Documentation: sysfs: Document Broadcom STB memc sysfs knobs

Document the "srpd" and "frequency" sysfs attributes exposed by
the brcmstb_memc driver.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220812222533.2428033-3-f.fainelli@gmail.com

diff --git a/Documentation/ABI/testing/sysfs-platform-brcmstb-memc b/Documentation/ABI/testing/sysfs-platform-brcmstb-memc
new file mode 100644 (file)
index 0000000..2f2b750
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-platform-brcmstb-memc
@@ -0,0 +1,15 @@
+What:          /sys/bus/platform/devices/*/srpd
+Date:          July 2022
+KernelVersion: 5.21
+Contact:       Florian Fainelli <f.fainelli@gmail.com>
+Description:
+               Self Refresh Power Down (SRPD) inactivity timeout counted in
+               internal DDR controller clock cycles. Possible values range
+               from 0 (disable inactivity timeout) to 65535 (0xffff).
+
+What:          /sys/bus/platform/devices/*/frequency
+Date:          July 2022
+KernelVersion: 5.21
+Contact:       Florian Fainelli <f.fainelli@gmail.com>
+Description:
+               DDR PHY frequency in Hz.