Hi,
On embedded platform we have a small diagnostic application which
has to record following emmc registers on every power cycle:
CID, CSD, EXT_CSD, OCR, RCA and DSR. The CID, CSD, EXT_CSD and OCR
are accessible via ioctl(MMC_IOC_CMD) or through sysfs. The RCA
should always be 1 on any linux platform. I can't find a better way
for accessing the DSR then as proposed below.
Regards,
Bojan
User space access to Driver Stage Register (DSR) can be useful
for diagnostics purpose.
Signed-off-by: Bojan Prtvar <prtvar.b@xxxxxxxxx>
---
Documentation/mmc/mmc-dev-attrs.txt | 1 +
drivers/mmc/core/mmc.c | 17 +++++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/Documentation/mmc/mmc-dev-attrs.txt b/Documentation/mmc/mmc-dev-attrs.txt
index 8163eca..404a0e9 100644
--- a/Documentation/mmc/mmc-dev-attrs.txt
+++ b/Documentation/mmc/mmc-dev-attrs.txt
@@ -29,6 +29,7 @@ All attributes are read-only.
raw_rpmb_size_mult RPMB partition size
rel_sectors Reliable write sector count
ocr Operation Conditions Register
+ dsr Driver Stage Register
Note on Erase Size and Preferred Erase Size:
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 1848334..4363fdc 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -745,6 +745,22 @@ static ssize_t mmc_fwrev_show(struct device *dev,
static DEVICE_ATTR(fwrev, S_IRUGO, mmc_fwrev_show, NULL);
+static ssize_t mmc_dsr_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct mmc_card *card = mmc_dev_to_card(dev);
+ struct mmc_host *host = card->host;
+
+ if (card->csd.dsr_imp && host->dsr_req)
+ return sprintf(buf, "0x%x\n", host->dsr);
+ else
+ /* return default DSR value */
+ return sprintf(buf, "0x%x\n", 0x404);
+}
+
+static DEVICE_ATTR(dsr, S_IRUGO, mmc_dsr_show, NULL);
+
static struct attribute *mmc_std_attrs[] = {
&dev_attr_cid.attr,
&dev_attr_csd.attr,
@@ -764,6 +780,7 @@ static struct attribute *mmc_std_attrs[] = {
&dev_attr_raw_rpmb_size_mult.attr,
&dev_attr_rel_sectors.attr,
&dev_attr_ocr.attr,
+ &dev_attr_dsr.attr,
NULL,
};
ATTRIBUTE_GROUPS(mmc_std);
--
2.8.0.GIT
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