summaryrefslogtreecommitdiffstats
path: root/drivers/soundwire/slave.c
blob: 6473fa602f82cc81b745f97cca97df1323618939 (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
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
// Copyright(c) 2015-17 Intel Corporation.

#include <linux/acpi.h>
#include <linux/of.h>
#include <linux/soundwire/sdw.h>
#include <linux/soundwire/sdw_type.h>
#include "bus.h"

static void sdw_slave_release(struct device *dev)
{
	struct sdw_slave *slave = dev_to_sdw_dev(dev);

	kfree(slave);
}

static int sdw_slave_add(struct sdw_bus *bus,
			 struct sdw_slave_id *id, struct fwnode_handle *fwnode)
{
	struct sdw_slave *slave;
	int ret;

	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
	if (!slave)
		return -ENOMEM;

	/* Initialize data structure */
	memcpy(&slave->id, id, sizeof(*id));
	slave->dev.parent = bus->dev;
	slave->dev.fwnode = fwnode;

	/* name shall be sdw:link:mfg:part:class:unique */
	dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
		     bus->link_id, id->mfg_id, id->part_id,
		     id->class_id, id->unique_id);

	slave->dev.release = sdw_slave_release;
	slave->dev.bus = &sdw_bus_type;
	slave->dev.of_node = of_node_get(to_of_node(fwnode));
	slave->bus = bus;
	slave->status = SDW_SLAVE_UNATTACHED;
	slave->dev_num = 0;

	mutex_lock(&bus->bus_lock);
	list_add_tail(&slave->node, &bus->slaves);
	mutex_unlock(&bus->bus_lock);

	ret = device_register(&slave->dev);
	if (ret) {
		dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);

		/*
		 * On err, don't free but drop ref as this will be freed
		 * when release method is invoked.
		 */
		mutex_lock(&bus->bus_lock);
		list_del(&slave->node);
		mutex_unlock(&bus->bus_lock);
		put_device(&slave->dev);
	}
	sdw_slave_debugfs_init(slave);

	return ret;
}

#if IS_ENABLED(CONFIG_ACPI)
/*
 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
 * @bus: SDW bus instance
 *
 * Scans Master ACPI node for SDW child Slave devices and registers it.
 */
int sdw_acpi_find_slaves(struct sdw_bus *bus)
{
	struct acpi_device *adev, *parent;

	parent = ACPI_COMPANION(bus->dev);
	if (!parent) {
		dev_err(bus->dev, "Can't find parent for acpi bind\n");
		return -ENODEV;
	}

	list_for_each_entry(adev, &parent->children, node) {
		unsigned long long addr;
		struct sdw_slave_id id;
		unsigned int link_id;
		acpi_status status;

		status = acpi_evaluate_integer(adev->handle,
					       METHOD_NAME__ADR, NULL, &addr);

		if (ACPI_FAILURE(status)) {
			dev_err(bus->dev, "_ADR resolution failed: %x\n",
				status);
			return status;
		}

		/* Extract link id from ADR, Bit 51 to 48 (included) */
		link_id = (addr >> 48) & GENMASK(3, 0);

		/* Check for link_id match */
		if (link_id != bus->link_id)
			continue;

		sdw_extract_slave_id(bus, addr, &id);

		/*
		 * don't error check for sdw_slave_add as we want to continue
		 * adding Slaves
		 */
		sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
	}

	return 0;
}

#endif

/*
 * sdw_of_find_slaves() - Find Slave devices in master device tree node
 * @bus: SDW bus instance
 *
 * Scans Master DT node for SDW child Slave devices and registers it.
 */
int sdw_of_find_slaves(struct sdw_bus *bus)
{
	struct device *dev = bus->dev;
	struct device_node *node;

	for_each_child_of_node(bus->dev->of_node, node) {
		int link_id, ret, len;
		unsigned int sdw_version;
		const char *compat = NULL;
		struct sdw_slave_id id;
		const __be32 *addr;

		compat = of_get_property(node, "compatible", NULL);
		if (!compat)
			continue;

		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
			     &id.mfg_id, &id.part_id, &id.class_id);

		if (ret != 4) {
			dev_err(dev, "Invalid compatible string found %s\n",
				compat);
			continue;
		}

		addr = of_get_property(node, "reg", &len);
		if (!addr || (len < 2 * sizeof(u32))) {
			dev_err(dev, "Invalid Link and Instance ID\n");
			continue;
		}

		link_id = be32_to_cpup(addr++);
		id.unique_id = be32_to_cpup(addr);
		id.sdw_version = sdw_version;

		/* Check for link_id match */
		if (link_id != bus->link_id)
			continue;

		sdw_slave_add(bus, &id, of_fwnode_handle(node));
	}

	return 0;
}