mmc: Add per-card debugfs support

For each card successfully added to the bus, create a subdirectory under
the host's debugfs root with information about the card.

At the moment, only a single file is added to the card directory for
all cards: "state". It reflects the "state" field in struct mmc_card,
indicating whether the card is present, readonly, etc.

For MMC and SD cards (not SDIO), another file is added: "status".
Reading this file will ask the card about its current status and
return it. This can be useful if the card just refuses to respond to
any commands, which might indicate that the card state is not what the
MMC core thinks it is (due to a missing stop command, for example.)

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c
index fd95b18e988b3c33496c309f41dcc38356a82c47..0d9b2d6f9ebfba638b2bba41a0a0f6d28c922cc6 100644 (file)
--- a/drivers/mmc/core/bus.c
+++ b/drivers/mmc/core/bus.c
@@ -252,6 +252,10 @@ int mmc_add_card(struct mmc_card *card)
        if (ret)
                return ret;
 
+#ifdef CONFIG_DEBUG_FS
+       mmc_add_card_debugfs(card);
+#endif
+
        mmc_card_set_present(card);
 
        return 0;
@@ -263,6 +267,10 @@ int mmc_add_card(struct mmc_card *card)
  */
 void mmc_remove_card(struct mmc_card *card)
 {
+#ifdef CONFIG_DEBUG_FS
+       mmc_remove_card_debugfs(card);
+#endif
+
        if (mmc_card_present(card)) {
                if (mmc_host_is_spi(card->host)) {
                        printk(KERN_INFO "%s: SPI card removed\n",

diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 745da9881aa7e3c5a38ac982d52d9d227eae7afd..c819effa1032c5ccebf896dff58d78f6e7ca13d5 100644 (file)
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -56,5 +56,8 @@ extern int use_spi_crc;
 void mmc_add_host_debugfs(struct mmc_host *host);
 void mmc_remove_host_debugfs(struct mmc_host *host);
 
+void mmc_add_card_debugfs(struct mmc_card *card);
+void mmc_remove_card_debugfs(struct mmc_card *card);
+
 #endif
 

diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index 133c6e51f26b7f66ffdda512083f9bb1ce9f6612..1237bb4c722bddbe1cb6a7376dbb35e0707c4b3c 100644 (file)
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -12,9 +12,11 @@
 #include <linux/seq_file.h>
 #include <linux/stat.h>
 
+#include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
 
 #include "core.h"
+#include "mmc_ops.h"
 
 /* The debugfs functions are optimized away when CONFIG_DEBUG_FS isn't set. */
 static int mmc_ios_show(struct seq_file *s, void *data)
@@ -162,3 +164,62 @@ void mmc_remove_host_debugfs(struct mmc_host *host)
 {
        debugfs_remove_recursive(host->debugfs_root);
 }
+
+static int mmc_dbg_card_status_get(void *data, u64 *val)
+{
+       struct mmc_card *card = data;
+       u32             status;
+       int             ret;
+
+       mmc_claim_host(card->host);
+
+       ret = mmc_send_status(data, &status);
+       if (!ret)
+               *val = status;
+
+       mmc_release_host(card->host);
+
+       return ret;
+}
+DEFINE_SIMPLE_ATTRIBUTE(mmc_dbg_card_status_fops, mmc_dbg_card_status_get,
+               NULL, "%08llx\n");
+
+void mmc_add_card_debugfs(struct mmc_card *card)
+{
+       struct mmc_host *host = card->host;
+       struct dentry   *root;
+
+       if (!host->debugfs_root)
+               return;
+
+       root = debugfs_create_dir(mmc_card_id(card), host->debugfs_root);
+       if (IS_ERR(root))
+               /* Don't complain -- debugfs just isn't enabled */
+               return;
+       if (!root)
+               /* Complain -- debugfs is enabled, but it failed to
+                * create the directory. */
+               goto err;
+
+       card->debugfs_root = root;
+
+       if (!debugfs_create_x32("state", S_IRUSR, root, &card->state))
+               goto err;
+
+       if (mmc_card_mmc(card) || mmc_card_sd(card))
+               if (!debugfs_create_file("status", S_IRUSR, root, card,
+                                       &mmc_dbg_card_status_fops))
+                       goto err;
+
+       return;
+
+err:
+       debugfs_remove_recursive(root);
+       card->debugfs_root = NULL;
+       dev_err(&card->dev, "failed to initialize debugfs\n");
+}
+
+void mmc_remove_card_debugfs(struct mmc_card *card)
+{
+       debugfs_remove_recursive(card->debugfs_root);
+}

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 0d508ac17d6452b5a35429fd38704c8de2c13de4..ee6e822d59947312d3bc464508e9f38ff1686e91 100644 (file)
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -111,6 +111,8 @@ struct mmc_card {
        unsigned                num_info;       /* number of info strings */
        const char              **info;         /* info strings */
        struct sdio_func_tuple  *tuples;        /* unknown common tuples */
+
+       struct dentry           *debugfs_root;
 };
 
 #define mmc_card_mmc(c)                ((c)->type == MMC_TYPE_MMC)