perf hwmon_pmu: Add hwmon filename parser

hwmon filenames have a specific encoding that will be used to give a
config value. The encoding is described in:
Documentation/hwmon/sysfs-interface.rst
Add a function to parse the filename into consituent enums/ints that
will then be amenable to config encoding.

Note, things are done this way to allow mapping names to config and
back without the use of hash/dynamic lookup tables.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Yoshihiro Furudera <fj5100bi@fujitsu.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ze Gao <zegao2021@gmail.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Junhao He <hejunhao3@huawei.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
[namhyung: add #include <linux/string.h> for strlcpy()]
Link: https://lore.kernel.org/r/20241109003759.473460-3-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

1 files changed, 111 insertions, 0 deletions

diff --git a/tools/perf/util/hwmon_pmu.h b/tools/perf/util/hwmon_pmu.h
new file mode 100644
index 000000000000..df0ab5ff7534
--- /dev/null
+++ b/tools/perf/util/hwmon_pmu.h
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+#ifndef __HWMON_PMU_H
+#define __HWMON_PMU_H
+
+#include <stdbool.h>
+
+/**
+ * enum hwmon_type:
+ *
+ * As described in Documentation/hwmon/sysfs-interface.rst hwmon events are
+ * defined over multiple files of the form <type><num>_<item>. This enum
+ * captures potential <type> values.
+ *
+ * This enum is exposed for testing.
+ */
+enum hwmon_type {
+	HWMON_TYPE_NONE,
+
+	HWMON_TYPE_CPU,
+	HWMON_TYPE_CURR,
+	HWMON_TYPE_ENERGY,
+	HWMON_TYPE_FAN,
+	HWMON_TYPE_HUMIDITY,
+	HWMON_TYPE_IN,
+	HWMON_TYPE_INTRUSION,
+	HWMON_TYPE_POWER,
+	HWMON_TYPE_PWM,
+	HWMON_TYPE_TEMP,
+
+	HWMON_TYPE_MAX
+};
+
+/**
+ * enum hwmon_item:
+ *
+ * Similar to enum hwmon_type but describes the item part of a a sysfs filename.
+ *
+ * This enum is exposed for testing.
+ */
+enum hwmon_item {
+	HWMON_ITEM_NONE,
+
+	HWMON_ITEM_ACCURACY,
+	HWMON_ITEM_ALARM,
+	HWMON_ITEM_AUTO_CHANNELS_TEMP,
+	HWMON_ITEM_AVERAGE,
+	HWMON_ITEM_AVERAGE_HIGHEST,
+	HWMON_ITEM_AVERAGE_INTERVAL,
+	HWMON_ITEM_AVERAGE_INTERVAL_MAX,
+	HWMON_ITEM_AVERAGE_INTERVAL_MIN,
+	HWMON_ITEM_AVERAGE_LOWEST,
+	HWMON_ITEM_AVERAGE_MAX,
+	HWMON_ITEM_AVERAGE_MIN,
+	HWMON_ITEM_BEEP,
+	HWMON_ITEM_CAP,
+	HWMON_ITEM_CAP_HYST,
+	HWMON_ITEM_CAP_MAX,
+	HWMON_ITEM_CAP_MIN,
+	HWMON_ITEM_CRIT,
+	HWMON_ITEM_CRIT_HYST,
+	HWMON_ITEM_DIV,
+	HWMON_ITEM_EMERGENCY,
+	HWMON_ITEM_EMERGENCY_HIST,
+	HWMON_ITEM_ENABLE,
+	HWMON_ITEM_FAULT,
+	HWMON_ITEM_FREQ,
+	HWMON_ITEM_HIGHEST,
+	HWMON_ITEM_INPUT,
+	HWMON_ITEM_LABEL,
+	HWMON_ITEM_LCRIT,
+	HWMON_ITEM_LCRIT_HYST,
+	HWMON_ITEM_LOWEST,
+	HWMON_ITEM_MAX,
+	HWMON_ITEM_MAX_HYST,
+	HWMON_ITEM_MIN,
+	HWMON_ITEM_MIN_HYST,
+	HWMON_ITEM_MOD,
+	HWMON_ITEM_OFFSET,
+	HWMON_ITEM_PULSES,
+	HWMON_ITEM_RATED_MAX,
+	HWMON_ITEM_RATED_MIN,
+	HWMON_ITEM_RESET_HISTORY,
+	HWMON_ITEM_TARGET,
+	HWMON_ITEM_TYPE,
+	HWMON_ITEM_VID,
+
+	HWMON_ITEM__MAX,
+};
+
+/**
+ * parse_hwmon_filename() - Parse filename into constituent parts.
+ *
+ * @filename: To be parsed, of the form <type><number>_<item>.
+ * @type: The type defined from the parsed file name.
+ * @number: The number of the type, for example there may be more than 1 fan.
+ * @item: A hwmon <type><number> may have multiple associated items.
+ * @alarm: Is the filename for an alarm value?
+ *
+ * An example of a hwmon filename is "temp1_input". The type is temp for a
+ * temperature value. The number is 1. The item within the file is an input
+ * value - the temperature itself. This file doesn't contain an alarm value.
+ *
+ * Exposed for testing.
+ */
+bool parse_hwmon_filename(const char *filename,
+			  enum hwmon_type *type,
+			  int *number,
+			  enum hwmon_item *item,
+			  bool *alarm);
+
+#endif /* __HWMON_PMU_H */