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/soundwire/sdw.h> 6 #include <linux/soundwire/sdw_type.h> 7 #include "bus.h" 8 9 static void sdw_slave_release(struct device *dev) 10 { 11 struct sdw_slave *slave = dev_to_sdw_dev(dev); 12 13 kfree(slave); 14 } 15 16 static int sdw_slave_add(struct sdw_bus *bus, 17 struct sdw_slave_id *id, struct fwnode_handle *fwnode) 18 { 19 struct sdw_slave *slave; 20 int ret; 21 22 slave = kzalloc(sizeof(*slave), GFP_KERNEL); 23 if (!slave) 24 return -ENOMEM; 25 26 /* Initialize data structure */ 27 memcpy(&slave->id, id, sizeof(*id)); 28 slave->dev.parent = bus->dev; 29 slave->dev.fwnode = fwnode; 30 31 /* name shall be sdw:link:mfg:part:class:unique */ 32 dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x", 33 bus->link_id, id->mfg_id, id->part_id, 34 id->class_id, id->unique_id); 35 36 slave->dev.release = sdw_slave_release; 37 slave->dev.bus = &sdw_bus_type; 38 slave->bus = bus; 39 slave->status = SDW_SLAVE_UNATTACHED; 40 slave->dev_num = 0; 41 42 mutex_lock(&bus->bus_lock); 43 list_add_tail(&slave->node, &bus->slaves); 44 mutex_unlock(&bus->bus_lock); 45 46 ret = device_register(&slave->dev); 47 if (ret) { 48 dev_err(bus->dev, "Failed to add slave: ret %d\n", ret); 49 50 /* 51 * On err, don't free but drop ref as this will be freed 52 * when release method is invoked. 53 */ 54 mutex_lock(&bus->bus_lock); 55 list_del(&slave->node); 56 mutex_unlock(&bus->bus_lock); 57 put_device(&slave->dev); 58 } 59 60 return ret; 61 } 62 63 #if IS_ENABLED(CONFIG_ACPI) 64 /* 65 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node 66 * @bus: SDW bus instance 67 * 68 * Scans Master ACPI node for SDW child Slave devices and registers it. 69 */ 70 int sdw_acpi_find_slaves(struct sdw_bus *bus) 71 { 72 struct acpi_device *adev, *parent; 73 74 parent = ACPI_COMPANION(bus->dev); 75 if (!parent) { 76 dev_err(bus->dev, "Can't find parent for acpi bind\n"); 77 return -ENODEV; 78 } 79 80 list_for_each_entry(adev, &parent->children, node) { 81 unsigned long long addr; 82 struct sdw_slave_id id; 83 unsigned int link_id; 84 acpi_status status; 85 86 status = acpi_evaluate_integer(adev->handle, 87 METHOD_NAME__ADR, NULL, &addr); 88 89 if (ACPI_FAILURE(status)) { 90 dev_err(bus->dev, "_ADR resolution failed: %x\n", 91 status); 92 return status; 93 } 94 95 /* Extract link id from ADR, Bit 51 to 48 (included) */ 96 link_id = (addr >> 48) & GENMASK(3, 0); 97 98 /* Check for link_id match */ 99 if (link_id != bus->link_id) 100 continue; 101 102 sdw_extract_slave_id(bus, addr, &id); 103 104 /* 105 * don't error check for sdw_slave_add as we want to continue 106 * adding Slaves 107 */ 108 sdw_slave_add(bus, &id, acpi_fwnode_handle(adev)); 109 } 110 111 return 0; 112 } 113 114 #endif 115