linux/drivers/greybus/module.c

237 lines
4.9 KiB
C

// 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);
}