[PATCH v3 04/11] i3c: Add sysfs ABI spec

Boris Brezillon
2018-03-23T11:00:13Z

From: Boris Brezillon <boris.brezillon@free-electrons.com>

Document sysfs files/directories/symlinks exposed by the I3C subsystem.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
Changes in v2:
- new patch
---
Documentation/ABI/testing/sysfs-bus-i3c | 95 +++++++++++++++++++++++++++++++++
1 file changed, 95 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-i3c

diff --git a/Documentation/ABI/testing/sysfs-bus-i3c b/Documentation/ABI/testing/sysfs-bus-i3c
new file mode 100644
index 000000000000..5e88cc093e0e
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-i3c
@@ -0,0 +1,95 @@
+What: /sys/bus/i3c/devices/i3c-<bus-id>
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ An I3C bus. This directory will contain one sub-directory per
+ I3C device present on the bus.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/current_master
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ Expose the master that owns the bus (<bus-id>-<master-pid>) at
+ the time this file is read. Note that bus ownership can change
+ overtime, so there's no guarantee that when the read() call
+ returns, the value returned is still valid.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/mode
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ I3C bus mode. Can be "pure", "mixed-fast" or "mixed-slow". See
+ the I3C specification for a detailed description of what each
+ of these modes implies.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/i3c_scl_frequency
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ The frequency (expressed in Hz) of the SCL signal when
+ operating in I3C SDR mode.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/i2c_scl_frequency
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ The frequency (expressed in Hz) of the SCL signal when
+ operating in I2C mode.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ An I3C device present on I3C bus identified by <bus-id>. Note
+ that all devices are represented including the master driving
+ the bus.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/address
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ Dynamic address assigned to device <bus-id>-<device-pid>. This
+ address may change if the bus is re-initialized.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/bcr
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ BCR stands for Bus Characteristics Register and express the
+ device capabilities in term of speed, maximum read/write
+ length, etc. See the I3C specification for more details.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/dcr
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ DCR stands for Device Characteristics Register and express the
+ device capabilities in term of exposed features. See the I3C
+ specification for more details.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/pid
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ PID stands for Provisional ID and is used to uniquely identify
+ a device on a bus. This PID contains information about the
+ vendor, the part and an instance ID so that several devices of
+ the same type can be connected on the same bus.
+ See the I3C specification for more details.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/hdrcap
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ Expose the HDR (High Data Rate) capabilities of a device.
+ Returns a list of supported HDR mode, each element is separated
+ by space. Modes can be "hdr-ddr", "hdr-tsp" and "hdr-tsl".
+ See the I3C specification for more details about these HDR
+ modes.
+
+What: /sys/bus/i3c/devices/<bus-id>-<device-pid>
+KernelVersion: 4.16
+Contact: linux-i3c@vger.kernel.org
+Description:
+ These directories are just symbolic links to
+ /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>.
--
2.14.1