drivers: hwmon: Add On-Chip Controller driver

From: "Edward A. James" <[email protected]>

Add a generic mechanism to expose the sensors provided by the OCC in sysfs.

Signed-off-by Edward A. James <[email protected]>

Signed-off-by Andrew Jeffery <[email protected]>

---
 Documentation/hwmon/occ       |  62 +++++++++++
 drivers/hwmon/occ/Makefile    |   2 +-
 drivers/hwmon/occ/occ_sysfs.c | 245 ++++++++++++++++++++++++++++++++++++++++++
 drivers/hwmon/occ/occ_sysfs.h |  25 +++++
 4 files changed, 333 insertions(+), 1 deletion(-)
 create mode 100644 drivers/hwmon/occ/occ_sysfs.c
 create mode 100644 drivers/hwmon/occ/occ_sysfs.h

Documentation/hwmon/occ +62 -0

index d1c863b..580af26 100644
@@ -27,6 +27,68 @@ Currently, all versions of the OCC support four types of sensor data: power,
 temperature, frequency, and "caps," which indicate limits and thresholds used
 internally on the OCC.
 
+sysfs Entries
+-------------
+
+The OCC driver uses the hwmon sysfs framework to provide data to userspace.
+
+The driver exports a number of sysfs files for each type of sensor. The
+sensor-specific files vary depending on the processor type, though many of the
+attributes are common for both the POWER8 and POWER9.
+
+The hwmon interface cannot define every type of sensor that may be used.
+Therefore, the frequency sensor on the OCC uses the "input" type sensor defined
+by the hwmon interface, rather than defining a new type of custom sensor.
+
+Below are detailed the names and meaning of each sensor file for both types of
+processors. All sensors are read-only unless otherwise specified. <x> indicates
+the hwmon index. sensor id indicates the unique internal OCC identifer. Please
+see the POWER OCC specification for details on all these sensor values.
+
+frequency:
+	all processors:
+		in<x>_input - frequency value
+		in<x>_label - sensor id
+temperature:
+	POWER8:
+		temp<x>_input - temperature value
+		temp<x>_label - sensor id
+	POWER9 (in addition to above):
+		temp<x>_type - FRU type
+
+power:
+	POWER8:
+		power<x>_input - power value
+		power<x>_label - sensor id
+		power<x>_average - accumulator
+		power<x>_average_interval - update tag (number of samples in
+			accumulator)
+	POWER9:
+		power<x>_input - power value
+		power<x>_label - sensor id
+		power<x>_average_min - accumulator[0]
+		power<x>_average_max - accumulator[1] (64 bits total)
+		power<x>_average_interval - update tag
+		power<x>_reset_history - (function_id | (apss_channel << 8)
+
+caps:
+	POWER8:
+		power<x>_cap - current powercap
+		power<x>_cap_max - max powercap
+		power<x>_cap_min - min powercap
+		power<x>_max - normal powercap
+		power<x>_alarm - user powercap, r/w
+	POWER9:
+		power<x>_cap_alarm - user powercap source
+
+The driver also provides two sysfs entries through hwmon to better
+control the driver and monitor the master OCC. Though there may be multiple
+OCCs present on the system, these two files are only present for the "master"
+OCC.
+	name - read the name of the driver
+	update_interval - read or write the minimum interval for polling the
+		OCC.
+
 BMC - Host Communications
 -------------------------
 

drivers/hwmon/occ/Makefile +1 -1

index 3ed79a5..67b5367 100644
@@ -1 +1 @@
-obj-$(CONFIG_SENSORS_IBM_OCC) += occ.o
+obj-$(CONFIG_SENSORS_IBM_OCC) += occ.o occ_sysfs.o

drivers/hwmon/occ/occ_sysfs.c new file +58 -0

new file mode 100644
index 0000000..d6baf8d
@@ -0,0 +1,245 @@
+/*
+ * occ_sysfs.c - OCC sysfs interface
+ *
+ * This file contains the methods and data structures for implementing the OCC
+ * hwmon sysfs entries.
+ *
+ * Copyright 2017 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include "occ.h"
+#include "occ_sysfs.h"
+
+#define OCC_HWMON_NAME_LENGTH	32
+
+struct occ_sysfs {
+	struct device *dev;
+	struct occ *occ;
+
+	char hwmon_name[OCC_HWMON_NAME_LENGTH + 1];
+	const u32 *sensor_hwmon_configs;
+	struct hwmon_channel_info **occ_sensors;
+	struct hwmon_chip_info occ_info;
+	u16 user_powercap;
+};
+
+static int occ_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+			  u32 attr, int channel, long *val)
+{
+	int rc;
+	struct occ_sysfs *driver = dev_get_drvdata(dev);
+	struct occ *occ = driver->occ;
+
+	switch (type) {
+	case hwmon_in:
+		rc = occ_get_sensor_field(occ, FREQ, channel, attr, val);
+		break;
+	case hwmon_temp:
+		rc = occ_get_sensor_field(occ, TEMP, channel, attr, val);
+		break;
+	case hwmon_power:
+		rc = occ_get_sensor_field(occ, POWER, channel, attr, val);
+		break;

drivers/hwmon/occ/occ_sysfs.c new file +5 -0

+{
+	int rc;
+	unsigned long val = 0;
+
+	if (!((type == hwmon_in && attr == hwmon_in_label) ||

drivers/hwmon/occ/occ_sysfs.c new file +162 -0

+	if (rc > 0)
+		rc = 0;
+
+	return rc;
+}
+
+static int occ_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
+			   u32 attr, int channel, long val)
+{
+	int rc;
+	struct occ_sysfs *driver = dev_get_drvdata(dev);
+
+	if (type == hwmon_power && attr == hwmon_power_alarm) {
+		rc = occ_set_user_powercap(driver->occ, val);
+		if (rc) {
+			dev_err(dev, "set user powercap failed:%d\n", rc);
+			return rc;
+		}
+
+		driver->user_powercap = val;
+
+		return rc;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static umode_t occ_is_visible(const void *data, enum hwmon_sensor_types type,
+			      u32 attr, int channel)
+{
+	const struct occ_sysfs *driver = data;
+
+	switch (type) {
+	case hwmon_chip:
+		if (attr == hwmon_chip_update_interval)
+			return 0644;
+		break;
+	case hwmon_in:
+		if (BIT(attr) & driver->sensor_hwmon_configs[0])
+			return 0444;
+		break;
+	case hwmon_temp:
+		if (BIT(attr) & driver->sensor_hwmon_configs[1])
+			return 0444;
+		break;
+	case hwmon_power:
+		/* user power limit */
+		if (attr == hwmon_power_alarm)
+			return 0644;
+		else if ((BIT(attr) & driver->sensor_hwmon_configs[2]) ||
+			 (BIT(attr) & driver->sensor_hwmon_configs[3]))
+			return 0444;
+		break;
+	default:
+		return 0;
+	}
+
+	return 0;
+}
+
+static const struct hwmon_ops occ_hwmon_ops = {
+	.is_visible = occ_is_visible,
+	.read = occ_hwmon_read,
+	.read_string = occ_hwmon_read_string,
+	.write = occ_hwmon_write,
+};
+
+static const enum hwmon_sensor_types occ_sensor_types[MAX_OCC_SENSOR_TYPE] = {
+	hwmon_in,
+	hwmon_temp,
+	hwmon_power,
+	hwmon_power
+};
+
+struct occ_sysfs *occ_sysfs_start(struct device *dev, struct occ *occ,
+				  const u32 *sensor_hwmon_configs,
+				  const char *name)
+{
+	int rc, i, j, num_sensors, index = 0, id;
+	char *brk;
+	struct occ_blocks *resp = NULL;
+	u32 *sensor_config;
+	struct occ_sysfs *hwmon = devm_kzalloc(dev, sizeof(struct occ_sysfs),
+					       GFP_KERNEL);
+	if (!hwmon)
+		return ERR_PTR(-ENOMEM);
+
+	/* need space for null-termination */
+	hwmon->occ_sensors =
+		devm_kzalloc(dev, sizeof(struct hwmon_channel_info *) *
+			     (MAX_OCC_SENSOR_TYPE + 1), GFP_KERNEL);
+	if (!hwmon->occ_sensors)
+		return ERR_PTR(-ENOMEM);
+
+	hwmon->occ = occ;
+	hwmon->sensor_hwmon_configs = sensor_hwmon_configs;
+	hwmon->occ_info.ops = &occ_hwmon_ops;
+	hwmon->occ_info.info =
+		(const struct hwmon_channel_info **)hwmon->occ_sensors;
+
+	occ_get_response_blocks(occ, &resp);
+
+	for (i = 0; i < MAX_OCC_SENSOR_TYPE; ++i)
+		resp->sensor_block_id[i] = -1;
+
+	/* read sensor data from occ */
+	rc = occ_update_device(occ);
+	if (rc)
+		return ERR_PTR(rc);
+
+	for (i = 0; i < MAX_OCC_SENSOR_TYPE; i++) {
+		id = resp->sensor_block_id[i];
+		if (id < 0)
+			continue;
+
+		num_sensors = resp->blocks[id].header.num_sensors;
+		/* need null-termination */
+		sensor_config = devm_kzalloc(dev,
+					     sizeof(u32) * (num_sensors + 1),
+					     GFP_KERNEL);
+		if (!sensor_config)
+			return ERR_PTR(-ENOMEM);
+
+		for (j = 0; j < num_sensors; j++)
+			sensor_config[j] = sensor_hwmon_configs[i];
+
+		hwmon->occ_sensors[index] =
+			devm_kzalloc(dev, sizeof(struct hwmon_channel_info),
+				     GFP_KERNEL);
+		if (!hwmon->occ_sensors[index])
+			return ERR_PTR(-ENOMEM);
+
+		hwmon->occ_sensors[index]->type = occ_sensor_types[i];
+		hwmon->occ_sensors[index]->config = sensor_config;
+		index++;
+	}
+
+	/* search for bad chars */
+	strncpy(hwmon->hwmon_name, name, OCC_HWMON_NAME_LENGTH);
+	brk = strpbrk(hwmon->hwmon_name, "-* \t\n");
+	while (brk) {
+		*brk = '_';
+		brk = strpbrk(brk,  "-* \t\n");
+	}
+
+	hwmon->dev = devm_hwmon_device_register_with_info(dev,
+							  hwmon->hwmon_name,
+							  hwmon,
+							  &hwmon->occ_info,
+							  NULL);
+	if (IS_ERR(hwmon->dev)) {
+		dev_err(dev, "cannot register hwmon device %s: %ld\n",
+			hwmon->hwmon_name, PTR_ERR(hwmon->dev));
+		return ERR_CAST(hwmon->dev);
+	}
+
+	return hwmon;
+}
+
+MODULE_AUTHOR("Eddie James <[email protected]>");
+MODULE_DESCRIPTION("OCC sysfs driver");
+MODULE_LICENSE("GPL");

drivers/hwmon/occ/occ_sysfs.h new file +25 -0

new file mode 100644
index 0000000..fcd4f59a
@@ -0,0 +1,25 @@
+/*
+ * occ_sysfs.h - OCC sysfs interface
+ *
+ * This file contains the data structures and function prototypes for the OCC
+ * hwmon sysfs entries.
+ *
+ * Copyright 2017 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __OCC_SYSFS_H__
+#define __OCC_SYSFS_H__
+
+struct occ;
+struct device;
+struct occ_sysfs;
+
+struct occ_sysfs *occ_sysfs_start(struct device *dev, struct occ *occ,
+				  const u32 *sensor_hwmon_configs,
+				  const char *name);
+#endif /* __OCC_SYSFS_H__ */

From: Eddie James <[email protected]>
To: [email protected]
Cc: [email protected], [email protected], linux- [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], wsa@the- dreams.de, [email protected], [email protected], [email protected], Edward James/Austin/IBM@IBMUS
Date: 02/14/2017 02:34 PM
Subject: [PATCH linux v8 0/6] drivers: hwmon: Add On-Chip Controller

From: "Edward A. James" <[email protected]>

This patchset adds a hwmon driver to support the OCC (On-Chip Controller) on the IBM POWER8 and POWER9 processors, from a BMC (Baseboard Management Controller). The OCC is an embedded processor that provides real time power and thermal monitoring.

The driver provides an interface on a BMC to poll OCC sensor data, set user power caps, and perform some basic OCC error handling. It interfaces with userspace through hwmon.

The driver is currently functional only for the OCC on POWER8 chips. Communicating with the POWER9 OCC requries FSI support.

Since v7:
* change Makefile and Kconfig to build a single module for the driver
* include p9 file in build
* change Kconfig from "PPC" to "IBM"
* remove EXPORT_SYMBOL
* bundle occ_config and occ_ops structures into occ_init_data structure
* few style tweaks suggested by Joel

Edward A. James (6):
hwmon: Add core On-Chip Controller support for POWER CPUs
hwmon: occ: Add sysfs interface
hwmon: occ: Add I2C transport implementation for SCOM operations
hwmon: occ: Add callbacks for parsing P8 OCC datastructures
hwmon: occ: Add hwmon implementation for the P8 OCC
hwmon: occ: Add callbacks for parsing P9 OCC datastructures

 Documentation/devicetree/bindings/hwmon/occ.txt |  13 +
 Documentation/hwmon/occ                         | 116 +++++++
 MAINTAINERS                                     |   7 +
 drivers/hwmon/Kconfig                           |   2 +
 drivers/hwmon/Makefile                          |   1 +
 drivers/hwmon/occ/Kconfig                       |  39 +++
 drivers/hwmon/occ/Makefile                      |   5 +
 drivers/hwmon/occ/occ.c                         | 440 +++++++++++++
+++++++++++
 drivers/hwmon/occ/occ.h                         |  77 +++++
 drivers/hwmon/occ/occ_p8.c                      | 256 ++++++++++++++
 drivers/hwmon/occ/occ_p8.h                      |  25 ++
 drivers/hwmon/occ/occ_p8_i2c.c                  |  99 ++++++
 drivers/hwmon/occ/occ_p9.c                      | 320 +++++++++++++++++
 drivers/hwmon/occ/occ_p9.h                      |  25 ++
 drivers/hwmon/occ/occ_scom_i2c.c                |  69 ++++
 drivers/hwmon/occ/occ_scom_i2c.h                |  21 ++
 drivers/hwmon/occ/occ_sysfs.c                   | 245 +++++++++++++
 drivers/hwmon/occ/occ_sysfs.h                   |  25 ++
 drivers/hwmon/occ/scom.h                        |  42 +++
 19 files changed, 1827 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/occ.txt
 create mode 100644 Documentation/hwmon/occ
 create mode 100644 drivers/hwmon/occ/Kconfig
 create mode 100644 drivers/hwmon/occ/Makefile
 create mode 100644 drivers/hwmon/occ/occ.c
 create mode 100644 drivers/hwmon/occ/occ.h
 create mode 100644 drivers/hwmon/occ/occ_p8.c
 create mode 100644 drivers/hwmon/occ/occ_p8.h
 create mode 100644 drivers/hwmon/occ/occ_p8_i2c.c
 create mode 100644 drivers/hwmon/occ/occ_p9.c
 create mode 100644 drivers/hwmon/occ/occ_p9.h
 create mode 100644 drivers/hwmon/occ/occ_scom_i2c.c
 create mode 100644 drivers/hwmon/occ/occ_scom_i2c.h
 create mode 100644 drivers/hwmon/occ/occ_sysfs.c
 create mode 100644 drivers/hwmon/occ/occ_sysfs.h
 create mode 100644 drivers/hwmon/occ/scom.h

--
1.8.3.1

Hi Guenter,

Any thoughts on this patch set? Others welcome to chime in too.

Thanks,
Eddie

Eddie James <[email protected]> wrote on 02/14/2017 02:34:17 PM:

Quoted 9 lines

From: Eddie James <[email protected]>
To: [email protected]
Cc: [email protected], [email protected], linux- [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], wsa@the- dreams.de, [email protected], [email protected], [email protected], Edward James/Austin/IBM@IBMUS
Date: 02/14/2017 02:34 PM
Subject: [PATCH linux v8 0/6] drivers: hwmon: Add On-Chip Controller

driver

Quoted 72 lines

From: "Edward A. James" <[email protected]>

This patchset adds a hwmon driver to support the OCC (On-Chip Controller) on the IBM POWER8 and POWER9 processors, from a BMC (Baseboard Management Controller). The OCC is an embedded processor that provides real time power and thermal monitoring.

The driver provides an interface on a BMC to poll OCC sensor data, set user power caps, and perform some basic OCC error handling. It interfaces with userspace through hwmon.

The driver is currently functional only for the OCC on POWER8 chips. Communicating with the POWER9 OCC requries FSI support.

Since v7:
* change Makefile and Kconfig to build a single module for the driver
* include p9 file in build
* change Kconfig from "PPC" to "IBM"
* remove EXPORT_SYMBOL
* bundle occ_config and occ_ops structures into occ_init_data structure
* few style tweaks suggested by Joel

Edward A. James (6):
hwmon: Add core On-Chip Controller support for POWER CPUs
hwmon: occ: Add sysfs interface
hwmon: occ: Add I2C transport implementation for SCOM operations
hwmon: occ: Add callbacks for parsing P8 OCC datastructures
hwmon: occ: Add hwmon implementation for the P8 OCC
hwmon: occ: Add callbacks for parsing P9 OCC datastructures

 Documentation/devicetree/bindings/hwmon/occ.txt |  13 +
 Documentation/hwmon/occ                         | 116 +++++++
 MAINTAINERS                                     |   7 +
 drivers/hwmon/Kconfig                           |   2 +
 drivers/hwmon/Makefile                          |   1 +
 drivers/hwmon/occ/Kconfig                       |  39 +++
 drivers/hwmon/occ/Makefile                      |   5 +
 drivers/hwmon/occ/occ.c                         | 440 +++++++++++++
+++++++++++
 drivers/hwmon/occ/occ.h                         |  77 +++++
 drivers/hwmon/occ/occ_p8.c                      | 256 ++++++++++++++
 drivers/hwmon/occ/occ_p8.h                      |  25 ++
 drivers/hwmon/occ/occ_p8_i2c.c                  |  99 ++++++
 drivers/hwmon/occ/occ_p9.c                      | 320 +++++++++++++++++
 drivers/hwmon/occ/occ_p9.h                      |  25 ++
 drivers/hwmon/occ/occ_scom_i2c.c                |  69 ++++
 drivers/hwmon/occ/occ_scom_i2c.h                |  21 ++
 drivers/hwmon/occ/occ_sysfs.c                   | 245 +++++++++++++
 drivers/hwmon/occ/occ_sysfs.h                   |  25 ++
 drivers/hwmon/occ/scom.h                        |  42 +++
 19 files changed, 1827 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/occ.txt
 create mode 100644 Documentation/hwmon/occ
 create mode 100644 drivers/hwmon/occ/Kconfig
 create mode 100644 drivers/hwmon/occ/Makefile
 create mode 100644 drivers/hwmon/occ/occ.c
 create mode 100644 drivers/hwmon/occ/occ.h
 create mode 100644 drivers/hwmon/occ/occ_p8.c
 create mode 100644 drivers/hwmon/occ/occ_p8.h
 create mode 100644 drivers/hwmon/occ/occ_p8_i2c.c
 create mode 100644 drivers/hwmon/occ/occ_p9.c
 create mode 100644 drivers/hwmon/occ/occ_p9.h
 create mode 100644 drivers/hwmon/occ/occ_scom_i2c.c
 create mode 100644 drivers/hwmon/occ/occ_scom_i2c.h
 create mode 100644 drivers/hwmon/occ/occ_sysfs.c
 create mode 100644 drivers/hwmon/occ/occ_sysfs.h
 create mode 100644 drivers/hwmon/occ/scom.h

--
1.8.3.1