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 void loongson2_guts_remove(struct platform_device *dev)
152{
153	soc_device_unregister(soc_dev);
154}
155
156/*
157 * Table for matching compatible strings, for device tree
158 * guts node, for Loongson-2 SoCs.
159 */
160static const struct of_device_id loongson2_guts_of_match[] = {
161	{ .compatible = "loongson,ls2k-chipid", },
162	{}
163};
164MODULE_DEVICE_TABLE(of, loongson2_guts_of_match);
165
166static struct platform_driver loongson2_guts_driver = {
167	.driver = {
168		.name = "loongson2-guts",
169		.of_match_table = loongson2_guts_of_match,
170	},
171	.probe = loongson2_guts_probe,
172	.remove_new = loongson2_guts_remove,
173};
174
175static int __init loongson2_guts_init(void)
176{
177	return platform_driver_register(&loongson2_guts_driver);
178}
179core_initcall(loongson2_guts_init);
180
181static void __exit loongson2_guts_exit(void)
182{
183	platform_driver_unregister(&loongson2_guts_driver);
184}
185module_exit(loongson2_guts_exit);
186
187MODULE_DESCRIPTION("Loongson2 GUTS driver");
188MODULE_LICENSE("GPL");