logic in userland.

Let's expose the cells and their content through sysfs to avoid these
situations. Of course the relevant NVMEM sysfs Kconfig option must be
enabled for this support to be available.

Not all nvmem devices expose cells. Indeed, the .bin_attrs attribute
group member will be filled at runtime only when relevant and will
remain empty otherwise. In this case, as the cells attribute group will
be empty, it will not lead to any additional folder/file creation.

Exposed cells are read-only. There is, in practice, everything in the
core to support a write path, but as I don't see any need for that, I
prefer to keep the interface simple (and probably safer). The interface
is documented as being in the "testing" state which means we can later
add a write attribute if though relevant.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-9-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/core.c      | 135 +++++++++++++++++++++++++++++++++++++++++++++-
 drivers/nvmem/internals.h |   1 +
 2 files changed, 135 insertions(+), 1 deletion(-)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 4c2154ddf8a7..ba559e81f77f 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -299,6 +299,43 @@ static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj,
 	return nvmem_bin_attr_get_umode(nvmem);
 }
 
+static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry,
+					    const char *id, int index);
+
+static ssize_t nvmem_cell_attr_read(struct file *filp, struct kobject *kobj,
+				    struct bin_attribute *attr, char *buf,
+				    loff_t pos, size_t count)
+{
+	struct nvmem_cell_entry *entry;
+	struct nvmem_cell *cell = NULL;
+	size_t cell_sz, read_len;
+	void *content;
+
+	entry = attr->private;
+	cell = nvmem_create_cell(entry, entry->name, 0);
+	if (IS_ERR(cell))
+		return PTR_ERR(cell);
+
+	if (!cell)
+		return -EINVAL;
+
+	content = nvmem_cell_read(cell, &cell_sz);
+	if (IS_ERR(content)) {
+		read_len = PTR_ERR(content);
+		goto destroy_cell;
+	}
+
+	read_len = min_t(unsigned int, cell_sz - pos, count);
+	memcpy(buf, content + pos, read_len);
+	kfree(content);
+
+destroy_cell:
+	kfree_const(cell->id);
+	kfree(cell);
+
+	return read_len;
+}
+
 /* default read/write permissions */
 static struct bin_attribute bin_attr_rw_nvmem = {
 	.attr	= {
@@ -320,11 +357,21 @@ static const struct attribute_group nvmem_bin_group = {
 	.is_bin_visible = nvmem_bin_attr_is_visible,
 };
 
+/* Cell attributes will be dynamically allocated */
+static struct attribute_group nvmem_cells_group = {
+	.name		= "cells",
+};
+
 static const struct attribute_group *nvmem_dev_groups[] = {
 	&nvmem_bin_group,
 	NULL,
 };
 
+static const struct attribute_group *nvmem_cells_groups[] = {
+	&nvmem_cells_group,
+	NULL,
+};
+
 static struct bin_attribute bin_attr_nvmem_eeprom_compat = {
 	.attr	= {
 		.name	= "eeprom",
@@ -380,6 +427,68 @@ static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
 		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
 }
 
+static int nvmem_populate_sysfs_cells(struct nvmem_device *nvmem)
+{
+	struct bin_attribute **cells_attrs, *attrs;
+	struct nvmem_cell_entry *entry;
+	unsigned int ncells = 0, i = 0;
+	int ret = 0;
+
+	mutex_lock(&nvmem_mutex);
+
+	if (list_empty(&nvmem->cells) || nvmem->sysfs_cells_populated) {
+		nvmem_cells_group.bin_attrs = NULL;
+		goto unlock_mutex;
+	}
+
+	/* Allocate an array of attributes with a sentinel */
+	ncells = list_count_nodes(&nvmem->cells);
+	cells_attrs = devm_kcalloc(&nvmem->dev, ncells + 1,
+				   sizeof(struct bin_attribute *), GFP_KERNEL);
+	if (!cells_attrs) {
+		ret = -ENOMEM;
+		goto unlock_mutex;
+	}
+
+	attrs = devm_kcalloc(&nvmem->dev, ncells, sizeof(struct bin_attribute), GFP_KERNEL);
+	if (!attrs) {
+		ret = -ENOMEM;
+		goto unlock_mutex;
+	}
+
+	/* Initialize each attribute to take the name and size of the cell */
+	list_for_each_entry(entry, &nvmem->cells, node) {
+		sysfs_bin_attr_init(&attrs[i]);
+		attrs[i].attr.name = devm_kasprintf(&nvmem->dev, GFP_KERNEL,
+						    "%s@%x", entry->name,
+						    entry->offset);
+		attrs[i].attr.mode = 0444;
+		attrs[i].size = entry->bytes;
+		attrs[i].read = &nvmem_cell_attr_read;
+		attrs[i].private = entry;
+		if (!attrs[i].attr.name) {
+			ret = -ENOMEM;
+			goto unlock_mutex;
+		}
+
+		cells_attrs[i] = &attrs[i];
+		i++;
+	}
+
+	nvmem_cells_group.bin_attrs = cells_attrs;
+
+	ret = devm_device_add_groups(&nvmem->dev, nvmem_cells_groups);
+	if (ret)
+		goto unlock_mutex;
+
+	nvmem->sysfs_cells_populated = true;
+
+unlock_mutex:
+	mutex_unlock(&nvmem_mutex);
+
+	return ret;
+}
+
 #else /* CONFIG_NVMEM_SYSFS */
 
 static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
@@ -739,11 +848,25 @@ static int nvmem_add_cells_from_fixed_layout(struct nvmem_device *nvmem)
 
 int nvmem_layout_register(struct nvmem_layout *layout)
 {
+	int ret;
+
 	if (!layout->add_cells)
 		return -EINVAL;
 
 	/* Populate the cells */
-	return layout->add_cells(&layout->nvmem->dev, layout->nvmem);
+	ret = layout->add_cells(&layout->nvmem->dev, layout->nvmem);
+	if (ret)
+		return ret;
+
+#ifdef CONFIG_NVMEM_SYSFS
+	ret = nvmem_populate_sysfs_cells(layout->nvmem);
+	if (ret) {
+		nvmem_device_remove_all_cells(layout->nvmem);
+		return ret;
+	}
+#endif
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(nvmem_layout_register);
 
@@ -902,10 +1025,20 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	if (rval)
 		goto err_remove_dev;
 
+#ifdef CONFIG_NVMEM_SYSFS
+	rval = nvmem_populate_sysfs_cells(nvmem);
+	if (rval)
+		goto err_destroy_layout;
+#endif
+
 	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
 
 	return nvmem;
 
+#ifdef CONFIG_NVMEM_SYSFS
+err_destroy_layout:
+	nvmem_destroy_layout(nvmem);
+#endif
 err_remove_dev:
 	device_del(&nvmem->dev);
 err_remove_cells:
diff --git a/drivers/nvmem/internals.h b/drivers/nvmem/internals.h
index 4946456c76c7..18fed57270e5 100644
--- a/drivers/nvmem/internals.h
+++ b/drivers/nvmem/internals.h
@@ -32,6 +32,7 @@ struct nvmem_device {
 	struct gpio_desc	*wp_gpio;
 	struct nvmem_layout	*layout;
 	void *priv;
+	bool			sysfs_cells_populated;
 };
 
 #if IS_ENABLED(CONFIG_OF)
-- 
cgit v1.2.3-70-g09d2


From f0ac5b23039610619ca4a4805528553ecb6bc815 Mon Sep 17 00:00:00 2001
From: Patrick Delaunay <patrick.delaunay@foss.st.com>
Date: Fri, 15 Dec 2023 11:15:36 +0000
Subject: nvmem: stm32: add support for STM32MP25 BSEC to control OTP data

On STM32MP25, OTP area may be read/written by using BSEC (boot, security
and OTP control). The BSEC internal peripheral is only managed by the
secure world.

The 12 Kbits of OTP (effective) are organized into the following regions:
- lower OTP (OTP0 to OTP127) = 4096 lower OTP bits,
  bitwise (1-bit) programmable
- mid OTP (OTP128 to OTP255) = 4096 middle OTP bits,
  bulk (32-bit) programmable
- upper OTP (OTP256 to OTP383) = 4096 upper OTP bits,
  bulk (32-bit) programmable,
  only accessible when BSEC is in closed state.

As HWKEY and ECIES key are only accessible by ROM code;
only 368 OTP words are managed in this driver (OTP0 to OTP267).

This patch adds the STM32MP25 configuration for reading and writing
the OTP data using the OP-TEE BSEC TA services.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-11-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/stm32-romem.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c
index 8a553b1799a8..82879b1c9eb9 100644
--- a/drivers/nvmem/stm32-romem.c
+++ b/drivers/nvmem/stm32-romem.c
@@ -269,6 +269,19 @@ static const struct stm32_romem_cfg stm32mp13_bsec_cfg = {
 	.ta = true,
 };
 
+/*
+ * STM32MP25 BSEC OTP: 3 regions of 32-bits data words
+ *   lower OTP (OTP0 to OTP127), bitwise (1-bit) programmable
+ *   mid OTP (OTP128 to OTP255), bulk (32-bit) programmable
+ *   upper OTP (OTP256 to OTP383), bulk (32-bit) programmable
+ *              but no access to HWKEY and ECIES key: limited at OTP367
+ */
+static const struct stm32_romem_cfg stm32mp25_bsec_cfg = {
+	.size = 368 * 4,
+	.lower = 127,
+	.ta = true,
+};
+
 static const struct of_device_id stm32_romem_of_match[] __maybe_unused = {
 	{ .compatible = "st,stm32f4-otp", }, {
 		.compatible = "st,stm32mp15-bsec",
@@ -276,6 +289,9 @@ static const struct of_device_id stm32_romem_of_match[] __maybe_unused = {
 	}, {
 		.compatible = "st,stm32mp13-bsec",
 		.data = (void *)&stm32mp13_bsec_cfg,
+	}, {
+		.compatible = "st,stm32mp25-bsec",
+		.data = (void *)&stm32mp25_bsec_cfg,
 	},
 	{ /* sentinel */ },
 };
-- 
cgit v1.2.3-70-g09d2


From 401df0d4f4098ecc9c5278da2f50756d62e5b37d Mon Sep 17 00:00:00 2001
From: Rafał Miłecki <rafal@milecki.pl>
Date: Tue, 19 Dec 2023 13:01:03 +0100
Subject: nvmem: layouts: refactor .add_cells() callback arguments
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Simply pass whole "struct nvmem_layout" instead of single variables.
There is nothing in "struct nvmem_layout" that we have to hide from
layout drivers. They also access it during .probe() and .remove().

Thanks to this change:

1. API gets more consistent
   All layouts drivers callbacks get the same argument

2. Layouts get correct device
   Before this change NVMEM core code was passing NVMEM device instead
   of layout device. That resulted in:
   * Confusing prints
   * Calling devm_*() helpers on wrong device
   * Helpers like of_device_get_match_data() dereferencing NULLs

3. It gets possible to get match data
   First of all nvmem_layout_get_match_data() requires passing "struct
   nvmem_layout" which .add_cells() callback didn't have before this. It
   doesn't matter much as it's rather useless now anyway (and will be
   dropped).
   What's more important however is that of_device_get_match_data() can
   be used now thanks to owning a proper device pointer.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20231219120104.3422-1-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/core.c             | 2 +-
 drivers/nvmem/layouts/onie-tlv.c | 4 +++-
 drivers/nvmem/layouts/sl28vpd.c  | 4 +++-
 include/linux/nvmem-provider.h   | 2 +-
 4 files changed, 8 insertions(+), 4 deletions(-)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index ba559e81f77f..441d132ebb61 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -854,7 +854,7 @@ int nvmem_layout_register(struct nvmem_layout *layout)
 		return -EINVAL;
 
 	/* Populate the cells */
-	ret = layout->add_cells(&layout->nvmem->dev, layout->nvmem);
+	ret = layout->add_cells(layout);
 	if (ret)
 		return ret;
 
diff --git a/drivers/nvmem/layouts/onie-tlv.c b/drivers/nvmem/layouts/onie-tlv.c
index b24cc5dcc6ee..9d2ad5f2dc10 100644
--- a/drivers/nvmem/layouts/onie-tlv.c
+++ b/drivers/nvmem/layouts/onie-tlv.c
@@ -182,8 +182,10 @@ static bool onie_tlv_crc_is_valid(struct device *dev, size_t table_len, u8 *tabl
 	return true;
 }
 
-static int onie_tlv_parse_table(struct device *dev, struct nvmem_device *nvmem)
+static int onie_tlv_parse_table(struct nvmem_layout *layout)
 {
+	struct nvmem_device *nvmem = layout->nvmem;
+	struct device *dev = &layout->dev;
 	struct onie_tlv_hdr hdr;
 	size_t table_len, data_len, hdr_len;
 	u8 *table, *data;
diff --git a/drivers/nvmem/layouts/sl28vpd.c b/drivers/nvmem/layouts/sl28vpd.c
index b8ffae646cc2..53fa50f17dca 100644
--- a/drivers/nvmem/layouts/sl28vpd.c
+++ b/drivers/nvmem/layouts/sl28vpd.c
@@ -80,8 +80,10 @@ static int sl28vpd_v1_check_crc(struct device *dev, struct nvmem_device *nvmem)
 	return 0;
 }
 
-static int sl28vpd_add_cells(struct device *dev, struct nvmem_device *nvmem)
+static int sl28vpd_add_cells(struct nvmem_layout *layout)
 {
+	struct nvmem_device *nvmem = layout->nvmem;
+	struct device *dev = &layout->dev;
 	const struct nvmem_cell_info *pinfo;
 	struct nvmem_cell_info info = {0};
 	struct device_node *layout_np;
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index 6fe65b35ea97..81a67642ac55 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -173,7 +173,7 @@ struct nvmem_cell_table {
 struct nvmem_layout {
 	struct device dev;
 	struct nvmem_device *nvmem;
-	int (*add_cells)(struct device *dev, struct nvmem_device *nvmem);
+	int (*add_cells)(struct nvmem_layout *layout);
 };
 
 struct nvmem_layout_driver {
-- 
cgit v1.2.3-70-g09d2


From 43f60e3fb62edc7bd8891de8779fb422f4ae23ae Mon Sep 17 00:00:00 2001
From: Rafał Miłecki <rafal@milecki.pl>
Date: Tue, 19 Dec 2023 13:01:04 +0100
Subject: nvmem: drop nvmem_layout_get_match_data()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Thanks for layouts refactoring we now have "struct device" associated
with layout. Also its OF pointer points directly to the "nvmem-layout"
DT node.

All it takes to get match data is a generic of_device_get_match_data().

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20231219120104.3422-2-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/core.c           | 13 -------------
 include/linux/nvmem-provider.h | 10 ----------
 2 files changed, 23 deletions(-)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 441d132ebb61..4ed54076346d 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -876,19 +876,6 @@ void nvmem_layout_unregister(struct nvmem_layout *layout)
 }
 EXPORT_SYMBOL_GPL(nvmem_layout_unregister);
 
-const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem,
-					struct nvmem_layout *layout)
-{
-	struct device_node __maybe_unused *layout_np;
-	const struct of_device_id *match;
-
-	layout_np = of_nvmem_layout_get_container(nvmem);
-	match = of_match_node(layout->dev.driver->of_match_table, layout_np);
-
-	return match ? match->data : NULL;
-}
-EXPORT_SYMBOL_GPL(nvmem_layout_get_match_data);
-
 /**
  * nvmem_register() - Register a nvmem device for given nvmem_config.
  * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index 81a67642ac55..f0ba0e03218f 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -205,9 +205,6 @@ void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv);
 	module_driver(__nvmem_layout_driver, nvmem_layout_driver_register, \
 		      nvmem_layout_driver_unregister)
 
-const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem,
-					struct nvmem_layout *layout);
-
 #else
 
 static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)
@@ -238,13 +235,6 @@ static inline int nvmem_layout_register(struct nvmem_layout *layout)
 
 static inline void nvmem_layout_unregister(struct nvmem_layout *layout) {}
 
-static inline const void *
-nvmem_layout_get_match_data(struct nvmem_device *nvmem,
-			    struct nvmem_layout *layout)
-{
-	return NULL;
-}
-
 #endif /* CONFIG_NVMEM */
 
 #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)
-- 
cgit v1.2.3-70-g09d2


From 33cf42e68efc8ff529a7eee08a4f0ba8c8d0a207 Mon Sep 17 00:00:00 2001
From: Rafał Miłecki <rafal@milecki.pl>
Date: Thu, 21 Dec 2023 18:34:17 +0100
Subject: nvmem: core: add nvmem_dev_size() helper
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This is required by layouts that need to read whole NVMEM content. It's
especially useful for NVMEM devices without hardcoded layout (like
U-Boot environment data block).

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231221173421.13737-2-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/core.c           | 13 +++++++++++++
 include/linux/nvmem-consumer.h |  1 +
 2 files changed, 14 insertions(+)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 4ed54076346d..980123fb4dde 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -2163,6 +2163,19 @@ const char *nvmem_dev_name(struct nvmem_device *nvmem)
 }
 EXPORT_SYMBOL_GPL(nvmem_dev_name);
 
+/**
+ * nvmem_dev_size() - Get the size of a given nvmem device.
+ *
+ * @nvmem: nvmem device.
+ *
+ * Return: size of the nvmem device.
+ */
+size_t nvmem_dev_size(struct nvmem_device *nvmem)
+{
+	return nvmem->size;
+}
+EXPORT_SYMBOL_GPL(nvmem_dev_size);
+
 static int __init nvmem_init(void)
 {
 	int ret;
diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
index 2d306fa13b1a..34c0e58dfa26 100644
--- a/include/linux/nvmem-consumer.h
+++ b/include/linux/nvmem-consumer.h
@@ -81,6 +81,7 @@ int nvmem_device_cell_write(struct nvmem_device *nvmem,
 			    struct nvmem_cell_info *info, void *buf);
 
 const char *nvmem_dev_name(struct nvmem_device *nvmem);
+size_t nvmem_dev_size(struct nvmem_device *nvmem);
 
 void nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries,
 			    size_t nentries);
-- 
cgit v1.2.3-70-g09d2


From 7c8979b42b1a9c5604f431ba804928e55919263c Mon Sep 17 00:00:00 2001
From: Rafał Miłecki <rafal@milecki.pl>
Date: Thu, 21 Dec 2023 18:34:18 +0100
Subject: nvmem: u-boot-env: use nvmem_add_one_cell() nvmem subsystem helper
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Simplify adding NVMEM cells.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231221173421.13737-3-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/u-boot-env.c | 55 ++++++++++++++++++----------------------------
 1 file changed, 21 insertions(+), 34 deletions(-)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/u-boot-env.c b/drivers/nvmem/u-boot-env.c
index c4ae94af4af7..dd9d0ad22712 100644
--- a/drivers/nvmem/u-boot-env.c
+++ b/drivers/nvmem/u-boot-env.c
@@ -23,13 +23,10 @@ enum u_boot_env_format {
 
 struct u_boot_env {
 	struct device *dev;
+	struct nvmem_device *nvmem;
 	enum u_boot_env_format format;
 
 	struct mtd_info *mtd;
-
-	/* Cells */
-	struct nvmem_cell_info *cells;
-	int ncells;
 };
 
 struct u_boot_env_image_single {
@@ -94,43 +91,36 @@ static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, i
 static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf,
 				size_t data_offset, size_t data_len)
 {
+	struct nvmem_device *nvmem = priv->nvmem;
 	struct device *dev = priv->dev;
 	char *data = buf + data_offset;
 	char *var, *value, *eq;
-	int idx;
-
-	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;
 
-	for (var = data, idx = 0;
+	for (var = data;
 	     var < data + data_len && *var;
-	     var = value + strlen(value) + 1, idx++) {
+	     var = value + strlen(value) + 1) {
+		struct nvmem_cell_info info = {};
+
 		eq = strchr(var, '=');
 		if (!eq)
 			break;
 		*eq = '\0';
 		value = eq + 1;
 
-		priv->cells[idx].name = devm_kstrdup(dev, var, GFP_KERNEL);
-		if (!priv->cells[idx].name)
+		info.name = devm_kstrdup(dev, var, GFP_KERNEL);
+		if (!info.name)
 			return -ENOMEM;
-		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);
+		info.offset = data_offset + value - data;
+		info.bytes = strlen(value);
+		info.np = of_get_child_by_name(dev->of_node, info.name);
 		if (!strcmp(var, "ethaddr")) {
-			priv->cells[idx].raw_len = strlen(value);
-			priv->cells[idx].bytes = ETH_ALEN;
-			priv->cells[idx].read_post_process = u_boot_env_read_post_process_ethaddr;
+			info.raw_len = strlen(value);
+			info.bytes = ETH_ALEN;
+			info.read_post_process = u_boot_env_read_post_process_ethaddr;
 		}
-	}
 
-	if (WARN_ON(idx != priv->ncells))
-		priv->ncells = idx;
+		nvmem_add_one_cell(nvmem, &info);
+	}
 
 	return 0;
 }
@@ -209,7 +199,6 @@ static int u_boot_env_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct u_boot_env *priv;
-	int err;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -224,17 +213,15 @@ static int u_boot_env_probe(struct platform_device *pdev)
 		return PTR_ERR(priv->mtd);
 	}
 
-	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));
+	priv->nvmem = devm_nvmem_register(dev, &config);
+	if (IS_ERR(priv->nvmem))
+		return PTR_ERR(priv->nvmem);
+
+	return u_boot_env_parse(priv);
 }
 
 static const struct of_device_id u_boot_env_of_match_table[] = {
-- 
cgit v1.2.3-70-g09d2


From a832556d23c5a11115f300011a5874d6107a0d62 Mon Sep 17 00:00:00 2001
From: Rafał Miłecki <rafal@milecki.pl>
Date: Thu, 21 Dec 2023 18:34:19 +0100
Subject: nvmem: u-boot-env: use nvmem device helpers
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Use nvmem_dev_size() and nvmem_device_read() to make this driver less
mtd dependent.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231221173421.13737-4-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/u-boot-env.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/u-boot-env.c b/drivers/nvmem/u-boot-env.c
index dd9d0ad22712..111905189341 100644
--- a/drivers/nvmem/u-boot-env.c
+++ b/drivers/nvmem/u-boot-env.c
@@ -127,27 +127,34 @@ static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf,
 
 static int u_boot_env_parse(struct u_boot_env *priv)
 {
+	struct nvmem_device *nvmem = priv->nvmem;
 	struct device *dev = priv->dev;
 	size_t crc32_data_offset;
 	size_t crc32_data_len;
 	size_t crc32_offset;
 	size_t data_offset;
 	size_t data_len;
+	size_t dev_size;
 	uint32_t crc32;
 	uint32_t calc;
-	size_t bytes;
 	uint8_t *buf;
+	int bytes;
 	int err;
 
-	buf = kcalloc(1, priv->mtd->size, GFP_KERNEL);
+	dev_size = nvmem_dev_size(nvmem);
+
+	buf = kcalloc(1, dev_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(nvmem, 0, dev_size, buf);
+	if (bytes < 0) {
+		err = bytes;
+		goto err_kfree;
+	} else if (bytes != dev_size) {
+		err = -EIO;
 		goto err_kfree;
 	}
 
@@ -169,8 +176,8 @@ 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 = dev_size - crc32_data_offset;
+	data_len = dev_size - data_offset;
 
 	calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L;
 	if (calc != crc32) {
@@ -179,7 +186,7 @@ static int u_boot_env_parse(struct u_boot_env *priv)
 		goto err_kfree;
 	}
 
-	buf[priv->mtd->size - 1] = '\0';
+	buf[dev_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);
-- 
cgit v1.2.3-70-g09d2


From 6bafe07c930676d6430be471310958070816a595 Mon Sep 17 00:00:00 2001
From: Rafał Miłecki <rafal@milecki.pl>
Date: Thu, 21 Dec 2023 18:34:20 +0100
Subject: nvmem: u-boot-env: improve coding style
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

1. Prefer kzalloc() over kcalloc()
   See memory-allocation.rst which says: "to be on the safe side it's
   best to use routines that set memory to zero, like kzalloc()"
2. Drop dev_err() for u_boot_env_add_cells() fail
   It can fail only on -ENOMEM. We don't want to print error then.
3. Add extra "crc32_addr" variable
   It makes code reading header's crc32 easier to understand / review.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231221173421.13737-5-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/u-boot-env.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'drivers/nvmem')

diff --git a/drivers/nvmem/u-boot-env.c b/drivers/nvmem/u-boot-env.c
index 111905189341..befbab156cda 100644
--- a/drivers/nvmem/u-boot-env.c
+++ b/drivers/nvmem/u-boot-env.c
@@ -132,6 +132,7 @@ static int u_boot_env_parse(struct u_boot_env *priv)
 	size_t crc32_data_offset;
 	size_t crc32_data_len;
 	size_t crc32_offset;
+	__le32 *crc32_addr;
 	size_t data_offset;
 	size_t data_len;
 	size_t dev_size;
@@ -143,7 +144,7 @@ static int u_boot_env_parse(struct u_boot_env *priv)
 
 	dev_size = nvmem_dev_size(nvmem);
 
-	buf = kcalloc(1, dev_size, GFP_KERNEL);
+	buf = kzalloc(dev_size, GFP_KERNEL);
 	if (!buf) {
 		err = -ENOMEM;
 		goto err_out;
@@ -175,7 +176,8 @@ static int u_boot_env_parse(struct u_boot_env *priv)
 		data_offset = offsetof(struct u_boot_env_image_broadcom, data);
 		break;
 	}
-	crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset));
+	crc32_addr = (__le32 *)(buf + crc32_offset);
+	crc32 = le32_to_cpu(*crc32_addr);
 	crc32_data_len = dev_size - crc32_data_offset;
 	data_len = dev_size - data_offset;
 
@@ -188,8 +190,6 @@ static int u_boot_env_parse(struct u_boot_env *priv)
 
 	buf[dev_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);
 
 err_kfree:
 	kfree(buf);
-- 
cgit v1.2.3-70-g09d2