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
 17static int sdw_slave_add(struct sdw_bus *bus,
 18			 struct sdw_slave_id *id, struct fwnode_handle *fwnode)
 19{
 20	struct sdw_slave *slave;
 21	int ret;
 22
 23	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 24	if (!slave)
 25		return -ENOMEM;
 26
 27	/* Initialize data structure */
 28	memcpy(&slave->id, id, sizeof(*id));
 29	slave->dev.parent = bus->dev;
 30	slave->dev.fwnode = fwnode;
 31
 32	/* name shall be sdw:link:mfg:part:class:unique */
 33	dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
 34		     bus->link_id, id->mfg_id, id->part_id,
 35		     id->class_id, id->unique_id);
 36
 37	slave->dev.release = sdw_slave_release;
 38	slave->dev.bus = &sdw_bus_type;
 39	slave->dev.of_node = of_node_get(to_of_node(fwnode));
 40	slave->bus = bus;
 41	slave->status = SDW_SLAVE_UNATTACHED;
 42	slave->dev_num = 0;
 43
 44	mutex_lock(&bus->bus_lock);
 45	list_add_tail(&slave->node, &bus->slaves);
 46	mutex_unlock(&bus->bus_lock);
 47
 48	ret = device_register(&slave->dev);
 49	if (ret) {
 50		dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
 51
 52		/*
 53		 * On err, don't free but drop ref as this will be freed
 54		 * when release method is invoked.
 55		 */
 56		mutex_lock(&bus->bus_lock);
 57		list_del(&slave->node);
 58		mutex_unlock(&bus->bus_lock);
 59		put_device(&slave->dev);
 60	}
 61	sdw_slave_debugfs_init(slave);
 62
 63	return ret;
 64}
 65
 66#if IS_ENABLED(CONFIG_ACPI)
 67/*
 68 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
 69 * @bus: SDW bus instance
 70 *
 71 * Scans Master ACPI node for SDW child Slave devices and registers it.
 72 */
 73int sdw_acpi_find_slaves(struct sdw_bus *bus)
 74{
 75	struct acpi_device *adev, *parent;
 76
 77	parent = ACPI_COMPANION(bus->dev);
 78	if (!parent) {
 79		dev_err(bus->dev, "Can't find parent for acpi bind\n");
 80		return -ENODEV;
 81	}
 82
 83	list_for_each_entry(adev, &parent->children, node) {
 84		unsigned long long addr;
 85		struct sdw_slave_id id;
 86		unsigned int link_id;
 87		acpi_status status;
 88
 89		status = acpi_evaluate_integer(adev->handle,
 90					       METHOD_NAME__ADR, NULL, &addr);
 91
 92		if (ACPI_FAILURE(status)) {
 93			dev_err(bus->dev, "_ADR resolution failed: %x\n",
 94				status);
 95			return status;
 96		}
 97
 98		/* Extract link id from ADR, Bit 51 to 48 (included) */
 99		link_id = (addr >> 48) & GENMASK(3, 0);
100
101		/* Check for link_id match */
102		if (link_id != bus->link_id)
103			continue;
104
105		sdw_extract_slave_id(bus, addr, &id);
106
107		/*
108		 * don't error check for sdw_slave_add as we want to continue
109		 * adding Slaves
110		 */
111		sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
112	}
113
114	return 0;
115}
116
117#endif
118
119/*
120 * sdw_of_find_slaves() - Find Slave devices in master device tree node
121 * @bus: SDW bus instance
122 *
123 * Scans Master DT node for SDW child Slave devices and registers it.
124 */
125int sdw_of_find_slaves(struct sdw_bus *bus)
126{
127	struct device *dev = bus->dev;
128	struct device_node *node;
129
130	for_each_child_of_node(bus->dev->of_node, node) {
131		int link_id, ret, len;
132		unsigned int sdw_version;
133		const char *compat = NULL;
134		struct sdw_slave_id id;
135		const __be32 *addr;
136
137		compat = of_get_property(node, "compatible", NULL);
138		if (!compat)
139			continue;
140
141		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
142			     &id.mfg_id, &id.part_id, &id.class_id);
143
144		if (ret != 4) {
145			dev_err(dev, "Invalid compatible string found %s\n",
146				compat);
147			continue;
148		}
149
150		addr = of_get_property(node, "reg", &len);
151		if (!addr || (len < 2 * sizeof(u32))) {
152			dev_err(dev, "Invalid Link and Instance ID\n");
153			continue;
154		}
155
156		link_id = be32_to_cpup(addr++);
157		id.unique_id = be32_to_cpup(addr);
158		id.sdw_version = sdw_version;
159
160		/* Check for link_id match */
161		if (link_id != bus->link_id)
162			continue;
163
164		sdw_slave_add(bus, &id, of_fwnode_handle(node));
165	}
166
167	return 0;
168}