mtd: maps: physmap: Remove the MAX_RESOURCES limitation

Remove the MAX_RESOURCES limitation by dynamically allocating the
->mtds[] and ->maps[] at probe time based on the number of iomem
resources attached to the platform device.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

drivers/mtd/maps/physmap.c

@@ -22,12 +22,11 @@
 #include <linux/mtd/concat.h>
 #include <linux/io.h>
 
-#define MAX_RESOURCES		4
-
 struct physmap_flash_info {
-	struct mtd_info		*mtds[MAX_RESOURCES];
+	unsigned int		nmaps;
+	struct mtd_info		**mtds;
 	struct mtd_info		*cmtd;
-	struct map_info		maps[MAX_RESOURCES];
+	struct map_info		*maps;
 	spinlock_t		vpp_lock;
 	int			vpp_refcnt;
 };
@@ -50,7 +49,7 @@ static int physmap_flash_remove(struct platform_device *dev)
 			mtd_concat_destroy(info->cmtd);
 	}
 
-	for (i = 0; i < MAX_RESOURCES; i++) {
+	for (i = 0; i < info->nmaps; i++) {
 		if (info->mtds[i] != NULL)
 			map_destroy(info->mtds[i]);
 	}
@@ -101,7 +100,6 @@ static int physmap_flash_probe(struct platform_device *dev)
 	const char * const *part_types;
 	int err = 0;
 	int i;
-	int devices_found = 0;
 
 	physmap_data = dev_get_platdata(&dev->dev);
 	if (physmap_data == NULL)
@@ -114,6 +112,24 @@ static int physmap_flash_probe(struct platform_device *dev)
 		goto err_out;
 	}
 
+	while (platform_get_resource(dev, IORESOURCE_MEM, info->nmaps))
+		info->nmaps++;
+
+	if (!info->nmaps)
+		return -ENODEV;
+
+	info->maps = devm_kzalloc(&dev->dev,
+				  sizeof(*info->maps) * info->nmaps,
+				  GFP_KERNEL);
+	if (!info->maps)
+		return -ENOMEM;
+
+	info->mtds = devm_kzalloc(&dev->dev,
+				  sizeof(*info->mtds) * info->nmaps,
+				  GFP_KERNEL);
+	if (!info->mtds)
+		return -ENOMEM;
+
 	if (physmap_data->init) {
 		err = physmap_data->init(dev);
 		if (err)
@@ -122,13 +138,10 @@ static int physmap_flash_probe(struct platform_device *dev)
 
 	platform_set_drvdata(dev, info);
 
-	for (i = 0; i < MAX_RESOURCES; i++) {
+	for (i = 0; i < info->nmaps; i++) {
 		struct resource *res;
 
 		res = platform_get_resource(dev, IORESOURCE_MEM, i);
-		if (!res)
-			break;
-
 		info->maps[i].virt = devm_ioremap_resource(&dev->dev, res);
 		if (IS_ERR(info->maps[i].virt)) {
 			err = PTR_ERR(info->maps[i].virt);
@@ -159,21 +172,18 @@ static int physmap_flash_probe(struct platform_device *dev)
 			dev_err(&dev->dev, "map_probe failed\n");
 			err = -ENXIO;
 			goto err_out;
-		} else {
-			devices_found++;
 		}
 		info->mtds[i]->dev.parent = &dev->dev;
 	}
 
-	if (!devices_found) {
-		err = -ENODEV;
-	} else if (devices_found == 1) {
+	if (info->nmaps == 1) {
 		info->cmtd = info->mtds[0];
 	} else {
 		/*
 		 * We detected multiple devices. Concatenate them together.
 		 */
-		info->cmtd = mtd_concat_create(info->mtds, devices_found, dev_name(&dev->dev));
+		info->cmtd = mtd_concat_create(info->mtds, info->nmaps,
+					       dev_name(&dev->dev));
 		if (info->cmtd == NULL)
 			err = -ENXIO;
 	}
@@ -199,7 +209,7 @@ static void physmap_flash_shutdown(struct platform_device *dev)
 	struct physmap_flash_info *info = platform_get_drvdata(dev);
 	int i;
 
-	for (i = 0; i < MAX_RESOURCES && info->mtds[i]; i++)
+	for (i = 0; i < info->nmaps && info->mtds[i]; i++)
 		if (mtd_suspend(info->mtds[i]) == 0)
 			mtd_resume(info->mtds[i]);
 }