[PATCH v3 0/4] fbdev: Make CONFIG_FB_DEVICE optional for drivers

[PATCH v3 0/4] fbdev: Make CONFIG_FB_DEVICE optional for drivers

[Chintan Patel]

This series makes CONFIG_FB_DEVICE optional for fbdev drivers that use
it only for sysfs interfaces, addressing Thomas Zimmermann’s TODO to
remove hard FB_DEVICE dependencies.

The series introduces a small helper, dev_of_fbinfo(), which returns
NULL when CONFIG_FB_DEVICE=n. This allows sysfs code paths to be skipped
via runtime checks, avoids #ifdef CONFIG_FB_DEVICE clutter, and keeps
full compile-time syntax checking.

Signed-off-by: Chintan Patel <chintanlike@gmail.com>
---
Changes in v3:
- Use PTR_IF() to conditionally include overlay_sysfs_group in 
  overlay_sysfs_groups
- Decouple variable definition and assignment in fbtft_sysfs_init/exit

Changes in v2:
- Add dev_of_fbinfo() helper (suggested by Geert Uytterhoeven)
- Replace #ifdef CONFIG_FB_DEVICE blocks with runtime NULL checks
- Switch to fb_dbg() / fb_info() logging (suggested by Thomas Zimmermann)

---

Chintan Patel (4):
  fb: Add dev_of_fbinfo() helper for optional sysfs support
  staging: fbtft: Make FB_DEVICE dependency optional
  fbdev: omapfb: Make FB_DEVICE dependency optional
  fbdev: sh_mobile_lcdc: Make FB_DEVICE dependency optional

 drivers/staging/fbtft/Kconfig                 |  5 ++++-
 drivers/staging/fbtft/fbtft-sysfs.c           | 20 +++++++++++++++----
 drivers/video/fbdev/omap2/omapfb/Kconfig      |  3 ++-
 .../video/fbdev/omap2/omapfb/omapfb-sysfs.c   | 16 +++++++++++----
 drivers/video/fbdev/sh_mobile_lcdcfb.c        | 12 ++++++++++-
 include/linux/fb.h                            |  9 +++++++++
 6 files changed, 54 insertions(+), 11 deletions(-)

-- 
2.43.0

[PATCH v3 1/4] fb: Add dev_of_fbinfo() helper for optional sysfs support

[Chintan Patel]

Add dev_of_fbinfo() to return the framebuffer struct device when
CONFIG_FB_DEVICE is enabled, or NULL otherwise.

This allows fbdev drivers to use sysfs interfaces via runtime checks
instead of CONFIG_FB_DEVICE ifdefs, keeping the code clean while
remaining fully buildable.

Suggested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Chintan Patel <chintanlike@gmail.com>
---
 include/linux/fb.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/fb.h b/include/linux/fb.h
index 05cc251035da..dad3fb61a06a 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -628,6 +628,15 @@ static inline void unlock_fb_info(struct fb_info *info)
 	mutex_unlock(&info->lock);
 }
 
+static inline struct device *dev_of_fbinfo(const struct fb_info *info)
+{
+#ifdef CONFIG_FB_DEVICE
+	return info->dev;
+#else
+	return NULL;
+#endif
+}
+
 static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
 					   u8 *src, u32 s_pitch, u32 height)
 {
-- 
2.43.0

[PATCH v3 2/4] staging: fbtft: Make FB_DEVICE dependency optional

[Chintan Patel]

fbtft provides sysfs interfaces for debugging and gamma configuration,
but these are not required for the core driver.

Drop the hard dependency on CONFIG_FB_DEVICE and make sysfs support
optional by using dev_of_fbinfo() at runtime. When FB_DEVICE is disabled,
sysfs operations are skipped while the code remains buildable and
type-checked.

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Suggested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Chintan Patel <chintanlike@gmail.com>
---
 drivers/staging/fbtft/Kconfig       |  5 ++++-
 drivers/staging/fbtft/fbtft-sysfs.c | 20 ++++++++++++++++----
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/fbtft/Kconfig b/drivers/staging/fbtft/Kconfig
index c2655768209a..578412a2f379 100644
--- a/drivers/staging/fbtft/Kconfig
+++ b/drivers/staging/fbtft/Kconfig
@@ -2,11 +2,14 @@
 menuconfig FB_TFT
 	tristate "Support for small TFT LCD display modules"
 	depends on FB && SPI
-	depends on FB_DEVICE
 	depends on BACKLIGHT_CLASS_DEVICE
 	depends on GPIOLIB || COMPILE_TEST
 	select FB_BACKLIGHT
 	select FB_SYSMEM_HELPERS_DEFERRED
+	help
+	  Support for small TFT LCD display modules over SPI bus. FB_DEVICE
+	  is not required, but if enabled, provides sysfs interface for debugging
+	  and gamma curve configuration.
 
 if FB_TFT
 
diff --git a/drivers/staging/fbtft/fbtft-sysfs.c b/drivers/staging/fbtft/fbtft-sysfs.c
index e45c90a03a90..d05599d80011 100644
--- a/drivers/staging/fbtft/fbtft-sysfs.c
+++ b/drivers/staging/fbtft/fbtft-sysfs.c
@@ -203,14 +203,26 @@ static struct device_attribute debug_device_attr =
 
 void fbtft_sysfs_init(struct fbtft_par *par)
 {
-	device_create_file(par->info->dev, &debug_device_attr);
+	struct device *dev;
+
+	dev = dev_of_fbinfo(par->info);
+	if (!dev)
+		return;
+
+	device_create_file(dev, &debug_device_attr);
 	if (par->gamma.curves && par->fbtftops.set_gamma)
-		device_create_file(par->info->dev, &gamma_device_attrs[0]);
+		device_create_file(dev, &gamma_device_attrs[0]);
 }
 
 void fbtft_sysfs_exit(struct fbtft_par *par)
 {
-	device_remove_file(par->info->dev, &debug_device_attr);
+	struct device *dev;
+
+	dev = dev_of_fbinfo(par->info);
+	if (!dev)
+		return;
+
+	device_remove_file(dev, &debug_device_attr);
 	if (par->gamma.curves && par->fbtftops.set_gamma)
-		device_remove_file(par->info->dev, &gamma_device_attrs[0]);
+		device_remove_file(dev, &gamma_device_attrs[0]);
 }
-- 
2.43.0

[PATCH v3 3/4] fbdev: omapfb: Make FB_DEVICE dependency optional

[Chintan Patel]

omapfb provides several sysfs interfaces for framebuffer configuration
and debugging, but these are not required for the core driver.

Remove the hard dependency on CONFIG_FB_DEVICE and make sysfs support
optional by using dev_of_fbinfo() to obtain the backing device at runtime.
When FB_DEVICE is disabled, sysfs operations are skipped while the code
still builds and is type-checked.

Suggested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Chintan Patel <chintanlike@gmail.com>
---
 drivers/video/fbdev/omap2/omapfb/Kconfig        |  3 ++-
 drivers/video/fbdev/omap2/omapfb/omapfb-sysfs.c | 16 ++++++++++++----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/video/fbdev/omap2/omapfb/Kconfig b/drivers/video/fbdev/omap2/omapfb/Kconfig
index f4cdf999a080..2d20e79adefc 100644
--- a/drivers/video/fbdev/omap2/omapfb/Kconfig
+++ b/drivers/video/fbdev/omap2/omapfb/Kconfig
@@ -5,7 +5,6 @@ config OMAP2_VRFB
 menuconfig FB_OMAP2
 	tristate "OMAP2+ frame buffer support"
 	depends on FB
-	depends on FB_DEVICE
 	depends on DRM_OMAP = n
 	depends on GPIOLIB
 	select FB_OMAP2_DSS
@@ -13,6 +12,8 @@ menuconfig FB_OMAP2
 	select FB_IOMEM_HELPERS
 	help
 	  Frame buffer driver for OMAP2+ based boards.
+	  FB_DEVICE is not required, but if enabled, provides sysfs interface
+	  for framebuffer configuration and debugging.
 
 if FB_OMAP2
 
diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-sysfs.c b/drivers/video/fbdev/omap2/omapfb/omapfb-sysfs.c
index 831b2c2fbdf9..ef555dd598aa 100644
--- a/drivers/video/fbdev/omap2/omapfb/omapfb-sysfs.c
+++ b/drivers/video/fbdev/omap2/omapfb/omapfb-sysfs.c
@@ -558,10 +558,14 @@ int omapfb_create_sysfs(struct omapfb2_device *fbdev)
 
 	DBG("create sysfs for fbs\n");
 	for (i = 0; i < fbdev->num_fbs; i++) {
+		struct device *dev = dev_of_fbinfo(fbdev->fbs[i]);
 		int t;
+
+		if (!dev)
+			continue;
+
 		for (t = 0; t < ARRAY_SIZE(omapfb_attrs); t++) {
-			r = device_create_file(fbdev->fbs[i]->dev,
-					&omapfb_attrs[t]);
+			r = device_create_file(dev, &omapfb_attrs[t]);
 
 			if (r) {
 				dev_err(fbdev->dev, "failed to create sysfs "
@@ -580,9 +584,13 @@ void omapfb_remove_sysfs(struct omapfb2_device *fbdev)
 
 	DBG("remove sysfs for fbs\n");
 	for (i = 0; i < fbdev->num_fbs; i++) {
+		struct device *dev = dev_of_fbinfo(fbdev->fbs[i]);
+
+		if (!dev)
+			continue;
+
 		for (t = 0; t < ARRAY_SIZE(omapfb_attrs); t++)
-			device_remove_file(fbdev->fbs[i]->dev,
-					&omapfb_attrs[t]);
+			device_remove_file(dev, &omapfb_attrs[t]);
 	}
 }
 
-- 
2.43.0

[PATCH v3 4/4] fbdev: sh_mobile_lcdc: Make FB_DEVICE dependency optional

[Chintan Patel]

The sh_mobile_lcdc driver exposes overlay configuration via sysfs, but the
core driver does not require CONFIG_FB_DEVICE.

Make sysfs support optional by defining overlay_sysfs_groups conditionally
using PTR_IF(). The driver always sets .dev_groups, and the kernel
naturally skips NULL attribute groups while the code remains buildable
and type-checked.

Suggested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Chintan Patel <chintanlike@gmail.com>
---
 drivers/video/fbdev/sh_mobile_lcdcfb.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/sh_mobile_lcdcfb.c b/drivers/video/fbdev/sh_mobile_lcdcfb.c
index dd950e4ab5ce..cb7ed1ff9165 100644
--- a/drivers/video/fbdev/sh_mobile_lcdcfb.c
+++ b/drivers/video/fbdev/sh_mobile_lcdcfb.c
@@ -1350,7 +1350,17 @@ static struct attribute *overlay_sysfs_attrs[] = {
 	&dev_attr_overlay_rop3.attr,
 	NULL,
 };
-ATTRIBUTE_GROUPS(overlay_sysfs);
+
+#ifdef CONFIG_FB_DEVICE
+static const struct attribute_group overlay_sysfs_group = {
+	.attrs = overlay_sysfs_attrs,
+};
+#endif
+
+static const struct attribute_group *overlay_sysfs_groups[] = {
+	PTR_IF(IS_ENABLED(CONFIG_FB_DEVICE), &overlay_sysfs_group),
+	NULL,
+};
 
 static const struct fb_fix_screeninfo sh_mobile_lcdc_overlay_fix  = {
 	.id =		"SH Mobile LCDC",
-- 
2.43.0

Re: [PATCH v3 1/4] fb: Add dev_of_fbinfo() helper for optional sysfs support

[Helge Deller]

* Chintan Patel <chintanlike@gmail.com>:
> Add dev_of_fbinfo() to return the framebuffer struct device when
> CONFIG_FB_DEVICE is enabled, or NULL otherwise.
> 
> This allows fbdev drivers to use sysfs interfaces via runtime checks
> instead of CONFIG_FB_DEVICE ifdefs, keeping the code clean while
> remaining fully buildable.
> 
> Suggested-by: Helge Deller <deller@gmx.de>
> Signed-off-by: Chintan Patel <chintanlike@gmail.com>

Reviewed-by: Helge Deller <deller@gmx.de>

Re: [PATCH v3 2/4] staging: fbtft: Make FB_DEVICE dependency optional

[Helge Deller]

* Chintan Patel <chintanlike@gmail.com>:
> fbtft provides sysfs interfaces for debugging and gamma configuration,
> but these are not required for the core driver.
> 
> Drop the hard dependency on CONFIG_FB_DEVICE and make sysfs support
> optional by using dev_of_fbinfo() at runtime. When FB_DEVICE is disabled,
> sysfs operations are skipped while the code remains buildable and
> type-checked.
> 
> Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
> Suggested-by: Helge Deller <deller@gmx.de>
> Signed-off-by: Chintan Patel <chintanlike@gmail.com>

Reviewed-by: Helge Deller <deller@gmx.de>

Re: [PATCH v3 3/4] fbdev: omapfb: Make FB_DEVICE dependency optional

[Helge Deller]

* Chintan Patel <chintanlike@gmail.com>:
> omapfb provides several sysfs interfaces for framebuffer configuration
> and debugging, but these are not required for the core driver.
> 
> Remove the hard dependency on CONFIG_FB_DEVICE and make sysfs support
> optional by using dev_of_fbinfo() to obtain the backing device at runtime.
> When FB_DEVICE is disabled, sysfs operations are skipped while the code
> still builds and is type-checked.
> 
> Suggested-by: Helge Deller <deller@gmx.de>
> Signed-off-by: Chintan Patel <chintanlike@gmail.com>

Reviewed-by: Helge Deller <deller@gmx.de>

> ---
>  drivers/video/fbdev/omap2/omapfb/Kconfig        |  3 ++-
>  drivers/video/fbdev/omap2/omapfb/omapfb-sysfs.c | 16 ++++++++++++----
>  2 files changed, 14 insertions(+), 5 deletions(-)

Re: [PATCH v3 4/4] fbdev: sh_mobile_lcdc: Make FB_DEVICE dependency optional

[Helge Deller]

* Chintan Patel <chintanlike@gmail.com>:
> The sh_mobile_lcdc driver exposes overlay configuration via sysfs, but the
> core driver does not require CONFIG_FB_DEVICE.
> 
> Make sysfs support optional by defining overlay_sysfs_groups conditionally
> using PTR_IF(). The driver always sets .dev_groups, and the kernel
> naturally skips NULL attribute groups while the code remains buildable
> and type-checked.
> 
> Suggested-by: Helge Deller <deller@gmx.de>
> Signed-off-by: Chintan Patel <chintanlike@gmail.com>
> ---
>  drivers/video/fbdev/sh_mobile_lcdcfb.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/fbdev/sh_mobile_lcdcfb.c b/drivers/video/fbdev/sh_mobile_lcdcfb.c
> index dd950e4ab5ce..cb7ed1ff9165 100644
> --- a/drivers/video/fbdev/sh_mobile_lcdcfb.c
> +++ b/drivers/video/fbdev/sh_mobile_lcdcfb.c
> @@ -1350,7 +1350,17 @@ static struct attribute *overlay_sysfs_attrs[] = {
>  	&dev_attr_overlay_rop3.attr,
>  	NULL,
>  };
> -ATTRIBUTE_GROUPS(overlay_sysfs);

Instead of replacing the ^ ATTRIBUTE_GROUPS() by the code below,
isn't it possible to just mark the overlay_sysfs_attrs[] array
_maybe_unused, and just do:
+ #ifdef CONFIG_FB_DEVICE
+ ATTRIBUTE_GROUPS(overlay_sysfs);
+ #endif

?

Helge


> +
> +#ifdef CONFIG_FB_DEVICE
> +static const struct attribute_group overlay_sysfs_group = {
> +	.attrs = overlay_sysfs_attrs,
> +};
> +#endif
> +
> +static const struct attribute_group *overlay_sysfs_groups[] = {
> +	PTR_IF(IS_ENABLED(CONFIG_FB_DEVICE), &overlay_sysfs_group),
> +	NULL,
> +};
>  
>  static const struct fb_fix_screeninfo sh_mobile_lcdc_overlay_fix  = {
>  	.id =		"SH Mobile LCDC",
> -- 
> 2.43.0
> 
> 

Re: [PATCH v3 0/4] fbdev: Make CONFIG_FB_DEVICE optional for drivers

[Geert Uytterhoeven]

Hi Chintan.

On Tue, 30 Dec 2025 at 06:29, Chintan Patel <chintanlike@gmail.com> wrote:
> This series makes CONFIG_FB_DEVICE optional for fbdev drivers that use
> it only for sysfs interfaces, addressing Thomas Zimmermann’s TODO to
> remove hard FB_DEVICE dependencies.
>
> The series introduces a small helper, dev_of_fbinfo(), which returns
> NULL when CONFIG_FB_DEVICE=n. This allows sysfs code paths to be skipped
> via runtime checks, avoids #ifdef CONFIG_FB_DEVICE clutter, and keeps
> full compile-time syntax checking.
>
> Signed-off-by: Chintan Patel <chintanlike@gmail.com>
> ---
> Changes in v3:
> - Use PTR_IF() to conditionally include overlay_sysfs_group in
>   overlay_sysfs_groups
> - Decouple variable definition and assignment in fbtft_sysfs_init/exit
>
> Changes in v2:
> - Add dev_of_fbinfo() helper (suggested by Geert Uytterhoeven)

by Helge Deller, not me.

> - Replace #ifdef CONFIG_FB_DEVICE blocks with runtime NULL checks
> - Switch to fb_dbg() / fb_info() logging (suggested by Thomas Zimmermann)

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 v3 0/4] fbdev: Make CONFIG_FB_DEVICE optional for drivers

[Andy Shevchenko]

On Mon, Dec 29, 2025 at 09:28:18PM -0800, Chintan Patel wrote:
> This series makes CONFIG_FB_DEVICE optional for fbdev drivers that use
> it only for sysfs interfaces, addressing Thomas Zimmermann’s TODO to
> remove hard FB_DEVICE dependencies.
> 
> The series introduces a small helper, dev_of_fbinfo(), which returns
> NULL when CONFIG_FB_DEVICE=n. This allows sysfs code paths to be skipped
> via runtime checks, avoids #ifdef CONFIG_FB_DEVICE clutter, and keeps
> full compile-time syntax checking.

> Signed-off-by: Chintan Patel <chintanlike@gmail.com>
> ---
> Changes in v3:
> - Use PTR_IF() to conditionally include overlay_sysfs_group in 
>   overlay_sysfs_groups
> - Decouple variable definition and assignment in fbtft_sysfs_init/exit

Any particular reasons you ignored my tag from v2?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v3 4/4] fbdev: sh_mobile_lcdc: Make FB_DEVICE dependency optional

[Andy Shevchenko]

On Mon, Dec 29, 2025 at 09:28:22PM -0800, Chintan Patel wrote:
> The sh_mobile_lcdc driver exposes overlay configuration via sysfs, but the
> core driver does not require CONFIG_FB_DEVICE.
> 
> Make sysfs support optional by defining overlay_sysfs_groups conditionally
> using PTR_IF(). The driver always sets .dev_groups, and the kernel
> naturally skips NULL attribute groups while the code remains buildable
> and type-checked.

...

> +static const struct attribute_group *overlay_sysfs_groups[] = {
> +	PTR_IF(IS_ENABLED(CONFIG_FB_DEVICE), &overlay_sysfs_group),
> +	NULL,

Please, drop comma at the end of the terminator entry.

> +};

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v3 3/4] fbdev: omapfb: Make FB_DEVICE dependency optional

[Andy Shevchenko]

On Mon, Dec 29, 2025 at 09:28:21PM -0800, Chintan Patel wrote:
> omapfb provides several sysfs interfaces for framebuffer configuration
> and debugging, but these are not required for the core driver.
> 
> Remove the hard dependency on CONFIG_FB_DEVICE and make sysfs support
> optional by using dev_of_fbinfo() to obtain the backing device at runtime.
> When FB_DEVICE is disabled, sysfs operations are skipped while the code
> still builds and is type-checked.

...

> +		struct device *dev = dev_of_fbinfo(fbdev->fbs[i]);

Still the same issue I pointed out in v2 review.

>  		int t;
> +
> +		if (!dev)
> +			continue;

...

> +		struct device *dev = dev_of_fbinfo(fbdev->fbs[i]);
> +
> +		if (!dev)
> +			continue;

Ditto.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v3 0/4] fbdev: Make CONFIG_FB_DEVICE optional for drivers

[Chintan Patel]

On 12/30/25 03:33, Andy Shevchenko wrote:
> On Mon, Dec 29, 2025 at 09:28:18PM -0800, Chintan Patel wrote:
>> This series makes CONFIG_FB_DEVICE optional for fbdev drivers that use
>> it only for sysfs interfaces, addressing Thomas Zimmermann’s TODO to
>> remove hard FB_DEVICE dependencies.
>>
>> The series introduces a small helper, dev_of_fbinfo(), which returns
>> NULL when CONFIG_FB_DEVICE=n. This allows sysfs code paths to be skipped
>> via runtime checks, avoids #ifdef CONFIG_FB_DEVICE clutter, and keeps
>> full compile-time syntax checking.
> 
>> Signed-off-by: Chintan Patel <chintanlike@gmail.com>
>> ---
>> Changes in v3:
>> - Use PTR_IF() to conditionally include overlay_sysfs_group in
>>    overlay_sysfs_groups
>> - Decouple variable definition and assignment in fbtft_sysfs_init/exit
> 
> Any particular reasons you ignored my tag from v2?
> 
Ah.. This is typo. I see what happened now. Looks like my script picked 
wrong or old patches instead of new updated one. Should I send v4 or v4 
is fine?

Re: [PATCH v3 3/4] fbdev: omapfb: Make FB_DEVICE dependency optional

[Chintan Patel]

On 12/30/25 03:37, Andy Shevchenko wrote:
> On Mon, Dec 29, 2025 at 09:28:21PM -0800, Chintan Patel wrote:
>> omapfb provides several sysfs interfaces for framebuffer configuration
>> and debugging, but these are not required for the core driver.
>>
>> Remove the hard dependency on CONFIG_FB_DEVICE and make sysfs support
>> optional by using dev_of_fbinfo() to obtain the backing device at runtime.
>> When FB_DEVICE is disabled, sysfs operations are skipped while the code
>> still builds and is type-checked.
> 
> ...
> 
>> +		struct device *dev = dev_of_fbinfo(fbdev->fbs[i]);
> 
> Still the same issue I pointed out in v2 review.
> 
>>   		int t;
>> +
>> +		if (!dev)
>> +			continue;
> 
> ...
> 
>> +		struct device *dev = dev_of_fbinfo(fbdev->fbs[i]);
>> +
>> +		if (!dev)
>> +			continue;
> 
> Ditto.
Sorry about that. I had actually made your suggested changes but somehow 
I mistakenly send old patches instead of updated one. I will send 
updated one. Should I send v4 or v3 is fine?

Re: [PATCH v3 4/4] fbdev: sh_mobile_lcdc: Make FB_DEVICE dependency optional

[Chintan Patel]

On 12/30/25 00:13, Helge Deller wrote:
> * Chintan Patel <chintanlike@gmail.com>:
>> The sh_mobile_lcdc driver exposes overlay configuration via sysfs, but the
>> core driver does not require CONFIG_FB_DEVICE.
>>
>> Make sysfs support optional by defining overlay_sysfs_groups conditionally
>> using PTR_IF(). The driver always sets .dev_groups, and the kernel
>> naturally skips NULL attribute groups while the code remains buildable
>> and type-checked.
>>
>> Suggested-by: Helge Deller <deller@gmx.de>
>> Signed-off-by: Chintan Patel <chintanlike@gmail.com>
>> ---
>>   drivers/video/fbdev/sh_mobile_lcdcfb.c | 12 +++++++++++-
>>   1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/video/fbdev/sh_mobile_lcdcfb.c b/drivers/video/fbdev/sh_mobile_lcdcfb.c
>> index dd950e4ab5ce..cb7ed1ff9165 100644
>> --- a/drivers/video/fbdev/sh_mobile_lcdcfb.c
>> +++ b/drivers/video/fbdev/sh_mobile_lcdcfb.c
>> @@ -1350,7 +1350,17 @@ static struct attribute *overlay_sysfs_attrs[] = {
>>   	&dev_attr_overlay_rop3.attr,
>>   	NULL,
>>   };
>> -ATTRIBUTE_GROUPS(overlay_sysfs);
> 
> Instead of replacing the ^ ATTRIBUTE_GROUPS() by the code below,
> isn't it possible to just mark the overlay_sysfs_attrs[] array
> _maybe_unused, and just do:
> + #ifdef CONFIG_FB_DEVICE
> + ATTRIBUTE_GROUPS(overlay_sysfs);
> + #endif
> 
> ?
Hi Helge,

Yes, the __maybe_unused + #ifdef ATTRIBUTE_GROUPS() approach would work.

I went with the PTR_IF(IS_ENABLED()) pattern because Andy suggested 
using PTR_IF() to conditionally include overlay_sysfs_group in 
overlay_sysfs_groups, and to keep .dev_groups always populated while 
letting the device core skip NULL groups. This avoids conditional wiring 
via #ifdef and keeps the code type-checked without CONFIG_FB_DEVICE.
If you still prefer the simpler #ifdef ATTRIBUTE_GROUPS() approach for 
this driver, I can switch to that, but I wanted to follow Andy’s 
guidance here.


Thanks!