xref: /openbmc/linux/drivers/soundwire/slave.c (revision e40573a4)
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 	mutex_destroy(&slave->sdw_dev_lock);
16 	kfree(slave);
17 }
18 
19 struct device_type sdw_slave_type = {
20 	.name =		"sdw_slave",
21 	.release =	sdw_slave_release,
22 	.uevent =	sdw_slave_uevent,
23 };
24 
25 int sdw_slave_add(struct sdw_bus *bus,
26 		  struct sdw_slave_id *id, struct fwnode_handle *fwnode)
27 {
28 	struct sdw_slave *slave;
29 	int ret;
30 	int i;
31 
32 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
33 	if (!slave)
34 		return -ENOMEM;
35 
36 	/* Initialize data structure */
37 	memcpy(&slave->id, id, sizeof(*id));
38 	slave->dev.parent = bus->dev;
39 	slave->dev.fwnode = fwnode;
40 
41 	if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
42 		/* name shall be sdw:link:mfg:part:class */
43 		dev_set_name(&slave->dev, "sdw:%01x:%04x:%04x:%02x",
44 			     bus->link_id, id->mfg_id, id->part_id,
45 			     id->class_id);
46 	} else {
47 		/* name shall be sdw:link:mfg:part:class:unique */
48 		dev_set_name(&slave->dev, "sdw:%01x:%04x:%04x:%02x:%01x",
49 			     bus->link_id, id->mfg_id, id->part_id,
50 			     id->class_id, id->unique_id);
51 	}
52 
53 	slave->dev.bus = &sdw_bus_type;
54 	slave->dev.of_node = of_node_get(to_of_node(fwnode));
55 	slave->dev.type = &sdw_slave_type;
56 	slave->dev.groups = sdw_slave_status_attr_groups;
57 	slave->bus = bus;
58 	slave->status = SDW_SLAVE_UNATTACHED;
59 	init_completion(&slave->enumeration_complete);
60 	init_completion(&slave->initialization_complete);
61 	slave->dev_num = 0;
62 	slave->probed = false;
63 	slave->first_interrupt_done = false;
64 	mutex_init(&slave->sdw_dev_lock);
65 
66 	for (i = 0; i < SDW_MAX_PORTS; i++)
67 		init_completion(&slave->port_ready[i]);
68 
69 	mutex_lock(&bus->bus_lock);
70 	list_add_tail(&slave->node, &bus->slaves);
71 	mutex_unlock(&bus->bus_lock);
72 
73 	ret = device_register(&slave->dev);
74 	if (ret) {
75 		dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
76 
77 		/*
78 		 * On err, don't free but drop ref as this will be freed
79 		 * when release method is invoked.
80 		 */
81 		mutex_lock(&bus->bus_lock);
82 		list_del(&slave->node);
83 		mutex_unlock(&bus->bus_lock);
84 		put_device(&slave->dev);
85 
86 		return ret;
87 	}
88 	sdw_slave_debugfs_init(slave);
89 
90 	return ret;
91 }
92 EXPORT_SYMBOL(sdw_slave_add);
93 
94 #if IS_ENABLED(CONFIG_ACPI)
95 
96 static bool find_slave(struct sdw_bus *bus,
97 		       struct acpi_device *adev,
98 		       struct sdw_slave_id *id)
99 {
100 	u64 addr;
101 	unsigned int link_id;
102 	acpi_status status;
103 
104 	status = acpi_evaluate_integer(adev->handle,
105 				       METHOD_NAME__ADR, NULL, &addr);
106 
107 	if (ACPI_FAILURE(status)) {
108 		dev_err(bus->dev, "_ADR resolution failed: %x\n",
109 			status);
110 		return false;
111 	}
112 
113 	if (bus->ops->override_adr)
114 		addr = bus->ops->override_adr(bus, addr);
115 
116 	if (!addr)
117 		return false;
118 
119 	/* Extract link id from ADR, Bit 51 to 48 (included) */
120 	link_id = SDW_DISCO_LINK_ID(addr);
121 
122 	/* Check for link_id match */
123 	if (link_id != bus->link_id)
124 		return false;
125 
126 	sdw_extract_slave_id(bus, addr, id);
127 
128 	return true;
129 }
130 
131 struct sdw_acpi_child_walk_data {
132 	struct sdw_bus *bus;
133 	struct acpi_device *adev;
134 	struct sdw_slave_id id;
135 	bool ignore_unique_id;
136 };
137 
138 static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
139 {
140 	struct sdw_acpi_child_walk_data *cwd = data;
141 	struct sdw_bus *bus = cwd->bus;
142 	struct sdw_slave_id id;
143 
144 	if (adev == cwd->adev)
145 		return 0;
146 
147 	if (!find_slave(bus, adev, &id))
148 		return 0;
149 
150 	if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
151 	    cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
152 		return 0;
153 
154 	if (cwd->id.unique_id != id.unique_id) {
155 		dev_dbg(bus->dev,
156 			"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
157 			cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,
158 			cwd->id.part_id);
159 		cwd->ignore_unique_id = false;
160 		return 0;
161 	}
162 
163 	dev_err(bus->dev,
164 		"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
165 		cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
166 	return -ENODEV;
167 }
168 
169 static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
170 {
171 	struct sdw_bus *bus = data;
172 	struct sdw_acpi_child_walk_data cwd = {
173 		.bus = bus,
174 		.adev = adev,
175 		.ignore_unique_id = true,
176 	};
177 	int ret;
178 
179 	if (!find_slave(bus, adev, &cwd.id))
180 		return 0;
181 
182 	/* Brute-force O(N^2) search for duplicates. */
183 	ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
184 				      sdw_acpi_check_duplicate, &cwd);
185 	if (ret)
186 		return ret;
187 
188 	if (cwd.ignore_unique_id)
189 		cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
190 
191 	/* Ignore errors and continue. */
192 	sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
193 	return 0;
194 }
195 
196 /*
197  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
198  * @bus: SDW bus instance
199  *
200  * Scans Master ACPI node for SDW child Slave devices and registers it.
201  */
202 int sdw_acpi_find_slaves(struct sdw_bus *bus)
203 {
204 	struct acpi_device *parent;
205 
206 	parent = ACPI_COMPANION(bus->dev);
207 	if (!parent) {
208 		dev_err(bus->dev, "Can't find parent for acpi bind\n");
209 		return -ENODEV;
210 	}
211 
212 	return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
213 }
214 
215 #endif
216 
217 /*
218  * sdw_of_find_slaves() - Find Slave devices in master device tree node
219  * @bus: SDW bus instance
220  *
221  * Scans Master DT node for SDW child Slave devices and registers it.
222  */
223 int sdw_of_find_slaves(struct sdw_bus *bus)
224 {
225 	struct device *dev = bus->dev;
226 	struct device_node *node;
227 
228 	for_each_child_of_node(bus->dev->of_node, node) {
229 		int link_id, ret, len;
230 		unsigned int sdw_version;
231 		const char *compat = NULL;
232 		struct sdw_slave_id id;
233 		const __be32 *addr;
234 
235 		compat = of_get_property(node, "compatible", NULL);
236 		if (!compat)
237 			continue;
238 
239 		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
240 			     &id.mfg_id, &id.part_id, &id.class_id);
241 
242 		if (ret != 4) {
243 			dev_err(dev, "Invalid compatible string found %s\n",
244 				compat);
245 			continue;
246 		}
247 
248 		addr = of_get_property(node, "reg", &len);
249 		if (!addr || (len < 2 * sizeof(u32))) {
250 			dev_err(dev, "Invalid Link and Instance ID\n");
251 			continue;
252 		}
253 
254 		link_id = be32_to_cpup(addr++);
255 		id.unique_id = be32_to_cpup(addr);
256 		id.sdw_version = sdw_version;
257 
258 		/* Check for link_id match */
259 		if (link_id != bus->link_id)
260 			continue;
261 
262 		sdw_slave_add(bus, &id, of_fwnode_handle(node));
263 	}
264 
265 	return 0;
266 }
267