fpga: dfl: fme: add thermal management support

This patch adds support to thermal management private feature for DFL
FPGA Management Engine (FME). This private feature driver registers
a hwmon for thermal/temperature monitoring (hwmon temp1_input).
If hardware automatic throttling is supported by this hardware, then
driver also exposes sysfs interfaces under hwmon for thresholds
(temp1_max/ crit/ emergency), threshold alarms (temp1_max_alarm/
temp1_crit_alarm) and throttling policy (temp1_max_policy).

Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

1 files changed, 64 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-platform-dfl-fme b/Documentation/ABI/testing/sysfs-platform-dfl-fme
index 72634d3ae4f4..8eb6d03e06e7 100644
--- a/Documentation/ABI/testing/sysfs-platform-dfl-fme
+++ b/Documentation/ABI/testing/sysfs-platform-dfl-fme
@@ -106,3 +106,67 @@ KernelVersion:  5.4
 Contact:	Wu Hao <hao.wu@intel.com>
 Description:	Read-only. Read this file to get the second error detected by
 		hardware.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/name
+Date:		October 2019
+KernelVersion:	5.5
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Only. Read this file to get the name of hwmon device, it
+		supports values:
+		    'dfl_fme_thermal' - thermal hwmon device name
+
+What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_input
+Date:		October 2019
+KernelVersion:	5.5
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Only. It returns FPGA device temperature in millidegrees
+		Celsius.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_max
+Date:		October 2019
+KernelVersion:	5.5
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Only. It returns hardware threshold1 temperature in
+		millidegrees Celsius. If temperature rises at or above this
+		threshold, hardware starts 50% or 90% throttling (see
+		'temp1_max_policy').
+
+What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_crit
+Date:		October 2019
+KernelVersion:	5.5
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Only. It returns hardware threshold2 temperature in
+		millidegrees Celsius. If temperature rises at or above this
+		threshold, hardware starts 100% throttling.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_emergency
+Date:		October 2019
+KernelVersion:	5.5
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Only. It returns hardware trip threshold temperature in
+		millidegrees Celsius. If temperature rises at or above this
+		threshold, a fatal event will be triggered to board management
+		controller (BMC) to shutdown FPGA.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_max_alarm
+Date:		October 2019
+KernelVersion:	5.5
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. It returns 1 if temperature is currently at or above
+		hardware threshold1 (see 'temp1_max'), otherwise 0.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_crit_alarm
+Date:		October 2019
+KernelVersion:	5.5
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. It returns 1 if temperature is currently at or above
+		hardware threshold2 (see 'temp1_crit'), otherwise 0.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/hwmon/hwmonX/temp1_max_policy
+Date:		October 2019
+KernelVersion:	5.5
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Only. Read this file to get the policy of hardware threshold1
+		(see 'temp1_max'). It only supports two values (policies):
+		    0 - AP2 state (90% throttling)
+		    1 - AP1 state (50% throttling)