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1// SPDX-License-Identifier: GPL-2.0
2// Copyright(c) 2015-17 Intel Corporation.
3
4#include <linux/module.h>
5#include <linux/pm_domain.h>
6#include <linux/soundwire/sdw.h>
7#include <linux/soundwire/sdw_type.h>
8#include "bus.h"
9#include "irq.h"
10#include "sysfs_local.h"
11
12/**
13 * sdw_get_device_id - find the matching SoundWire device id
14 * @slave: SoundWire Slave Device
15 * @drv: SoundWire Slave Driver
16 *
17 * The match is done by comparing the mfg_id and part_id from the
18 * struct sdw_device_id.
19 */
20static const struct sdw_device_id *
21sdw_get_device_id(struct sdw_slave *slave, const struct sdw_driver *drv)
22{
23 const struct sdw_device_id *id;
24
25 for (id = drv->id_table; id && id->mfg_id; id++)
26 if (slave->id.mfg_id == id->mfg_id &&
27 slave->id.part_id == id->part_id &&
28 (!id->sdw_version ||
29 slave->id.sdw_version == id->sdw_version) &&
30 (!id->class_id ||
31 slave->id.class_id == id->class_id))
32 return id;
33
34 return NULL;
35}
36
37static int sdw_bus_match(struct device *dev, const struct device_driver *ddrv)
38{
39 struct sdw_slave *slave;
40 const struct sdw_driver *drv;
41 int ret = 0;
42
43 if (is_sdw_slave(dev)) {
44 slave = dev_to_sdw_dev(dev);
45 drv = drv_to_sdw_driver(ddrv);
46
47 ret = !!sdw_get_device_id(slave, drv);
48 }
49 return ret;
50}
51
52int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
53{
54 /* modalias is sdw:m<mfg_id>p<part_id>v<version>c<class_id> */
55
56 return snprintf(buf, size, "sdw:m%04Xp%04Xv%02Xc%02X\n",
57 slave->id.mfg_id, slave->id.part_id,
58 slave->id.sdw_version, slave->id.class_id);
59}
60
61int sdw_slave_uevent(const struct device *dev, struct kobj_uevent_env *env)
62{
63 const struct sdw_slave *slave = dev_to_sdw_dev(dev);
64 char modalias[32];
65
66 sdw_slave_modalias(slave, modalias, sizeof(modalias));
67
68 if (add_uevent_var(env, "MODALIAS=%s", modalias))
69 return -ENOMEM;
70
71 return 0;
72}
73
74static int sdw_bus_probe(struct device *dev)
75{
76 struct sdw_slave *slave = dev_to_sdw_dev(dev);
77 struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
78 const struct sdw_device_id *id;
79 int ret;
80
81 /*
82 * fw description is mandatory to bind
83 */
84 if (!dev->fwnode)
85 return -ENODEV;
86
87 if (!IS_ENABLED(CONFIG_ACPI) && !dev->of_node)
88 return -ENODEV;
89
90 id = sdw_get_device_id(slave, drv);
91 if (!id)
92 return -ENODEV;
93
94 /*
95 * attach to power domain but don't turn on (last arg)
96 */
97 ret = dev_pm_domain_attach(dev, 0);
98 if (ret)
99 return ret;
100
101 ret = ida_alloc_max(&slave->bus->slave_ida, SDW_FW_MAX_DEVICES - 1, GFP_KERNEL);
102 if (ret < 0) {
103 dev_err(dev, "Failed to allocated ID: %d\n", ret);
104 return ret;
105 }
106 slave->index = ret;
107
108 /* Create IRQ mapping now so the driver can get it in probe() */
109 sdw_irq_create_mapping(slave);
110
111 ret = drv->probe(slave, id);
112 if (ret) {
113 ida_free(&slave->bus->slave_ida, slave->index);
114 return ret;
115 }
116
117 mutex_lock(&slave->sdw_dev_lock);
118
119 /* device is probed so let's read the properties now */
120 if (drv->ops && drv->ops->read_prop)
121 drv->ops->read_prop(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 void sdw_bus_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
165 mutex_lock(&slave->sdw_dev_lock);
166
167 slave->probed = false;
168
169 mutex_unlock(&slave->sdw_dev_lock);
170
171 if (drv->remove)
172 drv->remove(slave);
173
174 ida_free(&slave->bus->slave_ida, slave->index);
175}
176
177static void sdw_bus_shutdown(struct device *dev)
178{
179 struct sdw_slave *slave = dev_to_sdw_dev(dev);
180 struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
181
182 if (dev->driver && drv->shutdown)
183 drv->shutdown(slave);
184}
185
186const struct bus_type sdw_bus_type = {
187 .name = "soundwire",
188 .match = sdw_bus_match,
189 .probe = sdw_bus_probe,
190 .remove = sdw_bus_remove,
191 .shutdown = sdw_bus_shutdown,
192};
193EXPORT_SYMBOL_GPL(sdw_bus_type);
194
195/**
196 * __sdw_register_driver() - register a SoundWire Slave driver
197 * @drv: driver to register
198 * @owner: owning module/driver
199 *
200 * Return: zero on success, else a negative error code.
201 */
202int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
203{
204 drv->driver.bus = &sdw_bus_type;
205
206 if (!drv->probe) {
207 pr_err("driver %s didn't provide SDW probe routine\n",
208 drv->driver.name);
209 return -EINVAL;
210 }
211
212 drv->driver.owner = owner;
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");