[PATCH linux 4/6] hwmon: occ: Add callbacks for parsing P8 OCC datastructures

From: eajames . ibm
Date: Fri Dec 30 2016 - 12:56:56 EST


From: "Edward A. James" <eajames@xxxxxxxxxx>

Add functions to parse the data structures that are specific to the OCC on
the POWER8 processor. These are the sensor data structures, including
temperature, frequency, power, and "caps."

Signed-off-by: Edward A. James <eajames@xxxxxxxxxx>
Signed-off-by: Andrew Jeffery <andrew@xxxxxxxx>
Reviewed-by: Andrew Jeffery <andrew@xxxxxxxx>
---
Documentation/hwmon/occ | 9 ++
drivers/hwmon/occ/occ_p8.c | 217 +++++++++++++++++++++++++++++++++++++++++++++
drivers/hwmon/occ/occ_p8.h | 30 +++++++
3 files changed, 256 insertions(+)
create mode 100644 drivers/hwmon/occ/occ_p8.c
create mode 100644 drivers/hwmon/occ/occ_p8.h

diff --git a/Documentation/hwmon/occ b/Documentation/hwmon/occ
index 1ee8689..a6b3dd6 100644
--- a/Documentation/hwmon/occ
+++ b/Documentation/hwmon/occ
@@ -25,6 +25,15 @@ 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.

+The format for the POWER8 OCC sensor data can be found in the P8 OCC
+specification:
+github.com/open-power/docs/blob/master/occ/OCC_OpenPwr_FW_Interfaces.pdf
+This document provides the details of the OCC sensors: power, frequency,
+temperature, and caps. These sensor formats are specific to the POWER8 OCC. A
+number of data structures, such as command format, response headers, and the
+like, are also defined in this specification, and are common to both POWER8 and
+POWER9 OCCs.
+
sysfs Entries
-------------

diff --git a/drivers/hwmon/occ/occ_p8.c b/drivers/hwmon/occ/occ_p8.c
new file mode 100644
index 0000000..812df16
--- /dev/null
+++ b/drivers/hwmon/occ/occ_p8.c
@@ -0,0 +1,217 @@
+/*
+ * occ_p8.c - OCC hwmon driver
+ *
+ * This file contains the Power8-specific methods and data structures for
+ * the OCC hwmon driver.
+ *
+ * Copyright 2016 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <asm/unaligned.h>
+
+#include "occ.h"
+#include "occ_p8.h"
+
+/* P8 OCC sensor data format */
+struct p8_occ_sensor {
+ u16 sensor_id;
+ u16 value;
+};
+
+struct p8_power_sensor {
+ u16 sensor_id;
+ u32 update_tag;
+ u32 accumulator;
+ u16 value;
+};
+
+struct p8_caps_sensor {
+ u16 curr_powercap;
+ u16 curr_powerreading;
+ u16 norm_powercap;
+ u16 max_powercap;
+ u16 min_powercap;
+ u16 user_powerlimit;
+};
+
+void p8_parse_sensor(u8 *data, void *sensor, int sensor_type, int off,
+ int snum)
+{
+ switch (sensor_type) {
+ case FREQ:
+ case TEMP:
+ {
+ struct p8_occ_sensor *os =
+ &(((struct p8_occ_sensor *)sensor)[snum]);
+
+ os->sensor_id = be16_to_cpu(get_unaligned((u16 *)&data[off]));
+ os->value = be16_to_cpu(get_unaligned((u16 *)&data[off + 2]));
+ }
+ break;
+ case POWER:
+ {
+ struct p8_power_sensor *ps =
+ &(((struct p8_power_sensor *)sensor)[snum]);
+
+ ps->sensor_id = be16_to_cpu(get_unaligned((u16 *)&data[off]));
+ ps->update_tag =
+ be32_to_cpu(get_unaligned((u32 *)&data[off + 2]));
+ ps->accumulator =
+ be32_to_cpu(get_unaligned((u32 *)&data[off + 6]));
+ ps->value = be16_to_cpu(get_unaligned((u16 *)&data[off + 10]));
+ }
+ break;
+ case CAPS:
+ {
+ struct p8_caps_sensor *cs =
+ &(((struct p8_caps_sensor *)sensor)[snum]);
+
+ cs->curr_powercap =
+ be16_to_cpu(get_unaligned((u16 *)&data[off]));
+ cs->curr_powerreading =
+ be16_to_cpu(get_unaligned((u16 *)&data[off + 2]));
+ cs->norm_powercap =
+ be16_to_cpu(get_unaligned((u16 *)&data[off + 4]));
+ cs->max_powercap =
+ be16_to_cpu(get_unaligned((u16 *)&data[off + 6]));
+ cs->min_powercap =
+ be16_to_cpu(get_unaligned((u16 *)&data[off + 8]));
+ cs->user_powerlimit =
+ be16_to_cpu(get_unaligned((u16 *)&data[off + 10]));
+ }
+ break;
+ };
+}
+
+void *p8_alloc_sensor(int sensor_type, int num_sensors)
+{
+ switch (sensor_type) {
+ case FREQ:
+ case TEMP:
+ return kcalloc(num_sensors, sizeof(struct p8_occ_sensor),
+ GFP_KERNEL);
+ case POWER:
+ return kcalloc(num_sensors, sizeof(struct p8_power_sensor),
+ GFP_KERNEL);
+ case CAPS:
+ return kcalloc(num_sensors, sizeof(struct p8_caps_sensor),
+ GFP_KERNEL);
+ default:
+ return NULL;
+ }
+}
+
+int p8_get_sensor_value(struct occ *driver, int sensor_type, int snum)
+{
+ void *sensor;
+
+ if (sensor_type == CAPS)
+ return -EINVAL;
+
+ sensor = occ_get_sensor(driver, sensor_type);
+ if (!sensor)
+ return -ENODEV;
+
+ switch (sensor_type) {
+ case FREQ:
+ case TEMP:
+ return ((struct p8_occ_sensor *)sensor)[snum].value;
+ case POWER:
+ return ((struct p8_power_sensor *)sensor)[snum].value;
+ default:
+ return -EINVAL;
+ }
+}
+
+int p8_get_sensor_id(struct occ *driver, int sensor_type, int snum)
+{
+ void *sensor;
+ int i = snum;
+
+ if (sensor_type == CAPS)
+ return -EINVAL;
+
+ sensor = occ_get_sensor(driver, sensor_type);
+ if (!sensor)
+ return -ENODEV;
+
+ switch (sensor_type) {
+ case FREQ:
+ case TEMP:
+ return ((struct p8_occ_sensor *)sensor)[i].sensor_id;
+ case POWER:
+ return ((struct p8_power_sensor *)sensor)[i].sensor_id;
+ default:
+ return -EINVAL;
+ }
+}
+
+int p8_get_caps_value(void *sensor, int snum, int caps_field)
+{
+ struct p8_caps_sensor *caps_sensor = sensor;
+
+ switch (caps_field) {
+ case 0:
+ return caps_sensor[snum].curr_powercap;
+ case 1:
+ return caps_sensor[snum].curr_powerreading;
+ case 2:
+ return caps_sensor[snum].norm_powercap;
+ case 3:
+ return caps_sensor[snum].max_powercap;
+ case 4:
+ return caps_sensor[snum].min_powercap;
+ case 5:
+ return caps_sensor[snum].user_powerlimit;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct occ_ops p8_ops = {
+ .parse_sensor = p8_parse_sensor,
+ .alloc_sensor = p8_alloc_sensor,
+ .get_sensor_value = p8_get_sensor_value,
+ .get_sensor_id = p8_get_sensor_id,
+ .get_caps_value = p8_get_caps_value,
+};
+
+static const struct occ_config p8_config = {
+ .command_addr = 0xFFFF6000,
+ .response_addr = 0xFFFF7000,
+};
+
+struct occ *p8_occ_start(struct device *dev, void *bus,
+ struct occ_bus_ops *bus_ops)
+{
+ return occ_start(dev, bus, bus_ops, &p8_ops, &p8_config);
+}
+EXPORT_SYMBOL(p8_occ_start);
+
+int p8_occ_stop(struct occ *occ)
+{
+ return occ_stop(occ);
+}
+EXPORT_SYMBOL(p8_occ_stop);
+
+MODULE_AUTHOR("Eddie James <eajames@xxxxxxxxxx>");
+MODULE_DESCRIPTION("P8 OCC sensors");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hwmon/occ/occ_p8.h b/drivers/hwmon/occ/occ_p8.h
new file mode 100644
index 0000000..b44cdd4
--- /dev/null
+++ b/drivers/hwmon/occ/occ_p8.h
@@ -0,0 +1,30 @@
+/*
+ * occ_p8.h - OCC hwmon driver
+ *
+ * This file contains Power8-specific function prototypes
+ *
+ * Copyright 2016 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __OCC_P8_H__
+#define __OCC_P8_H__
+
+#include "scom.h"
+
+struct device;
+
+struct occ *p8_occ_start(struct device *dev, void *bus,
+ struct occ_bus_ops *bus_ops);
+int p8_occ_stop(struct occ *occ);
+
+#endif /* __OCC_P8_H__ */
--
1.9.1