1 /*
2  * Copyright (C) 2014 Linaro Ltd.
3  *
4  * Author: Linus Walleij <linus.walleij@linaro.org>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2, as
8  * published by the Free Software Foundation.
9  *
10  */
11 #include <linux/init.h>
12 #include <linux/io.h>
13 #include <linux/slab.h>
14 #include <linux/sys_soc.h>
15 #include <linux/platform_device.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/regmap.h>
18 #include <linux/of.h>
19 
20 /* System ID in syscon */
21 #define REALVIEW_SYS_ID_OFFSET 0x00
22 
23 static const struct of_device_id realview_soc_of_match[] = {
24 	{ .compatible = "arm,realview-eb-soc",	},
25 	{ .compatible = "arm,realview-pb1176-soc", },
26 	{ .compatible = "arm,realview-pb11mp-soc", },
27 	{ .compatible = "arm,realview-pba8-soc", },
28 	{ .compatible = "arm,realview-pbx-soc", },
29 	{ }
30 };
31 
32 static u32 realview_coreid;
33 
34 static const char *realview_board_str(u32 id)
35 {
36 	switch ((id >> 16) & 0xfff) {
37 	case 0x0147:
38 		return "HBI-0147";
39 	case 0x0159:
40 		return "HBI-0159";
41 	default:
42 		return "Unknown";
43 	}
44 }
45 
46 static const char *realview_arch_str(u32 id)
47 {
48 	switch ((id >> 8) & 0xf) {
49 	case 0x04:
50 		return "AHB";
51 	case 0x05:
52 		return "Multi-layer AXI";
53 	default:
54 		return "Unknown";
55 	}
56 }
57 
58 static ssize_t realview_get_manf(struct device *dev,
59 			      struct device_attribute *attr,
60 			      char *buf)
61 {
62 	return sprintf(buf, "%02x\n", realview_coreid >> 24);
63 }
64 
65 static struct device_attribute realview_manf_attr =
66 	__ATTR(manufacturer,  S_IRUGO, realview_get_manf,  NULL);
67 
68 static ssize_t realview_get_board(struct device *dev,
69 			      struct device_attribute *attr,
70 			      char *buf)
71 {
72 	return sprintf(buf, "%s\n", realview_board_str(realview_coreid));
73 }
74 
75 static struct device_attribute realview_board_attr =
76 	__ATTR(board,  S_IRUGO, realview_get_board,  NULL);
77 
78 static ssize_t realview_get_arch(struct device *dev,
79 			      struct device_attribute *attr,
80 			      char *buf)
81 {
82 	return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
83 }
84 
85 static struct device_attribute realview_arch_attr =
86 	__ATTR(fpga,  S_IRUGO, realview_get_arch,  NULL);
87 
88 static ssize_t realview_get_build(struct device *dev,
89 			       struct device_attribute *attr,
90 			       char *buf)
91 {
92 	return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
93 }
94 
95 static struct device_attribute realview_build_attr =
96 	__ATTR(build,  S_IRUGO, realview_get_build,  NULL);
97 
98 static int realview_soc_probe(struct platform_device *pdev)
99 {
100 	static struct regmap *syscon_regmap;
101 	struct soc_device *soc_dev;
102 	struct soc_device_attribute *soc_dev_attr;
103 	struct device_node *np = pdev->dev.of_node;
104 	int ret;
105 
106 	syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
107 	if (IS_ERR(syscon_regmap))
108 		return PTR_ERR(syscon_regmap);
109 
110 	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
111 	if (!soc_dev_attr)
112 		return -ENOMEM;
113 
114 	ret = of_property_read_string(np, "compatible",
115 				      &soc_dev_attr->soc_id);
116 	if (ret)
117 		return -EINVAL;
118 
119 	soc_dev_attr->machine = "RealView";
120 	soc_dev_attr->family = "Versatile";
121 	soc_dev = soc_device_register(soc_dev_attr);
122 	if (IS_ERR(soc_dev)) {
123 		kfree(soc_dev_attr);
124 		return -ENODEV;
125 	}
126 	ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
127 			  &realview_coreid);
128 	if (ret)
129 		return -ENODEV;
130 
131 	device_create_file(soc_device_to_device(soc_dev), &realview_manf_attr);
132 	device_create_file(soc_device_to_device(soc_dev), &realview_board_attr);
133 	device_create_file(soc_device_to_device(soc_dev), &realview_arch_attr);
134 	device_create_file(soc_device_to_device(soc_dev), &realview_build_attr);
135 
136 	dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x\n",
137 		 realview_coreid);
138 	/* FIXME: add attributes for SoC to sysfs */
139 	return 0;
140 }
141 
142 static struct platform_driver realview_soc_driver = {
143 	.probe = realview_soc_probe,
144 	.driver = {
145 		.name = "realview-soc",
146 		.of_match_table = realview_soc_of_match,
147 	},
148 };
149 builtin_platform_driver(realview_soc_driver);
150