[PATCH v3 3/4] bus: fsl-mc: add root dprc rescan attribute

Ioana Ciornei
2018-11-20T15:39:56Z

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

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

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
---
Changes in v2:
- remove the rescan dev_attr on the remove path
Changes in v3:
- none

Documentation/ABI/stable/sysfs-bus-fsl-mc | 9 ++++++++
MAINTAINERS | 1 +
drivers/bus/fsl-mc/dprc-driver.c | 36 +++++++++++++++++++++++++++++++
3 files changed, 46 insertions(+)
create mode 100644 Documentation/ABI/stable/sysfs-bus-fsl-mc

diff --git a/Documentation/ABI/stable/sysfs-bus-fsl-mc b/Documentation/ABI/stable/sysfs-bus-fsl-mc
new file mode 100644
index 0000000..9f3a95e
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-bus-fsl-mc
@@ -0,0 +1,9 @@
+What: /sys/bus/fsl-mc/devices/dprc.*/rescan
+Date: November 2018
+KernelVersion: 5.0
+Contact: Ioana Ciornei <ioana.ciornei@nxp.com>
+Description: Writing a non-zero value to this attribute will
+ force a rescan of dprc.X container in the system and
+ synchronize the objects under dprc.X and the
+ Management Complex firmware.
+Users: Userspace drivers and management tools
diff --git a/MAINTAINERS b/MAINTAINERS
index e841cc4..7b76a80 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12283,6 +12283,7 @@ F: drivers/bus/fsl-mc/
F: Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
F: Documentation/networking/dpaa2/overview.rst
F: include/uapi/linux/fsl_mc.h
+F: Documentation/ABI/stable/sysfs-bus-fsl-mc

QT1010 MEDIA DRIVER
M: Antti Palosaari <crope@iki.fi>
diff --git a/drivers/bus/fsl-mc/dprc-driver.c b/drivers/bus/fsl-mc/dprc-driver.c
index bab0d5a..2f94aba 100644
--- a/drivers/bus/fsl-mc/dprc-driver.c
+++ b/drivers/bus/fsl-mc/dprc-driver.c
@@ -354,6 +354,33 @@ static int dprc_scan_container(struct fsl_mc_device *mc_bus_dev)
return 0;
}

+static ssize_t rescan_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct fsl_mc_device *root_mc_dev;
+ struct fsl_mc_bus *root_mc_bus;
+ unsigned long val;
+
+ if (!fsl_mc_is_root_dprc(dev))
+ return -EINVAL;
+
+ root_mc_dev = to_fsl_mc_device(dev);
+ root_mc_bus = to_fsl_mc_bus(root_mc_dev);
+
+ if (kstrtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (val) {
+ mutex_lock(&root_mc_bus->scan_mutex);
+ dprc_scan_objects(root_mc_dev, NULL);
+ mutex_unlock(&root_mc_bus->scan_mutex);
+ }
+
+ return count;
+}
+static DEVICE_ATTR_WO(rescan);
+
/**
* dprc_irq0_handler - Regular ISR for DPRC interrupt 0
*
@@ -692,6 +719,13 @@ static int dprc_probe(struct fsl_mc_device *mc_dev)

mutex_init(&mc_bus->scan_mutex);

+ error = device_create_file(&mc_dev->dev, &dev_attr_rescan);
+ if (error < 0) {
+ dev_err(&mc_dev->dev, "device_create_file() failed: %d\n",
+ error);
+ goto error_cleanup_open;
+ }
+
/*
* Discover MC objects in DPRC object:
*/
@@ -788,6 +822,8 @@ static int dprc_remove(struct fsl_mc_device *mc_dev)
fsl_mc_uapi_remove_device_file(mc_bus);
}

+ device_remove_file(&mc_dev->dev, &dev_attr_rescan);
+
dev_info(&mc_dev->dev, "DPRC device unbound from driver");
return 0;
}
--
1.9.1