fbdev/ep93xx-fb: Initialize fb_ops to fbdev I/O-memory helpers

Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in I/O address space. Set the read/write,
draw and mmap callbacks to the correct implementation and avoid
implicit defaults. Also select the necessary I/O helpers in Kconfig.

Fbdev drivers sometimes rely on the callbacks being NULL for a
default implementation to be invoked; hence requiring the I/O
helpers to be built in any case. Setting all callbacks in all
drivers explicitly will allow to make the I/O helpers optional.
This benefits systems that do not use these functions.

No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230927074722.6197-15-tzimmermann@suse.de

drivers/video/fbdev/Kconfig

@@ -1866,9 +1866,7 @@ config FB_MB862XX_I2C
 config FB_EP93XX
 	tristate "EP93XX frame buffer support"
 	depends on FB && ARCH_EP93XX
-	select FB_CFB_FILLRECT
-	select FB_CFB_COPYAREA
-	select FB_CFB_IMAGEBLIT
+	select FB_IOMEM_HELPERS
 	help
 	  Framebuffer driver for the Cirrus Logic EP93XX series of processors.
 	  This driver is also available as a module. The module will be called

drivers/video/fbdev/ep93xx-fb.c

@@ -404,12 +404,11 @@ static int ep93xxfb_setcolreg(unsigned int regno, unsigned int red,
 
 static const struct fb_ops ep93xxfb_ops = {
 	.owner		= THIS_MODULE,
+	__FB_DEFAULT_IOMEM_OPS_RDWR,
 	.fb_check_var	= ep93xxfb_check_var,
 	.fb_set_par	= ep93xxfb_set_par,
 	.fb_blank	= ep93xxfb_blank,
-	.fb_fillrect	= cfb_fillrect,
-	.fb_copyarea	= cfb_copyarea,
-	.fb_imageblit	= cfb_imageblit,
+	__FB_DEFAULT_IOMEM_OPS_DRAW,
 	.fb_setcolreg	= ep93xxfb_setcolreg,
 	.fb_mmap	= ep93xxfb_mmap,
 };