libnvdimm: control character device and nvdimm_bus sysfs attributes
The control device for a nvdimm_bus is registered as an "nd" class
device. The expectation is that there will usually only be one "nd" bus
registered under /sys/class/nd. However, we allow for the possibility
of multiple buses and they will listed in discovery order as
ndctl0...ndctlN. This character device hosts the ioctl for passing
control messages. The initial command set has a 1:1 correlation with
the commands listed in the by the "NFIT DSM Example" document [1], but
this scheme is extensible to future command sets.
Note, nd_ioctl() and the backing ->ndctl() implementation are defined in
a subsequent patch. This is simply the initial registrations and sysfs
attributes.
[1]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf
Cc: Neil Brown <neilb@suse.de>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: <linux-acpi@vger.kernel.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 9f9a20b..162391b 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -354,6 +354,33 @@
return 0;
}
+static ssize_t revision_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
+ struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
+ struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
+
+ return sprintf(buf, "%d\n", acpi_desc->nfit->header.revision);
+}
+static DEVICE_ATTR_RO(revision);
+
+static struct attribute *acpi_nfit_attributes[] = {
+ &dev_attr_revision.attr,
+ NULL,
+};
+
+static struct attribute_group acpi_nfit_attribute_group = {
+ .name = "nfit",
+ .attrs = acpi_nfit_attributes,
+};
+
+static const struct attribute_group *acpi_nfit_attribute_groups[] = {
+ &nvdimm_bus_attribute_group,
+ &acpi_nfit_attribute_group,
+ NULL,
+};
+
static int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
{
struct device *dev = acpi_desc->dev;
@@ -410,6 +437,7 @@
nd_desc = &acpi_desc->nd_desc;
nd_desc->provider_name = "ACPI.NFIT";
nd_desc->ndctl = acpi_nfit_ctl;
+ nd_desc->attr_groups = acpi_nfit_attribute_groups;
acpi_desc->nvdimm_bus = nvdimm_bus_register(dev, nd_desc);
if (!acpi_desc->nvdimm_bus)