staging: unisys: add visorbus driver

This base driver provides bus functionality to visorhid, visorhba,
and visornic which will be later added to our driver base. Visorbus
supports sPar bus model and manages bus specific functionality. It
maintains the sysfs subtree /sys/devices/visorbus*/.It is
responsible for device creation and destruction of the devices on
its bus.

Signed-off-by: Erik Arfvidson <erik.arfvidson@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 227 insertions, 0 deletions

diff --git a/drivers/staging/unisys/visorbus/channel_attr.c b/drivers/staging/unisys/visorbus/channel_attr.c
new file mode 100644
index 0000000..0d7184a
--- /dev/null
+++ b/drivers/staging/unisys/visorbus/channel_attr.c
@@ -0,0 +1,227 @@
+/* channel_attr.c
+ *
+ * Copyright (C) 2010 - 2013 UNISYS CORPORATION
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ */
+
+/* Implement publishing of channel attributes under:
+ *
+ *     /sys/bus/visorbus<x>/dev<y>/channel
+ *
+ */
+
+#include "channel_attr.h"
+#define CURRENT_FILE_PC VISOR_BUS_PC_channel_attr_c
+#define to_channel_attr(_attr) \
+	container_of(_attr, struct channel_attribute, attr)
+#define to_visor_device_from_kobjchannel(obj) \
+	container_of(obj, struct visor_device, kobjchannel)
+
+struct channel_attribute {
+	struct attribute attr;
+	 ssize_t (*show)(struct visor_device*, char *buf);
+	 ssize_t (*store)(struct visor_device*, const char *buf, size_t count);
+};
+
+/* begin implementation of specific channel attributes to appear under
+* /sys/bus/visorbus<x>/dev<y>/channel
+*/
+static ssize_t devicechannel_attr_physaddr(struct visor_device *dev, char *buf)
+{
+	if (!dev->visorchannel)
+		return 0;
+	return snprintf(buf, PAGE_SIZE, "0x%Lx\n",
+			visorchannel_get_physaddr(dev->visorchannel));
+}
+
+static ssize_t devicechannel_attr_nbytes(struct visor_device *dev, char *buf)
+{
+	if (!dev->visorchannel)
+		return 0;
+	return snprintf(buf, PAGE_SIZE, "0x%lx\n",
+			visorchannel_get_nbytes(dev->visorchannel));
+}
+
+static ssize_t devicechannel_attr_clientpartition(struct visor_device *dev,
+						  char *buf) {
+	if (!dev->visorchannel)
+		return 0;
+	return snprintf(buf, PAGE_SIZE, "0x%Lx\n",
+			visorchannel_get_clientpartition(dev->visorchannel));
+}
+
+static ssize_t devicechannel_attr_typeguid(struct visor_device *dev, char *buf)
+{
+	char s[99];
+
+	if (!dev->visorchannel)
+		return 0;
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+			visorchannel_id(dev->visorchannel, s));
+}
+
+static ssize_t devicechannel_attr_zoneguid(struct visor_device *dev, char *buf)
+{
+	char s[99];
+
+	if (!dev->visorchannel)
+		return 0;
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+			visorchannel_zoneid(dev->visorchannel, s));
+}
+
+static ssize_t devicechannel_attr_typename(struct visor_device *dev, char *buf)
+{
+	int i = 0;
+	struct bus_type *xbus = dev->device.bus;
+	struct device_driver *xdrv = dev->device.driver;
+	struct visor_driver *drv = NULL;
+
+	if (!dev->visorchannel || !xbus || !xdrv)
+		return 0;
+	i = xbus->match(&dev->device, xdrv);
+	if (!i)
+		return 0;
+	drv = to_visor_driver(xdrv);
+	return snprintf(buf, PAGE_SIZE, "%s\n", drv->channel_types[i - 1].name);
+}
+
+static ssize_t devicechannel_attr_dump(struct visor_device *dev, char *buf)
+{
+	int count = 0;
+/* TODO: replace this with debugfs code
+	struct seq_file *m = NULL;
+	if (dev->visorchannel == NULL)
+		return 0;
+	m = visor_seq_file_new_buffer(buf, PAGE_SIZE - 1);
+	if (m == NULL)
+		return 0;
+	visorchannel_debug(dev->visorchannel, 1, m, 0);
+	count = m->count;
+	visor_seq_file_done_buffer(m);
+	m = NULL;
+*/
+	return count;
+}
+
+static struct channel_attribute all_channel_attrs[] = {
+	__ATTR(physaddr, S_IRUGO,
+	       devicechannel_attr_physaddr, NULL),
+	__ATTR(nbytes, S_IRUGO,
+	       devicechannel_attr_nbytes, NULL),
+	__ATTR(clientpartition, S_IRUGO,
+	       devicechannel_attr_clientpartition, NULL),
+	__ATTR(typeguid, S_IRUGO,
+	       devicechannel_attr_typeguid, NULL),
+	__ATTR(zoneguid, S_IRUGO,
+	       devicechannel_attr_zoneguid, NULL),
+	__ATTR(typename, S_IRUGO,
+	       devicechannel_attr_typename, NULL),
+	__ATTR(dump, S_IRUGO,
+	       devicechannel_attr_dump, NULL),
+};
+
+/* end implementation of specific channel attributes */
+
+static ssize_t channel_attr_show(struct kobject *kobj, struct attribute *attr,
+				 char *buf)
+{
+	struct channel_attribute *channel_attr = to_channel_attr(attr);
+	struct visor_device *dev = to_visor_device_from_kobjchannel(kobj);
+	ssize_t ret = 0;
+
+	if (channel_attr->show)
+		ret = channel_attr->show(dev, buf);
+	return ret;
+}
+
+static ssize_t channel_attr_store(struct kobject *kobj, struct attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct channel_attribute *channel_attr = to_channel_attr(attr);
+	struct visor_device *dev = to_visor_device_from_kobjchannel(kobj);
+	ssize_t ret = 0;
+
+	if (channel_attr->store)
+		ret = channel_attr->store(dev, buf, count);
+	return ret;
+}
+
+static int channel_create_file(struct visor_device *dev,
+			       struct channel_attribute *attr)
+{
+	return sysfs_create_file(&dev->kobjchannel, &attr->attr);
+}
+
+static void channel_remove_file(struct visor_device *dev,
+				struct channel_attribute *attr)
+{
+	sysfs_remove_file(&dev->kobjchannel, &attr->attr);
+}
+
+static const struct sysfs_ops channel_sysfs_ops = {
+	.show = channel_attr_show,
+	.store = channel_attr_store,
+};
+
+static struct kobj_type channel_kobj_type = {
+	.sysfs_ops = &channel_sysfs_ops
+};
+
+int register_channel_attributes(struct visor_device *dev)
+{
+	int rc = 0, i = 0, x = 0;
+
+	if (dev->kobjchannel.parent)
+		goto away;	/* already registered */
+	x = kobject_init_and_add(&dev->kobjchannel, &channel_kobj_type,
+				 &dev->device.kobj, "channel");
+	if (x < 0) {
+		rc = x;
+		goto away;
+	}
+
+	kobject_uevent(&dev->kobjchannel, KOBJ_ADD);
+
+	for (i = 0;
+	     i < sizeof(all_channel_attrs) / sizeof(struct channel_attribute);
+	     i++)
+		x = channel_create_file(dev, &all_channel_attrs[i]);
+	if (x < 0) {
+		while (--i >= 0)
+			channel_remove_file(dev, &all_channel_attrs[i]);
+		kobject_del(&dev->kobjchannel);
+		kobject_put(&dev->kobjchannel);
+		rc = x;
+		goto away;
+	}
+away:
+	return rc;
+}
+
+void unregister_channel_attributes(struct visor_device *dev)
+{
+	int i = 0;
+
+	if (!dev->kobjchannel.parent)
+		return;		/* already unregistered */
+	for (i = 0;
+	     i < sizeof(all_channel_attrs) / sizeof(struct channel_attribute);
+	     i++)
+		channel_remove_file(dev, &all_channel_attrs[i]);
+
+	kobject_del(&dev->kobjchannel);
+	kobject_put(&dev->kobjchannel);
+	dev->kobjchannel.parent = NULL;
+}