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![Vinod Koul](/assets/img/avatar_default.png)
MIPI Discovery And Configuration (DisCo) Specification for SoundWire specifies properties to be implemented for SoundWire Masters and Slaves. The DisCo spec doesn't mandate these properties. However, SDW bus cannot work without knowing these values. The helper functions read the Master and Slave properties. Implementers of Master or Slave drivers can use any of the below three mechanisms: a) Use these APIs here as .read_prop() callback for Master and Slave b) Implement own methods and set those as .read_prop(), but invoke APIs in this file for generic read and override the values with platform specific data c) Implement ones own methods which do not use anything provided here Signed-off-by: Sanyog Kale <sanyog.r.kale@intel.com> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Acked-By: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
193 lines
4.3 KiB
C
193 lines
4.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright(c) 2015-17 Intel Corporation.
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/pm_domain.h>
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#include <linux/soundwire/sdw.h>
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#include <linux/soundwire/sdw_type.h>
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/**
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* sdw_get_device_id - find the matching SoundWire device id
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* @slave: SoundWire Slave Device
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* @drv: SoundWire Slave Driver
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*
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* The match is done by comparing the mfg_id and part_id from the
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* struct sdw_device_id.
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*/
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static const struct sdw_device_id *
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sdw_get_device_id(struct sdw_slave *slave, struct sdw_driver *drv)
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{
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const struct sdw_device_id *id = drv->id_table;
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while (id && id->mfg_id) {
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if (slave->id.mfg_id == id->mfg_id &&
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slave->id.part_id == id->part_id)
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return id;
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id++;
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}
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return NULL;
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}
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static int sdw_bus_match(struct device *dev, struct device_driver *ddrv)
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{
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struct sdw_slave *slave = dev_to_sdw_dev(dev);
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struct sdw_driver *drv = drv_to_sdw_driver(ddrv);
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return !!sdw_get_device_id(slave, drv);
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}
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int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
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{
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/* modalias is sdw:m<mfg_id>p<part_id> */
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return snprintf(buf, size, "sdw:m%04Xp%04X\n",
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slave->id.mfg_id, slave->id.part_id);
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}
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static int sdw_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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struct sdw_slave *slave = dev_to_sdw_dev(dev);
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char modalias[32];
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sdw_slave_modalias(slave, modalias, sizeof(modalias));
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if (add_uevent_var(env, "MODALIAS=%s", modalias))
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return -ENOMEM;
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return 0;
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}
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struct bus_type sdw_bus_type = {
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.name = "soundwire",
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.match = sdw_bus_match,
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.uevent = sdw_uevent,
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};
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EXPORT_SYMBOL_GPL(sdw_bus_type);
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static int sdw_drv_probe(struct device *dev)
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{
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struct sdw_slave *slave = dev_to_sdw_dev(dev);
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struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
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const struct sdw_device_id *id;
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int ret;
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id = sdw_get_device_id(slave, drv);
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if (!id)
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return -ENODEV;
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slave->ops = drv->ops;
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/*
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* attach to power domain but don't turn on (last arg)
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*/
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ret = dev_pm_domain_attach(dev, false);
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if (ret != -EPROBE_DEFER) {
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ret = drv->probe(slave, id);
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if (ret) {
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dev_err(dev, "Probe of %s failed: %d\n", drv->name, ret);
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dev_pm_domain_detach(dev, false);
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}
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}
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if (ret)
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return ret;
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/* device is probed so let's read the properties now */
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if (slave->ops && slave->ops->read_prop)
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slave->ops->read_prop(slave);
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/*
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* Check for valid clk_stop_timeout, use DisCo worst case value of
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* 300ms
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*
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* TODO: check the timeouts and driver removal case
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*/
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if (slave->prop.clk_stop_timeout == 0)
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slave->prop.clk_stop_timeout = 300;
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slave->bus->clk_stop_timeout = max_t(u32, slave->bus->clk_stop_timeout,
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slave->prop.clk_stop_timeout);
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return 0;
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}
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static int sdw_drv_remove(struct device *dev)
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{
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struct sdw_slave *slave = dev_to_sdw_dev(dev);
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struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
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int ret = 0;
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if (drv->remove)
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ret = drv->remove(slave);
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dev_pm_domain_detach(dev, false);
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return ret;
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}
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static void sdw_drv_shutdown(struct device *dev)
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{
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struct sdw_slave *slave = dev_to_sdw_dev(dev);
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struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
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if (drv->shutdown)
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drv->shutdown(slave);
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}
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/**
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* __sdw_register_driver() - register a SoundWire Slave driver
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* @drv: driver to register
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* @owner: owning module/driver
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*
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* Return: zero on success, else a negative error code.
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*/
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int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
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{
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drv->driver.bus = &sdw_bus_type;
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if (!drv->probe) {
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pr_err("driver %s didn't provide SDW probe routine\n",
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drv->name);
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return -EINVAL;
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}
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drv->driver.owner = owner;
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drv->driver.probe = sdw_drv_probe;
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if (drv->remove)
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drv->driver.remove = sdw_drv_remove;
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if (drv->shutdown)
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drv->driver.shutdown = sdw_drv_shutdown;
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return driver_register(&drv->driver);
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}
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EXPORT_SYMBOL_GPL(__sdw_register_driver);
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/**
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* sdw_unregister_driver() - unregisters the SoundWire Slave driver
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* @drv: driver to unregister
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*/
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void sdw_unregister_driver(struct sdw_driver *drv)
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{
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driver_unregister(&drv->driver);
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}
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EXPORT_SYMBOL_GPL(sdw_unregister_driver);
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static int __init sdw_bus_init(void)
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{
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return bus_register(&sdw_bus_type);
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}
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static void __exit sdw_bus_exit(void)
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{
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bus_unregister(&sdw_bus_type);
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}
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postcore_initcall(sdw_bus_init);
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module_exit(sdw_bus_exit);
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MODULE_DESCRIPTION("SoundWire bus");
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MODULE_LICENSE("GPL v2");
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