File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/soc/versatile/soc-realview.c b/drivers/soc/versatile/soc-realview.c
new file mode 100644
index 0000000..e642c45
--- /dev/null
+++ b/drivers/soc/versatile/soc-realview.c
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2014 Linaro Ltd.
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+
+/* System ID in syscon */
+#define REALVIEW_SYS_ID_OFFSET 0x00
+
+static const struct of_device_id realview_soc_of_match[] = {
+	{ .compatible = "arm,realview-eb-soc",	},
+	{ .compatible = "arm,realview-pb1176-soc", },
+	{ .compatible = "arm,realview-pb11mp-soc", },
+	{ .compatible = "arm,realview-pba8-soc", },
+	{ .compatible = "arm,realview-pbx-soc", },
+	{ }
+};
+
+static u32 realview_coreid;
+
+static const char *realview_board_str(u32 id)
+{
+	switch ((id >> 16) & 0xfff) {
+	case 0x0147:
+		return "HBI-0147";
+	default:
+		return "Unknown";
+	}
+}
+
+static const char *realview_arch_str(u32 id)
+{
+	switch ((id >> 8) & 0xf) {
+	case 0x05:
+		return "Multi-layer AXI";
+	default:
+		return "Unknown";
+	}
+}
+
+static ssize_t realview_get_manf(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	return sprintf(buf, "%02x\n", realview_coreid >> 24);
+}
+
+static struct device_attribute realview_manf_attr =
+	__ATTR(manufacturer,  S_IRUGO, realview_get_manf,  NULL);
+
+static ssize_t realview_get_board(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	return sprintf(buf, "%s\n", realview_board_str(realview_coreid));
+}
+
+static struct device_attribute realview_board_attr =
+	__ATTR(board,  S_IRUGO, realview_get_board,  NULL);
+
+static ssize_t realview_get_arch(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
+}
+
+static struct device_attribute realview_arch_attr =
+	__ATTR(fpga,  S_IRUGO, realview_get_arch,  NULL);
+
+static ssize_t realview_get_build(struct device *dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
+}
+
+static struct device_attribute realview_build_attr =
+	__ATTR(build,  S_IRUGO, realview_get_build,  NULL);
+
+static int realview_soc_probe(struct platform_device *pdev)
+{
+	static struct regmap *syscon_regmap;
+	struct soc_device *soc_dev;
+	struct soc_device_attribute *soc_dev_attr;
+	struct device_node *np = pdev->dev.of_node;
+	int ret;
+
+	syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
+	if (IS_ERR(syscon_regmap))
+		return PTR_ERR(syscon_regmap);
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return -ENOMEM;
+
+	ret = of_property_read_string(np, "compatible",
+				      &soc_dev_attr->soc_id);
+	if (ret)
+		return -EINVAL;
+
+	soc_dev_attr->machine = "RealView";
+	soc_dev_attr->family = "Versatile";
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+		kfree(soc_dev_attr);
+		return -ENODEV;
+	}
+	ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
+			  &realview_coreid);
+	if (ret)
+		return -ENODEV;
+
+	device_create_file(soc_device_to_device(soc_dev), &realview_manf_attr);
+	device_create_file(soc_device_to_device(soc_dev), &realview_board_attr);
+	device_create_file(soc_device_to_device(soc_dev), &realview_arch_attr);
+	device_create_file(soc_device_to_device(soc_dev), &realview_build_attr);
+
+	dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x\n",
+		 realview_coreid);
+	/* FIXME: add attributes for SoC to sysfs */
+	return 0;
+}
+
+static struct platform_driver realview_soc_driver = {
+	.probe = realview_soc_probe,
+	.driver = {
+		.name = "realview-soc",
+		.of_match_table = realview_soc_of_match,
+	},
+};
+builtin_platform_driver(realview_soc_driver);