fbdev/vermilionfb: 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/20230927074722.6197-44-tzimmermann@suse.de

drivers/video/fbdev/Kconfig

@@ -849,10 +849,8 @@ config FB_I810_I2C
 config FB_LE80578
 	tristate "Intel LE80578 (Vermilion) support"
 	depends on FB && PCI && X86
+	select FB_IOMEM_HELPERS
 	select FB_MODE_HELPERS
-	select FB_CFB_FILLRECT
-	select FB_CFB_COPYAREA
-	select FB_CFB_IMAGEBLIT
 	select VIDEO_NOMODESET
 	help
 	  This driver supports the LE80578 (Vermilion Range) chipset

drivers/video/fbdev/vermilion/vermilion.c

@@ -1024,13 +1024,12 @@ static struct fb_ops vmlfb_ops = {
 	.owner = THIS_MODULE,
 	.fb_open = vmlfb_open,
 	.fb_release = vmlfb_release,
+	__FB_DEFAULT_IOMEM_OPS_RDWR,
 	.fb_check_var = vmlfb_check_var,
 	.fb_set_par = vmlfb_set_par,
 	.fb_blank = vmlfb_blank,
 	.fb_pan_display = vmlfb_pan_display,
-	.fb_fillrect = cfb_fillrect,
-	.fb_copyarea = cfb_copyarea,
-	.fb_imageblit = cfb_imageblit,
+	__FB_DEFAULT_IOMEM_OPS_DRAW,
 	.fb_cursor = vmlfb_cursor,
 	.fb_sync = vmlfb_sync,
 	.fb_mmap = vmlfb_mmap,