1 files changed, 67 insertions, 0 deletions

diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index 1237bb4c722b..610dbd1fcc82 100644
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -184,6 +184,68 @@ static int mmc_dbg_card_status_get(void *data, u64 *val)
 DEFINE_SIMPLE_ATTRIBUTE(mmc_dbg_card_status_fops, mmc_dbg_card_status_get,
                 NULL, "%08llx\n");
 
+#define EXT_CSD_STR_LEN 1025
+
+static int mmc_ext_csd_open(struct inode *inode, struct file *filp)
+{
+        struct mmc_card *card = inode->i_private;
+        char *buf;
+        ssize_t n = 0;
+        u8 *ext_csd;
+        int err, i;
+
+        buf = kmalloc(EXT_CSD_STR_LEN + 1, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        ext_csd = kmalloc(512, GFP_KERNEL);
+        if (!ext_csd) {
+                err = -ENOMEM;
+                goto out_free;
+        }
+
+        mmc_claim_host(card->host);
+        err = mmc_send_ext_csd(card, ext_csd);
+        mmc_release_host(card->host);
+        if (err)
+                goto out_free;
+
+        for (i = 511; i >= 0; i--)
+                n += sprintf(buf + n, "%02x", ext_csd[i]);
+        n += sprintf(buf + n, "\n");
+        BUG_ON(n != EXT_CSD_STR_LEN);
+
+        filp->private_data = buf;
+        kfree(ext_csd);
+        return 0;
+
+out_free:
+        kfree(buf);
+        kfree(ext_csd);
+        return err;
+}
+
+static ssize_t mmc_ext_csd_read(struct file *filp, char __user *ubuf,
+                                size_t cnt, loff_t *ppos)
+{
+        char *buf = filp->private_data;
+
+        return simple_read_from_buffer(ubuf, cnt, ppos,
+                                       buf, EXT_CSD_STR_LEN);
+}
+
+static int mmc_ext_csd_release(struct inode *inode, struct file *file)
+{
+        kfree(file->private_data);
+        return 0;
+}
+
+static struct file_operations mmc_dbg_ext_csd_fops = {
+        .open           = mmc_ext_csd_open,
+        .read           = mmc_ext_csd_read,
+        .release        = mmc_ext_csd_release,
+};
+
 void mmc_add_card_debugfs(struct mmc_card *card)
 {
         struct mmc_host *host = card->host;
@@ -211,6 +273,11 @@ void mmc_add_card_debugfs(struct mmc_card *card)
                                         &mmc_dbg_card_status_fops))
                         goto err;
 
+        if (mmc_card_mmc(card))
+                if (!debugfs_create_file("ext_csd", S_IRUSR, root, card,
+                                        &mmc_dbg_ext_csd_fops))
+                        goto err;
+
         return;
 
 err: