summaryrefslogtreecommitdiff
path: root/drivers/soundwire/bus_type.c
blob: 26c9a0a85d492dd9cde25c313975ee243debcd7e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
// 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>
#include "bus.h"
#include "sysfs_local.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;

	for (id = drv->id_table; id && id->mfg_id; id++)
		if (slave->id.mfg_id == id->mfg_id &&
		    slave->id.part_id == id->part_id  &&
		    (!id->sdw_version ||
		     slave->id.sdw_version == id->sdw_version) &&
		    (!id->class_id ||
		     slave->id.class_id == id->class_id))
			return id;

	return NULL;
}

static int sdw_bus_match(struct device *dev, struct device_driver *ddrv)
{
	struct sdw_slave *slave;
	struct sdw_driver *drv;
	int ret = 0;

	if (is_sdw_slave(dev)) {
		slave = dev_to_sdw_dev(dev);
		drv = drv_to_sdw_driver(ddrv);

		ret = !!sdw_get_device_id(slave, drv);
	}
	return ret;
}

int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
{
	/* modalias is sdw:m<mfg_id>p<part_id>v<version>c<class_id> */

	return snprintf(buf, size, "sdw:m%04Xp%04Xv%02Xc%02X\n",
			slave->id.mfg_id, slave->id.part_id,
			slave->id.sdw_version, slave->id.class_id);
}

int sdw_slave_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
	const 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,
};
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;
	const char *name;
	int ret;

	/*
	 * fw description is mandatory to bind
	 */
	if (!dev->fwnode)
		return -ENODEV;

	if (!IS_ENABLED(CONFIG_ACPI) && !dev->of_node)
		return -ENODEV;

	id = sdw_get_device_id(slave, drv);
	if (!id)
		return -ENODEV;

	/*
	 * attach to power domain but don't turn on (last arg)
	 */
	ret = dev_pm_domain_attach(dev, false);
	if (ret)
		return ret;

	mutex_lock(&slave->sdw_dev_lock);

	ret = drv->probe(slave, id);
	if (ret) {
		name = drv->name;
		if (!name)
			name = drv->driver.name;
		mutex_unlock(&slave->sdw_dev_lock);

		dev_err(dev, "Probe of %s failed: %d\n", name, ret);
		dev_pm_domain_detach(dev, false);
		return ret;
	}

	/* device is probed so let's read the properties now */
	if (drv->ops && drv->ops->read_prop)
		drv->ops->read_prop(slave);

	/* init the sysfs as we have properties now */
	ret = sdw_slave_sysfs_init(slave);
	if (ret < 0)
		dev_warn(dev, "Slave sysfs init failed:%d\n", ret);

	/*
	 * 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);

	slave->probed = true;

	/*
	 * if the probe happened after the bus was started, notify the codec driver
	 * of the current hardware status to e.g. start the initialization.
	 * Errors are only logged as warnings to avoid failing the probe.
	 */
	if (drv->ops && drv->ops->update_status) {
		ret = drv->ops->update_status(slave, slave->status);
		if (ret < 0)
			dev_warn(dev, "%s: update_status failed with status %d\n", __func__, ret);
	}

	mutex_unlock(&slave->sdw_dev_lock);

	dev_dbg(dev, "probe complete\n");

	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;

	mutex_lock(&slave->sdw_dev_lock);

	slave->probed = false;

	if (drv->remove)
		ret = drv->remove(slave);

	mutex_unlock(&slave->sdw_dev_lock);

	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)
{
	const char *name;

	drv->driver.bus = &sdw_bus_type;

	if (!drv->probe) {
		name = drv->name;
		if (!name)
			name = drv->driver.name;

		pr_err("driver %s didn't provide SDW probe routine\n", name);
		return -EINVAL;
	}

	drv->driver.owner = owner;
	drv->driver.probe = sdw_drv_probe;
	drv->driver.remove = sdw_drv_remove;
	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)
{
	sdw_debugfs_init();
	return bus_register(&sdw_bus_type);
}

static void __exit sdw_bus_exit(void)
{
	sdw_debugfs_exit();
	bus_unregister(&sdw_bus_type);
}

postcore_initcall(sdw_bus_init);
module_exit(sdw_bus_exit);

MODULE_DESCRIPTION("SoundWire bus");
MODULE_LICENSE("GPL v2");