sm501: restructure init to allow only 1 fb on an SM501

Add the ability to register only one of the two possible main framebuffer
devices on the SM501 by passing platform data for only the framebuffer
that you are interested in having.

As a side note, we update the init sequence to commonise the code that is
executed twice, and fix a pair of missing frees that we didn't do on
framebuffer exit, such as freeing the fb's cmap.

Signed-off-by: Ben Dooks <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/video/sm501fb.c

···
 			   unsigned int why, size_t size)
 {
 	unsigned int ptr = 0;
+	unsigned int end;
+	struct fb_info *fbi;
 
 	switch (why) {
 	case SM501_MEMF_CURSOR:
···
 
 	case SM501_MEMF_PANEL:
 		ptr = inf->fbmem_len - size;
-		if (ptr < inf->fb[0]->fix.smem_len)
+		fbi = inf->fb[0];
+
+		if (fbi && ptr < fbi->fix.smem_len)
 			return -ENOMEM;
 
 		break;
···
 		break;
 
 	case SM501_MEMF_ACCEL:
-		ptr = inf->fb[0]->fix.smem_len;
+		fbi = inf->fb[0];
+		ptr = fbi ? fbi->fix.smem_len : 0;
 
-		if ((ptr + size) >
-		    (inf->fb[1]->fix.smem_start - inf->fbmem_res->start))
+		fbi = inf->fb[1];
+		if (fbi)
+			end = (fbi->fix.smem_start - inf->fbmem_res->start);
+		else
+			end = inf->fbmem_len;
+
+		if ((ptr + size) > end)
 			return -ENOMEM;
+
 		break;
 
 	default:
···
 	.fb_imageblit	= cfb_imageblit,
 };
 
-/* sm501fb_info_alloc
- *
- * creates and initialises an sm501fb_info structure
-*/
-
-static struct sm501fb_info *sm501fb_info_alloc(struct fb_info *fbinfo_crt,
-					       struct fb_info *fbinfo_pnl)
-{
-	struct sm501fb_info *info;
-	struct sm501fb_par  *par;
-
-	info = kzalloc(sizeof(struct sm501fb_info), GFP_KERNEL);
-	if (info) {
-		/* set the references back */
-
-		par = fbinfo_crt->par;
-		par->info = info;
-		par->head = HEAD_CRT;
-		fbinfo_crt->pseudo_palette = &par->pseudo_palette;
-
-		par = fbinfo_pnl->par;
-		par->info = info;
-		par->head = HEAD_PANEL;
-		fbinfo_pnl->pseudo_palette = &par->pseudo_palette;
-
-		/* store the two fbs into our info */
-		info->fb[HEAD_CRT] = fbinfo_crt;
-		info->fb[HEAD_PANEL] = fbinfo_pnl;
-	}
-
-	return info;
-}
-
 /* sm501_init_cursor
  *
  * initialise hw cursor parameters
···
 
 static int sm501_init_cursor(struct fb_info *fbi, unsigned int reg_base)
 {
-	struct sm501fb_par *par = fbi->par;
-	struct sm501fb_info *info = par->info;
+	struct sm501fb_par *par;
+	struct sm501fb_info *info;
 	int ret;
+
+	if (fbi == NULL)
+		return 0;
+
+	par = fbi->par;
+	info = par->info;
 
 	par->cursor_regs = info->regs + reg_base;
 
···
 			 struct platform_device *pdev)
 {
 	struct resource	*res;
-	struct device *dev;
+	struct device *dev = &pdev->dev;
 	int k;
 	int ret;
-
-	info->dev = dev = &pdev->dev;
-	platform_set_drvdata(pdev, info);
 
 	info->irq = ret = platform_get_irq(pdev, 0);
 	if (ret < 0) {
···
 	iounmap(info->regs);
 	release_resource(info->regs_res);
 	kfree(info->regs_res);
-}
-
-static void sm501fb_info_release(struct sm501fb_info *info)
-{
-	kfree(info);
 }
 
 static int sm501fb_init_fb(struct fb_info *fb,
···
 static char driver_name_crt[] = "sm501fb-crt";
 static char driver_name_pnl[] = "sm501fb-panel";
 
-static int __init sm501fb_probe(struct platform_device *pdev)
+static int __devinit sm501fb_probe_one(struct sm501fb_info *info,
+				       enum sm501_controller head)
 {
-	struct sm501fb_info *info;
-	struct device	    *dev = &pdev->dev;
-	struct fb_info	    *fbinfo_crt;
-	struct fb_info	    *fbinfo_pnl;
-	int		     ret;
+	unsigned char *name = (head == HEAD_CRT) ? "crt" : "panel";
+	struct sm501_platdata_fbsub *pd;
+	struct sm501fb_par *par;
+	struct fb_info *fbi;
 
-	/* allocate our framebuffers */
+	pd = (head == HEAD_CRT) ? info->pdata->fb_crt : info->pdata->fb_pnl;
 
-	fbinfo_crt = framebuffer_alloc(sizeof(struct sm501fb_par), dev);
-	if (fbinfo_crt == NULL) {
-		dev_err(dev, "cannot allocate crt framebuffer\n");
+	/* Do not initialise if we've not been given any platform data */
+	if (pd == NULL) {
+		dev_info(info->dev, "no data for fb %s (disabled)\n", name);
+		return 0;
+	}
+
+	fbi = framebuffer_alloc(sizeof(struct sm501fb_par), info->dev);
+	if (fbi == NULL) {
+		dev_err(info->dev, "cannot allocate %s framebuffer\n", name);
 		return -ENOMEM;
 	}
 
-	fbinfo_pnl = framebuffer_alloc(sizeof(struct sm501fb_par), dev);
-	if (fbinfo_pnl == NULL) {
-		dev_err(dev, "cannot allocate panel framebuffer\n");
-		ret = -ENOMEM;
-		goto fbinfo_crt_alloc_fail;
+	par = fbi->par;
+	par->info = info;
+	par->head = head;
+	fbi->pseudo_palette = &par->pseudo_palette;
+
+	info->fb[head] = fbi;
+
+	return 0;
+}
+
+/* Free up anything allocated by sm501fb_init_fb */
+
+static void sm501_free_init_fb(struct sm501fb_info *info,
+				enum sm501_controller head)
+{
+	struct fb_info *fbi = info->fb[head];
+
+	fb_dealloc_cmap(&fbi->cmap);
+}
+
+static int __devinit sm501fb_start_one(struct sm501fb_info *info,
+				       enum sm501_controller head,
+				       const char *drvname)
+{
+	struct fb_info *fbi = info->fb[head];
+	int ret;
+
+	if (!fbi)
+		return 0;
+
+	ret = sm501fb_init_fb(info->fb[head], head, drvname);
+	if (ret) {
+		dev_err(info->dev, "cannot initialise fb %s\n", drvname);
+		return ret;
 	}
 
-	info = sm501fb_info_alloc(fbinfo_crt, fbinfo_pnl);
-	if (info == NULL) {
-		dev_err(dev, "cannot allocate par\n");
-		ret = -ENOMEM;
-		goto sm501fb_alloc_fail;
+	ret = register_framebuffer(info->fb[head]);
+	if (ret) {
+		dev_err(info->dev, "failed to register fb %s\n", drvname);
+		sm501_free_init_fb(info, head);
+		return ret;
 	}
+
+	dev_info(info->dev, "fb%d: %s frame buffer\n", fbi->node, fbi->fix.id);
+
+	return 0;
+}
+
+static int __devinit sm501fb_probe(struct platform_device *pdev)
+{
+	struct sm501fb_info *info;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	/* allocate our framebuffers */
+
+	info = kzalloc(sizeof(struct sm501fb_info), GFP_KERNEL);
+	if (!info) {
+		dev_err(dev, "failed to allocate state\n");
+		return -ENOMEM;
+	}
+
+	info->dev = dev = &pdev->dev;
+	platform_set_drvdata(pdev, info);
 
 	if (dev->parent->platform_data) {
 		struct sm501_platdata *pd = dev->parent->platform_data;
···
 		info->pdata = &sm501fb_def_pdata;
 	}
 
-	/* start the framebuffers */
+	/* probe for the presence of each panel */
+
+	ret = sm501fb_probe_one(info, HEAD_CRT);
+	if (ret < 0) {
+		dev_err(dev, "failed to probe CRT\n");
+		goto err_alloc;
+	}
+
+	ret = sm501fb_probe_one(info, HEAD_PANEL);
+	if (ret < 0) {
+		dev_err(dev, "failed to probe PANEL\n");
+		goto err_probed_crt;
+	}
+
+	if (info->fb[HEAD_PANEL] == NULL &&
+	    info->fb[HEAD_CRT] == NULL) {
+		dev_err(dev, "no framebuffers found\n");
+		goto err_alloc;
+	}
+
+	/* get the resources for both of the framebuffers */
 
 	ret = sm501fb_start(info, pdev);
 	if (ret) {
 		dev_err(dev, "cannot initialise SM501\n");
-		goto sm501fb_start_fail;
+		goto err_probed_panel;
 	}
 
-	/* CRT framebuffer setup */
-
-	ret = sm501fb_init_fb(fbinfo_crt, HEAD_CRT, driver_name_crt);
+	ret = sm501fb_start_one(info, HEAD_CRT, driver_name_crt);
 	if (ret) {
-		dev_err(dev, "cannot initialise CRT fb\n");
-		goto sm501fb_start_fail;
+		dev_err(dev, "failed to start CRT\n");
+		goto err_started;
 	}
 
-	/* Panel framebuffer setup */
-
-	ret = sm501fb_init_fb(fbinfo_pnl, HEAD_PANEL, driver_name_pnl);
+	ret = sm501fb_start_one(info, HEAD_PANEL, driver_name_pnl);
 	if (ret) {
-		dev_err(dev, "cannot initialise Panel fb\n");
-		goto sm501fb_start_fail;
+		dev_err(dev, "failed to start Panel\n");
+		goto err_started_crt;
 	}
-
-	/* register framebuffers */
-
-	ret = register_framebuffer(fbinfo_crt);
-	if (ret < 0) {
-		dev_err(dev, "failed to register CRT fb (%d)\n", ret);
-		goto register_crt_fail;
-	}
-
-	ret = register_framebuffer(fbinfo_pnl);
-	if (ret < 0) {
-		dev_err(dev, "failed to register panel fb (%d)\n", ret);
-		goto register_pnl_fail;
-	}
-
-	dev_info(dev, "fb%d: %s frame buffer device\n",
-		 fbinfo_crt->node, fbinfo_crt->fix.id);
-
-	dev_info(dev, "fb%d: %s frame buffer device\n",
-	       fbinfo_pnl->node, fbinfo_pnl->fix.id);
 
 	/* create device files */
 
 	ret = device_create_file(dev, &dev_attr_crt_src);
 	if (ret)
-		goto crtsrc_fail;
+		goto err_started_panel;
 
 	ret = device_create_file(dev, &dev_attr_fbregs_pnl);
 	if (ret)
-		goto fbregs_pnl_fail;
+		goto err_attached_crtsrc_file;
 
 	ret = device_create_file(dev, &dev_attr_fbregs_crt);
 	if (ret)
-		goto fbregs_crt_fail;
+		goto err_attached_pnlregs_file;
 
 	/* we registered, return ok */
 	return 0;
 
- fbregs_crt_fail:
+err_attached_pnlregs_file:
 	device_remove_file(dev, &dev_attr_fbregs_pnl);
 
- fbregs_pnl_fail:
+err_attached_crtsrc_file:
 	device_remove_file(dev, &dev_attr_crt_src);
 
- crtsrc_fail:
-	unregister_framebuffer(fbinfo_pnl);
+err_started_panel:
+	unregister_framebuffer(info->fb[HEAD_PANEL]);
+	sm501_free_init_fb(info, HEAD_PANEL);
 
- register_pnl_fail:
-	unregister_framebuffer(fbinfo_crt);
+err_started_crt:
+	unregister_framebuffer(info->fb[HEAD_CRT]);
+	sm501_free_init_fb(info, HEAD_CRT);
 
- register_crt_fail:
+err_started:
 	sm501fb_stop(info);
 
- sm501fb_start_fail:
-	sm501fb_info_release(info);
+err_probed_panel:
+	framebuffer_release(info->fb[HEAD_PANEL]);
 
- sm501fb_alloc_fail:
-	framebuffer_release(fbinfo_pnl);
+err_probed_crt:
+	framebuffer_release(info->fb[HEAD_CRT]);
 
- fbinfo_crt_alloc_fail:
-	framebuffer_release(fbinfo_crt);
+err_alloc:
+	kfree(info);
 
 	return ret;
 }
···
 	device_remove_file(&pdev->dev, &dev_attr_fbregs_pnl);
 	device_remove_file(&pdev->dev, &dev_attr_crt_src);
 
+	sm501_free_init_fb(info, HEAD_CRT);
+	sm501_free_init_fb(info, HEAD_PANEL);
+
 	unregister_framebuffer(fbinfo_crt);
 	unregister_framebuffer(fbinfo_pnl);
 
 	sm501fb_stop(info);
-	sm501fb_info_release(info);
+	kfree(info);
 
 	framebuffer_release(fbinfo_pnl);
 	framebuffer_release(fbinfo_crt);