1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Author: Yinbo Zhu <zhuyinbo@loongson.cn>
4 * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
5 */
6
7#include <linux/io.h>
8#include <linux/slab.h>
9#include <linux/module.h>
10#include <linux/of_fdt.h>
11#include <linux/sys_soc.h>
12#include <linux/of_address.h>
13#include <linux/platform_device.h>
14
15static struct soc_device_attribute soc_dev_attr;
16static struct soc_device *soc_dev;
17
18/*
19 * Global Utility Registers.
20 *
21 * Not all registers defined in this structure are available on all chips, so
22 * you are expected to know whether a given register actually exists on your
23 * chip before you access it.
24 *
25 * Also, some registers are similar on different chips but have slightly
26 * different names.  In these cases, one name is chosen to avoid extraneous
27 * #ifdefs.
28 */
29struct scfg_guts {
30	u32     svr;            /* Version Register */
31	u8      res0[4];
32	u16     feature;        /* Feature Register */
33	u32     vendor;         /* Vendor Register */
34	u8      res1[6];
35	u32     id;
36	u8      res2[0x3ff8 - 0x18];
37	u32     chip;
38};
39
40static struct guts {
41	struct scfg_guts __iomem *regs;
42	bool little_endian;
43} *guts;
44
45struct loongson2_soc_die_attr {
46	char	*die;
47	u32	svr;
48	u32	mask;
49};
50
51/* SoC die attribute definition for Loongson-2 platform */
52static const struct loongson2_soc_die_attr loongson2_soc_die[] = {
53
54	/*
55	 * LoongArch-based SoCs Loongson-2 Series
56	 */
57
58	/* Die: 2k1000, SoC: 2k1000 */
59	{ .die		= "2K1000",
60	  .svr		= 0x00000013,
61	  .mask		= 0x000000ff,
62	},
63	{ },
64};
65
66static const struct loongson2_soc_die_attr *loongson2_soc_die_match(
67	u32 svr, const struct loongson2_soc_die_attr *matches)
68{
69	while (matches->svr) {
70		if (matches->svr == (svr & matches->mask))
71			return matches;
72		matches++;
73	}
74
75	return NULL;
76}
77
78static u32 loongson2_guts_get_svr(void)
79{
80	u32 svr = 0;
81
82	if (!guts || !guts->regs)
83		return svr;
84
85	if (guts->little_endian)
86		svr = ioread32(&guts->regs->svr);
87	else
88		svr = ioread32be(&guts->regs->svr);
89
90	return svr;
91}
92
93static int loongson2_guts_probe(struct platform_device *pdev)
94{
95	struct device_node *root, *np = pdev->dev.of_node;
96	struct device *dev = &pdev->dev;
97	const struct loongson2_soc_die_attr *soc_die;
98	const char *machine;
99	u32 svr;
100
101	/* Initialize guts */
102	guts = devm_kzalloc(dev, sizeof(*guts), GFP_KERNEL);
103	if (!guts)
104		return -ENOMEM;
105
106	guts->little_endian = of_property_read_bool(np, "little-endian");
107
108	guts->regs = devm_platform_ioremap_resource(pdev, 0);
109	if (IS_ERR(guts->regs))
110		return PTR_ERR(guts->regs);
111
112	/* Register soc device */
113	root = of_find_node_by_path("/");
114	if (of_property_read_string(root, "model", &machine))
115		of_property_read_string_index(root, "compatible", 0, &machine);
116	of_node_put(root);
117	if (machine)
118		soc_dev_attr.machine = devm_kstrdup(dev, machine, GFP_KERNEL);
119
120	svr = loongson2_guts_get_svr();
121	soc_die = loongson2_soc_die_match(svr, loongson2_soc_die);
122	if (soc_die) {
123		soc_dev_attr.family = devm_kasprintf(dev, GFP_KERNEL,
124						     "Loongson %s", soc_die->die);
125	} else {
126		soc_dev_attr.family = devm_kasprintf(dev, GFP_KERNEL, "Loongson");
127	}
128	if (!soc_dev_attr.family)
129		return -ENOMEM;
130	soc_dev_attr.soc_id = devm_kasprintf(dev, GFP_KERNEL,
131					     "svr:0x%08x", svr);
132	if (!soc_dev_attr.soc_id)
133		return -ENOMEM;
134	soc_dev_attr.revision = devm_kasprintf(dev, GFP_KERNEL, "%d.%d",
135					       (svr >>  4) & 0xf, svr & 0xf);
136	if (!soc_dev_attr.revision)
137		return -ENOMEM;
138
139	soc_dev = soc_device_register(&soc_dev_attr);
140	if (IS_ERR(soc_dev))
141		return PTR_ERR(soc_dev);
142
143	pr_info("Machine: %s\n", soc_dev_attr.machine);
144	pr_info("SoC family: %s\n", soc_dev_attr.family);
145	pr_info("SoC ID: %s, Revision: %s\n",
146		soc_dev_attr.soc_id, soc_dev_attr.revision);
147
148	return 0;
149}
150
151static int loongson2_guts_remove(struct platform_device *dev)
152{
153	soc_device_unregister(soc_dev);
154
155	return 0;
156}
157
158/*
159 * Table for matching compatible strings, for device tree
160 * guts node, for Loongson-2 SoCs.
161 */
162static const struct of_device_id loongson2_guts_of_match[] = {
163	{ .compatible = "loongson,ls2k-chipid", },
164	{}
165};
166MODULE_DEVICE_TABLE(of, loongson2_guts_of_match);
167
168static struct platform_driver loongson2_guts_driver = {
169	.driver = {
170		.name = "loongson2-guts",
171		.of_match_table = loongson2_guts_of_match,
172	},
173	.probe = loongson2_guts_probe,
174	.remove = loongson2_guts_remove,
175};
176
177static int __init loongson2_guts_init(void)
178{
179	return platform_driver_register(&loongson2_guts_driver);
180}
181core_initcall(loongson2_guts_init);
182
183static void __exit loongson2_guts_exit(void)
184{
185	platform_driver_unregister(&loongson2_guts_driver);
186}
187module_exit(loongson2_guts_exit);
188
189MODULE_DESCRIPTION("Loongson2 GUTS driver");
190MODULE_LICENSE("GPL");
191