drivers/soc/qcom/rpm_master_stats.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
   4  * Copyright (c) 2023, Linaro Limited
   5  *
   6  * This driver supports what is known as "Master Stats v2" in Qualcomm
   7  * downstream kernel terms, which seems to be the only version which has
   8  * ever shipped, all the way from 2013 to 2023.
   9  */
  10
  11 #include <linux/debugfs.h>
  12 #include <linux/io.h>
  13 #include <linux/module.h>
  14 #include <linux/of.h>
  15 #include <linux/of_address.h>
  16 #include <linux/platform_device.h>
  17
  18 struct master_stats_data {
  19         void __iomem *base;
  20         const char *label;
  21 };
  22
  23 struct rpm_master_stats {
  24         u32 active_cores;
  25         u32 num_shutdowns;
  26         u64 shutdown_req;
  27         u64 wakeup_idx;
  28         u64 bringup_req;
  29         u64 bringup_ack;
  30         u32 wakeup_reason; /* 0 = "rude wakeup", 1 = scheduled wakeup */
  31         u32 last_sleep_trans_dur;
  32         u32 last_wake_trans_dur;
  33
  34         /* Per-subsystem (*not necessarily* SoC-wide) XO shutdown stats */
  35         u32 xo_count;
  36         u64 xo_last_enter;
  37         u64 last_exit;
  38         u64 xo_total_dur;
  39 } __packed;
  40
  41 static int master_stats_show(struct seq_file *s, void *unused)
  42 {
  43         struct master_stats_data *data = s->private;
  44         struct rpm_master_stats stat;
  45
  46         memcpy_fromio(&stat, data->base, sizeof(stat));
  47
  48         seq_printf(s, "%s:\n", data->label);
  49
  50         seq_printf(s, "\tLast shutdown @ %llu\n", stat.shutdown_req);
  51         seq_printf(s, "\tLast bringup req @ %llu\n", stat.bringup_req);
  52         seq_printf(s, "\tLast bringup ack @ %llu\n", stat.bringup_ack);
  53         seq_printf(s, "\tLast wakeup idx: %llu\n", stat.wakeup_idx);
  54         seq_printf(s, "\tLast XO shutdown enter @ %llu\n", stat.xo_last_enter);
  55         seq_printf(s, "\tLast XO shutdown exit @ %llu\n", stat.last_exit);
  56         seq_printf(s, "\tXO total duration: %llu\n", stat.xo_total_dur);
  57         seq_printf(s, "\tLast sleep transition duration: %u\n", stat.last_sleep_trans_dur);
  58         seq_printf(s, "\tLast wake transition duration: %u\n", stat.last_wake_trans_dur);
  59         seq_printf(s, "\tXO shutdown count: %u\n", stat.xo_count);
  60         seq_printf(s, "\tWakeup reason: 0x%x\n", stat.wakeup_reason);
  61         seq_printf(s, "\tShutdown count: %u\n", stat.num_shutdowns);
  62         seq_printf(s, "\tActive cores bitmask: 0x%x\n", stat.active_cores);
  63
  64         return 0;
  65 }
  66 DEFINE_SHOW_ATTRIBUTE(master_stats);
  67
  68 static int master_stats_probe(struct platform_device *pdev)
  69 {
  70         struct device *dev = &pdev->dev;
  71         struct master_stats_data *data;
  72         struct device_node *msgram_np;
  73         struct dentry *dent, *root;
  74         struct resource res;
  75         int count, i, ret;
  76
  77         count = of_property_count_strings(dev->of_node, "qcom,master-names");
  78         if (count < 0)
  79                 return count;
  80
  81         data = devm_kzalloc(dev, count * sizeof(*data), GFP_KERNEL);
  82         if (!data)
  83                 return -ENOMEM;
  84
  85         root = debugfs_create_dir("qcom_rpm_master_stats", NULL);
  86         platform_set_drvdata(pdev, root);
  87
  88         for (i = 0; i < count; i++) {
  89                 msgram_np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", i);
  90                 if (!msgram_np) {
  91                         debugfs_remove_recursive(root);
  92                         return dev_err_probe(dev, -ENODEV,
  93                                              "Couldn't parse MSG RAM phandle idx %d", i);
  94                 }
  95
  96                 /*
  97                  * Purposefully skip devm_platform helpers as we're using a
  98                  * shared resource.
  99                  */
 100                 ret = of_address_to_resource(msgram_np, 0, &res);
 101                 of_node_put(msgram_np);
 102                 if (ret < 0) {
 103                         debugfs_remove_recursive(root);
 104                         return ret;
 105                 }
 106
 107                 data[i].base = devm_ioremap(dev, res.start, resource_size(&res));
 108                 if (!data[i].base) {
 109                         debugfs_remove_recursive(root);
 110                         return dev_err_probe(dev, -EINVAL,
 111                                              "Could not map the MSG RAM slice idx %d!\n", i);
 112                 }
 113
 114                 ret = of_property_read_string_index(dev->of_node, "qcom,master-names", i,
 115                                                     &data[i].label);
 116                 if (ret < 0) {
 117                         debugfs_remove_recursive(root);
 118                         return dev_err_probe(dev, ret,
 119                                              "Could not read name idx %d!\n", i);
 120                 }
 121
 122                 /*
 123                  * Generally it's not advised to fail on debugfs errors, but this
 124                  * driver's only job is exposing data therein.
 125                  */
 126                 dent = debugfs_create_file(data[i].label, 0444, root,
 127                                            &data[i], &master_stats_fops);
 128                 if (IS_ERR(dent)) {
 129                         debugfs_remove_recursive(root);
 130                         return dev_err_probe(dev, PTR_ERR(dent),
 131                                              "Failed to create debugfs file %s!\n", data[i].label);
 132                 }
 133         }
 134
 135         device_set_pm_not_required(dev);
 136
 137         return 0;
 138 }
 139
 140 static void master_stats_remove(struct platform_device *pdev)
 141 {
 142         struct dentry *root = platform_get_drvdata(pdev);
 143
 144         debugfs_remove_recursive(root);
 145 }
 146
 147 static const struct of_device_id rpm_master_table[] = {
 148         { .compatible = "qcom,rpm-master-stats" },
 149         { },
 150 };
 151
 152 static struct platform_driver master_stats_driver = {
 153         .probe = master_stats_probe,
 154         .remove_new = master_stats_remove,
 155         .driver = {
 156                 .name = "qcom_rpm_master_stats",
 157                 .of_match_table = rpm_master_table,
 158         },
 159 };
 160 module_platform_driver(master_stats_driver);
 161
 162 MODULE_DESCRIPTION("Qualcomm RPM Master Statistics driver");
 163 MODULE_LICENSE("GPL");