fbdev/au1200fb: Initialize fb_ops with fbdev macros

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

Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based 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.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-18-tzimmermann@suse.de

drivers/video/fbdev/Kconfig

@@ -1457,10 +1457,7 @@ config FB_AU1100
 config FB_AU1200
 	bool "Au1200/Au1300 LCD Driver"
 	depends on (FB = y) && MIPS_ALCHEMY
-	select FB_SYS_FILLRECT
-	select FB_SYS_COPYAREA
-	select FB_SYS_IMAGEBLIT
-	select FB_SYS_FOPS
+	select FB_DMAMEM_HELPERS
 	help
 	  This is the framebuffer driver for the Au1200/Au1300 SOCs.
 	  It can drive various panels and CRTs by passing in kernel cmd line

drivers/video/fbdev/au1200fb.c

@@ -1488,15 +1488,12 @@ static int au1200fb_ioctl(struct fb_info *info, unsigned int cmd,
 
 static const struct fb_ops au1200fb_fb_ops = {
 	.owner		= THIS_MODULE,
+	__FB_DEFAULT_DMAMEM_OPS_RDWR,
 	.fb_check_var	= au1200fb_fb_check_var,
 	.fb_set_par	= au1200fb_fb_set_par,
 	.fb_setcolreg	= au1200fb_fb_setcolreg,
 	.fb_blank	= au1200fb_fb_blank,
-	.fb_fillrect	= sys_fillrect,
-	.fb_copyarea	= sys_copyarea,
-	.fb_imageblit	= sys_imageblit,
-	.fb_read	= fb_sys_read,
-	.fb_write	= fb_sys_write,
+	__FB_DEFAULT_DMAMEM_OPS_DRAW,
 	.fb_sync	= NULL,
 	.fb_ioctl	= au1200fb_ioctl,
 	.fb_mmap	= au1200fb_fb_mmap,