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authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>2020-09-24 14:44:30 -0500
committerVinod Koul <vkoul@kernel.org>2020-09-28 11:17:43 +0530
commit0173f525b2c1b02a51784e2119d434593235aed1 (patch)
treebe7fd015e55158bb0ce939863460626788948415 /Documentation/ABI
parentfcb9d730be1d3010e0c8fdc5aaff62836d7a942c (diff)
downloadlinux-0173f525b2c1b02a51784e2119d434593235aed1.tar.bz2
soundwire: sysfs: add slave status and device number before probe
The MIPI DisCo device properties that are read by the driver from platform firmware, or hard-coded in the driver, should only be provided as sysfs entries when a driver probes successfully. However the device status and device number is updated even when there is no driver present, and hence can be updated when a Slave device is detected on the bus without being described in platform firmware and without any driver registered/probed. As suggested by GregKH, the attribute group for Slave status and device number is is added by default upon device registration. Credits to Vinod Koul for the status_show() function, shared in a separate patch and used as is here. The status table was modified to remove an unnecessary enum and status_show() is handled in a different group attribute than what was suggested by Vinod. Tested-by: Srinivas Kandgatla <srinivas.kandagatla@linaro.org> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Co-developed-by: Vinod Koul <vkoul@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20200924194430.121058-3-pierre-louis.bossart@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-soundwire-slave18
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-soundwire-slave b/Documentation/ABI/testing/sysfs-bus-soundwire-slave
index db4c9511d1aa..d324aa0b678f 100644
--- a/Documentation/ABI/testing/sysfs-bus-soundwire-slave
+++ b/Documentation/ABI/testing/sysfs-bus-soundwire-slave
@@ -1,3 +1,21 @@
+What: /sys/bus/soundwire/devices/sdw:.../status
+ /sys/bus/soundwire/devices/sdw:.../device_number
+
+Date: September 2020
+
+Contact: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
+ Bard Liao <yung-chuan.liao@linux.intel.com>
+ Vinod Koul <vkoul@kernel.org>
+
+Description: SoundWire Slave status
+
+ These properties report the Slave status, e.g. if it
+ is UNATTACHED or not, and in the latter case show the
+ device_number. This status information is useful to
+ detect devices exposed by platform firmware but not
+ physically present on the bus, and conversely devices
+ not exposed in platform firmware but enumerated.
+
What: /sys/bus/soundwire/devices/sdw:.../dev-properties/mipi_revision
/sys/bus/soundwire/devices/sdw:.../dev-properties/wake_capable
/sys/bus/soundwire/devices/sdw:.../dev-properties/test_mode_capable