xref: /linux/drivers/soundwire/slave.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 	mutex_destroy(&slave->sdw_dev_lock);
17 	kfree(slave);
18 }
19 
20 const struct device_type sdw_slave_type = {
21 	.name =		"sdw_slave",
22 	.release =	sdw_slave_release,
23 	.uevent =	sdw_slave_uevent,
24 };
25 
26 int sdw_slave_add(struct sdw_bus *bus,
27 		  struct sdw_slave_id *id, struct fwnode_handle *fwnode)
28 {
29 	struct sdw_slave *slave;
30 	int ret;
31 	int i;
32 
33 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
34 	if (!slave)
35 		return -ENOMEM;
36 
37 	/* Initialize data structure */
38 	memcpy(&slave->id, id, sizeof(*id));
39 	slave->dev.parent = bus->dev;
40 	slave->dev.fwnode = fwnode;
41 
42 	if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
43 		/* name shall be sdw:ctrl:link:mfg:part:class */
44 		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x",
45 			     bus->controller_id, bus->link_id, id->mfg_id, id->part_id,
46 			     id->class_id);
47 	} else {
48 		/* name shall be sdw:ctrl:link:mfg:part:class:unique */
49 		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x:%01x",
50 			     bus->controller_id, bus->link_id, id->mfg_id, id->part_id,
51 			     id->class_id, id->unique_id);
52 	}
53 
54 	slave->dev.bus = &sdw_bus_type;
55 	slave->dev.of_node = of_node_get(to_of_node(fwnode));
56 	slave->dev.type = &sdw_slave_type;
57 	slave->dev.groups = sdw_slave_status_attr_groups;
58 	slave->bus = bus;
59 	slave->status = SDW_SLAVE_UNATTACHED;
60 	init_completion(&slave->enumeration_complete);
61 	init_completion(&slave->initialization_complete);
62 	slave->dev_num = 0;
63 	slave->probed = false;
64 	slave->first_interrupt_done = false;
65 	mutex_init(&slave->sdw_dev_lock);
66 
67 	for (i = 0; i < SDW_MAX_PORTS; i++)
68 		init_completion(&slave->port_ready[i]);
69 
70 	mutex_lock(&bus->bus_lock);
71 	list_add_tail(&slave->node, &bus->slaves);
72 	mutex_unlock(&bus->bus_lock);
73 
74 	/*
75 	 * The Soundwire driver probe may optionally register SDCA
76 	 * sub-devices, one per Function. This means the information
77 	 * on the SDCA revision and the number/type of Functions need
78 	 * to be extracted from platform firmware before the SoundWire
79 	 * driver probe, and as a consequence before the SoundWire
80 	 * device_register() below.
81 	 */
82 	sdca_lookup_interface_revision(slave);
83 	sdca_lookup_functions(slave);
84 
85 	ret = device_register(&slave->dev);
86 	if (ret) {
87 		dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
88 
89 		/*
90 		 * On err, don't free but drop ref as this will be freed
91 		 * when release method is invoked.
92 		 */
93 		mutex_lock(&bus->bus_lock);
94 		list_del(&slave->node);
95 		mutex_unlock(&bus->bus_lock);
96 		put_device(&slave->dev);
97 
98 		return ret;
99 	}
100 	sdw_slave_debugfs_init(slave);
101 
102 	return ret;
103 }
104 EXPORT_SYMBOL(sdw_slave_add);
105 
106 #if IS_ENABLED(CONFIG_ACPI)
107 
108 static bool find_slave(struct sdw_bus *bus,
109 		       struct acpi_device *adev,
110 		       struct sdw_slave_id *id)
111 {
112 	unsigned int link_id;
113 	u64 addr;
114 	int ret;
115 
116 	ret = acpi_get_local_u64_address(adev->handle, &addr);
117 	if (ret < 0)
118 		return false;
119 
120 	if (bus->ops->override_adr)
121 		addr = bus->ops->override_adr(bus, addr);
122 
123 	if (!addr)
124 		return false;
125 
126 	/* Extract link id from ADR, Bit 51 to 48 (included) */
127 	link_id = SDW_DISCO_LINK_ID(addr);
128 
129 	/* Check for link_id match */
130 	if (link_id != bus->link_id)
131 		return false;
132 
133 	sdw_extract_slave_id(bus, addr, id);
134 
135 	return true;
136 }
137 
138 struct sdw_acpi_child_walk_data {
139 	struct sdw_bus *bus;
140 	struct acpi_device *adev;
141 	struct sdw_slave_id id;
142 	bool ignore_unique_id;
143 };
144 
145 static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
146 {
147 	struct sdw_acpi_child_walk_data *cwd = data;
148 	struct sdw_bus *bus = cwd->bus;
149 	struct sdw_slave_id id;
150 
151 	if (adev == cwd->adev)
152 		return 0;
153 
154 	if (!find_slave(bus, adev, &id))
155 		return 0;
156 
157 	if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
158 	    cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
159 		return 0;
160 
161 	if (cwd->id.unique_id != id.unique_id) {
162 		dev_dbg(bus->dev,
163 			"Valid 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,
165 			cwd->id.part_id);
166 		cwd->ignore_unique_id = false;
167 		return 0;
168 	}
169 
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 		cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
173 	return -ENODEV;
174 }
175 
176 static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
177 {
178 	struct sdw_bus *bus = data;
179 	struct sdw_acpi_child_walk_data cwd = {
180 		.bus = bus,
181 		.adev = adev,
182 		.ignore_unique_id = true,
183 	};
184 	int ret;
185 
186 	if (!find_slave(bus, adev, &cwd.id))
187 		return 0;
188 
189 	/* Brute-force O(N^2) search for duplicates. */
190 	ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
191 				      sdw_acpi_check_duplicate, &cwd);
192 	if (ret)
193 		return ret;
194 
195 	if (cwd.ignore_unique_id)
196 		cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
197 
198 	/* Ignore errors and continue. */
199 	sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
200 	return 0;
201 }
202 
203 /*
204  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
205  * @bus: SDW bus instance
206  *
207  * Scans Master ACPI node for SDW child Slave devices and registers it.
208  */
209 int sdw_acpi_find_slaves(struct sdw_bus *bus)
210 {
211 	struct acpi_device *parent;
212 
213 	parent = ACPI_COMPANION(bus->dev);
214 	if (!parent) {
215 		dev_err(bus->dev, "Can't find parent for acpi bind\n");
216 		return -ENODEV;
217 	}
218 
219 	return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
220 }
221 
222 #endif
223 
224 /*
225  * sdw_of_find_slaves() - Find Slave devices in master device tree node
226  * @bus: SDW bus instance
227  *
228  * Scans Master DT node for SDW child Slave devices and registers it.
229  */
230 int sdw_of_find_slaves(struct sdw_bus *bus)
231 {
232 	struct device *dev = bus->dev;
233 	struct device_node *node;
234 
235 	for_each_child_of_node(bus->dev->of_node, node) {
236 		int link_id, ret, len;
237 		unsigned int sdw_version;
238 		const char *compat = NULL;
239 		struct sdw_slave_id id;
240 		const __be32 *addr;
241 
242 		compat = of_get_property(node, "compatible", NULL);
243 		if (!compat)
244 			continue;
245 
246 		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
247 			     &id.mfg_id, &id.part_id, &id.class_id);
248 
249 		if (ret != 4) {
250 			dev_err(dev, "Invalid compatible string found %s\n",
251 				compat);
252 			continue;
253 		}
254 
255 		addr = of_get_property(node, "reg", &len);
256 		if (!addr || (len < 2 * sizeof(u32))) {
257 			dev_err(dev, "Invalid Link and Instance ID\n");
258 			continue;
259 		}
260 
261 		link_id = be32_to_cpup(addr++);
262 		id.unique_id = be32_to_cpup(addr);
263 		id.sdw_version = sdw_version;
264 
265 		/* Check for link_id match */
266 		if (link_id != bus->link_id)
267 			continue;
268 
269 		sdw_slave_add(bus, &id, of_fwnode_handle(node));
270 	}
271 
272 	return 0;
273 }
274 
275 MODULE_IMPORT_NS(SND_SOC_SDCA);
276