ARM: ux500: export System-on-Chip information ux500 via sysfs

Here we make use of the new System-On-Chip bus driver to export
vital SoC information out to userspace via sysfs. This patch
provides a data structure of strings to populate the base
nodes found in:

/sys/devices/soc[0|1|2|...]/[family|machine|revision|soc_id].

It also adds one more node as requested by ST-Ericsson.
'process' depicts the way in which the silicon was manufactured.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 75 insertions, 0 deletions

diff --git a/arch/arm/mach-ux500/cpu.c b/arch/arm/mach-ux500/cpu.c
index f41857494375..055fb6e16ee2 100644
--- a/arch/arm/mach-ux500/cpu.c
+++ b/arch/arm/mach-ux500/cpu.c
@@ -2,6 +2,7 @@
  * Copyright (C) ST-Ericsson SA 2010
  *
  * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
+ * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson
  * License terms: GNU General Public License (GPL) version 2
  */
 
@@ -11,6 +12,10 @@
 #include <linux/mfd/db8500-prcmu.h>
 #include <linux/mfd/db5500-prcmu.h>
 #include <linux/clksrc-dbx500-prcmu.h>
+#include <linux/sys_soc.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
 
 #include <asm/hardware/gic.h>
 #include <asm/mach/map.h>
@@ -50,3 +55,73 @@ void __init ux500_init_irq(void)
 		db8500_prcmu_early_init();
 	clk_init();
 }
+
+static const char * __init ux500_get_machine(void)
+{
+	return kasprintf(GFP_KERNEL, "DB%4x", dbx500_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_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 ux500_get_process(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 void __init soc_info_populate(struct soc_device_attribute *soc_dev_attr,
+				     const char *soc_id)
+{
+	soc_dev_attr->soc_id   = soc_id;
+	soc_dev_attr->machine  = ux500_get_machine();
+	soc_dev_attr->family   = ux500_get_family();
+	soc_dev_attr->revision = ux500_get_revision();
+}
+
+struct device_attribute ux500_soc_attr =
+	__ATTR(process,  S_IRUGO, ux500_get_process,  NULL);
+
+struct device * __init ux500_soc_device_init(const char *soc_id)
+{
+	struct device *parent;
+	struct soc_device *soc_dev;
+	struct soc_device_attribute *soc_dev_attr;
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return ERR_PTR(-ENOMEM);
+
+	soc_info_populate(soc_dev_attr, soc_id);
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR_OR_NULL(soc_dev)) {
+	        kfree(soc_dev_attr);
+		return NULL;
+	}
+
+	parent = soc_device_to_device(soc_dev);
+	if (!IS_ERR_OR_NULL(parent))
+		device_create_file(parent, &ux500_soc_attr);
+
+	return parent;
+}