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 struct sdw_acpi_child_walk_data {
 131         struct sdw_bus *bus;
 132         struct acpi_device *adev;
 133         struct sdw_slave_id id;
 134         bool ignore_unique_id;
 135 };
 136
 137 static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
 138 {
 139         struct sdw_acpi_child_walk_data *cwd = data;
 140         struct sdw_bus *bus = cwd->bus;
 141         struct sdw_slave_id id;
 142
 143         if (adev == cwd->adev)
 144                 return 0;
 145
 146         if (!find_slave(bus, adev, &id))
 147                 return 0;
 148
 149         if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
 150             cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
 151                 return 0;
 152
 153         if (cwd->id.unique_id != id.unique_id) {
 154                 dev_dbg(bus->dev,
 155                         "Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
 156                         cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,
 157                         cwd->id.part_id);
 158                 cwd->ignore_unique_id = false;
 159                 return 0;
 160         }
 161
 162         dev_err(bus->dev,
 163                 "Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
 164                 cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
 165         return -ENODEV;
 166 }
 167
 168 static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
 169 {
 170         struct sdw_bus *bus = data;
 171         struct sdw_acpi_child_walk_data cwd = {
 172                 .bus = bus,
 173                 .adev = adev,
 174                 .ignore_unique_id = true,
 175         };
 176         int ret;
 177
 178         if (!find_slave(bus, adev, &cwd.id))
 179                 return 0;
 180
 181         /* Brute-force O(N^2) search for duplicates. */
 182         ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
 183                                       sdw_acpi_check_duplicate, &cwd);
 184         if (ret)
 185                 return ret;
 186
 187         if (cwd.ignore_unique_id)
 188                 cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
 189
 190         /* Ignore errors and continue. */
 191         sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
 192         return 0;
 193 }
 194
 195 /*
 196  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
 197  * @bus: SDW bus instance
 198  *
 199  * Scans Master ACPI node for SDW child Slave devices and registers it.
 200  */
 201 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 202 {
 203         struct acpi_device *parent;
 204
 205         parent = ACPI_COMPANION(bus->dev);
 206         if (!parent) {
 207                 dev_err(bus->dev, "Can't find parent for acpi bind\n");
 208                 return -ENODEV;
 209         }
 210
 211         return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
 212 }
 213
 214 #endif
 215
 216 /*
 217  * sdw_of_find_slaves() - Find Slave devices in master device tree node
 218  * @bus: SDW bus instance
 219  *
 220  * Scans Master DT node for SDW child Slave devices and registers it.
 221  */
 222 int sdw_of_find_slaves(struct sdw_bus *bus)
 223 {
 224         struct device *dev = bus->dev;
 225         struct device_node *node;
 226
 227         for_each_child_of_node(bus->dev->of_node, node) {
 228                 int link_id, ret, len;
 229                 unsigned int sdw_version;
 230                 const char *compat = NULL;
 231                 struct sdw_slave_id id;
 232                 const __be32 *addr;
 233
 234                 compat = of_get_property(node, "compatible", NULL);
 235                 if (!compat)
 236                         continue;
 237
 238                 ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
 239                              &id.mfg_id, &id.part_id, &id.class_id);
 240
 241                 if (ret != 4) {
 242                         dev_err(dev, "Invalid compatible string found %s\n",
 243                                 compat);
 244                         continue;
 245                 }
 246
 247                 addr = of_get_property(node, "reg", &len);
 248                 if (!addr || (len < 2 * sizeof(u32))) {
 249                         dev_err(dev, "Invalid Link and Instance ID\n");
 250                         continue;
 251                 }
 252
 253                 link_id = be32_to_cpup(addr++);
 254                 id.unique_id = be32_to_cpup(addr);
 255                 id.sdw_version = sdw_version;
 256
 257                 /* Check for link_id match */
 258                 if (link_id != bus->link_id)
 259                         continue;
 260
 261                 sdw_slave_add(bus, &id, of_fwnode_handle(node));
 262         }
 263
 264         return 0;
 265 }