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
realview_arch_str(u32 id)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
manufacturer_show(struct device * dev,struct device_attribute * attr,char * buf)43 manufacturer_show(struct device *dev, struct device_attribute *attr, char *buf)
44 {
45 return sprintf(buf, "%02x\n", realview_coreid >> 24);
46 }
47
48 static DEVICE_ATTR_RO(manufacturer);
49
50 static ssize_t
board_show(struct device * dev,struct device_attribute * attr,char * buf)51 board_show(struct device *dev, struct device_attribute *attr, char *buf)
52 {
53 return sprintf(buf, "HBI-%03x\n", ((realview_coreid >> 16) & 0xfff));
54 }
55
56 static DEVICE_ATTR_RO(board);
57
58 static ssize_t
fpga_show(struct device * dev,struct device_attribute * attr,char * buf)59 fpga_show(struct device *dev, struct device_attribute *attr, char *buf)
60 {
61 return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
62 }
63
64 static DEVICE_ATTR_RO(fpga);
65
66 static ssize_t
build_show(struct device * dev,struct device_attribute * attr,char * buf)67 build_show(struct device *dev, struct device_attribute *attr, char *buf)
68 {
69 return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
70 }
71
72 static DEVICE_ATTR_RO(build);
73
74 static struct attribute *realview_attrs[] = {
75 &dev_attr_manufacturer.attr,
76 &dev_attr_board.attr,
77 &dev_attr_fpga.attr,
78 &dev_attr_build.attr,
79 NULL
80 };
81
82 ATTRIBUTE_GROUPS(realview);
83
realview_soc_probe(struct platform_device * pdev)84 static int realview_soc_probe(struct platform_device *pdev)
85 {
86 struct regmap *syscon_regmap;
87 struct soc_device *soc_dev;
88 struct soc_device_attribute *soc_dev_attr;
89 struct device_node *np = pdev->dev.of_node;
90 int ret;
91
92 syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
93 if (IS_ERR(syscon_regmap))
94 return PTR_ERR(syscon_regmap);
95
96 soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
97 if (!soc_dev_attr)
98 return -ENOMEM;
99
100 ret = of_property_read_string(np, "compatible",
101 &soc_dev_attr->soc_id);
102 if (ret)
103 return -EINVAL;
104
105 soc_dev_attr->machine = "RealView";
106 soc_dev_attr->family = "Versatile";
107 soc_dev_attr->custom_attr_group = realview_groups[0];
108 soc_dev = soc_device_register(soc_dev_attr);
109 if (IS_ERR(soc_dev)) {
110 kfree(soc_dev_attr);
111 return -ENODEV;
112 }
113 ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
114 &realview_coreid);
115 if (ret)
116 return -ENODEV;
117
118 dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x, HBI-%03x\n",
119 realview_coreid,
120 ((realview_coreid >> 16) & 0xfff));
121 /* FIXME: add attributes for SoC to sysfs */
122 return 0;
123 }
124
125 static struct platform_driver realview_soc_driver = {
126 .probe = realview_soc_probe,
127 .driver = {
128 .name = "realview-soc",
129 .of_match_table = realview_soc_of_match,
130 },
131 };
132 builtin_platform_driver(realview_soc_driver);
133