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
 10static void sdw_slave_release(struct device *dev)
 11{
 12	struct sdw_slave *slave = dev_to_sdw_dev(dev);
 13
 14	kfree(slave);
 15}
 16
 17struct device_type sdw_slave_type = {
 18	.name =		"sdw_slave",
 19	.release =	sdw_slave_release,
 20	.uevent =	sdw_slave_uevent,
 21};
 22
 23static int sdw_slave_add(struct sdw_bus *bus,
 24			 struct sdw_slave_id *id, struct fwnode_handle *fwnode)
 25{
 26	struct sdw_slave *slave;
 27	int ret;
 28
 29	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 30	if (!slave)
 31		return -ENOMEM;
 32
 33	/* Initialize data structure */
 34	memcpy(&slave->id, id, sizeof(*id));
 35	slave->dev.parent = bus->dev;
 36	slave->dev.fwnode = fwnode;
 37
 38	if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
 39		/* name shall be sdw:link:mfg:part:class */
 40		dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x",
 41			     bus->link_id, id->mfg_id, id->part_id,
 42			     id->class_id);
 43	} else {
 44		/* name shall be sdw:link:mfg:part:class:unique */
 45		dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
 46			     bus->link_id, id->mfg_id, id->part_id,
 47			     id->class_id, id->unique_id);
 48	}
 49
 50	slave->dev.bus = &sdw_bus_type;
 51	slave->dev.of_node = of_node_get(to_of_node(fwnode));
 52	slave->dev.type = &sdw_slave_type;
 53	slave->bus = bus;
 54	slave->status = SDW_SLAVE_UNATTACHED;
 55	init_completion(&slave->enumeration_complete);
 56	init_completion(&slave->initialization_complete);
 57	slave->dev_num = 0;
 58	init_completion(&slave->probe_complete);
 59	slave->probed = false;
 60
 61	mutex_lock(&bus->bus_lock);
 62	list_add_tail(&slave->node, &bus->slaves);
 63	mutex_unlock(&bus->bus_lock);
 64
 65	ret = device_register(&slave->dev);
 66	if (ret) {
 67		dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
 68
 69		/*
 70		 * On err, don't free but drop ref as this will be freed
 71		 * when release method is invoked.
 72		 */
 73		mutex_lock(&bus->bus_lock);
 74		list_del(&slave->node);
 75		mutex_unlock(&bus->bus_lock);
 76		put_device(&slave->dev);
 77
 78		return ret;
 79	}
 80	sdw_slave_debugfs_init(slave);
 81
 82	return ret;
 83}
 84
 85#if IS_ENABLED(CONFIG_ACPI)
 86
 87static bool find_slave(struct sdw_bus *bus,
 88		       struct acpi_device *adev,
 89		       struct sdw_slave_id *id)
 90{
 91	unsigned long long addr;
 92	unsigned int link_id;
 93	acpi_status status;
 94
 95	status = acpi_evaluate_integer(adev->handle,
 96				       METHOD_NAME__ADR, NULL, &addr);
 97
 98	if (ACPI_FAILURE(status)) {
 99		dev_err(bus->dev, "_ADR resolution failed: %x\n",
100			status);
101		return false;
102	}
103
104	/* Extract link id from ADR, Bit 51 to 48 (included) */
105	link_id = (addr >> 48) & GENMASK(3, 0);
106
107	/* Check for link_id match */
108	if (link_id != bus->link_id)
109		return false;
110
111	sdw_extract_slave_id(bus, addr, id);
112
113	return true;
114}
115
116/*
117 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
118 * @bus: SDW bus instance
119 *
120 * Scans Master ACPI node for SDW child Slave devices and registers it.
121 */
122int sdw_acpi_find_slaves(struct sdw_bus *bus)
123{
124	struct acpi_device *adev, *parent;
125	struct acpi_device *adev2, *parent2;
126
127	parent = ACPI_COMPANION(bus->dev);
128	if (!parent) {
129		dev_err(bus->dev, "Can't find parent for acpi bind\n");
130		return -ENODEV;
131	}
132
133	list_for_each_entry(adev, &parent->children, node) {
134		struct sdw_slave_id id;
135		struct sdw_slave_id id2;
136		bool ignore_unique_id = true;
137
138		if (!find_slave(bus, adev, &id))
139			continue;
140
141		/* brute-force O(N^2) search for duplicates */
142		parent2 = parent;
143		list_for_each_entry(adev2, &parent2->children, node) {
144
145			if (adev == adev2)
146				continue;
147
148			if (!find_slave(bus, adev2, &id2))
149				continue;
150
151			if (id.sdw_version != id2.sdw_version ||
152			    id.mfg_id != id2.mfg_id ||
153			    id.part_id != id2.part_id ||
154			    id.class_id != id2.class_id)
155				continue;
156
157			if (id.unique_id != id2.unique_id) {
158				dev_dbg(bus->dev,
159					"Valid unique IDs %x %x for Slave mfg %x part %d\n",
160					id.unique_id, id2.unique_id,
161					id.mfg_id, id.part_id);
162				ignore_unique_id = false;
163			} else {
164				dev_err(bus->dev,
165					"Invalid unique IDs %x %x for Slave mfg %x part %d\n",
166					id.unique_id, id2.unique_id,
167					id.mfg_id, id.part_id);
168				return -ENODEV;
169			}
170		}
171
172		if (ignore_unique_id)
173			id.unique_id = SDW_IGNORED_UNIQUE_ID;
174
175		/*
176		 * don't error check for sdw_slave_add as we want to continue
177		 * adding Slaves
178		 */
179		sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
180	}
181
182	return 0;
183}
184
185#endif
186
187/*
188 * sdw_of_find_slaves() - Find Slave devices in master device tree node
189 * @bus: SDW bus instance
190 *
191 * Scans Master DT node for SDW child Slave devices and registers it.
192 */
193int sdw_of_find_slaves(struct sdw_bus *bus)
194{
195	struct device *dev = bus->dev;
196	struct device_node *node;
197
198	for_each_child_of_node(bus->dev->of_node, node) {
199		int link_id, ret, len;
200		unsigned int sdw_version;
201		const char *compat = NULL;
202		struct sdw_slave_id id;
203		const __be32 *addr;
204
205		compat = of_get_property(node, "compatible", NULL);
206		if (!compat)
207			continue;
208
209		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
210			     &id.mfg_id, &id.part_id, &id.class_id);
211
212		if (ret != 4) {
213			dev_err(dev, "Invalid compatible string found %s\n",
214				compat);
215			continue;
216		}
217
218		addr = of_get_property(node, "reg", &len);
219		if (!addr || (len < 2 * sizeof(u32))) {
220			dev_err(dev, "Invalid Link and Instance ID\n");
221			continue;
222		}
223
224		link_id = be32_to_cpup(addr++);
225		id.unique_id = be32_to_cpup(addr);
226		id.sdw_version = sdw_version;
227
228		/* Check for link_id match */
229		if (link_id != bus->link_id)
230			continue;
231
232		sdw_slave_add(bus, &id, of_fwnode_handle(node));
233	}
234
235	return 0;
236}