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