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 static u32 realview_coreid;
32 
33 static const char *realview_board_str(u32 id)
34 {
35 	switch ((id >> 16) & 0xfff) {
36 	case 0x0147:
37 		return "HBI-0147";
38 	default:
39 		return "Unknown";
40 	}
41 }
42 
43 static const char *realview_arch_str(u32 id)
44 {
45 	switch ((id >> 8) & 0xf) {
46 	case 0x05:
47 		return "Multi-layer AXI";
48 	default:
49 		return "Unknown";
50 	}
51 }
52 
53 static ssize_t realview_get_manf(struct device *dev,
54 			      struct device_attribute *attr,
55 			      char *buf)
56 {
57 	return sprintf(buf, "%02x\n", realview_coreid >> 24);
58 }
59 
60 static struct device_attribute realview_manf_attr =
61 	__ATTR(manufacturer,  S_IRUGO, realview_get_manf,  NULL);
62 
63 static ssize_t realview_get_board(struct device *dev,
64 			      struct device_attribute *attr,
65 			      char *buf)
66 {
67 	return sprintf(buf, "%s\n", realview_board_str(realview_coreid));
68 }
69 
70 static struct device_attribute realview_board_attr =
71 	__ATTR(board,  S_IRUGO, realview_get_board,  NULL);
72 
73 static ssize_t realview_get_arch(struct device *dev,
74 			      struct device_attribute *attr,
75 			      char *buf)
76 {
77 	return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
78 }
79 
80 static struct device_attribute realview_arch_attr =
81 	__ATTR(fpga,  S_IRUGO, realview_get_arch,  NULL);
82 
83 static ssize_t realview_get_build(struct device *dev,
84 			       struct device_attribute *attr,
85 			       char *buf)
86 {
87 	return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
88 }
89 
90 static struct device_attribute realview_build_attr =
91 	__ATTR(build,  S_IRUGO, realview_get_build,  NULL);
92 
93 static int realview_soc_probe(struct platform_device *pdev)
94 {
95 	static struct regmap *syscon_regmap;
96 	struct soc_device *soc_dev;
97 	struct soc_device_attribute *soc_dev_attr;
98 	struct device_node *np = pdev->dev.of_node;
99 	int ret;
100 
101 	syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
102 	if (IS_ERR(syscon_regmap))
103 		return PTR_ERR(syscon_regmap);
104 
105 	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
106 	if (!soc_dev_attr)
107 		return -ENOMEM;
108 
109 	ret = of_property_read_string(np, "compatible",
110 				      &soc_dev_attr->soc_id);
111 	if (ret)
112 		return -EINVAL;
113 
114 	soc_dev_attr->machine = "RealView";
115 	soc_dev_attr->family = "Versatile";
116 	soc_dev = soc_device_register(soc_dev_attr);
117 	if (IS_ERR(soc_dev)) {
118 		kfree(soc_dev_attr);
119 		return -ENODEV;
120 	}
121 	ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
122 			  &realview_coreid);
123 	if (ret)
124 		return -ENODEV;
125 
126 	device_create_file(soc_device_to_device(soc_dev), &realview_manf_attr);
127 	device_create_file(soc_device_to_device(soc_dev), &realview_board_attr);
128 	device_create_file(soc_device_to_device(soc_dev), &realview_arch_attr);
129 	device_create_file(soc_device_to_device(soc_dev), &realview_build_attr);
130 
131 	dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x\n",
132 		 realview_coreid);
133 	/* FIXME: add attributes for SoC to sysfs */
134 	return 0;
135 }
136 
137 static struct platform_driver realview_soc_driver = {
138 	.probe = realview_soc_probe,
139 	.driver = {
140 		.name = "realview-soc",
141 		.of_match_table = realview_soc_of_match,
142 	},
143 };
144 module_platform_driver(realview_soc_driver);
145