tpm_tis: Introduce durations sysfs entry

Display the TPM's command timeouts in a 'durations' sysfs entry. Display
the entries as having been adjusted when they were scaled due to their values
being reported in milliseconds rather than microseconds.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Guillaume Chazarain <guichaz@gmail.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 277cf22..27abfd9 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -597,6 +597,7 @@
 		chip->vendor.duration[TPM_SHORT] = HZ;
 		chip->vendor.duration[TPM_MEDIUM] *= 1000;
 		chip->vendor.duration[TPM_LONG] *= 1000;
+		chip->vendor.duration_adjusted = true;
 		dev_info(chip->dev, "Adjusting TPM timeout parameters.");
 	}
 }
@@ -944,6 +945,20 @@
 }
 EXPORT_SYMBOL_GPL(tpm_show_caps_1_2);
 
+ssize_t tpm_show_durations(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d %d %d [%s]\n",
+		       jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
+		       jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
+		       jiffies_to_usecs(chip->vendor.duration[TPM_LONG]),
+		       chip->vendor.duration_adjusted
+		       ? "adjusted" : "original");
+}
+EXPORT_SYMBOL_GPL(tpm_show_durations);
+
 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
 			const char *buf, size_t count)
 {