Re: [PATCH] MMC: Add Extended CSD as a device attribute

[Adrian Hunter]

From: Adrian Hunter <ext-adrian.hunter@xxxxxxxxx>
Date: Wed, 14 Jan 2009 17:45:53 +0200
Subject: [PATCH] MMC: Add Extended CSD as a device attribute

Extended CSD is a MMC card register.  The Card Identification
(CID) register and the Card-Specific Data (CSD) register are
already device attributes.  As increasingly interesting
fields are being added to Extended CSD, it seems reasonable to
add it too.  Note that SD cards do not have an Extended CSD
register, so it is MMC only.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@xxxxxxxxx>
---
drivers/mmc/core/mmc.c |   29 +++++++++++++++++++++++++++++
1 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 3f5b089..4eadba6 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -259,6 +259,34 @@ MMC_DEV_ATTR(name, "%s\n", card->cid.prod_name);
MMC_DEV_ATTR(oemid, "0x%04x\n", card->cid.oemid);
MMC_DEV_ATTR(serial, "0x%08x\n", card->cid.serial);

+static ssize_t mmc_ext_csd_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct mmc_card *card = container_of(dev, struct mmc_card, dev);
+	ssize_t n = 0;
+	u8 *ext_csd;
+	int err, i;
+
+	ext_csd = kmalloc(512, GFP_KERNEL);
+	if (!ext_csd)
+		return 0;
+
+	mmc_claim_host(card->host);
+	err = mmc_send_ext_csd(card, ext_csd);
+	mmc_release_host(card->host);
+
+	if (!err) {
+		for (i = 511; i >= 0; i--)
+			n += sprintf(buf + n, "%02x", ext_csd[i]);
+		n += sprintf(buf + n, "\n");
+	}
+
+	kfree(ext_csd);
+
+	return n;
+}
+
+static DEVICE_ATTR(ext_csd, S_IRUGO, mmc_ext_csd_show, NULL);
+
static struct attribute *mmc_std_attrs[] = {
	&dev_attr_cid.attr,
	&dev_attr_csd.attr,
@@ -269,6 +297,7 @@ static struct attribute *mmc_std_attrs[] = {
	&dev_attr_name.attr,
	&dev_attr_oemid.attr,
	&dev_attr_serial.attr,
+	&dev_attr_ext_csd.attr,
	NULL,
};

--
1.5.4.3
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