xref: /linux/drivers/soundwire/slave.c (revision f86d1fbbe7858884d6754534a0afbb74fc30bc26)
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:%01x:%04x:%04x:%02x",
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:%01x:%04x:%04x:%02x:%01x",
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 EXPORT_SYMBOL(sdw_slave_add);
92 
93 #if IS_ENABLED(CONFIG_ACPI)
94 
95 static bool find_slave(struct sdw_bus *bus,
96 		       struct acpi_device *adev,
97 		       struct sdw_slave_id *id)
98 {
99 	u64 addr;
100 	unsigned int link_id;
101 	acpi_status status;
102 
103 	status = acpi_evaluate_integer(adev->handle,
104 				       METHOD_NAME__ADR, NULL, &addr);
105 
106 	if (ACPI_FAILURE(status)) {
107 		dev_err(bus->dev, "_ADR resolution failed: %x\n",
108 			status);
109 		return false;
110 	}
111 
112 	if (bus->ops->override_adr)
113 		addr = bus->ops->override_adr(bus, addr);
114 
115 	if (!addr)
116 		return false;
117 
118 	/* Extract link id from ADR, Bit 51 to 48 (included) */
119 	link_id = SDW_DISCO_LINK_ID(addr);
120 
121 	/* Check for link_id match */
122 	if (link_id != bus->link_id)
123 		return false;
124 
125 	sdw_extract_slave_id(bus, addr, id);
126 
127 	return true;
128 }
129 
130 struct sdw_acpi_child_walk_data {
131 	struct sdw_bus *bus;
132 	struct acpi_device *adev;
133 	struct sdw_slave_id id;
134 	bool ignore_unique_id;
135 };
136 
137 static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
138 {
139 	struct sdw_acpi_child_walk_data *cwd = data;
140 	struct sdw_bus *bus = cwd->bus;
141 	struct sdw_slave_id id;
142 
143 	if (adev == cwd->adev)
144 		return 0;
145 
146 	if (!find_slave(bus, adev, &id))
147 		return 0;
148 
149 	if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
150 	    cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
151 		return 0;
152 
153 	if (cwd->id.unique_id != id.unique_id) {
154 		dev_dbg(bus->dev,
155 			"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
156 			cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,
157 			cwd->id.part_id);
158 		cwd->ignore_unique_id = false;
159 		return 0;
160 	}
161 
162 	dev_err(bus->dev,
163 		"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
164 		cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
165 	return -ENODEV;
166 }
167 
168 static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
169 {
170 	struct sdw_bus *bus = data;
171 	struct sdw_acpi_child_walk_data cwd = {
172 		.bus = bus,
173 		.adev = adev,
174 		.ignore_unique_id = true,
175 	};
176 	int ret;
177 
178 	if (!find_slave(bus, adev, &cwd.id))
179 		return 0;
180 
181 	/* Brute-force O(N^2) search for duplicates. */
182 	ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
183 				      sdw_acpi_check_duplicate, &cwd);
184 	if (ret)
185 		return ret;
186 
187 	if (cwd.ignore_unique_id)
188 		cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
189 
190 	/* Ignore errors and continue. */
191 	sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
192 	return 0;
193 }
194 
195 /*
196  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
197  * @bus: SDW bus instance
198  *
199  * Scans Master ACPI node for SDW child Slave devices and registers it.
200  */
201 int sdw_acpi_find_slaves(struct sdw_bus *bus)
202 {
203 	struct acpi_device *parent;
204 
205 	parent = ACPI_COMPANION(bus->dev);
206 	if (!parent) {
207 		dev_err(bus->dev, "Can't find parent for acpi bind\n");
208 		return -ENODEV;
209 	}
210 
211 	return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
212 }
213 
214 #endif
215 
216 /*
217  * sdw_of_find_slaves() - Find Slave devices in master device tree node
218  * @bus: SDW bus instance
219  *
220  * Scans Master DT node for SDW child Slave devices and registers it.
221  */
222 int sdw_of_find_slaves(struct sdw_bus *bus)
223 {
224 	struct device *dev = bus->dev;
225 	struct device_node *node;
226 
227 	for_each_child_of_node(bus->dev->of_node, node) {
228 		int link_id, ret, len;
229 		unsigned int sdw_version;
230 		const char *compat = NULL;
231 		struct sdw_slave_id id;
232 		const __be32 *addr;
233 
234 		compat = of_get_property(node, "compatible", NULL);
235 		if (!compat)
236 			continue;
237 
238 		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
239 			     &id.mfg_id, &id.part_id, &id.class_id);
240 
241 		if (ret != 4) {
242 			dev_err(dev, "Invalid compatible string found %s\n",
243 				compat);
244 			continue;
245 		}
246 
247 		addr = of_get_property(node, "reg", &len);
248 		if (!addr || (len < 2 * sizeof(u32))) {
249 			dev_err(dev, "Invalid Link and Instance ID\n");
250 			continue;
251 		}
252 
253 		link_id = be32_to_cpup(addr++);
254 		id.unique_id = be32_to_cpup(addr);
255 		id.sdw_version = sdw_version;
256 
257 		/* Check for link_id match */
258 		if (link_id != bus->link_id)
259 			continue;
260 
261 		sdw_slave_add(bus, &id, of_fwnode_handle(node));
262 	}
263 
264 	return 0;
265 }
266