1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 Linaro Ltd.
4  *
5  * Author: Linus Walleij <linus.walleij@linaro.org>
6  */
7 #include <linux/init.h>
8 #include <linux/io.h>
9 #include <linux/slab.h>
10 #include <linux/sys_soc.h>
11 #include <linux/platform_device.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/regmap.h>
14 #include <linux/of.h>
15 
16 /* System ID in syscon */
17 #define REALVIEW_SYS_ID_OFFSET 0x00
18 
19 static const struct of_device_id realview_soc_of_match[] = {
20 	{ .compatible = "arm,realview-eb-soc",	},
21 	{ .compatible = "arm,realview-pb1176-soc", },
22 	{ .compatible = "arm,realview-pb11mp-soc", },
23 	{ .compatible = "arm,realview-pba8-soc", },
24 	{ .compatible = "arm,realview-pbx-soc", },
25 	{ }
26 };
27 
28 static u32 realview_coreid;
29 
30 static const char *realview_arch_str(u32 id)
31 {
32 	switch ((id >> 8) & 0xf) {
33 	case 0x04:
34 		return "AHB";
35 	case 0x05:
36 		return "Multi-layer AXI";
37 	default:
38 		return "Unknown";
39 	}
40 }
41 
42 static ssize_t realview_get_manf(struct device *dev,
43 			      struct device_attribute *attr,
44 			      char *buf)
45 {
46 	return sprintf(buf, "%02x\n", realview_coreid >> 24);
47 }
48 
49 static struct device_attribute realview_manf_attr =
50 	__ATTR(manufacturer,  S_IRUGO, realview_get_manf,  NULL);
51 
52 static ssize_t realview_get_board(struct device *dev,
53 			      struct device_attribute *attr,
54 			      char *buf)
55 {
56 	return sprintf(buf, "HBI-%03x\n", ((realview_coreid >> 16) & 0xfff));
57 }
58 
59 static struct device_attribute realview_board_attr =
60 	__ATTR(board,  S_IRUGO, realview_get_board,  NULL);
61 
62 static ssize_t realview_get_arch(struct device *dev,
63 			      struct device_attribute *attr,
64 			      char *buf)
65 {
66 	return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
67 }
68 
69 static struct device_attribute realview_arch_attr =
70 	__ATTR(fpga,  S_IRUGO, realview_get_arch,  NULL);
71 
72 static ssize_t realview_get_build(struct device *dev,
73 			       struct device_attribute *attr,
74 			       char *buf)
75 {
76 	return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
77 }
78 
79 static struct device_attribute realview_build_attr =
80 	__ATTR(build,  S_IRUGO, realview_get_build,  NULL);
81 
82 static int realview_soc_probe(struct platform_device *pdev)
83 {
84 	struct regmap *syscon_regmap;
85 	struct soc_device *soc_dev;
86 	struct soc_device_attribute *soc_dev_attr;
87 	struct device_node *np = pdev->dev.of_node;
88 	int ret;
89 
90 	syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
91 	if (IS_ERR(syscon_regmap))
92 		return PTR_ERR(syscon_regmap);
93 
94 	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
95 	if (!soc_dev_attr)
96 		return -ENOMEM;
97 
98 	ret = of_property_read_string(np, "compatible",
99 				      &soc_dev_attr->soc_id);
100 	if (ret)
101 		return -EINVAL;
102 
103 	soc_dev_attr->machine = "RealView";
104 	soc_dev_attr->family = "Versatile";
105 	soc_dev = soc_device_register(soc_dev_attr);
106 	if (IS_ERR(soc_dev)) {
107 		kfree(soc_dev_attr);
108 		return -ENODEV;
109 	}
110 	ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
111 			  &realview_coreid);
112 	if (ret)
113 		return -ENODEV;
114 
115 	device_create_file(soc_device_to_device(soc_dev), &realview_manf_attr);
116 	device_create_file(soc_device_to_device(soc_dev), &realview_board_attr);
117 	device_create_file(soc_device_to_device(soc_dev), &realview_arch_attr);
118 	device_create_file(soc_device_to_device(soc_dev), &realview_build_attr);
119 
120 	dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x, HBI-%03x\n",
121 		 realview_coreid,
122 		 ((realview_coreid >> 16) & 0xfff));
123 	/* FIXME: add attributes for SoC to sysfs */
124 	return 0;
125 }
126 
127 static struct platform_driver realview_soc_driver = {
128 	.probe = realview_soc_probe,
129 	.driver = {
130 		.name = "realview-soc",
131 		.of_match_table = realview_soc_of_match,
132 	},
133 };
134 builtin_platform_driver(realview_soc_driver);
135