soc-realview.c

  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/device.h>
  8#include <linux/init.h>
  9#include <linux/io.h>
 10#include <linux/slab.h>
 11#include <linux/sys_soc.h>
 12#include <linux/platform_device.h>
 13#include <linux/mfd/syscon.h>
 14#include <linux/regmap.h>
 15#include <linux/of.h>
 16
 17/* System ID in syscon */
 18#define REALVIEW_SYS_ID_OFFSET 0x00
 19
 20static const struct of_device_id realview_soc_of_match[] = {
 21	{ .compatible = "arm,realview-eb-soc",	},
 22	{ .compatible = "arm,realview-pb1176-soc", },
 23	{ .compatible = "arm,realview-pb11mp-soc", },
 24	{ .compatible = "arm,realview-pba8-soc", },
 25	{ .compatible = "arm,realview-pbx-soc", },
 26	{ }
 27};
 28
 29static u32 realview_coreid;
 30
 31static const char *realview_arch_str(u32 id)
 32{
 33	switch ((id >> 8) & 0xf) {
 34	case 0x04:
 35		return "AHB";
 36	case 0x05:
 37		return "Multi-layer AXI";
 38	default:
 39		return "Unknown";
 40	}
 41}
 42
 43static ssize_t
 44manufacturer_show(struct device *dev, struct device_attribute *attr, char *buf)
 45{
 46	return sprintf(buf, "%02x\n", realview_coreid >> 24);
 47}
 48
 49static DEVICE_ATTR_RO(manufacturer);
 50
 51static ssize_t
 52board_show(struct device *dev, struct device_attribute *attr, char *buf)
 53{
 54	return sprintf(buf, "HBI-%03x\n", ((realview_coreid >> 16) & 0xfff));
 55}
 56
 57static DEVICE_ATTR_RO(board);
 58
 59static ssize_t
 60fpga_show(struct device *dev, struct device_attribute *attr, char *buf)
 61{
 62	return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
 63}
 64
 65static DEVICE_ATTR_RO(fpga);
 66
 67static ssize_t
 68build_show(struct device *dev, struct device_attribute *attr, char *buf)
 69{
 70	return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
 71}
 72
 73static DEVICE_ATTR_RO(build);
 74
 75static struct attribute *realview_attrs[] = {
 76	&dev_attr_manufacturer.attr,
 77	&dev_attr_board.attr,
 78	&dev_attr_fpga.attr,
 79	&dev_attr_build.attr,
 80	NULL
 81};
 82
 83ATTRIBUTE_GROUPS(realview);
 84
 85static void realview_soc_socdev_release(void *data)
 86{
 87	struct soc_device *soc_dev = data;
 88
 89	soc_device_unregister(soc_dev);
 90}
 91
 92static int realview_soc_probe(struct platform_device *pdev)
 93{
 94	struct regmap *syscon_regmap;
 95	struct soc_device *soc_dev;
 96	struct soc_device_attribute *soc_dev_attr;
 97	struct device_node *np = pdev->dev.of_node;
 98	int ret;
 99
100	syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
101	if (IS_ERR(syscon_regmap))
102		return PTR_ERR(syscon_regmap);
103
104	soc_dev_attr = devm_kzalloc(&pdev->dev, sizeof(*soc_dev_attr), GFP_KERNEL);
105	if (!soc_dev_attr)
106		return -ENOMEM;
107
108	ret = of_property_read_string(np, "compatible",
109				      &soc_dev_attr->soc_id);
110	if (ret)
111		return -EINVAL;
112
113	soc_dev_attr->machine = "RealView";
114	soc_dev_attr->family = "Versatile";
115	soc_dev_attr->custom_attr_group = realview_groups[0];
116	soc_dev = soc_device_register(soc_dev_attr);
117	if (IS_ERR(soc_dev))
118		return -ENODEV;
119
120	ret = devm_add_action_or_reset(&pdev->dev, realview_soc_socdev_release,
121				       soc_dev);
122	if (ret)
123		return ret;
124
125	ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
126			  &realview_coreid);
127	if (ret)
128		return -ENODEV;
129
130	dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x, HBI-%03x\n",
131		 realview_coreid,
132		 ((realview_coreid >> 16) & 0xfff));
133	/* FIXME: add attributes for SoC to sysfs */
134	return 0;
135}
136
137static 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};
144builtin_platform_driver(realview_soc_driver);