[PATCH v2 6/6] bus: fsl-mc: add bus rescan attribute

From: Ioana Ciornei
Date: Thu Mar 15 2018 - 13:07:01 EST


Introduce the rescan attribute as a bus attribute to
synchronize the fsl-mc bus objects and the MC firmware.

To rescan the fsl-mc bus, e.g.,
echo 1 > /sys/bus/fsl-mc/rescan

Signed-off-by: Ioana Ciornei <ioana.ciornei@xxxxxxx>
---
Changes in v2:
- added proper documentation in /Documentation/ABI/
- updated the MAINTAINERS file

Documentation/ABI/stable/sysfs-bus-fsl-mc | 7 +++++
drivers/bus/fsl-mc/fsl-mc-bus.c | 48 +++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+)

diff --git a/Documentation/ABI/stable/sysfs-bus-fsl-mc b/Documentation/ABI/stable/sysfs-bus-fsl-mc
index e530e8c..0663fbd 100644
--- a/Documentation/ABI/stable/sysfs-bus-fsl-mc
+++ b/Documentation/ABI/stable/sysfs-bus-fsl-mc
@@ -4,3 +4,10 @@ KernelVersion: 4.16
Contact: Ioana Ciornei <ioana.ciornei@xxxxxxx>
Description: Root dprc rescan attribute
Users: Userspace drivers and management tools
+
+What: /sys/bus/fsl-mc/rescan
+Date: March. 2018
+KernelVersion: 4.16
+Contact: Ioana Ciornei <ioana.ciornei@xxxxxxx>
+Description: Bus rescan attribute
+Users: Userspace drivers and management tools
diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index 9d02984..80010d1 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -172,11 +172,59 @@ static ssize_t rescan_store(struct device *dev,

ATTRIBUTE_GROUPS(fsl_mc_dev);

+static int scan_fsl_mc_bus(struct device *dev, void *data)
+{
+ struct fsl_mc_device *root_mc_dev;
+ struct fsl_mc_bus *root_mc_bus;
+
+ if (!fsl_mc_is_root_dprc(dev))
+ goto exit;
+
+ root_mc_dev = to_fsl_mc_device(dev);
+ root_mc_bus = to_fsl_mc_bus(root_mc_dev);
+ mutex_lock(&root_mc_bus->scan_mutex);
+ dprc_scan_objects(root_mc_dev, NULL);
+ mutex_unlock(&root_mc_bus->scan_mutex);
+
+exit:
+ return 0;
+}
+
+static ssize_t bus_rescan_store(struct bus_type *bus,
+ const char *buf, size_t count)
+{
+ unsigned long val;
+
+ if (kstrtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (val)
+ bus_for_each_dev(bus, NULL, NULL, scan_fsl_mc_bus);
+
+ return count;
+}
+static BUS_ATTR(rescan, 0220, NULL, bus_rescan_store);
+
+static struct attribute *fsl_mc_bus_attrs[] = {
+ &bus_attr_rescan.attr,
+ NULL,
+};
+
+static const struct attribute_group fsl_mc_bus_group = {
+ .attrs = fsl_mc_bus_attrs,
+};
+
+static const struct attribute_group *fsl_mc_bus_groups[] = {
+ &fsl_mc_bus_group,
+ NULL,
+};
+
struct bus_type fsl_mc_bus_type = {
.name = "fsl-mc",
.match = fsl_mc_bus_match,
.uevent = fsl_mc_bus_uevent,
.dev_groups = fsl_mc_dev_groups,
+ .bus_groups = fsl_mc_bus_groups,
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_type);

--
1.9.1