tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 "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, 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, struct device_driver *ddrv)
38{
39 struct sdw_slave *slave;
40 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(struct device *dev, struct kobj_uevent_env *env)
62{
63 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
74struct bus_type sdw_bus_type = {
75 .name = "soundwire",
76 .match = sdw_bus_match,
77};
78EXPORT_SYMBOL_GPL(sdw_bus_type);
79
80static int sdw_drv_probe(struct device *dev)
81{
82 struct sdw_slave *slave = dev_to_sdw_dev(dev);
83 struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
84 const struct sdw_device_id *id;
85 int ret;
86
87 id = sdw_get_device_id(slave, drv);
88 if (!id)
89 return -ENODEV;
90
91 slave->ops = drv->ops;
92
93 /*
94 * attach to power domain but don't turn on (last arg)
95 */
96 ret = dev_pm_domain_attach(dev, false);
97 if (ret)
98 return ret;
99
100 ret = drv->probe(slave, id);
101 if (ret) {
102 dev_err(dev, "Probe of %s failed: %d\n", drv->name, ret);
103 dev_pm_domain_detach(dev, false);
104 return ret;
105 }
106
107 /* device is probed so let's read the properties now */
108 if (slave->ops && slave->ops->read_prop)
109 slave->ops->read_prop(slave);
110
111 /* init the sysfs as we have properties now */
112 ret = sdw_slave_sysfs_init(slave);
113 if (ret < 0)
114 dev_warn(dev, "Slave sysfs init failed:%d\n", ret);
115
116 /*
117 * Check for valid clk_stop_timeout, use DisCo worst case value of
118 * 300ms
119 *
120 * TODO: check the timeouts and driver removal case
121 */
122 if (slave->prop.clk_stop_timeout == 0)
123 slave->prop.clk_stop_timeout = 300;
124
125 slave->bus->clk_stop_timeout = max_t(u32, slave->bus->clk_stop_timeout,
126 slave->prop.clk_stop_timeout);
127
128 slave->probed = true;
129 complete(&slave->probe_complete);
130
131 dev_dbg(dev, "probe complete\n");
132
133 return 0;
134}
135
136static int sdw_drv_remove(struct device *dev)
137{
138 struct sdw_slave *slave = dev_to_sdw_dev(dev);
139 struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
140 int ret = 0;
141
142 if (drv->remove)
143 ret = drv->remove(slave);
144
145 dev_pm_domain_detach(dev, false);
146
147 return ret;
148}
149
150static void sdw_drv_shutdown(struct device *dev)
151{
152 struct sdw_slave *slave = dev_to_sdw_dev(dev);
153 struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
154
155 if (drv->shutdown)
156 drv->shutdown(slave);
157}
158
159/**
160 * __sdw_register_driver() - register a SoundWire Slave driver
161 * @drv: driver to register
162 * @owner: owning module/driver
163 *
164 * Return: zero on success, else a negative error code.
165 */
166int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
167{
168 drv->driver.bus = &sdw_bus_type;
169
170 if (!drv->probe) {
171 pr_err("driver %s didn't provide SDW probe routine\n",
172 drv->name);
173 return -EINVAL;
174 }
175
176 drv->driver.owner = owner;
177 drv->driver.probe = sdw_drv_probe;
178
179 if (drv->remove)
180 drv->driver.remove = sdw_drv_remove;
181
182 if (drv->shutdown)
183 drv->driver.shutdown = sdw_drv_shutdown;
184
185 return driver_register(&drv->driver);
186}
187EXPORT_SYMBOL_GPL(__sdw_register_driver);
188
189/**
190 * sdw_unregister_driver() - unregisters the SoundWire Slave driver
191 * @drv: driver to unregister
192 */
193void sdw_unregister_driver(struct sdw_driver *drv)
194{
195 driver_unregister(&drv->driver);
196}
197EXPORT_SYMBOL_GPL(sdw_unregister_driver);
198
199static int __init sdw_bus_init(void)
200{
201 sdw_debugfs_init();
202 return bus_register(&sdw_bus_type);
203}
204
205static void __exit sdw_bus_exit(void)
206{
207 sdw_debugfs_exit();
208 bus_unregister(&sdw_bus_type);
209}
210
211postcore_initcall(sdw_bus_init);
212module_exit(sdw_bus_exit);
213
214MODULE_DESCRIPTION("SoundWire bus");
215MODULE_LICENSE("GPL v2");