3 files changed, 235 insertions, 0 deletions
diff --git a/drivers/soc/ux500/Kconfig b/drivers/soc/ux500/Kconfig
new file mode 100644
index 000000000..0e04272ed
--- /dev/null
+++ b/drivers/soc/ux500/Kconfig
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config UX500_SOC_ID
+	bool "SoC bus for ST-Ericsson ux500"
+	depends on ARCH_U8500 || COMPILE_TEST
+	default ARCH_U8500
+	help
+	  Include support for the SoC bus on the ARM RealView platforms
+	  providing some sysfs information about the ASIC variant.
diff --git a/drivers/soc/ux500/Makefile b/drivers/soc/ux500/Makefile
new file mode 100644
index 000000000..f1645397d
--- /dev/null
+++ b/drivers/soc/ux500/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_UX500_SOC_ID) += ux500-soc-id.o
diff --git a/drivers/soc/ux500/ux500-soc-id.c b/drivers/soc/ux500/ux500-soc-id.c
new file mode 100644
index 000000000..27d6e25a0
--- /dev/null
+++ b/drivers/soc/ux500/ux500-soc-id.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/sys_soc.h>
+
+#include <asm/cputype.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+#include <asm/mach/map.h>
+
+/**
+ * struct dbx500_asic_id - fields of the ASIC ID
+ * @process: the manufacturing process, 0x40 is 40 nm 0x00 is "standard"
+ * @partnumber: hithereto 0x8500 for DB8500
+ * @revision: version code in the series
+ */
+struct dbx500_asic_id {
+	u16	partnumber;
+	u8	revision;
+	u8	process;
+};
+
+static struct dbx500_asic_id dbx500_id;
+
+static unsigned int __init ux500_read_asicid(phys_addr_t addr)
+{
+	void __iomem *virt = ioremap(addr, 4);
+	unsigned int asicid;
+
+	if (!virt)
+		return 0;
+
+	asicid = readl(virt);
+	iounmap(virt);
+
+	return asicid;
+}
+
+static void ux500_print_soc_info(unsigned int asicid)
+{
+	unsigned int rev = dbx500_id.revision;
+
+	pr_info("DB%4x ", dbx500_id.partnumber);
+
+	if (rev == 0x01)
+		pr_cont("Early Drop");
+	else if (rev >= 0xA0)
+		pr_cont("v%d.%d" , (rev >> 4) - 0xA + 1, rev & 0xf);
+	else
+		pr_cont("Unknown");
+
+	pr_cont(" [%#010x]\n", asicid);
+}
+
+static unsigned int partnumber(unsigned int asicid)
+{
+	return (asicid >> 8) & 0xffff;
+}
+
+/*
+ * SOC		MIDR		ASICID ADDRESS		ASICID VALUE
+ * DB8500ed	0x410fc090	0x9001FFF4		0x00850001
+ * DB8500v1	0x411fc091	0x9001FFF4		0x008500A0
+ * DB8500v1.1	0x411fc091	0x9001FFF4		0x008500A1
+ * DB8500v2	0x412fc091	0x9001DBF4		0x008500B0
+ * DB8520v2.2	0x412fc091	0x9001DBF4		0x008500B2
+ * DB5500v1	0x412fc091	0x9001FFF4		0x005500A0
+ * DB9540	0x413fc090	0xFFFFDBF4		0x009540xx
+ */
+
+static void __init ux500_setup_id(void)
+{
+	unsigned int cpuid = read_cpuid_id();
+	unsigned int asicid = 0;
+	phys_addr_t addr = 0;
+
+	switch (cpuid) {
+	case 0x410fc090: /* DB8500ed */
+	case 0x411fc091: /* DB8500v1 */
+		addr = 0x9001FFF4;
+		break;
+
+	case 0x412fc091: /* DB8520 / DB8500v2 / DB5500v1 */
+		asicid = ux500_read_asicid(0x9001DBF4);
+		if (partnumber(asicid) == 0x8500 ||
+		    partnumber(asicid) == 0x8520)
+			/* DB8500v2 */
+			break;
+
+		/* DB5500v1 */
+		addr = 0x9001FFF4;
+		break;
+
+	case 0x413fc090: /* DB9540 */
+		addr = 0xFFFFDBF4;
+		break;
+	}
+
+	if (addr)
+		asicid = ux500_read_asicid(addr);
+
+	if (!asicid) {
+		pr_err("Unable to identify SoC\n");
+		BUG();
+	}
+
+	dbx500_id.process = asicid >> 24;
+	dbx500_id.partnumber = partnumber(asicid);
+	dbx500_id.revision = asicid & 0xff;
+
+	ux500_print_soc_info(asicid);
+}
+
+static const char * __init ux500_get_machine(void)
+{
+	return kasprintf(GFP_KERNEL, "DB%4x", dbx500_id.partnumber);
+}
+
+static const char * __init ux500_get_family(void)
+{
+	return kasprintf(GFP_KERNEL, "ux500");
+}
+
+static const char * __init ux500_get_revision(void)
+{
+	unsigned int rev = dbx500_id.revision;
+
+	if (rev == 0x01)
+		return kasprintf(GFP_KERNEL, "%s", "ED");
+	else if (rev >= 0xA0)
+		return kasprintf(GFP_KERNEL, "%d.%d",
+				 (rev >> 4) - 0xA + 1, rev & 0xf);
+
+	return kasprintf(GFP_KERNEL, "%s", "Unknown");
+}
+
+static ssize_t
+process_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	if (dbx500_id.process == 0x00)
+		return sprintf(buf, "Standard\n");
+
+	return sprintf(buf, "%02xnm\n", dbx500_id.process);
+}
+
+static DEVICE_ATTR_RO(process);
+
+static struct attribute *ux500_soc_attrs[] = {
+	&dev_attr_process.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(ux500_soc);
+
+static const char *db8500_read_soc_id(struct device_node *backupram)
+{
+	void __iomem *base;
+	const char *retstr;
+	u32 uid[5];
+
+	base = of_iomap(backupram, 0);
+	if (!base)
+		return NULL;
+	memcpy_fromio(uid, base + 0x1fc0, sizeof(uid));
+
+	/* Throw these device-specific numbers into the entropy pool */
+	add_device_randomness(uid, sizeof(uid));
+	retstr = kasprintf(GFP_KERNEL, "%08x%08x%08x%08x%08x",
+			   uid[0], uid[1], uid[2], uid[3], uid[4]);
+	iounmap(base);
+	return retstr;
+}
+
+static void __init soc_info_populate(struct soc_device_attribute *soc_dev_attr,
+				     struct device_node *backupram)
+{
+	soc_dev_attr->soc_id   = db8500_read_soc_id(backupram);
+	soc_dev_attr->machine  = ux500_get_machine();
+	soc_dev_attr->family   = ux500_get_family();
+	soc_dev_attr->revision = ux500_get_revision();
+	soc_dev_attr->custom_attr_group = ux500_soc_groups[0];
+}
+
+static int __init ux500_soc_device_init(void)
+{
+	struct soc_device *soc_dev;
+	struct soc_device_attribute *soc_dev_attr;
+	struct device_node *backupram;
+
+	backupram = of_find_compatible_node(NULL, NULL, "ste,dbx500-backupram");
+	if (!backupram)
+		return 0;
+
+	ux500_setup_id();
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr) {
+		of_node_put(backupram);
+		return -ENOMEM;
+	}
+
+	soc_info_populate(soc_dev_attr, backupram);
+	of_node_put(backupram);
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+	        kfree(soc_dev_attr);
+		return PTR_ERR(soc_dev);
+	}
+
+	return 0;
+}
+subsys_initcall(ux500_soc_device_init);