1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/greybus/module.c b/drivers/greybus/module.c
new file mode 100644
index 000000000000..36f77f9e1d74
--- /dev/null
+++ b/drivers/greybus/module.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Greybus Module code
+ *
+ * Copyright 2016 Google Inc.
+ * Copyright 2016 Linaro Ltd.
+ */
+
+#include <linux/greybus.h>
+#include "greybus_trace.h"
+
+static ssize_t eject_store(struct device *dev,
+			   struct device_attribute *attr,
+			   const char *buf, size_t len)
+{
+	struct gb_module *module = to_gb_module(dev);
+	struct gb_interface *intf;
+	size_t i;
+	long val;
+	int ret;
+
+	ret = kstrtol(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	if (!val)
+		return len;
+
+	for (i = 0; i < module->num_interfaces; ++i) {
+		intf = module->interfaces[i];
+
+		mutex_lock(&intf->mutex);
+		/* Set flag to prevent concurrent activation. */
+		intf->ejected = true;
+		gb_interface_disable(intf);
+		gb_interface_deactivate(intf);
+		mutex_unlock(&intf->mutex);
+	}
+
+	/* Tell the SVC to eject the primary interface. */
+	ret = gb_svc_intf_eject(module->hd->svc, module->module_id);
+	if (ret)
+		return ret;
+
+	return len;
+}
+static DEVICE_ATTR_WO(eject);
+
+static ssize_t module_id_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct gb_module *module = to_gb_module(dev);
+
+	return sprintf(buf, "%u\n", module->module_id);
+}
+static DEVICE_ATTR_RO(module_id);
+
+static ssize_t num_interfaces_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct gb_module *module = to_gb_module(dev);
+
+	return sprintf(buf, "%zu\n", module->num_interfaces);
+}
+static DEVICE_ATTR_RO(num_interfaces);
+
+static struct attribute *module_attrs[] = {
+	&dev_attr_eject.attr,
+	&dev_attr_module_id.attr,
+	&dev_attr_num_interfaces.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(module);
+
+static void gb_module_release(struct device *dev)
+{
+	struct gb_module *module = to_gb_module(dev);
+
+	trace_gb_module_release(module);
+
+	kfree(module);
+}
+
+struct device_type greybus_module_type = {
+	.name		= "greybus_module",
+	.release	= gb_module_release,
+};
+
+struct gb_module *gb_module_create(struct gb_host_device *hd, u8 module_id,
+				   size_t num_interfaces)
+{
+	struct gb_interface *intf;
+	struct gb_module *module;
+	int i;
+
+	module = kzalloc(struct_size(module, interfaces, num_interfaces),
+			 GFP_KERNEL);
+	if (!module)
+		return NULL;
+
+	module->hd = hd;
+	module->module_id = module_id;
+	module->num_interfaces = num_interfaces;
+
+	module->dev.parent = &hd->dev;
+	module->dev.bus = &greybus_bus_type;
+	module->dev.type = &greybus_module_type;
+	module->dev.groups = module_groups;
+	module->dev.dma_mask = hd->dev.dma_mask;
+	device_initialize(&module->dev);
+	dev_set_name(&module->dev, "%d-%u", hd->bus_id, module_id);
+
+	trace_gb_module_create(module);
+
+	for (i = 0; i < num_interfaces; ++i) {
+		intf = gb_interface_create(module, module_id + i);
+		if (!intf) {
+			dev_err(&module->dev, "failed to create interface %u\n",
+				module_id + i);
+			goto err_put_interfaces;
+		}
+		module->interfaces[i] = intf;
+	}
+
+	return module;
+
+err_put_interfaces:
+	for (--i; i >= 0; --i)
+		gb_interface_put(module->interfaces[i]);
+
+	put_device(&module->dev);
+
+	return NULL;
+}
+
+/*
+ * Register and enable an interface after first attempting to activate it.
+ */
+static void gb_module_register_interface(struct gb_interface *intf)
+{
+	struct gb_module *module = intf->module;
+	u8 intf_id = intf->interface_id;
+	int ret;
+
+	mutex_lock(&intf->mutex);
+
+	ret = gb_interface_activate(intf);
+	if (ret) {
+		if (intf->type != GB_INTERFACE_TYPE_DUMMY) {
+			dev_err(&module->dev,
+				"failed to activate interface %u: %d\n",
+				intf_id, ret);
+		}
+
+		gb_interface_add(intf);
+		goto err_unlock;
+	}
+
+	ret = gb_interface_add(intf);
+	if (ret)
+		goto err_interface_deactivate;
+
+	ret = gb_interface_enable(intf);
+	if (ret) {
+		dev_err(&module->dev, "failed to enable interface %u: %d\n",
+			intf_id, ret);
+		goto err_interface_deactivate;
+	}
+
+	mutex_unlock(&intf->mutex);
+
+	return;
+
+err_interface_deactivate:
+	gb_interface_deactivate(intf);
+err_unlock:
+	mutex_unlock(&intf->mutex);
+}
+
+static void gb_module_deregister_interface(struct gb_interface *intf)
+{
+	/* Mark as disconnected to prevent I/O during disable. */
+	if (intf->module->disconnected)
+		intf->disconnected = true;
+
+	mutex_lock(&intf->mutex);
+	intf->removed = true;
+	gb_interface_disable(intf);
+	gb_interface_deactivate(intf);
+	mutex_unlock(&intf->mutex);
+
+	gb_interface_del(intf);
+}
+
+/* Register a module and its interfaces. */
+int gb_module_add(struct gb_module *module)
+{
+	size_t i;
+	int ret;
+
+	ret = device_add(&module->dev);
+	if (ret) {
+		dev_err(&module->dev, "failed to register module: %d\n", ret);
+		return ret;
+	}
+
+	trace_gb_module_add(module);
+
+	for (i = 0; i < module->num_interfaces; ++i)
+		gb_module_register_interface(module->interfaces[i]);
+
+	return 0;
+}
+
+/* Deregister a module and its interfaces. */
+void gb_module_del(struct gb_module *module)
+{
+	size_t i;
+
+	for (i = 0; i < module->num_interfaces; ++i)
+		gb_module_deregister_interface(module->interfaces[i]);
+
+	trace_gb_module_del(module);
+
+	device_del(&module->dev);
+}
+
+void gb_module_put(struct gb_module *module)
+{
+	size_t i;
+
+	for (i = 0; i < module->num_interfaces; ++i)
+		gb_interface_put(module->interfaces[i]);
+
+	put_device(&module->dev);
+}