mtd: physmap_of: Add multiple regions and concatenation support

This patch adds support to handle multiple non-identical chips in one
flash device tree node. It also adds concat support to physmap_of. This
makes it possible to support e.g. the Intel P30 48F4400 chips which
internally consists of 2 non-identical NOR chips on one die. Additionally
partitions now can span over multiple chips.

To describe such a chip's, multiple "reg" tuples are now supported in one
flash device tree node. Here an dts example:

        flash@f0000000,0 {
                #address-cells = <1>;
                #size-cells = <1>;
                compatible = "cfi-flash";
                reg = <0 0x00000000 0x02000000
                       0 0x02000000 0x02000000>;
                bank-width = <2>;
                partition@0 {
                        label = "test-part1";
                        reg = <0 0x04000000>;
                };
        };

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 143 insertions, 56 deletions

diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c
index c83a60fada53..39d357b2eb47 100644
--- a/drivers/mtd/maps/physmap_of.c
+++ b/drivers/mtd/maps/physmap_of.c
@@ -20,16 +20,23 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/map.h>
 #include <linux/mtd/partitions.h>
+#include <linux/mtd/concat.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
 
+struct of_flash_list {
+        struct mtd_info *mtd;
+        struct map_info map;
+        struct resource *res;
+};
+
 struct of_flash {
-        struct mtd_info         *mtd;
-        struct map_info         map;
-        struct resource         *res;
+        struct mtd_info         *cmtd;
 #ifdef CONFIG_MTD_PARTITIONS
         struct mtd_partition    *parts;
 #endif
+        int list_size; /* number of elements in of_flash_list */
+        struct of_flash_list    list[0];
 };
 
 #ifdef CONFIG_MTD_PARTITIONS
@@ -88,30 +95,44 @@ static int parse_obsolete_partitions(struct of_device *dev,
 static int of_flash_remove(struct of_device *dev)
 {
         struct of_flash *info;
+        int i;
 
         info = dev_get_drvdata(&dev->dev);
         if (!info)
                 return 0;
         dev_set_drvdata(&dev->dev, NULL);
 
-        if (info->mtd) {
+#ifdef CONFIG_MTD_CONCAT
+        if (info->cmtd != info->list[0].mtd) {
+                del_mtd_device(info->cmtd);
+                mtd_concat_destroy(info->cmtd);
+        }
+#endif
+
+        if (info->cmtd) {
                 if (OF_FLASH_PARTS(info)) {
-                        del_mtd_partitions(info->mtd);
+                        del_mtd_partitions(info->cmtd);
                         kfree(OF_FLASH_PARTS(info));
                 } else {
-                        del_mtd_device(info->mtd);
+                        del_mtd_device(info->cmtd);
                 }
-                map_destroy(info->mtd);
         }
 
-        if (info->map.virt)
-                iounmap(info->map.virt);
+        for (i = 0; i < info->list_size; i++) {
+                if (info->list[i].mtd)
+                        map_destroy(info->list[i].mtd);
 
-        if (info->res) {
-                release_resource(info->res);
-                kfree(info->res);
+                if (info->list[i].map.virt)
+                        iounmap(info->list[i].map.virt);
+
+                if (info->list[i].res) {
+                        release_resource(info->list[i].res);
+                        kfree(info->list[i].res);
+                }
         }
 
+        kfree(info);
+
         return 0;
 }
 
@@ -164,68 +185,130 @@ static int __devinit of_flash_probe(struct of_device *dev,
         const char *probe_type = match->data;
         const u32 *width;
         int err;
-
-        err = -ENXIO;
-        if (of_address_to_resource(dp, 0, &res)) {
-                dev_err(&dev->dev, "Can't get IO address from device tree\n");
+        int i;
+        int count;
+        const u32 *p;
+        int reg_tuple_size;
+        struct mtd_info **mtd_list = NULL;
+
+        reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32);
+
+        /*
+         * Get number of "reg" tuples. Scan for MTD devices on area's
+         * described by each "reg" region. This makes it possible (including
+         * the concat support) to support the Intel P30 48F4400 chips which
+         * consists internally of 2 non-identical NOR chips on one die.
+         */
+        p = of_get_property(dp, "reg", &count);
+        if (count % reg_tuple_size != 0) {
+                dev_err(&dev->dev, "Malformed reg property on %s\n",
+                                dev->node->full_name);
+                err = -EINVAL;
                 goto err_out;
         }
-
-        dev_dbg(&dev->dev, "of_flash device: %.8llx-%.8llx\n",
-                (unsigned long long)res.start, (unsigned long long)res.end);
+        count /= reg_tuple_size;
 
         err = -ENOMEM;
-        info = kzalloc(sizeof(*info), GFP_KERNEL);
+        info = kzalloc(sizeof(struct of_flash) +
+                       sizeof(struct of_flash_list) * count, GFP_KERNEL);
+        if (!info)
+                goto err_out;
+
+        mtd_list = kzalloc(sizeof(struct mtd_info) * count, GFP_KERNEL);
         if (!info)
                 goto err_out;
 
         dev_set_drvdata(&dev->dev, info);
 
-        err = -EBUSY;
-        info->res = request_mem_region(res.start, res.end - res.start + 1,
-                                       dev_name(&dev->dev));
-        if (!info->res)
-                goto err_out;
+        for (i = 0; i < count; i++) {
+                err = -ENXIO;
+                if (of_address_to_resource(dp, i, &res)) {
+                        dev_err(&dev->dev, "Can't get IO address from device"
+                                " tree\n");
+                        goto err_out;
+                }
 
-        err = -ENXIO;
-        width = of_get_property(dp, "bank-width", NULL);
-        if (!width) {
-                dev_err(&dev->dev, "Can't get bank width from device tree\n");
-                goto err_out;
-        }
+                dev_dbg(&dev->dev, "of_flash device: %.8llx-%.8llx\n",
+                        (unsigned long long)res.start,
+                        (unsigned long long)res.end);
+
+                err = -EBUSY;
+                info->list[i].res = request_mem_region(res.start, res.end -
+                                                       res.start + 1,
+                                                       dev_name(&dev->dev));
+                if (!info->list[i].res)
+                        goto err_out;
+
+                err = -ENXIO;
+                width = of_get_property(dp, "bank-width", NULL);
+                if (!width) {
+                        dev_err(&dev->dev, "Can't get bank width from device"
+                                " tree\n");
+                        goto err_out;
+                }
 
-        info->map.name = dev_name(&dev->dev);
-        info->map.phys = res.start;
-        info->map.size = res.end - res.start + 1;
-        info->map.bankwidth = *width;
+                info->list[i].map.name = dev_name(&dev->dev);
+                info->list[i].map.phys = res.start;
+                info->list[i].map.size = res.end - res.start + 1;
+                info->list[i].map.bankwidth = *width;
+
+                err = -ENOMEM;
+                info->list[i].map.virt = ioremap(info->list[i].map.phys,
+                                                 info->list[i].map.size);
+                if (!info->list[i].map.virt) {
+                        dev_err(&dev->dev, "Failed to ioremap() flash"
+                                " region\n");
+                        goto err_out;
+                }
 
-        err = -ENOMEM;
-        info->map.virt = ioremap(info->map.phys, info->map.size);
-        if (!info->map.virt) {
-                dev_err(&dev->dev, "Failed to ioremap() flash region\n");
-                goto err_out;
-        }
+                simple_map_init(&info->list[i].map);
 
-        simple_map_init(&info->map);
+                if (probe_type) {
+                        info->list[i].mtd = do_map_probe(probe_type,
+                                                         &info->list[i].map);
+                } else {
+                        info->list[i].mtd = obsolete_probe(dev,
+                                                           &info->list[i].map);
+                }
+                mtd_list[i] = info->list[i].mtd;
 
-        if (probe_type)
-                info->mtd = do_map_probe(probe_type, &info->map);
-        else
-                info->mtd = obsolete_probe(dev, &info->map);
+                err = -ENXIO;
+                if (!info->list[i].mtd) {
+                        dev_err(&dev->dev, "do_map_probe() failed\n");
+                        goto err_out;
+                } else {
+                        info->list_size++;
+                }
+                info->list[i].mtd->owner = THIS_MODULE;
+                info->list[i].mtd->dev.parent = &dev->dev;
+        }
 
-        err = -ENXIO;
-        if (!info->mtd) {
-                dev_err(&dev->dev, "do_map_probe() failed\n");
-                goto err_out;
+        err = 0;
+        if (info->list_size == 1) {
+                info->cmtd = info->list[0].mtd;
+        } else if (info->list_size > 1) {
+                /*
+                 * We detected multiple devices. Concatenate them together.
+                 */
+#ifdef CONFIG_MTD_CONCAT
+                info->cmtd = mtd_concat_create(mtd_list, info->list_size,
+                                               dev_name(&dev->dev));
+                if (info->cmtd == NULL)
+                        err = -ENXIO;
+#else
+                printk(KERN_ERR "physmap_of: multiple devices "
+                       "found but MTD concat support disabled.\n");
+                err = -ENXIO;
+#endif
         }
-        info->mtd->owner = THIS_MODULE;
-        info->mtd->dev.parent = &dev->dev;
+        if (err)
+                goto err_out;
 
 #ifdef CONFIG_MTD_PARTITIONS
         /* First look for RedBoot table or partitions on the command
          * line, these take precedence over device tree information */
-        err = parse_mtd_partitions(info->mtd, part_probe_types,
-                                   &info->parts, 0);
+        err = parse_mtd_partitions(info->cmtd, part_probe_types,
+                                   &info->parts, 0);
         if (err < 0)
                 return err;
 
@@ -244,15 +327,19 @@ static int __devinit of_flash_probe(struct of_device *dev,
         }
 
         if (err > 0)
-                add_mtd_partitions(info->mtd, info->parts, err);
+                add_mtd_partitions(info->cmtd, info->parts, err);
         else
 #endif
-                add_mtd_device(info->mtd);
+                add_mtd_device(info->cmtd);
+
+        kfree(mtd_list);
 
         return 0;
 
 err_out:
+        kfree(mtd_list);
         of_flash_remove(dev);
+
         return err;
 }