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
15 static struct soc_device_attribute soc_dev_attr;
16 static 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 */
29 struct 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
40 static struct guts {
41 struct scfg_guts __iomem *regs;
42 bool little_endian;
43 } *guts;
44
45 struct loongson2_soc_die_attr {
46 char *die;
47 u32 svr;
48 u32 mask;
49 };
50
51 /* SoC die attribute definition for Loongson-2 platform */
52 static 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
loongson2_soc_die_match(u32 svr,const struct loongson2_soc_die_attr * matches)66 static 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
loongson2_guts_get_svr(void)78 static 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
loongson2_guts_probe(struct platform_device * pdev)93 static 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 if (!soc_dev_attr.machine)
120 return -ENOMEM;
121 }
122
123 svr = loongson2_guts_get_svr();
124 soc_die = loongson2_soc_die_match(svr, loongson2_soc_die);
125 if (soc_die) {
126 soc_dev_attr.family = devm_kasprintf(dev, GFP_KERNEL,
127 "Loongson %s", soc_die->die);
128 } else {
129 soc_dev_attr.family = devm_kasprintf(dev, GFP_KERNEL, "Loongson");
130 }
131 if (!soc_dev_attr.family)
132 return -ENOMEM;
133 soc_dev_attr.soc_id = devm_kasprintf(dev, GFP_KERNEL,
134 "svr:0x%08x", svr);
135 if (!soc_dev_attr.soc_id)
136 return -ENOMEM;
137 soc_dev_attr.revision = devm_kasprintf(dev, GFP_KERNEL, "%d.%d",
138 (svr >> 4) & 0xf, svr & 0xf);
139 if (!soc_dev_attr.revision)
140 return -ENOMEM;
141
142 soc_dev = soc_device_register(&soc_dev_attr);
143 if (IS_ERR(soc_dev))
144 return PTR_ERR(soc_dev);
145
146 pr_info("Machine: %s\n", soc_dev_attr.machine);
147 pr_info("SoC family: %s\n", soc_dev_attr.family);
148 pr_info("SoC ID: %s, Revision: %s\n",
149 soc_dev_attr.soc_id, soc_dev_attr.revision);
150
151 return 0;
152 }
153
loongson2_guts_remove(struct platform_device * dev)154 static int loongson2_guts_remove(struct platform_device *dev)
155 {
156 soc_device_unregister(soc_dev);
157
158 return 0;
159 }
160
161 /*
162 * Table for matching compatible strings, for device tree
163 * guts node, for Loongson-2 SoCs.
164 */
165 static const struct of_device_id loongson2_guts_of_match[] = {
166 { .compatible = "loongson,ls2k-chipid", },
167 {}
168 };
169 MODULE_DEVICE_TABLE(of, loongson2_guts_of_match);
170
171 static struct platform_driver loongson2_guts_driver = {
172 .driver = {
173 .name = "loongson2-guts",
174 .of_match_table = loongson2_guts_of_match,
175 },
176 .probe = loongson2_guts_probe,
177 .remove = loongson2_guts_remove,
178 };
179
loongson2_guts_init(void)180 static int __init loongson2_guts_init(void)
181 {
182 return platform_driver_register(&loongson2_guts_driver);
183 }
184 core_initcall(loongson2_guts_init);
185
loongson2_guts_exit(void)186 static void __exit loongson2_guts_exit(void)
187 {
188 platform_driver_unregister(&loongson2_guts_driver);
189 }
190 module_exit(loongson2_guts_exit);
191
192 MODULE_DESCRIPTION("Loongson2 GUTS driver");
193 MODULE_LICENSE("GPL");
194