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	struct resource *res;
 98	const struct loongson2_soc_die_attr *soc_die;
 99	const char *machine;
100	u32 svr;
101
102	/* Initialize guts */
103	guts = devm_kzalloc(dev, sizeof(*guts), GFP_KERNEL);
104	if (!guts)
105		return -ENOMEM;
106
107	guts->little_endian = of_property_read_bool(np, "little-endian");
108
109	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
110	guts->regs = ioremap(res->start, res->end - res->start + 1);
111	if (IS_ERR(guts->regs))
112		return PTR_ERR(guts->regs);
113
114	/* Register soc device */
115	root = of_find_node_by_path("/");
116	if (of_property_read_string(root, "model", &machine))
117		of_property_read_string_index(root, "compatible", 0, &machine);
118	of_node_put(root);
119	if (machine)
120		soc_dev_attr.machine = devm_kstrdup(dev, machine, GFP_KERNEL);
121
122	svr = loongson2_guts_get_svr();
123	soc_die = loongson2_soc_die_match(svr, loongson2_soc_die);
124	if (soc_die) {
125		soc_dev_attr.family = devm_kasprintf(dev, GFP_KERNEL,
126						     "Loongson %s", soc_die->die);
127	} else {
128		soc_dev_attr.family = devm_kasprintf(dev, GFP_KERNEL, "Loongson");
129	}
130	if (!soc_dev_attr.family)
131		return -ENOMEM;
132	soc_dev_attr.soc_id = devm_kasprintf(dev, GFP_KERNEL,
133					     "svr:0x%08x", svr);
134	if (!soc_dev_attr.soc_id)
135		return -ENOMEM;
136	soc_dev_attr.revision = devm_kasprintf(dev, GFP_KERNEL, "%d.%d",
137					       (svr >>  4) & 0xf, svr & 0xf);
138	if (!soc_dev_attr.revision)
139		return -ENOMEM;
140
141	soc_dev = soc_device_register(&soc_dev_attr);
142	if (IS_ERR(soc_dev))
143		return PTR_ERR(soc_dev);
144
145	pr_info("Machine: %s\n", soc_dev_attr.machine);
146	pr_info("SoC family: %s\n", soc_dev_attr.family);
147	pr_info("SoC ID: %s, Revision: %s\n",
148		soc_dev_attr.soc_id, soc_dev_attr.revision);
149
150	return 0;
151}
152
153static int loongson2_guts_remove(struct platform_device *dev)
154{
155	soc_device_unregister(soc_dev);
156
157	return 0;
158}
159
160/*
161 * Table for matching compatible strings, for device tree
162 * guts node, for Loongson-2 SoCs.
163 */
164static const struct of_device_id loongson2_guts_of_match[] = {
165	{ .compatible = "loongson,ls2k-chipid", },
166	{}
167};
168MODULE_DEVICE_TABLE(of, loongson2_guts_of_match);
169
170static struct platform_driver loongson2_guts_driver = {
171	.driver = {
172		.name = "loongson2-guts",
173		.of_match_table = loongson2_guts_of_match,
174	},
175	.probe = loongson2_guts_probe,
176	.remove = loongson2_guts_remove,
177};
178
179static int __init loongson2_guts_init(void)
180{
181	return platform_driver_register(&loongson2_guts_driver);
182}
183core_initcall(loongson2_guts_init);
184
185static void __exit loongson2_guts_exit(void)
186{
187	platform_driver_unregister(&loongson2_guts_driver);
188}
189module_exit(loongson2_guts_exit);
190
191MODULE_DESCRIPTION("Loongson2 GUTS driver");
192MODULE_LICENSE("GPL");