xref: /linux/drivers/soundwire/slave.c (revision 5ea5880764cbb164afb17a62e76ca75dc371409d)
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 <sound/sdca.h>
9 #include "bus.h"
10 #include "sysfs_local.h"
11 
12 static void sdw_slave_release(struct device *dev)
13 {
14 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
15 
16 	of_node_put(slave->dev.of_node);
17 	mutex_destroy(&slave->sdw_dev_lock);
18 	kfree(slave);
19 }
20 
21 const struct device_type sdw_slave_type = {
22 	.name =		"sdw_slave",
23 	.release =	sdw_slave_release,
24 	.uevent =	sdw_slave_uevent,
25 };
26 EXPORT_SYMBOL_GPL(sdw_slave_type);
27 
28 int sdw_slave_add(struct sdw_bus *bus,
29 		  struct sdw_slave_id *id, struct fwnode_handle *fwnode)
30 {
31 	struct sdw_slave *slave;
32 	int ret;
33 	int i;
34 
35 	slave = kzalloc_obj(*slave);
36 	if (!slave)
37 		return -ENOMEM;
38 
39 	/* Initialize data structure */
40 	memcpy(&slave->id, id, sizeof(*id));
41 	slave->dev.parent = bus->dev;
42 	slave->dev.fwnode = fwnode;
43 
44 	if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
45 		/* name shall be sdw:ctrl:link:mfg:part:class */
46 		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x",
47 			     bus->controller_id, bus->link_id, id->mfg_id, id->part_id,
48 			     id->class_id);
49 	} else {
50 		/* name shall be sdw:ctrl:link:mfg:part:class:unique */
51 		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x:%01x",
52 			     bus->controller_id, bus->link_id, id->mfg_id, id->part_id,
53 			     id->class_id, id->unique_id);
54 	}
55 
56 	slave->dev.bus = &sdw_bus_type;
57 	slave->dev.of_node = of_node_get(to_of_node(fwnode));
58 	slave->dev.type = &sdw_slave_type;
59 	slave->dev.groups = sdw_slave_status_attr_groups;
60 	slave->bus = bus;
61 	slave->status = SDW_SLAVE_UNATTACHED;
62 	init_completion(&slave->enumeration_complete);
63 	init_completion(&slave->initialization_complete);
64 	slave->dev_num = 0;
65 	slave->probed = false;
66 	slave->first_interrupt_done = false;
67 	mutex_init(&slave->sdw_dev_lock);
68 
69 	for (i = 0; i < SDW_MAX_PORTS; i++)
70 		init_completion(&slave->port_ready[i]);
71 
72 	mutex_lock(&bus->bus_lock);
73 	list_add_tail(&slave->node, &bus->slaves);
74 	mutex_unlock(&bus->bus_lock);
75 
76 	/*
77 	 * The Soundwire driver probe may optionally register SDCA
78 	 * sub-devices, one per Function. This means the information
79 	 * on the SDCA revision and the number/type of Functions need
80 	 * to be extracted from platform firmware before the SoundWire
81 	 * driver probe, and as a consequence before the SoundWire
82 	 * device_register() below.
83 	 */
84 	sdca_lookup_interface_revision(slave);
85 	sdca_lookup_functions(slave);
86 
87 	ret = device_register(&slave->dev);
88 	if (ret) {
89 		dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
90 
91 		/*
92 		 * On err, don't free but drop ref as this will be freed
93 		 * when release method is invoked.
94 		 */
95 		mutex_lock(&bus->bus_lock);
96 		list_del(&slave->node);
97 		mutex_unlock(&bus->bus_lock);
98 		put_device(&slave->dev);
99 
100 		return ret;
101 	}
102 	sdw_slave_debugfs_init(slave);
103 
104 	return ret;
105 }
106 EXPORT_SYMBOL(sdw_slave_add);
107 
108 #if IS_ENABLED(CONFIG_ACPI)
109 
110 static bool find_slave(struct sdw_bus *bus,
111 		       struct acpi_device *adev,
112 		       struct sdw_slave_id *id)
113 {
114 	unsigned int link_id;
115 	u64 addr;
116 	int ret;
117 
118 	if (acpi_bus_get_status(adev) || !acpi_dev_ready_for_enumeration(adev))
119 		return false;
120 
121 	ret = acpi_get_local_u64_address(adev->handle, &addr);
122 	if (ret < 0)
123 		return false;
124 
125 	if (bus->ops->override_adr)
126 		addr = bus->ops->override_adr(bus, addr);
127 
128 	if (!addr)
129 		return false;
130 
131 	/* Extract link id from ADR, Bit 51 to 48 (included) */
132 	link_id = SDW_DISCO_LINK_ID(addr);
133 
134 	/* Check for link_id match */
135 	if (link_id != bus->link_id)
136 		return false;
137 
138 	sdw_extract_slave_id(bus, addr, id);
139 
140 	return true;
141 }
142 
143 struct sdw_acpi_child_walk_data {
144 	struct sdw_bus *bus;
145 	struct acpi_device *adev;
146 	struct sdw_slave_id id;
147 	bool ignore_unique_id;
148 };
149 
150 static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
151 {
152 	struct sdw_acpi_child_walk_data *cwd = data;
153 	struct sdw_bus *bus = cwd->bus;
154 	struct sdw_slave_id id;
155 
156 	if (adev == cwd->adev)
157 		return 0;
158 
159 	if (!find_slave(bus, adev, &id))
160 		return 0;
161 
162 	if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
163 	    cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
164 		return 0;
165 
166 	if (cwd->id.unique_id != id.unique_id) {
167 		dev_dbg(bus->dev,
168 			"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
169 			cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,
170 			cwd->id.part_id);
171 		cwd->ignore_unique_id = false;
172 		return 0;
173 	}
174 
175 	dev_err(bus->dev,
176 		"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
177 		cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
178 	return -ENODEV;
179 }
180 
181 static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
182 {
183 	struct sdw_bus *bus = data;
184 	struct sdw_acpi_child_walk_data cwd = {
185 		.bus = bus,
186 		.adev = adev,
187 		.ignore_unique_id = true,
188 	};
189 	int ret;
190 
191 	if (!find_slave(bus, adev, &cwd.id))
192 		return 0;
193 
194 	/* Brute-force O(N^2) search for duplicates. */
195 	ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
196 				      sdw_acpi_check_duplicate, &cwd);
197 	if (ret)
198 		return ret;
199 
200 	if (cwd.ignore_unique_id)
201 		cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
202 
203 	/* Ignore errors and continue. */
204 	sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
205 	return 0;
206 }
207 
208 /*
209  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
210  * @bus: SDW bus instance
211  *
212  * Scans Master ACPI node for SDW child Slave devices and registers it.
213  */
214 int sdw_acpi_find_slaves(struct sdw_bus *bus)
215 {
216 	struct acpi_device *parent;
217 
218 	parent = ACPI_COMPANION(bus->dev);
219 	if (!parent) {
220 		dev_err(bus->dev, "Can't find parent for acpi bind\n");
221 		return -ENODEV;
222 	}
223 
224 	return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
225 }
226 
227 #endif
228 
229 /*
230  * sdw_of_find_slaves() - Find Slave devices in master device tree node
231  * @bus: SDW bus instance
232  *
233  * Scans Master DT node for SDW child Slave devices and registers it.
234  */
235 int sdw_of_find_slaves(struct sdw_bus *bus)
236 {
237 	struct device *dev = bus->dev;
238 	struct device_node *node;
239 
240 	for_each_child_of_node(bus->dev->of_node, node) {
241 		int link_id, ret, len;
242 		unsigned int sdw_version;
243 		const char *compat = NULL;
244 		struct sdw_slave_id id;
245 		const __be32 *addr;
246 
247 		compat = of_get_property(node, "compatible", NULL);
248 		if (!compat)
249 			continue;
250 
251 		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
252 			     &id.mfg_id, &id.part_id, &id.class_id);
253 
254 		if (ret != 4) {
255 			dev_err(dev, "Invalid compatible string found %s\n",
256 				compat);
257 			continue;
258 		}
259 
260 		addr = of_get_property(node, "reg", &len);
261 		if (!addr || (len < 2 * sizeof(u32))) {
262 			dev_err(dev, "Invalid Link and Instance ID\n");
263 			continue;
264 		}
265 
266 		link_id = be32_to_cpup(addr++);
267 		id.unique_id = be32_to_cpup(addr);
268 		id.sdw_version = sdw_version;
269 
270 		/* Check for link_id match */
271 		if (link_id != bus->link_id)
272 			continue;
273 
274 		sdw_slave_add(bus, &id, of_fwnode_handle(node));
275 	}
276 
277 	return 0;
278 }
279 
280 struct device *of_sdw_find_device_by_node(struct device_node *np)
281 {
282 	return bus_find_device_by_of_node(&sdw_bus_type, np);
283 }
284 EXPORT_SYMBOL_GPL(of_sdw_find_device_by_node);
285 
286 MODULE_IMPORT_NS("SND_SOC_SDCA");
287