[PATCH v2 0/9] soc: remove direct accesses to of_root from drivers/soc/

[PATCH v2 0/9] soc: remove direct accesses to of_root from drivers/soc/

[Bartosz Golaszewski]

linux/of.h declares a set of variables providing addresses of certain
key OF nodes. The pointers being variables can't profit from stubs
provided for when CONFIG_OF is disabled which means that drivers
accessing these variables can't profit from CONFIG_COMPILE_TEST=y
coverage.

There are drivers under drivers/soc/ that access the of_root node. This
series introduces new OF helpers for reading the machine compatible and
model strings, exports an existing SoC helper that reads the machine
string from the root node and finally replaces all direct accesses to
of_root with new or already existing helper functions.

Merging strategy: first two patches should be either acked by Rob or
picked up into an immutable branch based on v7.0-rc1, the rest can go
through the SoC tree.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
Changes in v2:
- rename of_machine_get_compatible() to of_machine_read_compatible() and
  add the index argument
- add a stub for of_machine_read_compatible() for !CONFIG_OF
- provide of_machine_read_model() to avoid having to look-up the root
  node via of_find_node_by_path("/")
- rename soc_device_get_machine() to soc_attr_read_machine() before
  making it an exported symbol
- Link to v1: https://lore.kernel.org/r/20260119-soc-of-root-v1-0-32a0fa9a78b4@oss.qualcomm.com

---
Bartosz Golaszewski (9):
      of: provide of_machine_read_compatible()
      of: provide of_machine_read_model()
      base: soc: order includes alphabetically
      base: soc: rename and export soc_device_get_machine()
      soc: fsl: guts: don't access of_root directly
      soc: imx8m: don't access of_root directly
      soc: imx9: don't access of_root directly
      soc: renesas: don't access of_root directly
      soc: sunxi: mbus: don't access of_root directly

 drivers/base/soc.c                | 23 ++++++++++-------------
 drivers/of/base.c                 | 28 ++++++++++++++++++++++++++++
 drivers/soc/fsl/guts.c            | 12 +++---------
 drivers/soc/imx/soc-imx8m.c       | 11 +++--------
 drivers/soc/imx/soc-imx9.c        |  4 ++--
 drivers/soc/renesas/renesas-soc.c |  7 ++++++-
 drivers/soc/sunxi/sunxi_mbus.c    |  2 +-
 include/linux/of.h                | 14 ++++++++++++++
 include/linux/sys_soc.h           | 10 ++++++++++
 9 files changed, 77 insertions(+), 34 deletions(-)
---
base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
change-id: 20260119-soc-of-root-77c86c54010f

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

[PATCH v2 1/9] of: provide of_machine_read_compatible()

[Bartosz Golaszewski]

Provide a helper function allowing users to read the compatible string
of the machine, hiding the access to the root node.

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/of/base.c  | 15 +++++++++++++++
 include/linux/of.h |  8 ++++++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 57420806c1a2b9a3c67b5dcc0f95610a87c2e46f..b70aec32e0e35ee232b413e548742491bf763df7 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -434,6 +434,21 @@ bool of_machine_compatible_match(const char *const *compats)
 }
 EXPORT_SYMBOL(of_machine_compatible_match);
 
+/**
+ * of_machine_read_compatible - Get the compatible string of this machine
+ * @compatible: address at which the address of the compatible string will be
+ *              stored
+ * @index: index of the compatible entry in the list
+ *
+ * Returns:
+ * 0 on success, negative error number on failure.
+ */
+int of_machine_read_compatible(const char **compatible, unsigned int index)
+{
+	return of_property_read_string_index(of_root, "compatible", index, compatible);
+}
+EXPORT_SYMBOL_GPL(of_machine_read_compatible);
+
 /**
  * of_machine_device_match - Test root of device tree against a of_device_id array
  * @matches:	NULL terminated array of of_device_id match structures to search in
diff --git a/include/linux/of.h b/include/linux/of.h
index be6ec4916adf522aa5e4dcb1480fe91e1a4e29d2..7df971d52b556f21b510a8b5ebfc8df49a2a6f64 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -426,6 +426,8 @@ static inline bool of_machine_is_compatible(const char *compat)
 	return of_machine_compatible_match(compats);
 }
 
+int of_machine_read_compatible(const char **compatible, unsigned int index);
+
 extern int of_add_property(struct device_node *np, struct property *prop);
 extern int of_remove_property(struct device_node *np, struct property *prop);
 extern int of_update_property(struct device_node *np, struct property *newprop);
@@ -851,6 +853,12 @@ static inline int of_machine_is_compatible(const char *compat)
 	return 0;
 }
 
+static inline int of_machine_read_compatible(const char **compatible,
+					     unsigned int index)
+{
+	return -ENOSYS;
+}
+
 static inline int of_add_property(struct device_node *np, struct property *prop)
 {
 	return 0;

-- 
2.47.3

[PATCH v2 2/9] of: provide of_machine_read_model()

[Bartosz Golaszewski]

Provide a helper function allowing users to read the model string of the
machine, hiding the access to the root node.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/of/base.c  | 13 +++++++++++++
 include/linux/of.h |  6 ++++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index b70aec32e0e35ee232b413e548742491bf763df7..bf4a51887d7422f5b8bfc63c7b20674bf03d800e 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -449,6 +449,19 @@ int of_machine_read_compatible(const char **compatible, unsigned int index)
 }
 EXPORT_SYMBOL_GPL(of_machine_read_compatible);
 
+/**
+ * of_machine_read_model - Get the model string of this machine
+ * @model: address at which the address of the model string will be stored
+ *
+ * Returns:
+ * 0 on success, negative error number on failure.
+ */
+int of_machine_read_model(const char **model)
+{
+	return of_property_read_string(of_root, "model", model);
+}
+EXPORT_SYMBOL_GPL(of_machine_read_model);
+
 /**
  * of_machine_device_match - Test root of device tree against a of_device_id array
  * @matches:	NULL terminated array of of_device_id match structures to search in
diff --git a/include/linux/of.h b/include/linux/of.h
index 7df971d52b556f21b510a8b5ebfc8df49a2a6f64..2b95777f16f6ea1fb1e4bd0d9902cc2640d14795 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -427,6 +427,7 @@ static inline bool of_machine_is_compatible(const char *compat)
 }
 
 int of_machine_read_compatible(const char **compatible, unsigned int index);
+int of_machine_read_model(const char **model);
 
 extern int of_add_property(struct device_node *np, struct property *prop);
 extern int of_remove_property(struct device_node *np, struct property *prop);
@@ -859,6 +860,11 @@ static inline int of_machine_read_compatible(const char **compatible,
 	return -ENOSYS;
 }
 
+static inline int of_machine_read_model(const char **model)
+{
+	return -ENOSYS;
+}
+
 static inline int of_add_property(struct device_node *np, struct property *prop)
 {
 	return 0;

-- 
2.47.3

[PATCH v2 3/9] base: soc: order includes alphabetically

[Bartosz Golaszewski]

For easier readability and maintenance, order the included headers
alphabetically.

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/base/soc.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/base/soc.c b/drivers/base/soc.c
index c8d3db9daa2f02c93aeefda9dd9c5ede148a676f..48e2f0dbd330b8d402135ffa7308f454eb4ab7a5 100644
--- a/drivers/base/soc.c
+++ b/drivers/base/soc.c
@@ -5,16 +5,16 @@
  * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson.
  */
 
-#include <linux/sysfs.h>
+#include <linux/err.h>
+#include <linux/glob.h>
+#include <linux/idr.h>
 #include <linux/init.h>
 #include <linux/of.h>
-#include <linux/stat.h>
 #include <linux/slab.h>
-#include <linux/idr.h>
 #include <linux/spinlock.h>
+#include <linux/stat.h>
+#include <linux/sysfs.h>
 #include <linux/sys_soc.h>
-#include <linux/err.h>
-#include <linux/glob.h>
 
 static DEFINE_IDA(soc_ida);
 

-- 
2.47.3

[PATCH v2 4/9] base: soc: rename and export soc_device_get_machine()

[Bartosz Golaszewski]

Some SoC drivers reimplement the functionality of
soc_device_get_machine(). Make this function accessible through the
sys_soc.h header and rename it to a more descriptive name.

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/base/soc.c      | 13 +++++--------
 include/linux/sys_soc.h | 10 ++++++++++
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/base/soc.c b/drivers/base/soc.c
index 48e2f0dbd330b8d402135ffa7308f454eb4ab7a5..65ce72d49230360c22a812cb9286e7fb4de0baf2 100644
--- a/drivers/base/soc.c
+++ b/drivers/base/soc.c
@@ -111,17 +111,14 @@ static void soc_release(struct device *dev)
 	kfree(soc_dev);
 }
 
-static void soc_device_get_machine(struct soc_device_attribute *soc_dev_attr)
+int soc_attr_read_machine(struct soc_device_attribute *soc_dev_attr)
 {
-	struct device_node *np;
-
 	if (soc_dev_attr->machine)
-		return;
+		return -EBUSY;
 
-	np = of_find_node_by_path("/");
-	of_property_read_string(np, "model", &soc_dev_attr->machine);
-	of_node_put(np);
+	return of_machine_read_model(&soc_dev_attr->machine);
 }
+EXPORT_SYMBOL_GPL(soc_attr_read_machine);
 
 static struct soc_device_attribute *early_soc_dev_attr;
 
@@ -131,7 +128,7 @@ struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr
 	const struct attribute_group **soc_attr_groups;
 	int ret;
 
-	soc_device_get_machine(soc_dev_attr);
+	soc_attr_read_machine(soc_dev_attr);
 
 	if (!soc_bus_registered) {
 		if (early_soc_dev_attr)
diff --git a/include/linux/sys_soc.h b/include/linux/sys_soc.h
index d9b3cf0f410c8cfb509a4c1a4d6c83fde6fe33c6..f19f5cec18e28461fef57f22702d2c44a41e4193 100644
--- a/include/linux/sys_soc.h
+++ b/include/linux/sys_soc.h
@@ -37,6 +37,16 @@ void soc_device_unregister(struct soc_device *soc_dev);
  */
 struct device *soc_device_to_device(struct soc_device *soc);
 
+/**
+ * soc_attr_read_machine - retrieve the machine model and store it in
+ *                         the soc_device_attribute structure
+ * @soc_dev_attr: SoC attribute structure to store the model in
+ *
+ * Returns:
+ * 0 on success, negative error number on failure.
+ */
+int soc_attr_read_machine(struct soc_device_attribute *soc_dev_attr);
+
 #ifdef CONFIG_SOC_BUS
 const struct soc_device_attribute *soc_device_match(
 	const struct soc_device_attribute *matches);

-- 
2.47.3

[PATCH v2 5/9] soc: fsl: guts: don't access of_root directly

[Bartosz Golaszewski]

Don't access of_root directly as it reduces the build test coverage for
this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
to retrieve the relevant information.

Suggested-by: Rob Herring <robh@kernel.org>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Acked-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/soc/fsl/guts.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/soc/fsl/guts.c b/drivers/soc/fsl/guts.c
index 40afb27b582b1bbea004ca91b96d0a998e7a6582..9bee7baec2b9b3a548b16661f9ba86db2b982910 100644
--- a/drivers/soc/fsl/guts.c
+++ b/drivers/soc/fsl/guts.c
@@ -186,7 +186,6 @@ static int __init fsl_guts_init(void)
 	const struct fsl_soc_data *soc_data;
 	const struct of_device_id *match;
 	struct ccsr_guts __iomem *regs;
-	const char *machine = NULL;
 	struct device_node *np;
 	bool little_endian;
 	u64 soc_uid = 0;
@@ -217,13 +216,9 @@ static int __init fsl_guts_init(void)
 	if (!soc_dev_attr)
 		return -ENOMEM;
 
-	if (of_property_read_string(of_root, "model", &machine))
-		of_property_read_string_index(of_root, "compatible", 0, &machine);
-	if (machine) {
-		soc_dev_attr->machine = kstrdup(machine, GFP_KERNEL);
-		if (!soc_dev_attr->machine)
-			goto err_nomem;
-	}
+	ret = soc_attr_read_machine(soc_dev_attr);
+	if (ret)
+		of_machine_read_compatible(&soc_dev_attr->machine, 0);
 
 	soc_die = fsl_soc_die_match(svr, fsl_soc_die);
 	if (soc_die) {
@@ -267,7 +262,6 @@ static int __init fsl_guts_init(void)
 err_nomem:
 	ret = -ENOMEM;
 err:
-	kfree(soc_dev_attr->machine);
 	kfree(soc_dev_attr->family);
 	kfree(soc_dev_attr->soc_id);
 	kfree(soc_dev_attr->revision);

-- 
2.47.3

[PATCH v2 6/9] soc: imx8m: don't access of_root directly

[Bartosz Golaszewski]

Don't access of_root directly as it reduces the build test coverage for
this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
to retrieve the relevant information.

Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/soc/imx/soc-imx8m.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
index 8e2322999f0996d2723768469c6893b0ea22eb9d..77763a107edbd11302017e3f61ecb4369fda1ab0 100644
--- a/drivers/soc/imx/soc-imx8m.c
+++ b/drivers/soc/imx/soc-imx8m.c
@@ -226,7 +226,6 @@ static int imx8m_soc_probe(struct platform_device *pdev)
 	const struct imx8_soc_data *data;
 	struct imx8_soc_drvdata *drvdata;
 	struct device *dev = &pdev->dev;
-	const struct of_device_id *id;
 	struct soc_device *soc_dev;
 	u32 soc_rev = 0;
 	u64 soc_uid[2] = {0, 0};
@@ -244,15 +243,11 @@ static int imx8m_soc_probe(struct platform_device *pdev)
 
 	soc_dev_attr->family = "Freescale i.MX";
 
-	ret = of_property_read_string(of_root, "model", &soc_dev_attr->machine);
+	ret = soc_attr_read_machine(soc_dev_attr);
 	if (ret)
 		return ret;
 
-	id = of_match_node(imx8_soc_match, of_root);
-	if (!id)
-		return -ENODEV;
-
-	data = id->data;
+	data = device_get_match_data(dev);
 	if (data) {
 		soc_dev_attr->soc_id = data->name;
 		ret = imx8m_soc_prepare(pdev, data->ocotp_compatible);
@@ -326,7 +321,7 @@ static int __init imx8_soc_init(void)
 	int ret;
 
 	/* No match means this is non-i.MX8M hardware, do nothing. */
-	if (!of_match_node(imx8_soc_match, of_root))
+	if (!of_machine_device_match(imx8_soc_match))
 		return 0;
 
 	ret = platform_driver_register(&imx8m_soc_driver);

-- 
2.47.3

[PATCH v2 7/9] soc: imx9: don't access of_root directly

[Bartosz Golaszewski]

Don't access of_root directly as it reduces the build test coverage for
this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
to retrieve the relevant information.

Suggested-by: Rob Herring <robh@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/soc/imx/soc-imx9.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/imx/soc-imx9.c b/drivers/soc/imx/soc-imx9.c
index d67bc7402b10e2966ff77cbf3b15c087540bd377..58eef7d4f9089ae56891507e8dec383e69884ec5 100644
--- a/drivers/soc/imx/soc-imx9.c
+++ b/drivers/soc/imx/soc-imx9.c
@@ -30,7 +30,7 @@ static int imx9_soc_probe(struct platform_device *pdev)
 	if (!attr)
 		return -ENOMEM;
 
-	err = of_property_read_string(of_root, "model", &attr->machine);
+	err = soc_attr_read_machine(attr);
 	if (err)
 		return dev_err_probe(dev, err, "%s: missing model property\n", __func__);
 
@@ -89,7 +89,7 @@ static int __init imx9_soc_init(void)
 	struct platform_device *pdev;
 
 	/* No match means it is not an i.MX 9 series SoC, do nothing. */
-	if (!of_match_node(imx9_soc_match, of_root))
+	if (!of_machine_device_match(imx9_soc_match))
 		return 0;
 
 	ret = platform_driver_register(&imx9_soc_driver);

-- 
2.47.3

[PATCH v2 8/9] soc: renesas: don't access of_root directly

[Bartosz Golaszewski]

Don't access of_root directly as it reduces the build test coverage for
this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
to retrieve the relevant information.

Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/soc/renesas/renesas-soc.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/renesas/renesas-soc.c b/drivers/soc/renesas/renesas-soc.c
index 38ff0b823bdaf1ba106bfb57ed423158d9103f8d..bd8ba0ac30fa91fcf2a10edd0d58b064650085cf 100644
--- a/drivers/soc/renesas/renesas-soc.c
+++ b/drivers/soc/renesas/renesas-soc.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/cleanup.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
@@ -468,7 +469,11 @@ static int __init renesas_soc_init(void)
 	const char *soc_id;
 	int ret;
 
-	match = of_match_node(renesas_socs, of_root);
+	struct device_node *root __free(device_node) = of_find_node_by_path("/");
+	if (!root)
+		return -ENOENT;
+
+	match = of_match_node(renesas_socs, root);
 	if (!match)
 		return -ENODEV;
 

-- 
2.47.3

[PATCH v2 9/9] soc: sunxi: mbus: don't access of_root directly

[Bartosz Golaszewski]

Don't access of_root directly as it reduces the build test coverage for
this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
to retrieve the relevant information.

Suggested-by: Rob Herring <robh@kernel.org>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/soc/sunxi/sunxi_mbus.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/sunxi/sunxi_mbus.c b/drivers/soc/sunxi/sunxi_mbus.c
index 1734da357ca21b249740e089698275507ea98a8a..8bc5f62ff258837d3f3b30cb84b60d1872b31c27 100644
--- a/drivers/soc/sunxi/sunxi_mbus.c
+++ b/drivers/soc/sunxi/sunxi_mbus.c
@@ -118,7 +118,7 @@ static const char * const sunxi_mbus_platforms[] __initconst = {
 
 static int __init sunxi_mbus_init(void)
 {
-	if (!of_device_compatible_match(of_root, sunxi_mbus_platforms))
+	if (!of_machine_compatible_match(sunxi_mbus_platforms))
 		return 0;
 
 	bus_register_notifier(&platform_bus_type, &sunxi_mbus_nb);

-- 
2.47.3

Re: [PATCH v2 8/9] soc: renesas: don't access of_root directly

[Rob Herring]

On Mon, Feb 23, 2026 at 02:37:23PM +0100, Bartosz Golaszewski wrote:
> Don't access of_root directly as it reduces the build test coverage for
> this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
> to retrieve the relevant information.
> 
> Suggested-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> ---
>  drivers/soc/renesas/renesas-soc.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/renesas/renesas-soc.c b/drivers/soc/renesas/renesas-soc.c
> index 38ff0b823bdaf1ba106bfb57ed423158d9103f8d..bd8ba0ac30fa91fcf2a10edd0d58b064650085cf 100644
> --- a/drivers/soc/renesas/renesas-soc.c
> +++ b/drivers/soc/renesas/renesas-soc.c
> @@ -6,6 +6,7 @@
>   */
>  
>  #include <linux/bitfield.h>
> +#include <linux/cleanup.h>
>  #include <linux/io.h>
>  #include <linux/of.h>
>  #include <linux/of_address.h>
> @@ -468,7 +469,11 @@ static int __init renesas_soc_init(void)
>  	const char *soc_id;
>  	int ret;
>  
> -	match = of_match_node(renesas_socs, of_root);
> +	struct device_node *root __free(device_node) = of_find_node_by_path("/");
> +	if (!root)
> +		return -ENOENT;
> +
> +	match = of_match_node(renesas_socs, root);

Doesn't of_machine_device_match() work here?

Re: [PATCH v2 0/9] soc: remove direct accesses to of_root from drivers/soc/

[Rob Herring]

On Mon, Feb 23, 2026 at 02:37:15PM +0100, Bartosz Golaszewski wrote:
> linux/of.h declares a set of variables providing addresses of certain
> key OF nodes. The pointers being variables can't profit from stubs
> provided for when CONFIG_OF is disabled which means that drivers
> accessing these variables can't profit from CONFIG_COMPILE_TEST=y
> coverage.
> 
> There are drivers under drivers/soc/ that access the of_root node. This
> series introduces new OF helpers for reading the machine compatible and
> model strings, exports an existing SoC helper that reads the machine
> string from the root node and finally replaces all direct accesses to
> of_root with new or already existing helper functions.
> 
> Merging strategy: first two patches should be either acked by Rob or
> picked up into an immutable branch based on v7.0-rc1, the rest can go
> through the SoC tree.

SoC tree is good.

> 
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> ---
> Changes in v2:
> - rename of_machine_get_compatible() to of_machine_read_compatible() and
>   add the index argument
> - add a stub for of_machine_read_compatible() for !CONFIG_OF
> - provide of_machine_read_model() to avoid having to look-up the root
>   node via of_find_node_by_path("/")
> - rename soc_device_get_machine() to soc_attr_read_machine() before
>   making it an exported symbol
> - Link to v1: https://lore.kernel.org/r/20260119-soc-of-root-v1-0-32a0fa9a78b4@oss.qualcomm.com
> 
> ---
> Bartosz Golaszewski (9):
>       of: provide of_machine_read_compatible()
>       of: provide of_machine_read_model()
>       base: soc: order includes alphabetically
>       base: soc: rename and export soc_device_get_machine()
>       soc: fsl: guts: don't access of_root directly
>       soc: imx8m: don't access of_root directly
>       soc: imx9: don't access of_root directly
>       soc: renesas: don't access of_root directly
>       soc: sunxi: mbus: don't access of_root directly

For all but patch 8,

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

Re: [PATCH v2 6/9] soc: imx8m: don't access of_root directly

[Peng Fan]

On Mon, Feb 23, 2026 at 02:37:21PM +0100, Bartosz Golaszewski wrote:
>Don't access of_root directly as it reduces the build test coverage for
>this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
>to retrieve the relevant information.
>
>Suggested-by: Rob Herring <robh@kernel.org>
>Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Reviewed-by: Peng Fan <peng.fan@nxp.com>

Re: [PATCH v2 8/9] soc: renesas: don't access of_root directly

[Bartosz Golaszewski]

On Tue, Feb 24, 2026 at 7:32 PM Rob Herring <robh@kernel.org> wrote:
>
> On Mon, Feb 23, 2026 at 02:37:23PM +0100, Bartosz Golaszewski wrote:
> > Don't access of_root directly as it reduces the build test coverage for
> > this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
> > to retrieve the relevant information.
> >
> > Suggested-by: Rob Herring <robh@kernel.org>
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> > ---
> >  drivers/soc/renesas/renesas-soc.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/soc/renesas/renesas-soc.c b/drivers/soc/renesas/renesas-soc.c
> > index 38ff0b823bdaf1ba106bfb57ed423158d9103f8d..bd8ba0ac30fa91fcf2a10edd0d58b064650085cf 100644
> > --- a/drivers/soc/renesas/renesas-soc.c
> > +++ b/drivers/soc/renesas/renesas-soc.c
> > @@ -6,6 +6,7 @@
> >   */
> >
> >  #include <linux/bitfield.h>
> > +#include <linux/cleanup.h>
> >  #include <linux/io.h>
> >  #include <linux/of.h>
> >  #include <linux/of_address.h>
> > @@ -468,7 +469,11 @@ static int __init renesas_soc_init(void)
> >       const char *soc_id;
> >       int ret;
> >
> > -     match = of_match_node(renesas_socs, of_root);
> > +     struct device_node *root __free(device_node) = of_find_node_by_path("/");
> > +     if (!root)
> > +             return -ENOENT;
> > +
> > +     match = of_match_node(renesas_socs, root);
>
> Doesn't of_machine_device_match() work here?
>

No, because we're using the returned address of the matching struct
of_device_id later in the function. If you think it's a better idea to
introduce of_machine_match_node(), let me know but I think that should
be done separately.

Bart

Re: [PATCH v2 8/9] soc: renesas: don't access of_root directly

[Rob Herring]

On Wed, Feb 25, 2026 at 3:42 AM Bartosz Golaszewski <brgl@kernel.org> wrote:
>
> On Tue, Feb 24, 2026 at 7:32 PM Rob Herring <robh@kernel.org> wrote:
> >
> > On Mon, Feb 23, 2026 at 02:37:23PM +0100, Bartosz Golaszewski wrote:
> > > Don't access of_root directly as it reduces the build test coverage for
> > > this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
> > > to retrieve the relevant information.
> > >
> > > Suggested-by: Rob Herring <robh@kernel.org>
> > > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> > > ---
> > >  drivers/soc/renesas/renesas-soc.c | 7 ++++++-
> > >  1 file changed, 6 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/soc/renesas/renesas-soc.c b/drivers/soc/renesas/renesas-soc.c
> > > index 38ff0b823bdaf1ba106bfb57ed423158d9103f8d..bd8ba0ac30fa91fcf2a10edd0d58b064650085cf 100644
> > > --- a/drivers/soc/renesas/renesas-soc.c
> > > +++ b/drivers/soc/renesas/renesas-soc.c
> > > @@ -6,6 +6,7 @@
> > >   */
> > >
> > >  #include <linux/bitfield.h>
> > > +#include <linux/cleanup.h>
> > >  #include <linux/io.h>
> > >  #include <linux/of.h>
> > >  #include <linux/of_address.h>
> > > @@ -468,7 +469,11 @@ static int __init renesas_soc_init(void)
> > >       const char *soc_id;
> > >       int ret;
> > >
> > > -     match = of_match_node(renesas_socs, of_root);
> > > +     struct device_node *root __free(device_node) = of_find_node_by_path("/");
> > > +     if (!root)
> > > +             return -ENOENT;
> > > +
> > > +     match = of_match_node(renesas_socs, root);
> >
> > Doesn't of_machine_device_match() work here?
> >
>
> No, because we're using the returned address of the matching struct
> of_device_id later in the function. If you think it's a better idea to
> introduce of_machine_match_node(), let me know but I think that should
> be done separately.

No, it's fine.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

Re: [PATCH v2 0/9] soc: remove direct accesses to of_root from drivers/soc/

[Bartosz Golaszewski]

On Tue, Feb 24, 2026 at 7:38 PM Rob Herring <robh@kernel.org> wrote:
>
> On Mon, Feb 23, 2026 at 02:37:15PM +0100, Bartosz Golaszewski wrote:
> > linux/of.h declares a set of variables providing addresses of certain
> > key OF nodes. The pointers being variables can't profit from stubs
> > provided for when CONFIG_OF is disabled which means that drivers
> > accessing these variables can't profit from CONFIG_COMPILE_TEST=y
> > coverage.
> >
> > There are drivers under drivers/soc/ that access the of_root node. This
> > series introduces new OF helpers for reading the machine compatible and
> > model strings, exports an existing SoC helper that reads the machine
> > string from the root node and finally replaces all direct accesses to
> > of_root with new or already existing helper functions.
> >
> > Merging strategy: first two patches should be either acked by Rob or
> > picked up into an immutable branch based on v7.0-rc1, the rest can go
> > through the SoC tree.
>
> SoC tree is good.
>
> For all but patch 8,
>
> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
>

FYI Rob also reviewed patch 8 now. Who would pick the patches up? Greg
KH? There does not seem to be a centralized SoC maintainer in
MAINTAINERS?

Bart

Re: [PATCH v2 8/9] soc: renesas: don't access of_root directly

[Geert Uytterhoeven]

Hi Bartosz,

On Mon, 23 Feb 2026 at 14:38, Bartosz Golaszewski
<bartosz.golaszewski@oss.qualcomm.com> wrote:
> Don't access of_root directly as it reduces the build test coverage for
> this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
> to retrieve the relevant information.
>
> Suggested-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

> --- a/drivers/soc/renesas/renesas-soc.c
> +++ b/drivers/soc/renesas/renesas-soc.c

> @@ -468,7 +469,11 @@ static int __init renesas_soc_init(void)
>         const char *soc_id;
>         int ret;
>
> -       match = of_match_node(renesas_socs, of_root);
> +       struct device_node *root __free(device_node) = of_find_node_by_path("/");
> +       if (!root)
> +               return -ENOENT;
> +
> +       match = of_match_node(renesas_socs, root);
>         if (!match)
>                 return -ENODEV;
>

I still find it silly to add a call to of_find_node_by_path().
In your reply to my comment on v1, you said you don't want to add
another helper.

Currently we have two helpers in this area:
  1. of_machine_device_match(), which returns bool, and tells if a
     match is available,
  2. of_machine_get_match_data(), which returns the match data, if a
     match is available.
But there is no helper to return the actual match?
of_machine_device_match() would be fine, if it wouldn't cast the result
to bool...

As there is no cost (binary size-wise) in having the helper that returns
the match, too, I have sent a series[1] to do that. The last patch[2]
is an alternative to this patch, avoiding the need to add a call to
of_find_node_by_path().

[1] "[PATCH 0/7] of: Add and use of_machine_get_match() helper"
    https://lore.kernel.org/cover.1772468323.git.geert+renesas@glider.be
[2] "[PATCH 7/7] soc: renesas: Convert to of_machine_get_match()"
    https://lore.kernel.org/10876b30a8bdb7d1cfcc2f23fb859f2ffea335fe.1772468323.git.geert+renesas@glider.be

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2 8/9] soc: renesas: don't access of_root directly

[Bartosz Golaszewski]

On Mon, Mar 2, 2026 at 5:47 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Bartosz,
>
> On Mon, 23 Feb 2026 at 14:38, Bartosz Golaszewski
> <bartosz.golaszewski@oss.qualcomm.com> wrote:
> > Don't access of_root directly as it reduces the build test coverage for
> > this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
> > to retrieve the relevant information.
> >
> > Suggested-by: Rob Herring <robh@kernel.org>
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
>
> > --- a/drivers/soc/renesas/renesas-soc.c
> > +++ b/drivers/soc/renesas/renesas-soc.c
>
> > @@ -468,7 +469,11 @@ static int __init renesas_soc_init(void)
> >         const char *soc_id;
> >         int ret;
> >
> > -       match = of_match_node(renesas_socs, of_root);
> > +       struct device_node *root __free(device_node) = of_find_node_by_path("/");
> > +       if (!root)
> > +               return -ENOENT;
> > +
> > +       match = of_match_node(renesas_socs, root);
> >         if (!match)
> >                 return -ENODEV;
> >
>
> I still find it silly to add a call to of_find_node_by_path().
> In your reply to my comment on v1, you said you don't want to add
> another helper.
>
> Currently we have two helpers in this area:
>   1. of_machine_device_match(), which returns bool, and tells if a
>      match is available,
>   2. of_machine_get_match_data(), which returns the match data, if a
>      match is available.
> But there is no helper to return the actual match?
> of_machine_device_match() would be fine, if it wouldn't cast the result
> to bool...
>
> As there is no cost (binary size-wise) in having the helper that returns
> the match, too, I have sent a series[1] to do that. The last patch[2]
> is an alternative to this patch, avoiding the need to add a call to
> of_find_node_by_path().
>
> [1] "[PATCH 0/7] of: Add and use of_machine_get_match() helper"
>     https://lore.kernel.org/cover.1772468323.git.geert+renesas@glider.be
> [2] "[PATCH 7/7] soc: renesas: Convert to of_machine_get_match()"
>     https://lore.kernel.org/10876b30a8bdb7d1cfcc2f23fb859f2ffea335fe.1772468323.git.geert+renesas@glider.be
>

Sure, I'm fine with this patch being dropped and your series queued instead.

Bart

Re: [PATCH v2 0/9] soc: remove direct accesses to of_root from drivers/soc/

[Greg Kroah-Hartman]

On Thu, Feb 26, 2026 at 10:28:26AM +0100, Bartosz Golaszewski wrote:
> On Tue, Feb 24, 2026 at 7:38 PM Rob Herring <robh@kernel.org> wrote:
> >
> > On Mon, Feb 23, 2026 at 02:37:15PM +0100, Bartosz Golaszewski wrote:
> > > linux/of.h declares a set of variables providing addresses of certain
> > > key OF nodes. The pointers being variables can't profit from stubs
> > > provided for when CONFIG_OF is disabled which means that drivers
> > > accessing these variables can't profit from CONFIG_COMPILE_TEST=y
> > > coverage.
> > >
> > > There are drivers under drivers/soc/ that access the of_root node. This
> > > series introduces new OF helpers for reading the machine compatible and
> > > model strings, exports an existing SoC helper that reads the machine
> > > string from the root node and finally replaces all direct accesses to
> > > of_root with new or already existing helper functions.
> > >
> > > Merging strategy: first two patches should be either acked by Rob or
> > > picked up into an immutable branch based on v7.0-rc1, the rest can go
> > > through the SoC tree.
> >
> > SoC tree is good.
> >
> > For all but patch 8,
> >
> > Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> >
> 
> FYI Rob also reviewed patch 8 now. Who would pick the patches up? Greg
> KH? There does not seem to be a centralized SoC maintainer in
> MAINTAINERS?

Sure, let me take them now, thanks.

greg k-h

Re: [PATCH v2 0/9] soc: remove direct accesses to of_root from drivers/soc/

[Bartosz Golaszewski]

On Thu, 12 Mar 2026 16:18:38 +0100, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> said:
> On Thu, Feb 26, 2026 at 10:28:26AM +0100, Bartosz Golaszewski wrote:
>> On Tue, Feb 24, 2026 at 7:38 PM Rob Herring <robh@kernel.org> wrote:
>> >
>> > On Mon, Feb 23, 2026 at 02:37:15PM +0100, Bartosz Golaszewski wrote:
>> > > linux/of.h declares a set of variables providing addresses of certain
>> > > key OF nodes. The pointers being variables can't profit from stubs
>> > > provided for when CONFIG_OF is disabled which means that drivers
>> > > accessing these variables can't profit from CONFIG_COMPILE_TEST=y
>> > > coverage.
>> > >
>> > > There are drivers under drivers/soc/ that access the of_root node. This
>> > > series introduces new OF helpers for reading the machine compatible and
>> > > model strings, exports an existing SoC helper that reads the machine
>> > > string from the root node and finally replaces all direct accesses to
>> > > of_root with new or already existing helper functions.
>> > >
>> > > Merging strategy: first two patches should be either acked by Rob or
>> > > picked up into an immutable branch based on v7.0-rc1, the rest can go
>> > > through the SoC tree.
>> >
>> > SoC tree is good.
>> >
>> > For all but patch 8,
>> >
>> > Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
>> >
>>
>> FYI Rob also reviewed patch 8 now. Who would pick the patches up? Greg
>> KH? There does not seem to be a centralized SoC maintainer in
>> MAINTAINERS?
>
> Sure, let me take them now, thanks.
>
> greg k-h
>

In the meantime Geert sent an alternative to patch 8/9 so this single one can
be dropped from the series.

Thanks,
Bartosz

Re: [PATCH v2 0/9] soc: remove direct accesses to of_root from drivers/soc/

[Greg Kroah-Hartman]

On Fri, Mar 13, 2026 at 01:36:49AM -0700, Bartosz Golaszewski wrote:
> On Thu, 12 Mar 2026 16:18:38 +0100, Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> said:
> > On Thu, Feb 26, 2026 at 10:28:26AM +0100, Bartosz Golaszewski wrote:
> >> On Tue, Feb 24, 2026 at 7:38 PM Rob Herring <robh@kernel.org> wrote:
> >> >
> >> > On Mon, Feb 23, 2026 at 02:37:15PM +0100, Bartosz Golaszewski wrote:
> >> > > linux/of.h declares a set of variables providing addresses of certain
> >> > > key OF nodes. The pointers being variables can't profit from stubs
> >> > > provided for when CONFIG_OF is disabled which means that drivers
> >> > > accessing these variables can't profit from CONFIG_COMPILE_TEST=y
> >> > > coverage.
> >> > >
> >> > > There are drivers under drivers/soc/ that access the of_root node. This
> >> > > series introduces new OF helpers for reading the machine compatible and
> >> > > model strings, exports an existing SoC helper that reads the machine
> >> > > string from the root node and finally replaces all direct accesses to
> >> > > of_root with new or already existing helper functions.
> >> > >
> >> > > Merging strategy: first two patches should be either acked by Rob or
> >> > > picked up into an immutable branch based on v7.0-rc1, the rest can go
> >> > > through the SoC tree.
> >> >
> >> > SoC tree is good.
> >> >
> >> > For all but patch 8,
> >> >
> >> > Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> >> >
> >>
> >> FYI Rob also reviewed patch 8 now. Who would pick the patches up? Greg
> >> KH? There does not seem to be a centralized SoC maintainer in
> >> MAINTAINERS?
> >
> > Sure, let me take them now, thanks.
> >
> > greg k-h
> >
> 
> In the meantime Geert sent an alternative to patch 8/9 so this single one can
> be dropped from the series.

Ick, ok, I've now dropped that one commit from the tree.

thanks,

greg k-h

Re: [PATCH v2 6/9] soc: imx8m: don't access of_root directly

[Alexander Stein]

Hi,

Am Montag, 23. Februar 2026, 14:37:21 CET schrieb Bartosz Golaszewski:
> Don't access of_root directly as it reduces the build test coverage for
> this driver with COMPILE_TEST=y and OF=n. Use existing helper functions
> to retrieve the relevant information.
> 
> Suggested-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

today I noticed the following warning running next-20260323:
> caam 30900000.crypto: No clock data provided for i.MX SoC

This happens when there is no matching against the soc_id.

Checking the source it turns out this patch is the cause that the SoC info
does not provide soc_id anymore.
next-20260323:
> $ grep . /sys/devices/soc0/*
> /sys/devices/soc0/family:Freescale i.MX
> /sys/devices/soc0/machine:TQ-Systems i.MX8MPlus TQMa8MPxL on MBa8MP-RAS314
> grep: /sys/devices/soc0/power: Is a directory
> /sys/devices/soc0/revision:unknown
> /sys/devices/soc0/serial_number:0000000000000000
> grep: /sys/devices/soc0/subsystem: Is a directory

reverting this patch (2524b293a59e586afd06358d0b191ab57208a920):
> $ grep . /sys/devices/soc0/*
> /sys/devices/soc0/family:Freescale i.MX
> /sys/devices/soc0/machine:TQ-Systems i.MX8MPlus TQMa8MPxL on MBa8MP-RAS314
> grep: /sys/devices/soc0/power: Is a directory
> /sys/devices/soc0/revision:1.1
> /sys/devices/soc0/serial_number:469677A693A4B8CE131D180033E44903
> /sys/devices/soc0/soc_id:i.MX8MP
> grep: /sys/devices/soc0/subsystem: Is a directory

soc_id is restored. Now that I write these lines I noticed that
serial_number also contained empty value which is restored with the revert.

Best regards,
Alexander

> ---
>  drivers/soc/imx/soc-imx8m.c | 11 +++--------
>  1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
> index 8e2322999f0996d2723768469c6893b0ea22eb9d..77763a107edbd11302017e3f61ecb4369fda1ab0 100644
> --- a/drivers/soc/imx/soc-imx8m.c
> +++ b/drivers/soc/imx/soc-imx8m.c
> @@ -226,7 +226,6 @@ static int imx8m_soc_probe(struct platform_device *pdev)
>  	const struct imx8_soc_data *data;
>  	struct imx8_soc_drvdata *drvdata;
>  	struct device *dev = &pdev->dev;
> -	const struct of_device_id *id;
>  	struct soc_device *soc_dev;
>  	u32 soc_rev = 0;
>  	u64 soc_uid[2] = {0, 0};
> @@ -244,15 +243,11 @@ static int imx8m_soc_probe(struct platform_device *pdev)
>  
>  	soc_dev_attr->family = "Freescale i.MX";
>  
> -	ret = of_property_read_string(of_root, "model", &soc_dev_attr->machine);
> +	ret = soc_attr_read_machine(soc_dev_attr);
>  	if (ret)
>  		return ret;
>  
> -	id = of_match_node(imx8_soc_match, of_root);
> -	if (!id)
> -		return -ENODEV;
> -
> -	data = id->data;
> +	data = device_get_match_data(dev);
>  	if (data) {
>  		soc_dev_attr->soc_id = data->name;
>  		ret = imx8m_soc_prepare(pdev, data->ocotp_compatible);
> @@ -326,7 +321,7 @@ static int __init imx8_soc_init(void)
>  	int ret;
>  
>  	/* No match means this is non-i.MX8M hardware, do nothing. */
> -	if (!of_match_node(imx8_soc_match, of_root))
> +	if (!of_machine_device_match(imx8_soc_match))
>  		return 0;
>  
>  	ret = platform_driver_register(&imx8m_soc_driver);
> 
> 


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