drivers: qcom: Add SoC sleep stats driver

Qualcomm Technologies Inc's (QTI) chipsets support SoC level
low power modes. Statistics for SoC sleep stats are produced
by remote processor.

Lets's add a driver to read the shared memory exported by the
remote processor and export to sysfs.

Change-Id: I48d27380c0ecd22d5b35da39f3ed8baf2fa1aeef
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Maulik Shah <mkshah@codeaurora.org>

drivers/soc/qcom/Kconfig

@@ -449,4 +449,13 @@ config QTI_DDR_STATS_LOG
 	  frequency residency and counts. The driver outputs information using
 	  sysfs.
 
+config QCOM_SOC_SLEEP_STATS
+	tristate "Qualcomm Technologies, Inc. (QTI) SoC sleep stats driver"
+	depends on QGKI
+	help
+	  Qualcomm Technologies Inc (QTI) SoC sleep stats driver to read
+	  the shared memory exported by the remote processor related to
+	  various SoC level low power modes statistics and export to sysfs
+	  interface.
+
 endmenu

drivers/soc/qcom/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_QCOM_RMTFS_MEM)	+= rmtfs_mem.o
 obj-$(CONFIG_QCOM_RPMH)		+= qcom_rpmh.o
 qcom_rpmh-y			+= rpmh-rsc.o
 qcom_rpmh-y			+= rpmh.o
+obj-$(CONFIG_QCOM_SOC_SLEEP_STATS)	+= soc_sleep_stats.o
 obj-$(CONFIG_QCOM_SMD_RPM)	+= smd-rpm.o
 obj-$(CONFIG_QCOM_SMEM) +=	smem.o
 obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o

drivers/soc/qcom/soc_sleep_stats.c

@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Copyright (c) 2011-2019, The Linux Foundation. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#include <clocksource/arm_arch_timer.h>
+
+struct stats_config {
+	u32 offset_addr;
+	u32 num_records;
+	bool appended_stats_avail;
+};
+
+struct soc_sleep_stats_data {
+	phys_addr_t stats_base;
+	resource_size_t stats_size;
+	const struct stats_config *config;
+	struct kobject *kobj;
+	struct kobj_attribute ka;
+	void __iomem *reg;
+};
+
+struct entry {
+	__le32 stat_type;
+	__le32 count;
+	__le64 last_entered_at;
+	__le64 last_exited_at;
+	__le64 accumulated;
+};
+
+struct appended_entry {
+	__le32 client_votes;
+	__le32 reserved[3];
+};
+
+struct stats_entry {
+	struct entry entry;
+	struct appended_entry appended_entry;
+};
+
+static inline u64 get_time_in_sec(u64 counter)
+{
+	do_div(counter, arch_timer_get_rate());
+
+	return counter;
+}
+
+static inline ssize_t append_data_to_buf(char *buf, int length,
+					 struct stats_entry *data)
+{
+	char stat_type[5] = {0};
+
+	memcpy(stat_type, &data->entry.stat_type, sizeof(u32));
+
+	return scnprintf(buf, length,
+			 "%s\n"
+			 "\tCount                    :%u\n"
+			 "\tLast Entered At(sec)     :%llu\n"
+			 "\tLast Exited At(sec)      :%llu\n"
+			 "\tAccumulated Duration(sec):%llu\n"
+			 "\tClient Votes             :0x%x\n\n",
+			 stat_type, data->entry.count,
+			 data->entry.last_entered_at,
+			 data->entry.last_exited_at,
+			 data->entry.accumulated,
+			 data->appended_entry.client_votes);
+}
+
+static ssize_t stats_show(struct kobject *obj, struct kobj_attribute *attr,
+			  char *buf)
+{
+	int i;
+	uint32_t offset;
+	ssize_t length = 0, op_length;
+	struct stats_entry data;
+	struct entry *e = &data.entry;
+	struct appended_entry *ae = &data.appended_entry;
+	struct soc_sleep_stats_data *drv = container_of(attr,
+					   struct soc_sleep_stats_data, ka);
+	void __iomem *reg = drv->reg;
+
+	for (i = 0; i < drv->config->num_records; i++) {
+		offset = offsetof(struct entry, stat_type);
+		e->stat_type = le32_to_cpu(readl_relaxed(reg + offset));
+
+		offset = offsetof(struct entry, count);
+		e->count = le32_to_cpu(readl_relaxed(reg + offset));
+
+		offset = offsetof(struct entry, last_entered_at);
+		e->last_entered_at = le64_to_cpu(readq_relaxed(reg + offset));
+
+		offset = offsetof(struct entry, last_exited_at);
+		e->last_exited_at = le64_to_cpu(readq_relaxed(reg + offset));
+
+		offset = offsetof(struct entry, last_exited_at);
+		e->accumulated = le64_to_cpu(readq_relaxed(reg + offset));
+
+		e->last_entered_at = get_time_in_sec(e->last_entered_at);
+		e->last_exited_at = get_time_in_sec(e->last_exited_at);
+		e->accumulated = get_time_in_sec(e->accumulated);
+
+		reg += sizeof(struct entry);
+
+		if (drv->config->appended_stats_avail) {
+			offset = offsetof(struct appended_entry, client_votes);
+			ae->client_votes = le32_to_cpu(readl_relaxed(reg +
+								     offset));
+
+			reg += sizeof(struct appended_entry);
+		} else {
+			ae->client_votes = 0;
+		}
+
+		op_length = append_data_to_buf(buf + length, PAGE_SIZE - length,
+					       &data);
+		if (op_length >= PAGE_SIZE - length)
+			goto exit;
+
+		length += op_length;
+	}
+exit:
+	return length;
+}
+
+static int soc_sleep_stats_create_sysfs(struct platform_device *pdev,
+					struct soc_sleep_stats_data *drv)
+{
+	drv->kobj = kobject_create_and_add("soc_sleep", power_kobj);
+	if (!drv->kobj)
+		return -ENOMEM;
+
+	sysfs_attr_init(drv->ka.attr);
+	drv->ka.attr.mode = 0444;
+	drv->ka.attr.name = "stats";
+	drv->ka.show = stats_show;
+
+	return sysfs_create_file(drv->kobj, &drv->ka.attr);
+}
+
+static const struct stats_config rpm_data = {
+	.offset_addr = 0x14,
+	.num_records = 2,
+	.appended_stats_avail = true,
+};
+
+static const struct stats_config rpmh_data = {
+	.offset_addr = 0x4,
+	.num_records = 3,
+	.appended_stats_avail = false,
+};
+
+static const struct of_device_id soc_sleep_stats_table[] = {
+	{ .compatible = "qcom,rpm-sleep-stats", .data = &rpm_data},
+	{ .compatible = "qcom,rpmh-sleep-stats", .data = &rpmh_data},
+	{ },
+};
+
+static int soc_sleep_stats_probe(struct platform_device *pdev)
+{
+	struct soc_sleep_stats_data *drv;
+	struct resource *res;
+	void __iomem *offset_addr;
+	int ret;
+
+	drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
+	if (!drv)
+		return -ENOMEM;
+
+	drv->config = of_device_get_match_data(&pdev->dev);
+	if (!drv->config)
+		return -ENODEV;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return PTR_ERR(res);
+
+	offset_addr = ioremap_nocache(res->start + drv->config->offset_addr,
+				      sizeof(u32));
+	if (IS_ERR(offset_addr))
+		return PTR_ERR(offset_addr);
+
+	drv->stats_base = res->start | readl_relaxed(offset_addr);
+	drv->stats_size = resource_size(res);
+	iounmap(offset_addr);
+
+	ret = soc_sleep_stats_create_sysfs(pdev, drv);
+	if (ret) {
+		pr_err("Failed to create sysfs interface\n");
+		return ret;
+	}
+
+	drv->reg = devm_ioremap(&pdev->dev, drv->stats_base, drv->stats_size);
+	if (!drv->reg) {
+		pr_err("ioremap failed\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, drv);
+	return 0;
+}
+
+static int soc_sleep_stats_remove(struct platform_device *pdev)
+{
+	struct soc_sleep_stats_data *drv = platform_get_drvdata(pdev);
+
+	sysfs_remove_file(drv->kobj, &drv->ka.attr);
+	kobject_put(drv->kobj);
+
+	return 0;
+}
+
+static struct platform_driver soc_sleep_stats_driver = {
+	.probe = soc_sleep_stats_probe,
+	.remove = soc_sleep_stats_remove,
+	.driver = {
+		.name = "soc_sleep_stats",
+		.of_match_table = soc_sleep_stats_table,
+	},
+};
+module_platform_driver(soc_sleep_stats_driver);
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. SoC sleep stats driver");
+MODULE_LICENSE("GPL v2");