staging/sm750fb: Declare fb_ops as constant

Split up lynxfb_ops and declare each as constant. The fb_ops
instance used to be modified while initializing the driver. It is
now constant and the driver picks the correct instance, depending
on the settings for acceleration and cursor support.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Teddy Wang <teddy.wang@siliconmotion.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-staging@lists.linux.dev
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-26-tzimmermann@suse.de

drivers/staging/sm750fb/sm750.c

@@ -663,16 +663,53 @@ static int sm750fb_set_drv(struct lynxfb_par *par)
 	return ret;
 }
 
-static struct fb_ops lynxfb_ops = {
+static const struct fb_ops lynxfb_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var =  lynxfb_ops_check_var,
 	.fb_set_par = lynxfb_ops_set_par,
 	.fb_setcolreg = lynxfb_ops_setcolreg,
 	.fb_blank = lynxfb_ops_blank,
+	.fb_pan_display = lynxfb_ops_pan_display,
 	.fb_fillrect = cfb_fillrect,
 	.fb_imageblit = cfb_imageblit,
 	.fb_copyarea = cfb_copyarea,
-	/* cursor */
+};
+
+static const struct fb_ops lynxfb_ops_with_cursor = {
+	.owner = THIS_MODULE,
+	.fb_check_var =  lynxfb_ops_check_var,
+	.fb_set_par = lynxfb_ops_set_par,
+	.fb_setcolreg = lynxfb_ops_setcolreg,
+	.fb_blank = lynxfb_ops_blank,
+	.fb_pan_display = lynxfb_ops_pan_display,
+	.fb_fillrect = cfb_fillrect,
+	.fb_copyarea = cfb_copyarea,
+	.fb_imageblit = cfb_imageblit,
+	.fb_cursor = lynxfb_ops_cursor,
+};
+
+static const struct fb_ops lynxfb_ops_accel = {
+	.owner = THIS_MODULE,
+	.fb_check_var =  lynxfb_ops_check_var,
+	.fb_set_par = lynxfb_ops_set_par,
+	.fb_setcolreg = lynxfb_ops_setcolreg,
+	.fb_blank = lynxfb_ops_blank,
+	.fb_pan_display = lynxfb_ops_pan_display,
+	.fb_fillrect = lynxfb_ops_fillrect,
+	.fb_copyarea = lynxfb_ops_copyarea,
+	.fb_imageblit = lynxfb_ops_imageblit,
+};
+
+static const struct fb_ops lynxfb_ops_accel_with_cursor = {
+	.owner = THIS_MODULE,
+	.fb_check_var =  lynxfb_ops_check_var,
+	.fb_set_par = lynxfb_ops_set_par,
+	.fb_setcolreg = lynxfb_ops_setcolreg,
+	.fb_blank = lynxfb_ops_blank,
+	.fb_pan_display = lynxfb_ops_pan_display,
+	.fb_fillrect = lynxfb_ops_fillrect,
+	.fb_copyarea = lynxfb_ops_copyarea,
+	.fb_imageblit = lynxfb_ops_imageblit,
 	.fb_cursor = lynxfb_ops_cursor,
 };
 
@@ -714,7 +751,6 @@ static int lynxfb_set_fbinfo(struct fb_info *info, int index)
 	par->index = index;
 	output->channel = &crtc->channel;
 	sm750fb_set_drv(par);
-	lynxfb_ops.fb_pan_display = lynxfb_ops_pan_display;
 
 	/*
 	 * set current cursor variable and proc pointer,
@@ -731,19 +767,22 @@ static int lynxfb_set_fbinfo(struct fb_info *info, int index)
 	crtc->cursor.vstart = sm750_dev->pvMem + crtc->cursor.offset;
 
 	memset_io(crtc->cursor.vstart, 0, crtc->cursor.size);
-	if (!g_hwcursor) {
-		lynxfb_ops.fb_cursor = NULL;
+	if (!g_hwcursor)
 		sm750_hw_cursor_disable(&crtc->cursor);
-	}
 
 	/* set info->fbops, must be set before fb_find_mode */
 	if (!sm750_dev->accel_off) {
 		/* use 2d acceleration */
-		lynxfb_ops.fb_fillrect = lynxfb_ops_fillrect;
-		lynxfb_ops.fb_copyarea = lynxfb_ops_copyarea;
-		lynxfb_ops.fb_imageblit = lynxfb_ops_imageblit;
+		if (!g_hwcursor)
+			info->fbops = &lynxfb_ops_accel;
+		else
+			info->fbops = &lynxfb_ops_accel_with_cursor;
+	} else {
+		if (!g_hwcursor)
+			info->fbops = &lynxfb_ops;
+		else
+			info->fbops = &lynxfb_ops_with_cursor;
 	}
-	info->fbops = &lynxfb_ops;
 
 	if (!g_fbmode[index]) {
 		g_fbmode[index] = g_def_fbmode;