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         mutex_destroy(&slave->sdw_dev_lock);
  16         kfree(slave);
  17 }
  18
  19 struct device_type sdw_slave_type = {
  20         .name =         "sdw_slave",
  21         .release =      sdw_slave_release,
  22         .uevent =       sdw_slave_uevent,
  23 };
  24
  25 int sdw_slave_add(struct sdw_bus *bus,
  26                   struct sdw_slave_id *id, struct fwnode_handle *fwnode)
  27 {
  28         struct sdw_slave *slave;
  29         int ret;
  30         int i;
  31
  32         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
  33         if (!slave)
  34                 return -ENOMEM;
  35
  36         /* Initialize data structure */
  37         memcpy(&slave->id, id, sizeof(*id));
  38         slave->dev.parent = bus->dev;
  39         slave->dev.fwnode = fwnode;
  40
  41         if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
  42                 /* name shall be sdw:link:mfg:part:class */
  43                 dev_set_name(&slave->dev, "sdw:%01x:%04x:%04x:%02x",
  44                              bus->link_id, id->mfg_id, id->part_id,
  45                              id->class_id);
  46         } else {
  47                 /* name shall be sdw:link:mfg:part:class:unique */
  48                 dev_set_name(&slave->dev, "sdw:%01x:%04x:%04x:%02x:%01x",
  49                              bus->link_id, id->mfg_id, id->part_id,
  50                              id->class_id, id->unique_id);
  51         }
  52
  53         slave->dev.bus = &sdw_bus_type;
  54         slave->dev.of_node = of_node_get(to_of_node(fwnode));
  55         slave->dev.type = &sdw_slave_type;
  56         slave->dev.groups = sdw_slave_status_attr_groups;
  57         slave->bus = bus;
  58         slave->status = SDW_SLAVE_UNATTACHED;
  59         init_completion(&slave->enumeration_complete);
  60         init_completion(&slave->initialization_complete);
  61         slave->dev_num = 0;
  62         slave->probed = false;
  63         slave->first_interrupt_done = false;
  64         mutex_init(&slave->sdw_dev_lock);
  65
  66         for (i = 0; i < SDW_MAX_PORTS; i++)
  67                 init_completion(&slave->port_ready[i]);
  68
  69         mutex_lock(&bus->bus_lock);
  70         list_add_tail(&slave->node, &bus->slaves);
  71         mutex_unlock(&bus->bus_lock);
  72
  73         ret = device_register(&slave->dev);
  74         if (ret) {
  75                 dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
  76
  77                 /*
  78                  * On err, don't free but drop ref as this will be freed
  79                  * when release method is invoked.
  80                  */
  81                 mutex_lock(&bus->bus_lock);
  82                 list_del(&slave->node);
  83                 mutex_unlock(&bus->bus_lock);
  84                 put_device(&slave->dev);
  85
  86                 return ret;
  87         }
  88         sdw_slave_debugfs_init(slave);
  89
  90         return ret;
  91 }
  92 EXPORT_SYMBOL(sdw_slave_add);
  93
  94 #if IS_ENABLED(CONFIG_ACPI)
  95
  96 static bool find_slave(struct sdw_bus *bus,
  97                        struct acpi_device *adev,
  98                        struct sdw_slave_id *id)
  99 {
 100         u64 addr;
 101         unsigned int link_id;
 102         acpi_status status;
 103
 104         status = acpi_evaluate_integer(adev->handle,
 105                                        METHOD_NAME__ADR, NULL, &addr);
 106
 107         if (ACPI_FAILURE(status)) {
 108                 dev_err(bus->dev, "_ADR resolution failed: %x\n",
 109                         status);
 110                 return false;
 111         }
 112
 113         if (bus->ops->override_adr)
 114                 addr = bus->ops->override_adr(bus, addr);
 115
 116         if (!addr)
 117                 return false;
 118
 119         /* Extract link id from ADR, Bit 51 to 48 (included) */
 120         link_id = SDW_DISCO_LINK_ID(addr);
 121
 122         /* Check for link_id match */
 123         if (link_id != bus->link_id)
 124                 return false;
 125
 126         sdw_extract_slave_id(bus, addr, id);
 127
 128         return true;
 129 }
 130
 131 struct sdw_acpi_child_walk_data {
 132         struct sdw_bus *bus;
 133         struct acpi_device *adev;
 134         struct sdw_slave_id id;
 135         bool ignore_unique_id;
 136 };
 137
 138 static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
 139 {
 140         struct sdw_acpi_child_walk_data *cwd = data;
 141         struct sdw_bus *bus = cwd->bus;
 142         struct sdw_slave_id id;
 143
 144         if (adev == cwd->adev)
 145                 return 0;
 146
 147         if (!find_slave(bus, adev, &id))
 148                 return 0;
 149
 150         if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
 151             cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
 152                 return 0;
 153
 154         if (cwd->id.unique_id != id.unique_id) {
 155                 dev_dbg(bus->dev,
 156                         "Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
 157                         cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,
 158                         cwd->id.part_id);
 159                 cwd->ignore_unique_id = false;
 160                 return 0;
 161         }
 162
 163         dev_err(bus->dev,
 164                 "Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
 165                 cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
 166         return -ENODEV;
 167 }
 168
 169 static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
 170 {
 171         struct sdw_bus *bus = data;
 172         struct sdw_acpi_child_walk_data cwd = {
 173                 .bus = bus,
 174                 .adev = adev,
 175                 .ignore_unique_id = true,
 176         };
 177         int ret;
 178
 179         if (!find_slave(bus, adev, &cwd.id))
 180                 return 0;
 181
 182         /* Brute-force O(N^2) search for duplicates. */
 183         ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
 184                                       sdw_acpi_check_duplicate, &cwd);
 185         if (ret)
 186                 return ret;
 187
 188         if (cwd.ignore_unique_id)
 189                 cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
 190
 191         /* Ignore errors and continue. */
 192         sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
 193         return 0;
 194 }
 195
 196 /*
 197  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
 198  * @bus: SDW bus instance
 199  *
 200  * Scans Master ACPI node for SDW child Slave devices and registers it.
 201  */
 202 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 203 {
 204         struct acpi_device *parent;
 205
 206         parent = ACPI_COMPANION(bus->dev);
 207         if (!parent) {
 208                 dev_err(bus->dev, "Can't find parent for acpi bind\n");
 209                 return -ENODEV;
 210         }
 211
 212         return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
 213 }
 214
 215 #endif
 216
 217 /*
 218  * sdw_of_find_slaves() - Find Slave devices in master device tree node
 219  * @bus: SDW bus instance
 220  *
 221  * Scans Master DT node for SDW child Slave devices and registers it.
 222  */
 223 int sdw_of_find_slaves(struct sdw_bus *bus)
 224 {
 225         struct device *dev = bus->dev;
 226         struct device_node *node;
 227
 228         for_each_child_of_node(bus->dev->of_node, node) {
 229                 int link_id, ret, len;
 230                 unsigned int sdw_version;
 231                 const char *compat = NULL;
 232                 struct sdw_slave_id id;
 233                 const __be32 *addr;
 234
 235                 compat = of_get_property(node, "compatible", NULL);
 236                 if (!compat)
 237                         continue;
 238
 239                 ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
 240                              &id.mfg_id, &id.part_id, &id.class_id);
 241
 242                 if (ret != 4) {
 243                         dev_err(dev, "Invalid compatible string found %s\n",
 244                                 compat);
 245                         continue;
 246                 }
 247
 248                 addr = of_get_property(node, "reg", &len);
 249                 if (!addr || (len < 2 * sizeof(u32))) {
 250                         dev_err(dev, "Invalid Link and Instance ID\n");
 251                         continue;
 252                 }
 253
 254                 link_id = be32_to_cpup(addr++);
 255                 id.unique_id = be32_to_cpup(addr);
 256                 id.sdw_version = sdw_version;
 257
 258                 /* Check for link_id match */
 259                 if (link_id != bus->link_id)
 260                         continue;
 261
 262                 sdw_slave_add(bus, &id, of_fwnode_handle(node));
 263         }
 264
 265         return 0;
 266 }