hwmon: Add hwmon driver for Intel MAX 10 BMC

This patch adds hwmon functionality for Intel MAX 10 BMC chip. This BMC
chip connects to a set of sensor chips to monitor current, voltage,
thermal and power of different components on board. The BMC firmware is
responsible for sensor data sampling and recording in shared registers.
Host driver reads the sensor data from these shared registers and
exposes them to users as hwmon interfaces.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1600669071-26235-3-git-send-email-yilun.xu@intel.com
[groeck: Adjusted subject]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 78 insertions, 0 deletions

diff --git a/Documentation/hwmon/intel-m10-bmc-hwmon.rst b/Documentation/hwmon/intel-m10-bmc-hwmon.rst
new file mode 100644
index 000000000000..3d148c6e3256
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+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver intel-m10-bmc-hwmon
+=================================
+
+Supported chips:
+
+ * Intel MAX 10 BMC for Intel PAC N3000
+
+   Prefix: 'n3000bmc-hwmon'
+
+Author: Xu Yilun <yilun.xu@intel.com>
+
+
+Description
+-----------
+
+This driver adds the temperature, voltage, current and power reading
+support for the Intel MAX 10 Board Management Controller (BMC) chip.
+The BMC chip is integrated in some Intel Programmable Acceleration
+Cards (PAC). It connects to a set of sensor chips to monitor the
+sensor data of different components on the board. The BMC firmware is
+responsible for sensor data sampling and recording in shared
+registers. The host driver reads the sensor data from these shared
+registers and exposes them to users as hwmon interfaces.
+
+The BMC chip is implemented using the Intel MAX 10 CPLD. It could be
+reprogramed to some variants in order to support different Intel
+PACs. The driver is designed to be able to distinguish between the
+variants, but now it only supports the BMC for Intel PAC N3000.
+
+
+Sysfs attributes
+----------------
+
+The following attributes are supported:
+
+- Intel MAX 10 BMC for Intel PAC N3000:
+
+======================= =======================================================
+tempX_input             Temperature of the component (specified by tempX_label)
+tempX_max               Temperature maximum setpoint of the component
+tempX_crit              Temperature critical setpoint of the component
+tempX_max_hyst          Hysteresis for temperature maximum of the component
+tempX_crit_hyst         Hysteresis for temperature critical of the component
+temp1_label             "Board Temperature"
+temp2_label             "FPGA Die Temperature"
+temp3_label             "QSFP0 Temperature"
+temp4_label             "QSFP1 Temperature"
+temp5_label             "Retimer A Temperature"
+temp6_label             "Retimer A SerDes Temperature"
+temp7_label             "Retimer B Temperature"
+temp8_label             "Retimer B SerDes Temperature"
+
+inX_input               Measured voltage of the component (specified by
+                        inX_label)
+in0_label               "QSFP0 Supply Voltage"
+in1_label               "QSFP1 Supply Voltage"
+in2_label               "FPGA Core Voltage"
+in3_label               "12V Backplane Voltage"
+in4_label               "1.2V Voltage"
+in5_label               "12V AUX Voltage"
+in6_label               "1.8V Voltage"
+in7_label               "3.3V Voltage"
+
+currX_input             Measured current of the component (specified by
+                        currX_label)
+curr1_label             "FPGA Core Current"
+curr2_label             "12V Backplane Current"
+curr3_label             "12V AUX Current"
+
+powerX_input            Measured power of the component (specified by
+                        powerX_label)
+power1_label            "Board Power"
+
+======================= =======================================================
+
+All the attributes are read-only.