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_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
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
152static 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};
160module_platform_driver(master_stats_driver);
161
162MODULE_DESCRIPTION("Qualcomm RPM Master Statistics driver");
163MODULE_LICENSE("GPL");
164