FogBugz #143478: drivers/misc: Add sysid from arch to drivers

Add sysid driver.
The Altera Sysid component is generally part of an FPGA design. The
component can be hotplugged when the FPGA is reconfigured.  This patch
fixes the driver to support the component being hotplugged.

Usage:
  cat /sys/bus/platform/devices/[addr.sysid]/sysid/id
  cat /sys/bus/platform/devices/[addr.sysid]/sysid/timestamp

v2:
- Updated license header
- Removed ID and timestamp from documentation

v3:
- Removed ID and timestamp from optional properties in documentation

Signed-off-by: Ley Foon Tan <[email protected]>

Author: Ley Foon Tan

Documentation/devicetree/bindings/misc/altera_sysid.txt

@@ -0,0 +1,11 @@
+Altera Sysid IP core driver
+
+Required properties:
+- compatible: altr,sysid-1.0
+
+Example:
+
+sysid_qsys: sysid@0x10000 {
+	compatible = "altr,sysid-1.0";
+	reg = < 0x10000 0x00000008 >;
+};

drivers/misc/Kconfig

@@ -472,6 +472,11 @@ config PVPANIC
 	  a paravirtualized device provided by QEMU; it lets a virtual machine
 	  (guest) communicate panic events to the host.
 
+config ALTERA_SYSID
+	tristate "Altera System ID"
+	help
+	This enables Altera System ID soft core driver.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"

drivers/misc/Makefile

@@ -42,6 +42,7 @@ obj-y				+= ti-st/
 obj-y				+= lis3lv02d/
 obj-$(CONFIG_ALTERA_STAPL)	+=altera-stapl/
 obj-$(CONFIG_ALTERA_HWMUTEX)	+= altera_hwmutex.o
+obj-$(CONFIG_ALTERA_SYSID)	+= altera_sysid.o
 obj-$(CONFIG_INTEL_MEI)		+= mei/
 obj-$(CONFIG_VMWARE_VMCI)	+= vmw_vmci/
 obj-$(CONFIG_LATTICE_ECP3_CONFIG)	+= lattice-ecp3-config.o

drivers/misc/altera_sysid.c

@@ -0,0 +1,141 @@
+/*
+ * Copyright Altera Corporation (C) 2013.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Credit:
+ * Walter Goossens
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#define DRV_NAME	"altera_sysid"
+
+struct altera_sysid {
+	void __iomem		*regs;
+};
+
+/* System ID Registers*/
+#define SYSID_REG_ID		(0x0)
+#define SYSID_REG_TIMESTAMP	(0x4)
+
+static ssize_t altera_sysid_show_id(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct altera_sysid *sysid = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", readl(sysid->regs + SYSID_REG_ID));
+}
+
+static ssize_t altera_sysid_show_timestamp(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	unsigned int reg;
+	struct tm timestamp;
+	struct altera_sysid *sysid = dev_get_drvdata(dev);
+
+	reg = readl(sysid->regs + SYSID_REG_TIMESTAMP);
+
+	time64_to_tm(reg, 0, &timestamp);
+
+	return sprintf(buf, "%u (%u-%u-%u %u:%u:%u UTC)\n", reg,
+		(unsigned int)(timestamp.tm_year + 1900),
+		timestamp.tm_mon + 1, timestamp.tm_mday, timestamp.tm_hour,
+		timestamp.tm_min, timestamp.tm_sec);
+}
+
+static DEVICE_ATTR(id, S_IRUGO, altera_sysid_show_id, NULL);
+static DEVICE_ATTR(timestamp, S_IRUGO, altera_sysid_show_timestamp, NULL);
+
+static struct attribute *altera_sysid_attrs[] = {
+	&dev_attr_id.attr,
+	&dev_attr_timestamp.attr,
+	NULL,
+};
+
+struct attribute_group altera_sysid_attr_group = {
+	.name = "sysid",
+	.attrs = altera_sysid_attrs,
+};
+
+static int altera_sysid_probe(struct platform_device *pdev)
+{
+	struct altera_sysid *sysid;
+	struct resource	*regs;
+
+	sysid = devm_kzalloc(&pdev->dev, sizeof(struct altera_sysid),
+		GFP_KERNEL);
+	if (!sysid)
+		return -ENOMEM;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs)
+		return -ENXIO;
+
+	sysid->regs = devm_ioremap_resource(&pdev->dev, regs);
+	if (IS_ERR(sysid->regs))
+		return PTR_ERR(sysid->regs);
+
+	platform_set_drvdata(pdev, sysid);
+
+	return sysfs_create_group(&pdev->dev.kobj, &altera_sysid_attr_group);
+}
+
+static int altera_sysid_remove(struct platform_device *pdev)
+{
+	sysfs_remove_group(&pdev->dev.kobj, &altera_sysid_attr_group);
+
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static const struct of_device_id altera_sysid_match[] = {
+	{ .compatible = "altr,sysid-1.0" },
+	{ /* Sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, altera_sysid_match);
+
+static struct platform_driver altera_sysid_platform_driver = {
+	.driver = {
+		.name		= DRV_NAME,
+		.owner		= THIS_MODULE,
+		.of_match_table	= of_match_ptr(altera_sysid_match),
+	},
+	.probe			= altera_sysid_probe,
+	.remove			= altera_sysid_remove,
+};
+
+static int __init altera_sysid_init(void)
+{
+	return platform_driver_register(&altera_sysid_platform_driver);
+}
+
+static void __exit altera_sysid_exit(void)
+{
+	platform_driver_unregister(&altera_sysid_platform_driver);
+}
+
+module_init(altera_sysid_init);
+module_exit(altera_sysid_exit);
+
+MODULE_AUTHOR("Ley Foon Tan <[email protected]>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Altera System ID driver");
+MODULE_ALIAS("platform:" DRV_NAME);