[PATCH] soc: qcom: Introduce subsystem sleep stats driver

[Maulik Shah]

Multiple subsystems like modem, spss, adsp, cdsp present on
Qualcomm Technologies Inc's (QTI) SoCs maintains low power mode
statistics in shared memory (SMEM). Lets add a driver to read
and display this information using sysfs.

Signed-off-by: Maulik Shah <mkshah@xxxxxxxxxxxxxx>
---
 Documentation/ABI/testing/sysfs-power    |  10 ++
 drivers/soc/qcom/Kconfig                 |   9 ++
 drivers/soc/qcom/Makefile                |   1 +
 drivers/soc/qcom/subsystem_sleep_stats.c | 146 +++++++++++++++++++++++
 4 files changed, 166 insertions(+)
 create mode 100644 drivers/soc/qcom/subsystem_sleep_stats.c

diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
index 18b7dc929234..1f8bb201246a 100644
--- a/Documentation/ABI/testing/sysfs-power
+++ b/Documentation/ABI/testing/sysfs-power
@@ -288,6 +288,16 @@ Description:
 		writing a "0" (default) to it disables them.  Reads from
 		this file return the current value.
 
+What:		/sys/power/subsystem_sleep/stats
+Date:		December 2017
+Contact:	Maulik Shah <mkshah@xxxxxxxxxxxxxx>
+Description:
+		The /sys/power/subsystem_sleep/stats file prints the subsystem
+		sleep information on Qualcomm Technologies, Inc. (QTI) SoCs.
+
+		Reading from this file will display subsystem level low power
+		mode statistics.
+
 What:		/sys/power/resume_offset
 Date:		April 2018
 Contact:	Mario Limonciello <mario.limonciello@xxxxxxxx>
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 880cf0290962..da53a96c6cce 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -163,6 +163,15 @@ config QCOM_SMSM
 	  Say yes here to support the Qualcomm Shared Memory State Machine.
 	  The state machine is represented by bits in shared memory.
 
+config QCOM_SS_SLEEP_STATS
+	tristate "Qualcomm Technologies Inc. Subsystem Sleep Stats driver"
+	depends on QCOM_SMEM
+	help
+	  Say y here to enable support for the Qualcomm Technologies Inc (QTI)
+	  SS sleep stats driver to read the sleep stats of various subsystems
+	  from SMEM. The stats are exported to sysfs. The driver also maintains
+	  application processor sleep stats.
+
 config QCOM_WCNSS_CTRL
 	tristate "Qualcomm WCNSS control driver"
 	depends on ARCH_QCOM || COMPILE_TEST
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index ffe519b0cb66..657e9494fc51 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_QCOM_SMEM) +=	smem.o
 obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
 obj-$(CONFIG_QCOM_SMP2P)	+= smp2p.o
 obj-$(CONFIG_QCOM_SMSM)	+= smsm.o
+qcom_rpmh-y	+= subsystem_sleep_stats.o
 obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
 obj-$(CONFIG_QCOM_APR) += apr.o
 obj-$(CONFIG_QCOM_LLCC) += llcc-slice.o
diff --git a/drivers/soc/qcom/subsystem_sleep_stats.c b/drivers/soc/qcom/subsystem_sleep_stats.c
new file mode 100644
index 000000000000..5379714b6ba4
--- /dev/null
+++ b/drivers/soc/qcom/subsystem_sleep_stats.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Copyright (c) 2017-2019, The Linux Foundation. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, KBUILD_MODNAME
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/soc/qcom/smem.h>
+
+enum subsystem_item_id {
+	MODEM = 605,
+	ADSP,
+	CDSP,
+	SLPI,
+	GPU,
+	DISPLAY,
+};
+
+enum subsystem_pid {
+	PID_APSS = 0,
+	PID_MODEM = 1,
+	PID_ADSP = 2,
+	PID_SLPI = 3,
+	PID_CDSP = 5,
+	PID_GPU = PID_APSS,
+	PID_DISPLAY = PID_APSS,
+};
+
+struct subsystem_data {
+	char *name;
+	enum subsystem_item_id item_id;
+	enum subsystem_pid pid;
+};
+
+static const struct subsystem_data subsystems[] = {
+	{"MODEM", MODEM, PID_MODEM},
+	{"ADSP", ADSP, PID_ADSP},
+	{"CDSP", CDSP, PID_CDSP},
+	{"SLPI", SLPI, PID_SLPI},
+	{"GPU", GPU, PID_GPU},
+	{"DISPLAY", DISPLAY, PID_DISPLAY},
+};
+
+struct subsystem_stats {
+	uint32_t version_id;
+	uint32_t count;
+	uint64_t last_entered;
+	uint64_t last_exited;
+	uint64_t accumulated_duration;
+};
+
+struct subsystem_stats_prv_data {
+	struct kobj_attribute ka;
+	struct kobject *kobj;
+};
+
+static struct subsystem_stats_prv_data *prvdata;
+
+static inline ssize_t subsystem_stats_print(char *prvbuf, ssize_t length,
+					    struct subsystem_stats *record,
+					    const char *name)
+{
+	return scnprintf(prvbuf, length, "%s\n\tVersion:0x%x\n"
+			"\tSleep Count:0x%x\n"
+			"\tSleep Last Entered At:0x%llx\n"
+			"\tSleep Last Exited At:0x%llx\n"
+			"\tSleep Accumulated Duration:0x%llx\n\n",
+			name, record->version_id, record->count,
+			record->last_entered, record->last_exited,
+			record->accumulated_duration);
+}
+
+static ssize_t subsystem_stats_show(struct kobject *kobj,
+				    struct kobj_attribute *attr, char *buf)
+{
+	ssize_t length = 0;
+	int i = 0;
+	size_t size = 0;
+	struct subsystem_stats *record = NULL;
+
+	/* Read SMEM data written by other subsystems */
+	for (i = 0; i < ARRAY_SIZE(subsystems); i++) {
+		record = (struct subsystem_stats *) qcom_smem_get(
+			  subsystems[i].pid, subsystems[i].item_id, &size);
+
+		if (!IS_ERR_OR_NULL(record) && (PAGE_SIZE - length > 0))
+			length += subsystem_stats_print(buf + length,
+							PAGE_SIZE - length,
+							record,
+							subsystems[i].name);
+	}
+
+	return length;
+}
+
+static int __init subsystem_sleep_stats_init(void)
+{
+	struct kobject *ss_stats_kobj;
+	int ret;
+
+	prvdata = kmalloc(sizeof(*prvdata), GFP_KERNEL);
+	if (!prvdata)
+		return -ENOMEM;
+
+	ss_stats_kobj = kobject_create_and_add("subsystem_sleep",
+					       power_kobj);
+	if (!ss_stats_kobj)
+		return -ENOMEM;
+
+	prvdata->kobj = ss_stats_kobj;
+
+	sysfs_attr_init(&prvdata->ka.attr);
+	prvdata->ka.attr.mode = 0444;
+	prvdata->ka.attr.name = "stats";
+	prvdata->ka.show = subsystem_stats_show;
+	prvdata->ka.store = NULL;
+
+	ret = sysfs_create_file(prvdata->kobj, &prvdata->ka.attr);
+	if (ret) {
+		pr_err("sysfs_create_file failed\n");
+		kobject_put(prvdata->kobj);
+		kfree(prvdata);
+		return ret;
+	}
+
+	return ret;
+}
+
+static void __exit subsystem_sleep_stats_exit(void)
+{
+	sysfs_remove_file(prvdata->kobj, &prvdata->ka.attr);
+	kobject_put(prvdata->kobj);
+	kfree(prvdata);
+}
+
+module_init(subsystem_sleep_stats_init);
+module_exit(subsystem_sleep_stats_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc subsystem sleep stats driver");
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation.