soc: qcom: Introduce RPM master stats driver

Introduce a driver to query and expose detailed, per-subsystem (as opposed
to the existing qcom_stats driver which exposes SoC-wide data) about low
power mode states of a given RPM master. That includes the APSS (ARM),
MPSS (modem) and other remote cores, depending on the platform
configuration.

This is a vastly cleaned up and restructured version of a similar
driver found in msm-5.4.

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230405-topic-master_stats-v6-2-2277b4433748@linaro.org

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index a491718f8064f9b0c347e9851e75a7d8cf6fd246..e597799e8121dad29c640ed933a52953458de426 100644 (file)
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -135,6 +135,17 @@ config QCOM_RMTFS_MEM
 
          Say y here if you intend to boot the modem remoteproc.
 
+config QCOM_RPM_MASTER_STATS
+       tristate "Qualcomm RPM Master stats"
+       depends on ARCH_QCOM || COMPILE_TEST
+       help
+         The RPM Master sleep stats driver provides detailed per-subsystem
+         sleep/wake data, read from the RPM message RAM. It can be used to
+         assess whether all the low-power modes available are entered as
+         expected or to check which part of the SoC prevents it from sleeping.
+
+         Say y here if you intend to debug or monitor platform sleep.
+
 config QCOM_RPMH
        tristate "Qualcomm RPM-Hardened (RPMH) Communication"
        depends on ARCH_QCOM || COMPILE_TEST

diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 0f43a88b4894e4675b7e456a08d906890c538829..7349371fdea1d6b2c34baf25f5cbbb94e0a42c37 100644 (file)
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_QCOM_QMI_HELPERS)        += qmi_helpers.o
 qmi_helpers-y  += qmi_encdec.o qmi_interface.o
 obj-$(CONFIG_QCOM_RAMP_CTRL)   += ramp_controller.o
 obj-$(CONFIG_QCOM_RMTFS_MEM)   += rmtfs_mem.o
+obj-$(CONFIG_QCOM_RPM_MASTER_STATS)    += rpm_master_stats.o
 obj-$(CONFIG_QCOM_RPMH)                += qcom_rpmh.o
 qcom_rpmh-y                    += rpmh-rsc.o
 qcom_rpmh-y                    += rpmh.o

diff --git a/drivers/soc/qcom/rpm_master_stats.c b/drivers/soc/qcom/rpm_master_stats.c
new file mode 100644 (file)
index 0000000..6dd98b9
--- /dev/null
+++ b/drivers/soc/qcom/rpm_master_stats.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023, Linaro Limited
+ *
+ * This driver supports what is known as "Master Stats v2" in Qualcomm
+ * downstream kernel terms, which seems to be the only version which has
+ * ever shipped, all the way from 2013 to 2023.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+
+struct master_stats_data {
+       void __iomem *base;
+       const char *label;
+};
+
+struct rpm_master_stats {
+       u32 active_cores;
+       u32 num_shutdowns;
+       u64 shutdown_req;
+       u64 wakeup_idx;
+       u64 bringup_req;
+       u64 bringup_ack;
+       u32 wakeup_reason; /* 0 = "rude wakeup", 1 = scheduled wakeup */
+       u32 last_sleep_trans_dur;
+       u32 last_wake_trans_dur;
+
+       /* Per-subsystem (*not necessarily* SoC-wide) XO shutdown stats */
+       u32 xo_count;
+       u64 xo_last_enter;
+       u64 last_exit;
+       u64 xo_total_dur;
+} __packed;
+
+static int master_stats_show(struct seq_file *s, void *unused)
+{
+       struct master_stats_data *data = s->private;
+       struct rpm_master_stats stat;
+
+       memcpy_fromio(&stat, data->base, sizeof(stat));
+
+       seq_printf(s, "%s:\n", data->label);
+
+       seq_printf(s, "\tLast shutdown @ %llu\n", stat.shutdown_req);
+       seq_printf(s, "\tLast bringup req @ %llu\n", stat.bringup_req);
+       seq_printf(s, "\tLast bringup ack @ %llu\n", stat.bringup_ack);
+       seq_printf(s, "\tLast wakeup idx: %llu\n", stat.wakeup_idx);
+       seq_printf(s, "\tLast XO shutdown enter @ %llu\n", stat.xo_last_enter);
+       seq_printf(s, "\tLast XO shutdown exit @ %llu\n", stat.last_exit);
+       seq_printf(s, "\tXO total duration: %llu\n", stat.xo_total_dur);
+       seq_printf(s, "\tLast sleep transition duration: %u\n", stat.last_sleep_trans_dur);
+       seq_printf(s, "\tLast wake transition duration: %u\n", stat.last_wake_trans_dur);
+       seq_printf(s, "\tXO shutdown count: %u\n", stat.xo_count);
+       seq_printf(s, "\tWakeup reason: 0x%x\n", stat.wakeup_reason);
+       seq_printf(s, "\tShutdown count: %u\n", stat.num_shutdowns);
+       seq_printf(s, "\tActive cores bitmask: 0x%x\n", stat.active_cores);
+
+       return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(master_stats);
+
+static int master_stats_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct master_stats_data *data;
+       struct device_node *msgram_np;
+       struct dentry *dent, *root;
+       struct resource res;
+       int count, i, ret;
+
+       count = of_property_count_strings(dev->of_node, "qcom,master-names");
+       if (count < 0)
+               return count;
+
+       data = devm_kzalloc(dev, count * sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       root = debugfs_create_dir("qcom_rpm_master_stats", NULL);
+       platform_set_drvdata(pdev, root);
+
+       for (i = 0; i < count; i++) {
+               msgram_np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", i);
+               if (!msgram_np) {
+                       debugfs_remove_recursive(root);
+                       return dev_err_probe(dev, -ENODEV,
+                                            "Couldn't parse MSG RAM phandle idx %d", i);
+               }
+
+               /*
+                * Purposefully skip devm_platform helpers as we're using a
+                * shared resource.
+                */
+               ret = of_address_to_resource(msgram_np, 0, &res);
+               of_node_put(msgram_np);
+               if (ret < 0) {
+                       debugfs_remove_recursive(root);
+                       return ret;
+               }
+
+               data[i].base = devm_ioremap(dev, res.start, resource_size(&res));
+               if (IS_ERR(data[i].base)) {
+                       debugfs_remove_recursive(root);
+                       return dev_err_probe(dev, -EINVAL,
+                                            "Could not map the MSG RAM slice idx %d!\n", i);
+               }
+
+               ret = of_property_read_string_index(dev->of_node, "qcom,master-names", i,
+                                                   &data[i].label);
+               if (ret < 0) {
+                       debugfs_remove_recursive(root);
+                       return dev_err_probe(dev, ret,
+                                            "Could not read name idx %d!\n", i);
+               }
+
+               /*
+                * Generally it's not advised to fail on debugfs errors, but this
+                * driver's only job is exposing data therein.
+                */
+               dent = debugfs_create_file(data[i].label, 0444, root,
+                                          &data[i], &master_stats_fops);
+               if (IS_ERR(dent)) {
+                       debugfs_remove_recursive(root);
+                       return dev_err_probe(dev, PTR_ERR(dent),
+                                            "Failed to create debugfs file %s!\n", data[i].label);
+               }
+       }
+
+       device_set_pm_not_required(dev);
+
+       return 0;
+}
+
+static void master_stats_remove(struct platform_device *pdev)
+{
+       struct dentry *root = platform_get_drvdata(pdev);
+
+       debugfs_remove_recursive(root);
+}
+
+static const struct of_device_id rpm_master_table[] = {
+       { .compatible = "qcom,rpm-master-stats" },
+       { },
+};
+
+static struct platform_driver master_stats_driver = {
+       .probe = master_stats_probe,
+       .remove_new = master_stats_remove,
+       .driver = {
+               .name = "qcom_rpm_master_stats",
+               .of_match_table = rpm_master_table,
+       },
+};
+module_platform_driver(master_stats_driver);
+
+MODULE_DESCRIPTION("Qualcomm RPM Master Statistics driver");
+MODULE_LICENSE("GPL");