slave.c

  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
 12static 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
 21const struct device_type sdw_slave_type = {
 22	.name =		"sdw_slave",
 23	.release =	sdw_slave_release,
 24	.uevent =	sdw_slave_uevent,
 25};
 26EXPORT_SYMBOL_GPL(sdw_slave_type);
 27
 28int 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(sizeof(*slave), GFP_KERNEL);
 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}
106EXPORT_SYMBOL(sdw_slave_add);
107
108#if IS_ENABLED(CONFIG_ACPI)
109
110static 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	ret = acpi_get_local_u64_address(adev->handle, &addr);
119	if (ret < 0)
120		return false;
121
122	if (bus->ops->override_adr)
123		addr = bus->ops->override_adr(bus, addr);
124
125	if (!addr)
126		return false;
127
128	/* Extract link id from ADR, Bit 51 to 48 (included) */
129	link_id = SDW_DISCO_LINK_ID(addr);
130
131	/* Check for link_id match */
132	if (link_id != bus->link_id)
133		return false;
134
135	sdw_extract_slave_id(bus, addr, id);
136
137	return true;
138}
139
140struct sdw_acpi_child_walk_data {
141	struct sdw_bus *bus;
142	struct acpi_device *adev;
143	struct sdw_slave_id id;
144	bool ignore_unique_id;
145};
146
147static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
148{
149	struct sdw_acpi_child_walk_data *cwd = data;
150	struct sdw_bus *bus = cwd->bus;
151	struct sdw_slave_id id;
152
153	if (adev == cwd->adev)
154		return 0;
155
156	if (!find_slave(bus, adev, &id))
157		return 0;
158
159	if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
160	    cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
161		return 0;
162
163	if (cwd->id.unique_id != id.unique_id) {
164		dev_dbg(bus->dev,
165			"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
166			cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,
167			cwd->id.part_id);
168		cwd->ignore_unique_id = false;
169		return 0;
170	}
171
172	dev_err(bus->dev,
173		"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
174		cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
175	return -ENODEV;
176}
177
178static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
179{
180	struct sdw_bus *bus = data;
181	struct sdw_acpi_child_walk_data cwd = {
182		.bus = bus,
183		.adev = adev,
184		.ignore_unique_id = true,
185	};
186	int ret;
187
188	if (!find_slave(bus, adev, &cwd.id))
189		return 0;
190
191	/* Brute-force O(N^2) search for duplicates. */
192	ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
193				      sdw_acpi_check_duplicate, &cwd);
194	if (ret)
195		return ret;
196
197	if (cwd.ignore_unique_id)
198		cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
199
200	/* Ignore errors and continue. */
201	sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
202	return 0;
203}
204
205/*
206 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
207 * @bus: SDW bus instance
208 *
209 * Scans Master ACPI node for SDW child Slave devices and registers it.
210 */
211int sdw_acpi_find_slaves(struct sdw_bus *bus)
212{
213	struct acpi_device *parent;
214
215	parent = ACPI_COMPANION(bus->dev);
216	if (!parent) {
217		dev_err(bus->dev, "Can't find parent for acpi bind\n");
218		return -ENODEV;
219	}
220
221	return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
222}
223
224#endif
225
226/*
227 * sdw_of_find_slaves() - Find Slave devices in master device tree node
228 * @bus: SDW bus instance
229 *
230 * Scans Master DT node for SDW child Slave devices and registers it.
231 */
232int sdw_of_find_slaves(struct sdw_bus *bus)
233{
234	struct device *dev = bus->dev;
235	struct device_node *node;
236
237	for_each_child_of_node(bus->dev->of_node, node) {
238		int link_id, ret, len;
239		unsigned int sdw_version;
240		const char *compat = NULL;
241		struct sdw_slave_id id;
242		const __be32 *addr;
243
244		compat = of_get_property(node, "compatible", NULL);
245		if (!compat)
246			continue;
247
248		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
249			     &id.mfg_id, &id.part_id, &id.class_id);
250
251		if (ret != 4) {
252			dev_err(dev, "Invalid compatible string found %s\n",
253				compat);
254			continue;
255		}
256
257		addr = of_get_property(node, "reg", &len);
258		if (!addr || (len < 2 * sizeof(u32))) {
259			dev_err(dev, "Invalid Link and Instance ID\n");
260			continue;
261		}
262
263		link_id = be32_to_cpup(addr++);
264		id.unique_id = be32_to_cpup(addr);
265		id.sdw_version = sdw_version;
266
267		/* Check for link_id match */
268		if (link_id != bus->link_id)
269			continue;
270
271		sdw_slave_add(bus, &id, of_fwnode_handle(node));
272	}
273
274	return 0;
275}
276
277struct device *of_sdw_find_device_by_node(struct device_node *np)
278{
279	return bus_find_device_by_of_node(&sdw_bus_type, np);
280}
281EXPORT_SYMBOL_GPL(of_sdw_find_device_by_node);
282
283MODULE_IMPORT_NS("SND_SOC_SDCA");