1// SPDX-License-Identifier: GPL-2.0
  2// Copyright(c) 2015-17 Intel Corporation.
  3
  4#include <linux/module.h>
  5#include <linux/mod_devicetable.h>
  6#include <linux/pm_domain.h>
  7#include <linux/soundwire/sdw.h>
  8#include <linux/soundwire/sdw_type.h>
  9#include "bus.h"
 10#include "irq.h"
 11#include "sysfs_local.h"
 12
 13/**
 14 * sdw_get_device_id - find the matching SoundWire device id
 15 * @slave: SoundWire Slave Device
 16 * @drv: SoundWire Slave Driver
 17 *
 18 * The match is done by comparing the mfg_id and part_id from the
 19 * struct sdw_device_id.
 20 */
 21static const struct sdw_device_id *
 22sdw_get_device_id(struct sdw_slave *slave, const struct sdw_driver *drv)
 23{
 24	const struct sdw_device_id *id;
 25
 26	for (id = drv->id_table; id && id->mfg_id; id++)
 27		if (slave->id.mfg_id == id->mfg_id &&
 28		    slave->id.part_id == id->part_id  &&
 29		    (!id->sdw_version ||
 30		     slave->id.sdw_version == id->sdw_version) &&
 31		    (!id->class_id ||
 32		     slave->id.class_id == id->class_id))
 33			return id;
 34
 35	return NULL;
 36}
 37
 38static int sdw_bus_match(struct device *dev, const struct device_driver *ddrv)
 39{
 40	struct sdw_slave *slave;
 41	const struct sdw_driver *drv;
 42	int ret = 0;
 43
 44	if (is_sdw_slave(dev)) {
 45		slave = dev_to_sdw_dev(dev);
 46		drv = drv_to_sdw_driver(ddrv);
 47
 48		ret = !!sdw_get_device_id(slave, drv);
 49	}
 50	return ret;
 51}
 52
 53int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
 54{
 55	/* modalias is sdw:m<mfg_id>p<part_id>v<version>c<class_id> */
 56
 57	return snprintf(buf, size, "sdw:m%04Xp%04Xv%02Xc%02X\n",
 58			slave->id.mfg_id, slave->id.part_id,
 59			slave->id.sdw_version, slave->id.class_id);
 60}
 61
 62int sdw_slave_uevent(const struct device *dev, struct kobj_uevent_env *env)
 63{
 64	const struct sdw_slave *slave = dev_to_sdw_dev(dev);
 65	char modalias[32];
 66
 67	sdw_slave_modalias(slave, modalias, sizeof(modalias));
 68
 69	if (add_uevent_var(env, "MODALIAS=%s", modalias))
 70		return -ENOMEM;
 71
 72	return 0;
 73}
 74
 75const struct bus_type sdw_bus_type = {
 76	.name = "soundwire",
 77	.match = sdw_bus_match,
 78};
 79EXPORT_SYMBOL_GPL(sdw_bus_type);
 80
 81static int sdw_drv_probe(struct device *dev)
 82{
 83	struct sdw_slave *slave = dev_to_sdw_dev(dev);
 84	struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
 85	const struct sdw_device_id *id;
 86	int ret;
 87
 88	/*
 89	 * fw description is mandatory to bind
 90	 */
 91	if (!dev->fwnode)
 92		return -ENODEV;
 93
 94	if (!IS_ENABLED(CONFIG_ACPI) && !dev->of_node)
 95		return -ENODEV;
 96
 97	id = sdw_get_device_id(slave, drv);
 98	if (!id)
 99		return -ENODEV;
100
101	/*
102	 * attach to power domain but don't turn on (last arg)
103	 */
104	ret = dev_pm_domain_attach(dev, false);
105	if (ret)
106		return ret;
107
108	ret = drv->probe(slave, id);
109	if (ret) {
110		dev_pm_domain_detach(dev, false);
111		return ret;
112	}
113
114	mutex_lock(&slave->sdw_dev_lock);
115
116	/* device is probed so let's read the properties now */
117	if (drv->ops && drv->ops->read_prop)
118		drv->ops->read_prop(slave);
119
120	if (slave->prop.use_domain_irq)
121		sdw_irq_create_mapping(slave);
122
123	/* init the dynamic sysfs attributes we need */
124	ret = sdw_slave_sysfs_dpn_init(slave);
125	if (ret < 0)
126		dev_warn(dev, "failed to initialise sysfs: %d\n", ret);
127
128	/*
129	 * Check for valid clk_stop_timeout, use DisCo worst case value of
130	 * 300ms
131	 *
132	 * TODO: check the timeouts and driver removal case
133	 */
134	if (slave->prop.clk_stop_timeout == 0)
135		slave->prop.clk_stop_timeout = 300;
136
137	slave->bus->clk_stop_timeout = max_t(u32, slave->bus->clk_stop_timeout,
138					     slave->prop.clk_stop_timeout);
139
140	slave->probed = true;
141
142	/*
143	 * if the probe happened after the bus was started, notify the codec driver
144	 * of the current hardware status to e.g. start the initialization.
145	 * Errors are only logged as warnings to avoid failing the probe.
146	 */
147	if (drv->ops && drv->ops->update_status) {
148		ret = drv->ops->update_status(slave, slave->status);
149		if (ret < 0)
150			dev_warn(dev, "failed to update status at probe: %d\n", ret);
151	}
152
153	mutex_unlock(&slave->sdw_dev_lock);
154
155	dev_dbg(dev, "probe complete\n");
156
157	return 0;
158}
159
160static int sdw_drv_remove(struct device *dev)
161{
162	struct sdw_slave *slave = dev_to_sdw_dev(dev);
163	struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
164	int ret = 0;
165
166	mutex_lock(&slave->sdw_dev_lock);
167
168	slave->probed = false;
169
170	if (slave->prop.use_domain_irq)
171		sdw_irq_dispose_mapping(slave);
172
173	mutex_unlock(&slave->sdw_dev_lock);
174
175	if (drv->remove)
176		ret = drv->remove(slave);
177
178	dev_pm_domain_detach(dev, false);
179
180	return ret;
181}
182
183static void sdw_drv_shutdown(struct device *dev)
184{
185	struct sdw_slave *slave = dev_to_sdw_dev(dev);
186	struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
187
188	if (drv->shutdown)
189		drv->shutdown(slave);
190}
191
192/**
193 * __sdw_register_driver() - register a SoundWire Slave driver
194 * @drv: driver to register
195 * @owner: owning module/driver
196 *
197 * Return: zero on success, else a negative error code.
198 */
199int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
200{
201	drv->driver.bus = &sdw_bus_type;
202
203	if (!drv->probe) {
204		pr_err("driver %s didn't provide SDW probe routine\n",
205				drv->driver.name);
206		return -EINVAL;
207	}
208
209	drv->driver.owner = owner;
210	drv->driver.probe = sdw_drv_probe;
211	drv->driver.remove = sdw_drv_remove;
212	drv->driver.shutdown = sdw_drv_shutdown;
213	drv->driver.dev_groups = sdw_attr_groups;
214
215	return driver_register(&drv->driver);
216}
217EXPORT_SYMBOL_GPL(__sdw_register_driver);
218
219/**
220 * sdw_unregister_driver() - unregisters the SoundWire Slave driver
221 * @drv: driver to unregister
222 */
223void sdw_unregister_driver(struct sdw_driver *drv)
224{
225	driver_unregister(&drv->driver);
226}
227EXPORT_SYMBOL_GPL(sdw_unregister_driver);
228
229static int __init sdw_bus_init(void)
230{
231	sdw_debugfs_init();
232	return bus_register(&sdw_bus_type);
233}
234
235static void __exit sdw_bus_exit(void)
236{
237	sdw_debugfs_exit();
238	bus_unregister(&sdw_bus_type);
239}
240
241postcore_initcall(sdw_bus_init);
242module_exit(sdw_bus_exit);
243
244MODULE_DESCRIPTION("SoundWire bus");
245MODULE_LICENSE("GPL v2");