1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 // Copyright(c) 2015-17 Intel Corporation.
3
4 #include <linux/acpi.h>
5 #include <linux/soundwire/sdw.h>
6 #include <linux/soundwire/sdw_type.h>
7 #include "bus.h"
8
sdw_slave_release(struct device * dev)9 static void sdw_slave_release(struct device *dev)
10 {
11 struct sdw_slave *slave = dev_to_sdw_dev(dev);
12
13 kfree(slave);
14 }
15
sdw_slave_add(struct sdw_bus * bus,struct sdw_slave_id * id,struct fwnode_handle * fwnode)16 static int sdw_slave_add(struct sdw_bus *bus,
17 struct sdw_slave_id *id, struct fwnode_handle *fwnode)
18 {
19 struct sdw_slave *slave;
20 int ret;
21
22 slave = kzalloc(sizeof(*slave), GFP_KERNEL);
23 if (!slave)
24 return -ENOMEM;
25
26 /* Initialize data structure */
27 memcpy(&slave->id, id, sizeof(*id));
28 slave->dev.parent = bus->dev;
29 slave->dev.fwnode = fwnode;
30
31 /* name shall be sdw:link:mfg:part:class:unique */
32 dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
33 bus->link_id, id->mfg_id, id->part_id,
34 id->class_id, id->unique_id);
35
36 slave->dev.release = sdw_slave_release;
37 slave->dev.bus = &sdw_bus_type;
38 slave->bus = bus;
39 slave->status = SDW_SLAVE_UNATTACHED;
40 slave->dev_num = 0;
41
42 mutex_lock(&bus->bus_lock);
43 list_add_tail(&slave->node, &bus->slaves);
44 mutex_unlock(&bus->bus_lock);
45
46 ret = device_register(&slave->dev);
47 if (ret) {
48 dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
49
50 /*
51 * On err, don't free but drop ref as this will be freed
52 * when release method is invoked.
53 */
54 mutex_lock(&bus->bus_lock);
55 list_del(&slave->node);
56 mutex_unlock(&bus->bus_lock);
57 put_device(&slave->dev);
58 }
59
60 return ret;
61 }
62
63 #if IS_ENABLED(CONFIG_ACPI)
64 /*
65 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
66 * @bus: SDW bus instance
67 *
68 * Scans Master ACPI node for SDW child Slave devices and registers it.
69 */
sdw_acpi_find_slaves(struct sdw_bus * bus)70 int sdw_acpi_find_slaves(struct sdw_bus *bus)
71 {
72 struct acpi_device *adev, *parent;
73
74 parent = ACPI_COMPANION(bus->dev);
75 if (!parent) {
76 dev_err(bus->dev, "Can't find parent for acpi bind\n");
77 return -ENODEV;
78 }
79
80 list_for_each_entry(adev, &parent->children, node) {
81 unsigned long long addr;
82 struct sdw_slave_id id;
83 unsigned int link_id;
84 acpi_status status;
85
86 status = acpi_evaluate_integer(adev->handle,
87 METHOD_NAME__ADR, NULL, &addr);
88
89 if (ACPI_FAILURE(status)) {
90 dev_err(bus->dev, "_ADR resolution failed: %x\n",
91 status);
92 return status;
93 }
94
95 /* Extract link id from ADR, Bit 51 to 48 (included) */
96 link_id = (addr >> 48) & GENMASK(3, 0);
97
98 /* Check for link_id match */
99 if (link_id != bus->link_id)
100 continue;
101
102 sdw_extract_slave_id(bus, addr, &id);
103
104 /*
105 * don't error check for sdw_slave_add as we want to continue
106 * adding Slaves
107 */
108 sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
109 }
110
111 return 0;
112 }
113
114 #endif
115