[PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[Rob Herring (Arm)]

Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
"syscon" compatible") broke drivers which call device_node_to_regmap()
on nodes without a "syscon" compatible. Restore the prior behavior for
device_node_to_regmap().

This also makes using device_node_to_regmap() incompatible with
of_syscon_register_regmap() again, so add kerneldoc for
device_node_to_regmap() and syscon_node_to_regmap() to make it clear
how and when each one should be used.

Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
Cc: Will McVicker <willmcvicker@google.com>
Cc: John Madieu <john.madieu.xa@bp.renesas.com>
Cc: Nishanth Menon <nm@ti.com>
Reported-by: Vaishnav Achath <vaishnav.a@ti.com>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---
 drivers/mfd/syscon.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index 226915ca3c93..aa4a9940b569 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -159,6 +159,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res)
 }
 
 static struct regmap *device_node_get_regmap(struct device_node *np,
+					     bool create_regmap,
 					     bool check_res)
 {
 	struct syscon *entry, *syscon = NULL;
@@ -172,7 +173,7 @@ static struct regmap *device_node_get_regmap(struct device_node *np,
 		}
 
 	if (!syscon) {
-		if (of_device_is_compatible(np, "syscon"))
+		if (create_regmap)
 			syscon = of_syscon_register(np, check_res);
 		else
 			syscon = ERR_PTR(-EINVAL);
@@ -233,15 +234,37 @@ int of_syscon_register_regmap(struct device_node *np, struct regmap *regmap)
 }
 EXPORT_SYMBOL_GPL(of_syscon_register_regmap);
 
+/**
+ * device_node_to_regmap() - Get or create a regmap for specified device node
+ * @np: Device tree node
+ *
+ * Get a regmap for the specified device node. If there's not an existing
+ * regmap, then one is instantiated. This function should not be used if the
+ * device node has a custom regmap driver or has resources (clocks, resets) to
+ * be managed. Use syscon_node_to_regmap() instead for those cases.
+ *
+ * Return: regmap ptr on success, negative error code on failure.
+ */
 struct regmap *device_node_to_regmap(struct device_node *np)
 {
-	return device_node_get_regmap(np, false);
+	return device_node_get_regmap(np, true, false);
 }
 EXPORT_SYMBOL_GPL(device_node_to_regmap);
 
+/**
+ * syscon_node_to_regmap() - Get or create a regmap for specified syscon device node
+ * @np: Device tree node
+ *
+ * Get a regmap for the specified device node. If there's not an existing
+ * regmap, then one is instantiated if the node is a generic "syscon". This
+ * function is safe to use for a syscon registered with
+ * of_syscon_register_regmap().
+ *
+ * Return: regmap ptr on success, negative error code on failure.
+ */
 struct regmap *syscon_node_to_regmap(struct device_node *np)
 {
-	return device_node_get_regmap(np, true);
+	return device_node_get_regmap(np, of_device_is_compatible(np, "syscon"), true);
 }
 EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
 
-- 
2.45.2

Re: [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[Nishanth Menon]

On 13:16-20250124, Rob Herring wrote:
> Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
> "syscon" compatible") broke drivers which call device_node_to_regmap()
> on nodes without a "syscon" compatible. Restore the prior behavior for
> device_node_to_regmap().
> 
> This also makes using device_node_to_regmap() incompatible with
> of_syscon_register_regmap() again, so add kerneldoc for
> device_node_to_regmap() and syscon_node_to_regmap() to make it clear
> how and when each one should be used.
> 
> Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
> Cc: Will McVicker <willmcvicker@google.com>
> Cc: John Madieu <john.madieu.xa@bp.renesas.com>
> Cc: Nishanth Menon <nm@ti.com>
> Reported-by: Vaishnav Achath <vaishnav.a@ti.com>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Thanks Rob.

Tested with next-20250124 on TI K3 platforms

Tested-by: Nishanth Menon <nm@ti.com>

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D

Re: [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[Nícolas F. R. A. Prado]

On Fri, Jan 24, 2025 at 01:16:44PM -0600, Rob Herring (Arm) wrote:
> Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
> "syscon" compatible") broke drivers which call device_node_to_regmap()
> on nodes without a "syscon" compatible. Restore the prior behavior for
> device_node_to_regmap().
> 
> This also makes using device_node_to_regmap() incompatible with
> of_syscon_register_regmap() again, so add kerneldoc for
> device_node_to_regmap() and syscon_node_to_regmap() to make it clear
> how and when each one should be used.
> 
> Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
> Cc: Will McVicker <willmcvicker@google.com>
> Cc: John Madieu <john.madieu.xa@bp.renesas.com>
> Cc: Nishanth Menon <nm@ti.com>
> Reported-by: Vaishnav Achath <vaishnav.a@ti.com>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Still hitting this as of next-20250128. This patch fixed the issue which
otherwise prevents boot on the Genio 700 EVK and Genio 1200 EVK boards.

Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

Thanks,
Nícolas

Re: [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[Daniel Golle]

On Fri, Jan 24, 2025 at 01:16:44PM -0600, Rob Herring (Arm) wrote:
> Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
> "syscon" compatible") broke drivers which call device_node_to_regmap()
> on nodes without a "syscon" compatible. Restore the prior behavior for
> device_node_to_regmap().
> 
> This also makes using device_node_to_regmap() incompatible with
> of_syscon_register_regmap() again, so add kerneldoc for
> device_node_to_regmap() and syscon_node_to_regmap() to make it clear
> how and when each one should be used.
> 
> Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
> Cc: Will McVicker <willmcvicker@google.com>
> Cc: John Madieu <john.madieu.xa@bp.renesas.com>
> Cc: Nishanth Menon <nm@ti.com>
> Reported-by: Vaishnav Achath <vaishnav.a@ti.com>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
> ---

Reviewed-by: Daniel Golle <daniel@makrotopia.org>
Texted-by: Daniel Golle <daniel@makrotopia.org>

This fix is required to un-break various Mediatek clock drivers as
device_node_to_regmap() is used all over the place there (in
reset.c, clk-gate.c, clk-cpumux.c, clk-mux.c) and commit
3ba5a6159434 ("arm64: dts: mediatek: mt7622: fix clock controllers")
has droped all those unneeded "syscon"s.

>  drivers/mfd/syscon.c | 29 ++++++++++++++++++++++++++---
>  1 file changed, 26 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> index 226915ca3c93..aa4a9940b569 100644
> --- a/drivers/mfd/syscon.c
> +++ b/drivers/mfd/syscon.c
> @@ -159,6 +159,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res)
>  }
>  
>  static struct regmap *device_node_get_regmap(struct device_node *np,
> +					     bool create_regmap,
>  					     bool check_res)
>  {
>  	struct syscon *entry, *syscon = NULL;
> @@ -172,7 +173,7 @@ static struct regmap *device_node_get_regmap(struct device_node *np,
>  		}
>  
>  	if (!syscon) {
> -		if (of_device_is_compatible(np, "syscon"))
> +		if (create_regmap)
>  			syscon = of_syscon_register(np, check_res);
>  		else
>  			syscon = ERR_PTR(-EINVAL);
> @@ -233,15 +234,37 @@ int of_syscon_register_regmap(struct device_node *np, struct regmap *regmap)
>  }
>  EXPORT_SYMBOL_GPL(of_syscon_register_regmap);
>  
> +/**
> + * device_node_to_regmap() - Get or create a regmap for specified device node
> + * @np: Device tree node
> + *
> + * Get a regmap for the specified device node. If there's not an existing
> + * regmap, then one is instantiated. This function should not be used if the
> + * device node has a custom regmap driver or has resources (clocks, resets) to
> + * be managed. Use syscon_node_to_regmap() instead for those cases.
> + *
> + * Return: regmap ptr on success, negative error code on failure.
> + */
>  struct regmap *device_node_to_regmap(struct device_node *np)
>  {
> -	return device_node_get_regmap(np, false);
> +	return device_node_get_regmap(np, true, false);
>  }
>  EXPORT_SYMBOL_GPL(device_node_to_regmap);
>  
> +/**
> + * syscon_node_to_regmap() - Get or create a regmap for specified syscon device node
> + * @np: Device tree node
> + *
> + * Get a regmap for the specified device node. If there's not an existing
> + * regmap, then one is instantiated if the node is a generic "syscon". This
> + * function is safe to use for a syscon registered with
> + * of_syscon_register_regmap().
> + *
> + * Return: regmap ptr on success, negative error code on failure.
> + */
>  struct regmap *syscon_node_to_regmap(struct device_node *np)
>  {
> -	return device_node_get_regmap(np, true);
> +	return device_node_get_regmap(np, of_device_is_compatible(np, "syscon"), true);
>  }
>  EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
>  
> -- 
> 2.45.2
> 

Aw: Re: [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[Frank Wunderlich]

regards Frank


> Gesendet: Sonntag, 2. Februar 2025 um 23:57
> Von: "Daniel Golle" <daniel@makrotopia.org>
> Betreff: Re: [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes
>
> On Fri, Jan 24, 2025 at 01:16:44PM -0600, Rob Herring (Arm) wrote:
> > Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
> > "syscon" compatible") broke drivers which call device_node_to_regmap()
> > on nodes without a "syscon" compatible. Restore the prior behavior for
> > device_node_to_regmap().
> >
> > This also makes using device_node_to_regmap() incompatible with
> > of_syscon_register_regmap() again, so add kerneldoc for
> > device_node_to_regmap() and syscon_node_to_regmap() to make it clear
> > how and when each one should be used.
> >
> > Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
> > Cc: Will McVicker <willmcvicker@google.com>
> > Cc: John Madieu <john.madieu.xa@bp.renesas.com>
> > Cc: Nishanth Menon <nm@ti.com>
> > Reported-by: Vaishnav Achath <vaishnav.a@ti.com>
> > Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
> > ---
>
> Reviewed-by: Daniel Golle <daniel@makrotopia.org>
> Texted-by: Daniel Golle <daniel@makrotopia.org>

fixing Daniels Tested-by-tag :)
Tested-by: Daniel Golle <daniel@makrotopia.org>
and confirming the patch fixes the clock-syscon-issue (on mt7988)
Tested-by: Frank Wunderlich <frank-w@public-files.de>

> This fix is required to un-break various Mediatek clock drivers as
> device_node_to_regmap() is used all over the place there (in
> reset.c, clk-gate.c, clk-cpumux.c, clk-mux.c) and commit
> 3ba5a6159434 ("arm64: dts: mediatek: mt7622: fix clock controllers")
> has droped all those unneeded "syscon"s.

Re: [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[Dhruva Gole]

On Jan 24, 2025 at 13:16:44 -0600, Rob Herring (Arm) wrote:
> Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
> "syscon" compatible") broke drivers which call device_node_to_regmap()
> on nodes without a "syscon" compatible. Restore the prior behavior for
> device_node_to_regmap().
> 
> This also makes using device_node_to_regmap() incompatible with
> of_syscon_register_regmap() again, so add kerneldoc for
> device_node_to_regmap() and syscon_node_to_regmap() to make it clear
> how and when each one should be used.
> 
> Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
> Cc: Will McVicker <willmcvicker@google.com>
> Cc: John Madieu <john.madieu.xa@bp.renesas.com>
> Cc: Nishanth Menon <nm@ti.com>
> Reported-by: Vaishnav Achath <vaishnav.a@ti.com>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
> ---
>  drivers/mfd/syscon.c | 29 ++++++++++++++++++++++++++---
>  1 file changed, 26 insertions(+), 3 deletions(-)

Tested this for basic boot on TI K3 AM625-SK with next-20250204.
Tested-by: Dhruva Gole <d-gole@ti.com>

-- 
Best regards,
Dhruva Gole
Texas Instruments Incorporated

Re: [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[Lee Jones]

On Fri, 24 Jan 2025, Rob Herring (Arm) wrote:

> Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
> "syscon" compatible") broke drivers which call device_node_to_regmap()
> on nodes without a "syscon" compatible. Restore the prior behavior for
> device_node_to_regmap().
> 
> This also makes using device_node_to_regmap() incompatible with
> of_syscon_register_regmap() again, so add kerneldoc for
> device_node_to_regmap() and syscon_node_to_regmap() to make it clear
> how and when each one should be used.
> 
> Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
> Cc: Will McVicker <willmcvicker@google.com>
> Cc: John Madieu <john.madieu.xa@bp.renesas.com>
> Cc: Nishanth Menon <nm@ti.com>
> Reported-by: Vaishnav Achath <vaishnav.a@ti.com>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
> ---
>  drivers/mfd/syscon.c | 29 ++++++++++++++++++++++++++---
>  1 file changed, 26 insertions(+), 3 deletions(-)

NOTE TO SELF: -rcs

-- 
Lee Jones [李琼斯]

Re: [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[Chen-Yu Tsai]

On Fri, Jan 24, 2025 at 01:16:44PM -0600, Rob Herring (Arm) wrote:
> Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
> "syscon" compatible") broke drivers which call device_node_to_regmap()
> on nodes without a "syscon" compatible. Restore the prior behavior for
> device_node_to_regmap().
> 
> This also makes using device_node_to_regmap() incompatible with
> of_syscon_register_regmap() again, so add kerneldoc for
> device_node_to_regmap() and syscon_node_to_regmap() to make it clear
> how and when each one should be used.
> 
> Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
> Cc: Will McVicker <willmcvicker@google.com>
> Cc: John Madieu <john.madieu.xa@bp.renesas.com>
> Cc: Nishanth Menon <nm@ti.com>
> Reported-by: Vaishnav Achath <vaishnav.a@ti.com>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Tested-by: Chen-Yu Tsai <wenst@chromium.org>

This restored the power controller and everything depending on it on the
MT8183 Chromebooks.

Re: [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[AngeloGioacchino Del Regno]

Il 24/01/25 20:16, Rob Herring (Arm) ha scritto:
> Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
> "syscon" compatible") broke drivers which call device_node_to_regmap()
> on nodes without a "syscon" compatible. Restore the prior behavior for
> device_node_to_regmap().
> 
> This also makes using device_node_to_regmap() incompatible with
> of_syscon_register_regmap() again, so add kerneldoc for
> device_node_to_regmap() and syscon_node_to_regmap() to make it clear
> how and when each one should be used.
> 
> Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
> Cc: Will McVicker <willmcvicker@google.com>
> Cc: John Madieu <john.madieu.xa@bp.renesas.com>
> Cc: Nishanth Menon <nm@ti.com>
> Reported-by: Vaishnav Achath <vaishnav.a@ti.com>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

...and tested on

Radxa NIO 12L (MT8395/8195), MediaTek Genio 700 EVK (MT8390/MT8188), and on
MT8195 Tomato Chromebook

Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

> ---
>   drivers/mfd/syscon.c | 29 ++++++++++++++++++++++++++---
>   1 file changed, 26 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> index 226915ca3c93..aa4a9940b569 100644
> --- a/drivers/mfd/syscon.c
> +++ b/drivers/mfd/syscon.c
> @@ -159,6 +159,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res)
>   }
>   
>   static struct regmap *device_node_get_regmap(struct device_node *np,
> +					     bool create_regmap,
>   					     bool check_res)
>   {
>   	struct syscon *entry, *syscon = NULL;
> @@ -172,7 +173,7 @@ static struct regmap *device_node_get_regmap(struct device_node *np,
>   		}
>   
>   	if (!syscon) {
> -		if (of_device_is_compatible(np, "syscon"))
> +		if (create_regmap)
>   			syscon = of_syscon_register(np, check_res);
>   		else
>   			syscon = ERR_PTR(-EINVAL);
> @@ -233,15 +234,37 @@ int of_syscon_register_regmap(struct device_node *np, struct regmap *regmap)
>   }
>   EXPORT_SYMBOL_GPL(of_syscon_register_regmap);
>   
> +/**
> + * device_node_to_regmap() - Get or create a regmap for specified device node
> + * @np: Device tree node
> + *
> + * Get a regmap for the specified device node. If there's not an existing
> + * regmap, then one is instantiated. This function should not be used if the
> + * device node has a custom regmap driver or has resources (clocks, resets) to
> + * be managed. Use syscon_node_to_regmap() instead for those cases.
> + *
> + * Return: regmap ptr on success, negative error code on failure.
> + */
>   struct regmap *device_node_to_regmap(struct device_node *np)
>   {
> -	return device_node_get_regmap(np, false);
> +	return device_node_get_regmap(np, true, false);
>   }
>   EXPORT_SYMBOL_GPL(device_node_to_regmap);
>   
> +/**
> + * syscon_node_to_regmap() - Get or create a regmap for specified syscon device node
> + * @np: Device tree node
> + *
> + * Get a regmap for the specified device node. If there's not an existing
> + * regmap, then one is instantiated if the node is a generic "syscon". This
> + * function is safe to use for a syscon registered with
> + * of_syscon_register_regmap().
> + *
> + * Return: regmap ptr on success, negative error code on failure.
> + */
>   struct regmap *syscon_node_to_regmap(struct device_node *np)
>   {
> -	return device_node_get_regmap(np, true);
> +	return device_node_get_regmap(np, of_device_is_compatible(np, "syscon"), true);
>   }
>   EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
>   

Re: (subset) [PATCH] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

[Lee Jones]

On Fri, 24 Jan 2025 13:16:44 -0600, Rob Herring (Arm) wrote:
> Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
> "syscon" compatible") broke drivers which call device_node_to_regmap()
> on nodes without a "syscon" compatible. Restore the prior behavior for
> device_node_to_regmap().
> 
> This also makes using device_node_to_regmap() incompatible with
> of_syscon_register_regmap() again, so add kerneldoc for
> device_node_to_regmap() and syscon_node_to_regmap() to make it clear
> how and when each one should be used.
> 
> [...]

Applied, thanks!

[1/1] mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes
      commit: 5728c92ae112301936006c5e305677beb1a7f578

--
Lee Jones [李琼斯]