xref: /linux/drivers/firmware/imx/sm-misc.c (revision 69050f8d6d075dc01af7a5f2f550a8067510366f)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2024 NXP
4  */
5 
6 #include <linux/debugfs.h>
7 #include <linux/device/devres.h>
8 #include <linux/firmware/imx/sm.h>
9 #include <linux/module.h>
10 #include <linux/of.h>
11 #include <linux/platform_device.h>
12 #include <linux/scmi_protocol.h>
13 #include <linux/scmi_imx_protocol.h>
14 #include <linux/seq_file.h>
15 #include <linux/sizes.h>
16 
17 static const struct scmi_imx_misc_proto_ops *imx_misc_ctrl_ops;
18 static struct scmi_protocol_handle *ph;
19 struct notifier_block scmi_imx_misc_ctrl_nb;
20 
21 int scmi_imx_misc_ctrl_set(u32 id, u32 val)
22 {
23 	if (!ph)
24 		return -EPROBE_DEFER;
25 
26 	return imx_misc_ctrl_ops->misc_ctrl_set(ph, id, 1, &val);
27 };
28 EXPORT_SYMBOL(scmi_imx_misc_ctrl_set);
29 
30 int scmi_imx_misc_ctrl_get(u32 id, u32 *num, u32 *val)
31 {
32 	if (!ph)
33 		return -EPROBE_DEFER;
34 
35 	return imx_misc_ctrl_ops->misc_ctrl_get(ph, id, num, val);
36 }
37 EXPORT_SYMBOL(scmi_imx_misc_ctrl_get);
38 
39 static int scmi_imx_misc_ctrl_notifier(struct notifier_block *nb,
40 				       unsigned long event, void *data)
41 {
42 	/*
43 	 * notifier_chain_register requires a valid notifier_block and
44 	 * valid notifier_call. SCMI_EVENT_IMX_MISC_CONTROL is needed
45 	 * to let SCMI firmware enable control events, but the hook here
46 	 * is just a dummy function to avoid kernel panic as of now.
47 	 */
48 	return 0;
49 }
50 
51 static int syslog_show(struct seq_file *file, void *priv)
52 {
53 	/* 4KB is large enough for syslog */
54 	void *syslog __free(kfree) = kmalloc(SZ_4K, GFP_KERNEL);
55 	/* syslog API use num words, not num bytes */
56 	u16 size = SZ_4K / 4;
57 	int ret;
58 
59 	if (!ph)
60 		return -ENODEV;
61 
62 	ret = imx_misc_ctrl_ops->misc_syslog(ph, &size, syslog);
63 	if (ret)
64 		return ret;
65 
66 	seq_hex_dump(file, " ", DUMP_PREFIX_NONE, 16, sizeof(u32), syslog, size * 4, false);
67 	seq_putc(file, '\n');
68 
69 	return 0;
70 }
71 DEFINE_SHOW_ATTRIBUTE(syslog);
72 
73 static void scmi_imx_misc_put(void *p)
74 {
75 	debugfs_remove((struct dentry *)p);
76 }
77 
78 static int scmi_imx_misc_ctrl_probe(struct scmi_device *sdev)
79 {
80 	const struct scmi_handle *handle = sdev->handle;
81 	struct device_node *np = sdev->dev.of_node;
82 	struct dentry *scmi_imx_dentry;
83 	u32 src_id, flags;
84 	int ret, i, num;
85 
86 	if (!handle)
87 		return -ENODEV;
88 
89 	if (imx_misc_ctrl_ops) {
90 		dev_err(&sdev->dev, "misc ctrl already initialized\n");
91 		return -EEXIST;
92 	}
93 
94 	imx_misc_ctrl_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_IMX_MISC, &ph);
95 	if (IS_ERR(imx_misc_ctrl_ops))
96 		return PTR_ERR(imx_misc_ctrl_ops);
97 
98 	num = of_property_count_u32_elems(np, "nxp,ctrl-ids");
99 	if (num % 2) {
100 		dev_err(&sdev->dev, "Invalid wakeup-sources\n");
101 		return -EINVAL;
102 	}
103 
104 	scmi_imx_misc_ctrl_nb.notifier_call = &scmi_imx_misc_ctrl_notifier;
105 	for (i = 0; i < num; i += 2) {
106 		ret = of_property_read_u32_index(np, "nxp,ctrl-ids", i, &src_id);
107 		if (ret) {
108 			dev_err(&sdev->dev, "Failed to read ctrl-id: %i\n", i);
109 			continue;
110 		}
111 
112 		ret = of_property_read_u32_index(np, "nxp,ctrl-ids", i + 1, &flags);
113 		if (ret) {
114 			dev_err(&sdev->dev, "Failed to read ctrl-id value: %d\n", i + 1);
115 			continue;
116 		}
117 
118 		ret = handle->notify_ops->devm_event_notifier_register(sdev, SCMI_PROTOCOL_IMX_MISC,
119 								       SCMI_EVENT_IMX_MISC_CONTROL,
120 								       &src_id,
121 								       &scmi_imx_misc_ctrl_nb);
122 		if (ret) {
123 			dev_err(&sdev->dev, "Failed to register scmi misc event: %d\n", src_id);
124 		} else {
125 			ret = imx_misc_ctrl_ops->misc_ctrl_req_notify(ph, src_id,
126 								      SCMI_EVENT_IMX_MISC_CONTROL,
127 								      flags);
128 			if (ret)
129 				dev_err(&sdev->dev, "Failed to req notify: %d\n", src_id);
130 		}
131 	}
132 
133 	scmi_imx_dentry = debugfs_create_dir("scmi_imx", NULL);
134 	debugfs_create_file("syslog", 0444, scmi_imx_dentry, &sdev->dev, &syslog_fops);
135 
136 	return devm_add_action_or_reset(&sdev->dev, scmi_imx_misc_put, scmi_imx_dentry);
137 }
138 
139 static const struct scmi_device_id scmi_id_table[] = {
140 	{ SCMI_PROTOCOL_IMX_MISC, "imx-misc-ctrl" },
141 	{ },
142 };
143 MODULE_DEVICE_TABLE(scmi, scmi_id_table);
144 
145 static struct scmi_driver scmi_imx_misc_ctrl_driver = {
146 	.name = "scmi-imx-misc-ctrl",
147 	.probe = scmi_imx_misc_ctrl_probe,
148 	.id_table = scmi_id_table,
149 };
150 module_scmi_driver(scmi_imx_misc_ctrl_driver);
151 
152 MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
153 MODULE_DESCRIPTION("IMX SM MISC driver");
154 MODULE_LICENSE("GPL");
155