drivers/soundwire/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 "bus.h"
   9 #include "sysfs_local.h"
  10
  11 static void sdw_slave_release(struct device *dev)
  12 {
  13         struct sdw_slave *slave = dev_to_sdw_dev(dev);
  14
  15         kfree(slave);
  16 }
  17
  18 struct device_type sdw_slave_type = {
  19         .name =         "sdw_slave",
  20         .release =      sdw_slave_release,
  21         .uevent =       sdw_slave_uevent,
  22 };
  23
  24 int sdw_slave_add(struct sdw_bus *bus,
  25                   struct sdw_slave_id *id, struct fwnode_handle *fwnode)
  26 {
  27         struct sdw_slave *slave;
  28         int ret;
  29         int i;
  30
  31         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
  32         if (!slave)
  33                 return -ENOMEM;
  34
  35         /* Initialize data structure */
  36         memcpy(&slave->id, id, sizeof(*id));
  37         slave->dev.parent = bus->dev;
  38         slave->dev.fwnode = fwnode;
  39
  40         if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
  41                 /* name shall be sdw:link:mfg:part:class */
  42                 dev_set_name(&slave->dev, "sdw:%01x:%04x:%04x:%02x",
  43                              bus->link_id, id->mfg_id, id->part_id,
  44                              id->class_id);
  45         } else {
  46                 /* name shall be sdw:link:mfg:part:class:unique */
  47                 dev_set_name(&slave->dev, "sdw:%01x:%04x:%04x:%02x:%01x",
  48                              bus->link_id, id->mfg_id, id->part_id,
  49                              id->class_id, id->unique_id);
  50         }
  51
  52         slave->dev.bus = &sdw_bus_type;
  53         slave->dev.of_node = of_node_get(to_of_node(fwnode));
  54         slave->dev.type = &sdw_slave_type;
  55         slave->dev.groups = sdw_slave_status_attr_groups;
  56         slave->bus = bus;
  57         slave->status = SDW_SLAVE_UNATTACHED;
  58         init_completion(&slave->enumeration_complete);
  59         init_completion(&slave->initialization_complete);
  60         slave->dev_num = 0;
  61         init_completion(&slave->probe_complete);
  62         slave->probed = false;
  63         slave->first_interrupt_done = false;
  64
  65         for (i = 0; i < SDW_MAX_PORTS; i++)
  66                 init_completion(&slave->port_ready[i]);
  67
  68         mutex_lock(&bus->bus_lock);
  69         list_add_tail(&slave->node, &bus->slaves);
  70         mutex_unlock(&bus->bus_lock);
  71
  72         ret = device_register(&slave->dev);
  73         if (ret) {
  74                 dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
  75
  76                 /*
  77                  * On err, don't free but drop ref as this will be freed
  78                  * when release method is invoked.
  79                  */
  80                 mutex_lock(&bus->bus_lock);
  81                 list_del(&slave->node);
  82                 mutex_unlock(&bus->bus_lock);
  83                 put_device(&slave->dev);
  84
  85                 return ret;
  86         }
  87         sdw_slave_debugfs_init(slave);
  88
  89         return ret;
  90 }
  91 EXPORT_SYMBOL(sdw_slave_add);
  92
  93 #if IS_ENABLED(CONFIG_ACPI)
  94
  95 static bool find_slave(struct sdw_bus *bus,
  96                        struct acpi_device *adev,
  97                        struct sdw_slave_id *id)
  98 {
  99         u64 addr;
 100         unsigned int link_id;
 101         acpi_status status;
 102
 103         status = acpi_evaluate_integer(adev->handle,
 104                                        METHOD_NAME__ADR, NULL, &addr);
 105
 106         if (ACPI_FAILURE(status)) {
 107                 dev_err(bus->dev, "_ADR resolution failed: %x\n",
 108                         status);
 109                 return false;
 110         }
 111
 112         if (bus->ops->override_adr)
 113                 addr = bus->ops->override_adr(bus, addr);
 114
 115         if (!addr)
 116                 return false;
 117
 118         /* Extract link id from ADR, Bit 51 to 48 (included) */
 119         link_id = SDW_DISCO_LINK_ID(addr);
 120
 121         /* Check for link_id match */
 122         if (link_id != bus->link_id)
 123                 return false;
 124
 125         sdw_extract_slave_id(bus, addr, id);
 126
 127         return true;
 128 }
 129
 130 /*
 131  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
 132  * @bus: SDW bus instance
 133  *
 134  * Scans Master ACPI node for SDW child Slave devices and registers it.
 135  */
 136 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 137 {
 138         struct acpi_device *adev, *parent;
 139         struct acpi_device *adev2, *parent2;
 140
 141         parent = ACPI_COMPANION(bus->dev);
 142         if (!parent) {
 143                 dev_err(bus->dev, "Can't find parent for acpi bind\n");
 144                 return -ENODEV;
 145         }
 146
 147         list_for_each_entry(adev, &parent->children, node) {
 148                 struct sdw_slave_id id;
 149                 struct sdw_slave_id id2;
 150                 bool ignore_unique_id = true;
 151
 152                 if (!find_slave(bus, adev, &id))
 153                         continue;
 154
 155                 /* brute-force O(N^2) search for duplicates */
 156                 parent2 = parent;
 157                 list_for_each_entry(adev2, &parent2->children, node) {
 158
 159                         if (adev == adev2)
 160                                 continue;
 161
 162                         if (!find_slave(bus, adev2, &id2))
 163                                 continue;
 164
 165                         if (id.sdw_version != id2.sdw_version ||
 166                             id.mfg_id != id2.mfg_id ||
 167                             id.part_id != id2.part_id ||
 168                             id.class_id != id2.class_id)
 169                                 continue;
 170
 171                         if (id.unique_id != id2.unique_id) {
 172                                 dev_dbg(bus->dev,
 173                                         "Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
 174                                         id.unique_id, id2.unique_id, id.mfg_id, id.part_id);
 175                                 ignore_unique_id = false;
 176                         } else {
 177                                 dev_err(bus->dev,
 178                                         "Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
 179                                         id.unique_id, id2.unique_id, id.mfg_id, id.part_id);
 180                                 return -ENODEV;
 181                         }
 182                 }
 183
 184                 if (ignore_unique_id)
 185                         id.unique_id = SDW_IGNORED_UNIQUE_ID;
 186
 187                 /*
 188                  * don't error check for sdw_slave_add as we want to continue
 189                  * adding Slaves
 190                  */
 191                 sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
 192         }
 193
 194         return 0;
 195 }
 196
 197 #endif
 198
 199 /*
 200  * sdw_of_find_slaves() - Find Slave devices in master device tree node
 201  * @bus: SDW bus instance
 202  *
 203  * Scans Master DT node for SDW child Slave devices and registers it.
 204  */
 205 int sdw_of_find_slaves(struct sdw_bus *bus)
 206 {
 207         struct device *dev = bus->dev;
 208         struct device_node *node;
 209
 210         for_each_child_of_node(bus->dev->of_node, node) {
 211                 int link_id, ret, len;
 212                 unsigned int sdw_version;
 213                 const char *compat = NULL;
 214                 struct sdw_slave_id id;
 215                 const __be32 *addr;
 216
 217                 compat = of_get_property(node, "compatible", NULL);
 218                 if (!compat)
 219                         continue;
 220
 221                 ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
 222                              &id.mfg_id, &id.part_id, &id.class_id);
 223
 224                 if (ret != 4) {
 225                         dev_err(dev, "Invalid compatible string found %s\n",
 226                                 compat);
 227                         continue;
 228                 }
 229
 230                 addr = of_get_property(node, "reg", &len);
 231                 if (!addr || (len < 2 * sizeof(u32))) {
 232                         dev_err(dev, "Invalid Link and Instance ID\n");
 233                         continue;
 234                 }
 235
 236                 link_id = be32_to_cpup(addr++);
 237                 id.unique_id = be32_to_cpup(addr);
 238                 id.sdw_version = sdw_version;
 239
 240                 /* Check for link_id match */
 241                 if (link_id != bus->link_id)
 242                         continue;
 243
 244                 sdw_slave_add(bus, &id, of_fwnode_handle(node));
 245         }
 246
 247         return 0;
 248 }