xref: /linux/drivers/soundwire/slave.c (revision 4e9903b0861c9df3464b82db4a7025863bac1897)
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 const 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:ctrl:link:mfg:part:class */
43 		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x",
44 			     bus->controller_id, bus->link_id, id->mfg_id, id->part_id,
45 			     id->class_id);
46 	} else {
47 		/* name shall be sdw:ctrl:link:mfg:part:class:unique */
48 		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x:%01x",
49 			     bus->controller_id, 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 	unsigned int link_id;
101 	u64 addr;
102 	int ret;
103 
104 	ret = acpi_get_local_u64_address(adev->handle, &addr);
105 	if (ret < 0)
106 		return false;
107 
108 	if (bus->ops->override_adr)
109 		addr = bus->ops->override_adr(bus, addr);
110 
111 	if (!addr)
112 		return false;
113 
114 	/* Extract link id from ADR, Bit 51 to 48 (included) */
115 	link_id = SDW_DISCO_LINK_ID(addr);
116 
117 	/* Check for link_id match */
118 	if (link_id != bus->link_id)
119 		return false;
120 
121 	sdw_extract_slave_id(bus, addr, id);
122 
123 	return true;
124 }
125 
126 struct sdw_acpi_child_walk_data {
127 	struct sdw_bus *bus;
128 	struct acpi_device *adev;
129 	struct sdw_slave_id id;
130 	bool ignore_unique_id;
131 };
132 
133 static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
134 {
135 	struct sdw_acpi_child_walk_data *cwd = data;
136 	struct sdw_bus *bus = cwd->bus;
137 	struct sdw_slave_id id;
138 
139 	if (adev == cwd->adev)
140 		return 0;
141 
142 	if (!find_slave(bus, adev, &id))
143 		return 0;
144 
145 	if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
146 	    cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
147 		return 0;
148 
149 	if (cwd->id.unique_id != id.unique_id) {
150 		dev_dbg(bus->dev,
151 			"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
152 			cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,
153 			cwd->id.part_id);
154 		cwd->ignore_unique_id = false;
155 		return 0;
156 	}
157 
158 	dev_err(bus->dev,
159 		"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
160 		cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
161 	return -ENODEV;
162 }
163 
164 static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
165 {
166 	struct sdw_bus *bus = data;
167 	struct sdw_acpi_child_walk_data cwd = {
168 		.bus = bus,
169 		.adev = adev,
170 		.ignore_unique_id = true,
171 	};
172 	int ret;
173 
174 	if (!find_slave(bus, adev, &cwd.id))
175 		return 0;
176 
177 	/* Brute-force O(N^2) search for duplicates. */
178 	ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
179 				      sdw_acpi_check_duplicate, &cwd);
180 	if (ret)
181 		return ret;
182 
183 	if (cwd.ignore_unique_id)
184 		cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
185 
186 	/* Ignore errors and continue. */
187 	sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
188 	return 0;
189 }
190 
191 /*
192  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
193  * @bus: SDW bus instance
194  *
195  * Scans Master ACPI node for SDW child Slave devices and registers it.
196  */
197 int sdw_acpi_find_slaves(struct sdw_bus *bus)
198 {
199 	struct acpi_device *parent;
200 
201 	parent = ACPI_COMPANION(bus->dev);
202 	if (!parent) {
203 		dev_err(bus->dev, "Can't find parent for acpi bind\n");
204 		return -ENODEV;
205 	}
206 
207 	return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
208 }
209 
210 #endif
211 
212 /*
213  * sdw_of_find_slaves() - Find Slave devices in master device tree node
214  * @bus: SDW bus instance
215  *
216  * Scans Master DT node for SDW child Slave devices and registers it.
217  */
218 int sdw_of_find_slaves(struct sdw_bus *bus)
219 {
220 	struct device *dev = bus->dev;
221 	struct device_node *node;
222 
223 	for_each_child_of_node(bus->dev->of_node, node) {
224 		int link_id, ret, len;
225 		unsigned int sdw_version;
226 		const char *compat = NULL;
227 		struct sdw_slave_id id;
228 		const __be32 *addr;
229 
230 		compat = of_get_property(node, "compatible", NULL);
231 		if (!compat)
232 			continue;
233 
234 		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
235 			     &id.mfg_id, &id.part_id, &id.class_id);
236 
237 		if (ret != 4) {
238 			dev_err(dev, "Invalid compatible string found %s\n",
239 				compat);
240 			continue;
241 		}
242 
243 		addr = of_get_property(node, "reg", &len);
244 		if (!addr || (len < 2 * sizeof(u32))) {
245 			dev_err(dev, "Invalid Link and Instance ID\n");
246 			continue;
247 		}
248 
249 		link_id = be32_to_cpup(addr++);
250 		id.unique_id = be32_to_cpup(addr);
251 		id.sdw_version = sdw_version;
252 
253 		/* Check for link_id match */
254 		if (link_id != bus->link_id)
255 			continue;
256 
257 		sdw_slave_add(bus, &id, of_fwnode_handle(node));
258 	}
259 
260 	return 0;
261 }
262