[PATCH v4 1/5] base: soc: Add serial_number attribute to soc

From: Vaishali Thakkar
Date: Mon Feb 25 2019 - 01:50:59 EST


From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

Add new attribute named "serial_number" as a standard interface for
user space to acquire the serial number of the device.

For ST-Ericsson SoCs this is exposed by the cryptically named "soc_id"
attribute, but this provides a human readable standardized name for this
property.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@xxxxxxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
Changes since v3:
- Add Greg's Reviewed-by
Changes since v2:
- None
Changes since v1:
- Make comment more clear for the case when serial
number is not available
---
Documentation/ABI/testing/sysfs-devices-soc | 7 +++++++
drivers/base/soc.c | 7 +++++++
include/linux/sys_soc.h | 1 +
3 files changed, 15 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-devices-soc b/Documentation/ABI/testing/sysfs-devices-soc
index 6d9cc253f2b2..ba3a3fac0ee1 100644
--- a/Documentation/ABI/testing/sysfs-devices-soc
+++ b/Documentation/ABI/testing/sysfs-devices-soc
@@ -26,6 +26,13 @@ Description:
Read-only attribute common to all SoCs. Contains SoC family name
(e.g. DB8500).

+What: /sys/devices/socX/serial_number
+Date: January 2019
+contact: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
+Description:
+ Read-only attribute supported by most SoCs. Contains the SoC's
+ serial number, if available.
+
What: /sys/devices/socX/soc_id
Date: January 2012
contact: Lee Jones <lee.jones@xxxxxxxxxx>
diff --git a/drivers/base/soc.c b/drivers/base/soc.c
index 10b280f30217..b0933b9fe67f 100644
--- a/drivers/base/soc.c
+++ b/drivers/base/soc.c
@@ -33,6 +33,7 @@ static struct bus_type soc_bus_type = {

static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL);
static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL);
+static DEVICE_ATTR(serial_number, S_IRUGO, soc_info_get, NULL);
static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL);
static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL);

@@ -57,6 +58,9 @@ static umode_t soc_attribute_mode(struct kobject *kobj,
if ((attr == &dev_attr_revision.attr)
&& (soc_dev->attr->revision != NULL))
return attr->mode;
+ if ((attr == &dev_attr_serial_number.attr)
+ && (soc_dev->attr->serial_number != NULL))
+ return attr->mode;
if ((attr == &dev_attr_soc_id.attr)
&& (soc_dev->attr->soc_id != NULL))
return attr->mode;
@@ -77,6 +81,8 @@ static ssize_t soc_info_get(struct device *dev,
return sprintf(buf, "%s\n", soc_dev->attr->family);
if (attr == &dev_attr_revision)
return sprintf(buf, "%s\n", soc_dev->attr->revision);
+ if (attr == &dev_attr_serial_number)
+ return sprintf(buf, "%s\n", soc_dev->attr->serial_number);
if (attr == &dev_attr_soc_id)
return sprintf(buf, "%s\n", soc_dev->attr->soc_id);

@@ -87,6 +93,7 @@ static ssize_t soc_info_get(struct device *dev,
static struct attribute *soc_attr[] = {
&dev_attr_machine.attr,
&dev_attr_family.attr,
+ &dev_attr_serial_number.attr,
&dev_attr_soc_id.attr,
&dev_attr_revision.attr,
NULL,
diff --git a/include/linux/sys_soc.h b/include/linux/sys_soc.h
index bed223b70217..2a13bc033bd6 100644
--- a/include/linux/sys_soc.h
+++ b/include/linux/sys_soc.h
@@ -12,6 +12,7 @@ struct soc_device_attribute {
const char *machine;
const char *family;
const char *revision;
+ const char *serial_number;
const char *soc_id;
const void *data;
};
--
2.17.1