diff options
Diffstat (limited to 'drivers/soundwire/bus_type.c')
| -rw-r--r-- | drivers/soundwire/bus_type.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c new file mode 100644 index 000000000000..d5f3a70c06b0 --- /dev/null +++ b/drivers/soundwire/bus_type.c @@ -0,0 +1,193 @@ +// 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> + +/** + * 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 = drv->id_table; + + while (id && id->mfg_id) { + if (slave->id.mfg_id == id->mfg_id && + slave->id.part_id == id->part_id) + return id; + id++; + } + + return NULL; +} + +static int sdw_bus_match(struct device *dev, struct device_driver *ddrv) +{ + struct sdw_slave *slave = dev_to_sdw_dev(dev); + struct sdw_driver *drv = drv_to_sdw_driver(ddrv); + + return !!sdw_get_device_id(slave, drv); +} + +int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size) +{ + /* modalias is sdw:m<mfg_id>p<part_id> */ + + return snprintf(buf, size, "sdw:m%04Xp%04X\n", + slave->id.mfg_id, slave->id.part_id); +} + +static int sdw_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, + .uevent = sdw_uevent, +}; +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; + int ret; + + 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 != -EPROBE_DEFER) { + ret = drv->probe(slave, id); + if (ret) { + dev_err(dev, "Probe of %s failed: %d\n", drv->name, ret); + dev_pm_domain_detach(dev, false); + } + } + + if (ret) + return ret; + + /* device is probed so let's read the properties now */ + if (slave->ops && slave->ops->read_prop) + slave->ops->read_prop(slave); + + /* + * 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); + + 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) +{ + drv->driver.bus = &sdw_bus_type; + + if (!drv->probe) { + pr_err("driver %s didn't provide SDW probe routine\n", + drv->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) +{ + return bus_register(&sdw_bus_type); +} + +static void __exit sdw_bus_exit(void) +{ + bus_unregister(&sdw_bus_type); +} + +postcore_initcall(sdw_bus_init); +module_exit(sdw_bus_exit); + +MODULE_DESCRIPTION("SoundWire bus"); +MODULE_LICENSE("GPL v2"); |