fbdev/matroxfb: Initialize fb_ops to fbdev I/O-memory helpers

Initialize each 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/20230927074722.6197-23-tzimmermann@suse.de

drivers/video/fbdev/Kconfig

@@ -903,6 +903,7 @@ config FB_MATROX
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
+	select FB_IOMEM_FOPS
 	select FB_TILEBLITTING
 	select FB_MACMODES if PPC_PMAC
 	select VIDEO_NOMODESET
@@ -989,6 +990,7 @@ config FB_MATROX_I2C
 config FB_MATROX_MAVEN
 	tristate "G400 second head support"
 	depends on FB_MATROX_G && FB_MATROX_I2C
+	select FB_IOMEM_HELPERS
 	help
 	  WARNING !!! This support does not work with G450 !!!
 

drivers/video/fbdev/matrox/matroxfb_base.c

@@ -1204,6 +1204,7 @@ static const struct fb_ops matroxfb_ops = {
 	.owner =	THIS_MODULE,
 	.fb_open =	matroxfb_open,
 	.fb_release =	matroxfb_release,
+	__FB_DEFAULT_IOMEM_OPS_RDWR,
 	.fb_check_var =	matroxfb_check_var,
 	.fb_set_par =	matroxfb_set_par,
 	.fb_setcolreg =	matroxfb_setcolreg,
@@ -1214,6 +1215,7 @@ static const struct fb_ops matroxfb_ops = {
 /*	.fb_copyarea =	<set by matrox_cfbX_init>, */
 /*	.fb_imageblit =	<set by matrox_cfbX_init>, */
 /*	.fb_cursor =	<set by matrox_cfbX_init>, */
+	__FB_DEFAULT_IOMEM_OPS_MMAP,
 };
 
 #define RSDepth(X)	(((X) >> 8) & 0x0F)

drivers/video/fbdev/matrox/matroxfb_crtc2.c

@@ -567,15 +567,13 @@ static const struct fb_ops matroxfb_dh_ops = {
 	.owner =	THIS_MODULE,
 	.fb_open =	matroxfb_dh_open,
 	.fb_release =	matroxfb_dh_release,
+	FB_DEFAULT_IOMEM_OPS,
 	.fb_check_var =	matroxfb_dh_check_var,
 	.fb_set_par =	matroxfb_dh_set_par,
 	.fb_setcolreg =	matroxfb_dh_setcolreg,
 	.fb_pan_display =matroxfb_dh_pan_display,
 	.fb_blank =	matroxfb_dh_blank,
 	.fb_ioctl =	matroxfb_dh_ioctl,
-	.fb_fillrect =	cfb_fillrect,
-	.fb_copyarea =	cfb_copyarea,
-	.fb_imageblit =	cfb_imageblit,
 };
 
 static struct fb_var_screeninfo matroxfb_dh_defined = {