linux-kernel - [PATCH v3 2/4] staging: fbtft: Make FB

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Message-ID: <20251230052827.4676-3-chintanlike@gmail.com>
Date: Mon, 29 Dec 2025 21:28:20 -0800
From: Chintan Patel <chintanlike@...il.com>
To: linux-fbdev@...r.kernel.org,
	linux-staging@...ts.linux.dev,
	linux-omap@...r.kernel.org
Cc: linux-kernel@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	tzimmermann@...e.de,
	andy@...nel.org,
	deller@....de,
	gregkh@...uxfoundation.org,
	Chintan Patel <chintanlike@...il.com>
Subject: [PATCH v3 2/4] staging: fbtft: Make FB_DEVICE dependency optional

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@...e.de>
Suggested-by: Helge Deller <deller@....de>
Signed-off-by: Chintan Patel <chintanlike@...il.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