mmc: block: attach partitions fwnode if found in mmc-card

Attach partitions fwnode if found in mmc-card and register disk with it.

This permits block partition to reference the node and register a
partition table defined in DT for the special case for embedded device
that doesn't have a partition table flashed but have an hardcoded
partition table passed from the system.

JEDEC BOOT partition boot0/boot1 are supported but in DT we refer with
the JEDEC name of boot1 and boot2 to better adhere to documentation.

Also JEDEC GP partition gp0/1/2/3 are supported but in DT we refer with
the JEDEC name of gp1/2/3/4 to better adhere to documentration.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20241002221306.4403-5-ansuelsmth@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index ef06a4d5d65bb2850e0395fd6a3b4d63bac4802a..79f6fad97a80541e9d7e7f73d8e9886b9ee7ab63 100644 (file)
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2501,6 +2501,56 @@ static inline int mmc_blk_readonly(struct mmc_card *card)
               !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 }
 
+/*
+ * Search for a declared partitions node for the disk in mmc-card related node.
+ *
+ * This is to permit support for partition table defined in DT in special case
+ * where a partition table is not written in the disk and is expected to be
+ * passed from the running system.
+ *
+ * For the user disk, "partitions" node is searched.
+ * For the special HW disk, "partitions-" node with the appended name is used
+ * following this conversion table (to adhere to JEDEC naming)
+ * - boot0 -> partitions-boot1
+ * - boot1 -> partitions-boot2
+ * - gp0 -> partitions-gp1
+ * - gp1 -> partitions-gp2
+ * - gp2 -> partitions-gp3
+ * - gp3 -> partitions-gp4
+ */
+static struct fwnode_handle *mmc_blk_get_partitions_node(struct device *mmc_dev,
+                                                        const char *subname)
+{
+       const char *node_name = "partitions";
+
+       if (subname) {
+               mmc_dev = mmc_dev->parent;
+
+               /*
+                * Check if we are allocating a BOOT disk boot0/1 disk.
+                * In DT we use the JEDEC naming boot1/2.
+                */
+               if (!strcmp(subname, "boot0"))
+                       node_name = "partitions-boot1";
+               if (!strcmp(subname, "boot1"))
+                       node_name = "partitions-boot2";
+               /*
+                * Check if we are allocating a GP disk gp0/1/2/3 disk.
+                * In DT we use the JEDEC naming gp1/2/3/4.
+                */
+               if (!strcmp(subname, "gp0"))
+                       node_name = "partitions-gp1";
+               if (!strcmp(subname, "gp1"))
+                       node_name = "partitions-gp2";
+               if (!strcmp(subname, "gp2"))
+                       node_name = "partitions-gp3";
+               if (!strcmp(subname, "gp3"))
+                       node_name = "partitions-gp4";
+       }
+
+       return device_get_named_child_node(mmc_dev, node_name);
+}
+
 static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
                                              struct device *parent,
                                              sector_t size,
@@ -2509,6 +2559,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
                                              int area_type,
                                              unsigned int part_type)
 {
+       struct fwnode_handle *disk_fwnode;
        struct mmc_blk_data *md;
        int devidx, ret;
        char cap_str[10];
@@ -2610,7 +2661,9 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
        /* used in ->open, must be set before add_disk: */
        if (area_type == MMC_BLK_DATA_AREA_MAIN)
                dev_set_drvdata(&card->dev, md);
-       ret = device_add_disk(md->parent, md->disk, mmc_disk_attr_groups);
+       disk_fwnode = mmc_blk_get_partitions_node(parent, subname);
+       ret = add_disk_fwnode(md->parent, md->disk, mmc_disk_attr_groups,
+                             disk_fwnode);
        if (ret)
                goto err_put_disk;
        return md;