xref: /openbmc/linux/drivers/soundwire/slave.c (revision 910499e1)
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/of.h>
6 #include <linux/soundwire/sdw.h>
7 #include <linux/soundwire/sdw_type.h>
8 #include "bus.h"
9 #include "sysfs_local.h"
10 
11 static void sdw_slave_release(struct device *dev)
12 {
13 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
14 
15 	kfree(slave);
16 }
17 
18 struct device_type sdw_slave_type = {
19 	.name =		"sdw_slave",
20 	.release =	sdw_slave_release,
21 	.uevent =	sdw_slave_uevent,
22 };
23 
24 int sdw_slave_add(struct sdw_bus *bus,
25 		  struct sdw_slave_id *id, struct fwnode_handle *fwnode)
26 {
27 	struct sdw_slave *slave;
28 	int ret;
29 	int i;
30 
31 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
32 	if (!slave)
33 		return -ENOMEM;
34 
35 	/* Initialize data structure */
36 	memcpy(&slave->id, id, sizeof(*id));
37 	slave->dev.parent = bus->dev;
38 	slave->dev.fwnode = fwnode;
39 
40 	if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
41 		/* name shall be sdw:link:mfg:part:class */
42 		dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x",
43 			     bus->link_id, id->mfg_id, id->part_id,
44 			     id->class_id);
45 	} else {
46 		/* name shall be sdw:link:mfg:part:class:unique */
47 		dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
48 			     bus->link_id, id->mfg_id, id->part_id,
49 			     id->class_id, id->unique_id);
50 	}
51 
52 	slave->dev.bus = &sdw_bus_type;
53 	slave->dev.of_node = of_node_get(to_of_node(fwnode));
54 	slave->dev.type = &sdw_slave_type;
55 	slave->dev.groups = sdw_slave_status_attr_groups;
56 	slave->bus = bus;
57 	slave->status = SDW_SLAVE_UNATTACHED;
58 	init_completion(&slave->enumeration_complete);
59 	init_completion(&slave->initialization_complete);
60 	slave->dev_num = 0;
61 	init_completion(&slave->probe_complete);
62 	slave->probed = false;
63 	slave->first_interrupt_done = false;
64 
65 	for (i = 0; i < SDW_MAX_PORTS; i++)
66 		init_completion(&slave->port_ready[i]);
67 
68 	mutex_lock(&bus->bus_lock);
69 	list_add_tail(&slave->node, &bus->slaves);
70 	mutex_unlock(&bus->bus_lock);
71 
72 	ret = device_register(&slave->dev);
73 	if (ret) {
74 		dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
75 
76 		/*
77 		 * On err, don't free but drop ref as this will be freed
78 		 * when release method is invoked.
79 		 */
80 		mutex_lock(&bus->bus_lock);
81 		list_del(&slave->node);
82 		mutex_unlock(&bus->bus_lock);
83 		put_device(&slave->dev);
84 
85 		return ret;
86 	}
87 	sdw_slave_debugfs_init(slave);
88 
89 	return ret;
90 }
91 
92 #if IS_ENABLED(CONFIG_ACPI)
93 
94 static bool find_slave(struct sdw_bus *bus,
95 		       struct acpi_device *adev,
96 		       struct sdw_slave_id *id)
97 {
98 	unsigned long long addr;
99 	unsigned int link_id;
100 	acpi_status status;
101 
102 	status = acpi_evaluate_integer(adev->handle,
103 				       METHOD_NAME__ADR, NULL, &addr);
104 
105 	if (ACPI_FAILURE(status)) {
106 		dev_err(bus->dev, "_ADR resolution failed: %x\n",
107 			status);
108 		return false;
109 	}
110 
111 	/* Extract link id from ADR, Bit 51 to 48 (included) */
112 	link_id = SDW_DISCO_LINK_ID(addr);
113 
114 	/* Check for link_id match */
115 	if (link_id != bus->link_id)
116 		return false;
117 
118 	sdw_extract_slave_id(bus, addr, id);
119 
120 	return true;
121 }
122 
123 /*
124  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
125  * @bus: SDW bus instance
126  *
127  * Scans Master ACPI node for SDW child Slave devices and registers it.
128  */
129 int sdw_acpi_find_slaves(struct sdw_bus *bus)
130 {
131 	struct acpi_device *adev, *parent;
132 	struct acpi_device *adev2, *parent2;
133 
134 	parent = ACPI_COMPANION(bus->dev);
135 	if (!parent) {
136 		dev_err(bus->dev, "Can't find parent for acpi bind\n");
137 		return -ENODEV;
138 	}
139 
140 	list_for_each_entry(adev, &parent->children, node) {
141 		struct sdw_slave_id id;
142 		struct sdw_slave_id id2;
143 		bool ignore_unique_id = true;
144 
145 		if (!find_slave(bus, adev, &id))
146 			continue;
147 
148 		/* brute-force O(N^2) search for duplicates */
149 		parent2 = parent;
150 		list_for_each_entry(adev2, &parent2->children, node) {
151 
152 			if (adev == adev2)
153 				continue;
154 
155 			if (!find_slave(bus, adev2, &id2))
156 				continue;
157 
158 			if (id.sdw_version != id2.sdw_version ||
159 			    id.mfg_id != id2.mfg_id ||
160 			    id.part_id != id2.part_id ||
161 			    id.class_id != id2.class_id)
162 				continue;
163 
164 			if (id.unique_id != id2.unique_id) {
165 				dev_dbg(bus->dev,
166 					"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
167 					id.unique_id, id2.unique_id, id.mfg_id, id.part_id);
168 				ignore_unique_id = false;
169 			} else {
170 				dev_err(bus->dev,
171 					"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
172 					id.unique_id, id2.unique_id, id.mfg_id, id.part_id);
173 				return -ENODEV;
174 			}
175 		}
176 
177 		if (ignore_unique_id)
178 			id.unique_id = SDW_IGNORED_UNIQUE_ID;
179 
180 		/*
181 		 * don't error check for sdw_slave_add as we want to continue
182 		 * adding Slaves
183 		 */
184 		sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
185 	}
186 
187 	return 0;
188 }
189 
190 #endif
191 
192 /*
193  * sdw_of_find_slaves() - Find Slave devices in master device tree node
194  * @bus: SDW bus instance
195  *
196  * Scans Master DT node for SDW child Slave devices and registers it.
197  */
198 int sdw_of_find_slaves(struct sdw_bus *bus)
199 {
200 	struct device *dev = bus->dev;
201 	struct device_node *node;
202 
203 	for_each_child_of_node(bus->dev->of_node, node) {
204 		int link_id, ret, len;
205 		unsigned int sdw_version;
206 		const char *compat = NULL;
207 		struct sdw_slave_id id;
208 		const __be32 *addr;
209 
210 		compat = of_get_property(node, "compatible", NULL);
211 		if (!compat)
212 			continue;
213 
214 		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
215 			     &id.mfg_id, &id.part_id, &id.class_id);
216 
217 		if (ret != 4) {
218 			dev_err(dev, "Invalid compatible string found %s\n",
219 				compat);
220 			continue;
221 		}
222 
223 		addr = of_get_property(node, "reg", &len);
224 		if (!addr || (len < 2 * sizeof(u32))) {
225 			dev_err(dev, "Invalid Link and Instance ID\n");
226 			continue;
227 		}
228 
229 		link_id = be32_to_cpup(addr++);
230 		id.unique_id = be32_to_cpup(addr);
231 		id.sdw_version = sdw_version;
232 
233 		/* Check for link_id match */
234 		if (link_id != bus->link_id)
235 			continue;
236 
237 		sdw_slave_add(bus, &id, of_fwnode_handle(node));
238 	}
239 
240 	return 0;
241 }
242