xref: /linux/drivers/soc/vt8500/wmt-socinfo.c (revision 297d9111e9fcf47dd1dcc6f79bba915f35378d01)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2025 Alexey Charkov <alchark@gmail.com>
4  * Based on aspeed-socinfo.c
5  */
6 
7 #include <linux/dev_printk.h>
8 #include <linux/device.h>
9 #include <linux/io.h>
10 #include <linux/of.h>
11 #include <linux/platform_device.h>
12 #include <linux/sys_soc.h>
13 
14 static const struct {
15 	const char *name;
16 	const u32 id;
17 } chip_id_table[] = {
18 	/* VIA */
19 	{ "VT8420", 0x3300 },
20 	{ "VT8430", 0x3357 },
21 	{ "VT8500", 0x3400 },
22 
23 	/* WonderMedia */
24 	{ "WM8425", 0x3429 },
25 	{ "WM8435", 0x3437 },
26 	{ "WM8440", 0x3451 },
27 	{ "WM8505", 0x3426 },
28 	{ "WM8650", 0x3465 },
29 	{ "WM8750", 0x3445 },
30 	{ "WM8850", 0x3481 },
31 	{ "WM8880", 0x3498 },
32 };
33 
sccid_to_name(u32 sccid)34 static const char *sccid_to_name(u32 sccid)
35 {
36 	u32 id = sccid >> 16;
37 	unsigned int i;
38 
39 	for (i = 0 ; i < ARRAY_SIZE(chip_id_table) ; ++i) {
40 		if (chip_id_table[i].id == id)
41 			return chip_id_table[i].name;
42 	}
43 
44 	return "Unknown";
45 }
46 
wmt_socinfo_probe(struct platform_device * pdev)47 static int wmt_socinfo_probe(struct platform_device *pdev)
48 {
49 	struct device_node *np = pdev->dev.of_node;
50 	struct soc_device_attribute *attrs;
51 	struct soc_device *soc_dev;
52 	char letter, digit;
53 	void __iomem *reg;
54 	u32 sccid;
55 
56 	reg = devm_of_iomap(&pdev->dev, np, 0, NULL);
57 	if (IS_ERR(reg))
58 		return PTR_ERR(reg);
59 
60 	sccid = readl(reg);
61 
62 	attrs = devm_kzalloc(&pdev->dev, sizeof(*attrs), GFP_KERNEL);
63 	if (!attrs)
64 		return -ENOMEM;
65 
66 	/*
67 	 * Machine: VIA APC Rock
68 	 * Family: WM8850
69 	 * Revision: A2
70 	 * SoC ID: raw silicon revision id (34810103 in hexadecimal)
71 	 */
72 
73 	attrs->family = sccid_to_name(sccid);
74 
75 	letter = (sccid >> 8) & 0xf;
76 	letter = (letter - 1) + 'A';
77 	digit = sccid & 0xff;
78 	digit = (digit - 1) + '0';
79 	attrs->revision = devm_kasprintf(&pdev->dev, GFP_KERNEL,
80 					 "%c%c", letter, digit);
81 
82 	attrs->soc_id = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%08x", sccid);
83 
84 	if (!attrs->revision || !attrs->soc_id)
85 		return -ENOMEM;
86 
87 	soc_dev = soc_device_register(attrs);
88 	if (IS_ERR(soc_dev))
89 		return PTR_ERR(soc_dev);
90 
91 	dev_info(&pdev->dev,
92 		 "VIA/WonderMedia %s rev %s (%s)\n",
93 		 attrs->family,
94 		 attrs->revision,
95 		 attrs->soc_id);
96 
97 	platform_set_drvdata(pdev, soc_dev);
98 	return 0;
99 }
100 
wmt_socinfo_remove(struct platform_device * pdev)101 static void wmt_socinfo_remove(struct platform_device *pdev)
102 {
103 	struct soc_device *soc_dev = platform_get_drvdata(pdev);
104 
105 	soc_device_unregister(soc_dev);
106 }
107 
108 static const struct of_device_id wmt_socinfo_ids[] = {
109 	{ .compatible = "via,vt8500-scc-id" },
110 	{ /* Sentinel */ },
111 };
112 
113 static struct platform_driver wmt_socinfo = {
114 	.probe = wmt_socinfo_probe,
115 	.remove = wmt_socinfo_remove,
116 	.driver = {
117 		.name = "wmt-socinfo",
118 		.of_match_table = wmt_socinfo_ids,
119 	},
120 };
121 module_platform_driver(wmt_socinfo);
122 
123 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
124 MODULE_DESCRIPTION("VIA/WonderMedia socinfo driver");
125 MODULE_LICENSE("GPL");
126