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 10 static void sdw_slave_release(struct device *dev) 11 { 12 struct sdw_slave *slave = dev_to_sdw_dev(dev); 13 14 kfree(slave); 15 } 16 17 static 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 static bool find_slave(struct sdw_bus *bus, 69 struct acpi_device *adev, 70 struct sdw_slave_id *id) 71 { 72 unsigned long long addr; 73 unsigned int link_id; 74 acpi_status status; 75 76 status = acpi_evaluate_integer(adev->handle, 77 METHOD_NAME__ADR, NULL, &addr); 78 79 if (ACPI_FAILURE(status)) { 80 dev_err(bus->dev, "_ADR resolution failed: %x\n", 81 status); 82 return false; 83 } 84 85 /* Extract link id from ADR, Bit 51 to 48 (included) */ 86 link_id = (addr >> 48) & GENMASK(3, 0); 87 88 /* Check for link_id match */ 89 if (link_id != bus->link_id) 90 return false; 91 92 sdw_extract_slave_id(bus, addr, id); 93 94 return true; 95 } 96 97 /* 98 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node 99 * @bus: SDW bus instance 100 * 101 * Scans Master ACPI node for SDW child Slave devices and registers it. 102 */ 103 int sdw_acpi_find_slaves(struct sdw_bus *bus) 104 { 105 struct acpi_device *adev, *parent; 106 107 parent = ACPI_COMPANION(bus->dev); 108 if (!parent) { 109 dev_err(bus->dev, "Can't find parent for acpi bind\n"); 110 return -ENODEV; 111 } 112 113 list_for_each_entry(adev, &parent->children, node) { 114 struct sdw_slave_id id; 115 116 if (!find_slave(bus, adev, &id)) 117 continue; 118 119 /* 120 * don't error check for sdw_slave_add as we want to continue 121 * adding Slaves 122 */ 123 sdw_slave_add(bus, &id, acpi_fwnode_handle(adev)); 124 } 125 126 return 0; 127 } 128 129 #endif 130 131 /* 132 * sdw_of_find_slaves() - Find Slave devices in master device tree node 133 * @bus: SDW bus instance 134 * 135 * Scans Master DT node for SDW child Slave devices and registers it. 136 */ 137 int sdw_of_find_slaves(struct sdw_bus *bus) 138 { 139 struct device *dev = bus->dev; 140 struct device_node *node; 141 142 for_each_child_of_node(bus->dev->of_node, node) { 143 int link_id, sdw_version, ret, len; 144 const char *compat = NULL; 145 struct sdw_slave_id id; 146 const __be32 *addr; 147 148 compat = of_get_property(node, "compatible", NULL); 149 if (!compat) 150 continue; 151 152 ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version, 153 &id.mfg_id, &id.part_id, &id.class_id); 154 155 if (ret != 4) { 156 dev_err(dev, "Invalid compatible string found %s\n", 157 compat); 158 continue; 159 } 160 161 addr = of_get_property(node, "reg", &len); 162 if (!addr || (len < 2 * sizeof(u32))) { 163 dev_err(dev, "Invalid Link and Instance ID\n"); 164 continue; 165 } 166 167 link_id = be32_to_cpup(addr++); 168 id.unique_id = be32_to_cpup(addr); 169 id.sdw_version = sdw_version; 170 171 /* Check for link_id match */ 172 if (link_id != bus->link_id) 173 continue; 174 175 sdw_slave_add(bus, &id, of_fwnode_handle(node)); 176 } 177 178 return 0; 179 } 180