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
 18struct master_stats_data {
 19	void __iomem *base;
 20	const char *label;
 21};
 22
 23struct 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
 41static 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}
 66DEFINE_SHOW_ATTRIBUTE(master_stats);
 67
 68static 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_kcalloc(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
140static 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
147static const struct of_device_id rpm_master_table[] = {
148	{ .compatible = "qcom,rpm-master-stats" },
149	{ },
150};
151/*
152 * No MODULE_DEVICE_TABLE intentionally: that's a debugging module, to be
153 * loaded manually only.
154 */
155
156static struct platform_driver master_stats_driver = {
157	.probe = master_stats_probe,
158	.remove = master_stats_remove,
159	.driver = {
160		.name = "qcom_rpm_master_stats",
161		.of_match_table = rpm_master_table,
162	},
163};
164module_platform_driver(master_stats_driver);
165
166MODULE_DESCRIPTION("Qualcomm RPM Master Statistics driver");
167MODULE_LICENSE("GPL");