bus_type.c
// SPDX-License-Identifier: GPL-2.0
// Copyright(c) 2015-17 Intel Corporation.
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/pm_domain.h>
#include <linux/soundwire/sdw.h>
#include <linux/soundwire/sdw_type.h>
#include "bus.h"
#include "sysfs_local.h"
/**
* sdw_get_device_id - find the matching SoundWire device id
* @slave: SoundWire Slave Device
* @drv: SoundWire Slave Driver
*
* The match is done by comparing the mfg_id and part_id from the
* struct sdw_device_id.
*/
static const struct sdw_device_id *
sdw_get_device_id(struct sdw_slave *slave, struct sdw_driver *drv)
{
const struct sdw_device_id *id;
for (id = drv->id_table; id && id->mfg_id; id++)
if (slave->id.mfg_id == id->mfg_id &&
slave->id.part_id == id->part_id &&
(!id->sdw_version ||
slave->id.sdw_version == id->sdw_version) &&
(!id->class_id ||
slave->id.class_id == id->class_id))
return id;
return NULL;
}
static int sdw_bus_match(struct device *dev, struct device_driver *ddrv)
{
struct sdw_slave *slave;
struct sdw_driver *drv;
int ret = 0;
if (is_sdw_slave(dev)) {
slave = dev_to_sdw_dev(dev);
drv = drv_to_sdw_driver(ddrv);
ret = !!sdw_get_device_id(slave, drv);
}
return ret;
}
int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
{
/* modalias is sdw:m<mfg_id>p<part_id>v<version>c<class_id> */
return snprintf(buf, size, "sdw:m%04Xp%04Xv%02Xc%02X\n",
slave->id.mfg_id, slave->id.part_id,
slave->id.sdw_version, slave->id.class_id);
}
int sdw_slave_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct sdw_slave *slave = dev_to_sdw_dev(dev);
char modalias[32];
sdw_slave_modalias(slave, modalias, sizeof(modalias));
if (add_uevent_var(env, "MODALIAS=%s", modalias))
return -ENOMEM;
return 0;
}
struct bus_type sdw_bus_type = {
.name = "soundwire",
.match = sdw_bus_match,
};
EXPORT_SYMBOL_GPL(sdw_bus_type);
static int sdw_drv_probe(struct device *dev)
{
struct sdw_slave *slave = dev_to_sdw_dev(dev);
struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
const struct sdw_device_id *id;
const char *name;
int ret;
/*
* fw description is mandatory to bind
*/
if (!dev->fwnode)
return -ENODEV;
if (!IS_ENABLED(CONFIG_ACPI) && !dev->of_node)
return -ENODEV;
id = sdw_get_device_id(slave, drv);
if (!id)
return -ENODEV;
slave->ops = drv->ops;
/*
* attach to power domain but don't turn on (last arg)
*/
ret = dev_pm_domain_attach(dev, false);
if (ret)
return ret;
ret = drv->probe(slave, id);
if (ret) {
name = drv->name;
if (!name)
name = drv->driver.name;
dev_err(dev, "Probe of %s failed: %d\n", name, ret);
dev_pm_domain_detach(dev, false);
return ret;
}
/* device is probed so let's read the properties now */
if (slave->ops && slave->ops->read_prop)
slave->ops->read_prop(slave);
/* init the sysfs as we have properties now */
ret = sdw_slave_sysfs_init(slave);
if (ret < 0)
dev_warn(dev, "Slave sysfs init failed:%d\n", ret);
/*
* Check for valid clk_stop_timeout, use DisCo worst case value of
* 300ms
*
* TODO: check the timeouts and driver removal case
*/
if (slave->prop.clk_stop_timeout == 0)
slave->prop.clk_stop_timeout = 300;
slave->bus->clk_stop_timeout = max_t(u32, slave->bus->clk_stop_timeout,
slave->prop.clk_stop_timeout);
slave->probed = true;
complete(&slave->probe_complete);
dev_dbg(dev, "probe complete\n");
return 0;
}
static int sdw_drv_remove(struct device *dev)
{
struct sdw_slave *slave = dev_to_sdw_dev(dev);
struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
int ret = 0;
if (drv->remove)
ret = drv->remove(slave);
dev_pm_domain_detach(dev, false);
return ret;
}
static void sdw_drv_shutdown(struct device *dev)
{
struct sdw_slave *slave = dev_to_sdw_dev(dev);
struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
if (drv->shutdown)
drv->shutdown(slave);
}
/**
* __sdw_register_driver() - register a SoundWire Slave driver
* @drv: driver to register
* @owner: owning module/driver
*
* Return: zero on success, else a negative error code.
*/
int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
{
const char *name;
drv->driver.bus = &sdw_bus_type;
if (!drv->probe) {
name = drv->name;
if (!name)
name = drv->driver.name;
pr_err("driver %s didn't provide SDW probe routine\n", name);
return -EINVAL;
}
drv->driver.owner = owner;
drv->driver.probe = sdw_drv_probe;
if (drv->remove)
drv->driver.remove = sdw_drv_remove;
if (drv->shutdown)
drv->driver.shutdown = sdw_drv_shutdown;
return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(__sdw_register_driver);
/**
* sdw_unregister_driver() - unregisters the SoundWire Slave driver
* @drv: driver to unregister
*/
void sdw_unregister_driver(struct sdw_driver *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(sdw_unregister_driver);
static int __init sdw_bus_init(void)
{
sdw_debugfs_init();
return bus_register(&sdw_bus_type);
}
static void __exit sdw_bus_exit(void)
{
sdw_debugfs_exit();
bus_unregister(&sdw_bus_type);
}
postcore_initcall(sdw_bus_init);
module_exit(sdw_bus_exit);
MODULE_DESCRIPTION("SoundWire bus");
MODULE_LICENSE("GPL v2");