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
  29         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
  30         if (!slave)
  31                 return -ENOMEM;
  32
  33         /* Initialize data structure */
  34         memcpy(&slave->id, id, sizeof(*id));
  35         slave->dev.parent = bus->dev;
  36         slave->dev.fwnode = fwnode;
  37
  38         if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
  39                 /* name shall be sdw:link:mfg:part:class */
  40                 dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x",
  41                              bus->link_id, id->mfg_id, id->part_id,
  42                              id->class_id);
  43         } else {
  44                 /* name shall be sdw:link:mfg:part:class:unique */
  45                 dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
  46                              bus->link_id, id->mfg_id, id->part_id,
  47                              id->class_id, id->unique_id);
  48         }
  49
  50         slave->dev.bus = &sdw_bus_type;
  51         slave->dev.of_node = of_node_get(to_of_node(fwnode));
  52         slave->dev.type = &sdw_slave_type;
  53         slave->bus = bus;
  54         slave->status = SDW_SLAVE_UNATTACHED;
  55         init_completion(&slave->enumeration_complete);
  56         init_completion(&slave->initialization_complete);
  57         slave->dev_num = 0;
  58         init_completion(&slave->probe_complete);
  59         slave->probed = false;
  60
  61         mutex_lock(&bus->bus_lock);
  62         list_add_tail(&slave->node, &bus->slaves);
  63         mutex_unlock(&bus->bus_lock);
  64
  65         ret = device_register(&slave->dev);
  66         if (ret) {
  67                 dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
  68
  69                 /*
  70                  * On err, don't free but drop ref as this will be freed
  71                  * when release method is invoked.
  72                  */
  73                 mutex_lock(&bus->bus_lock);
  74                 list_del(&slave->node);
  75                 mutex_unlock(&bus->bus_lock);
  76                 put_device(&slave->dev);
  77
  78                 return ret;
  79         }
  80         sdw_slave_debugfs_init(slave);
  81
  82         return ret;
  83 }
  84
  85 #if IS_ENABLED(CONFIG_ACPI)
  86
  87 static bool find_slave(struct sdw_bus *bus,
  88                        struct acpi_device *adev,
  89                        struct sdw_slave_id *id)
  90 {
  91         unsigned long long addr;
  92         unsigned int link_id;
  93         acpi_status status;
  94
  95         status = acpi_evaluate_integer(adev->handle,
  96                                        METHOD_NAME__ADR, NULL, &addr);
  97
  98         if (ACPI_FAILURE(status)) {
  99                 dev_err(bus->dev, "_ADR resolution failed: %x\n",
 100                         status);
 101                 return false;
 102         }
 103
 104         /* Extract link id from ADR, Bit 51 to 48 (included) */
 105         link_id = (addr >> 48) & GENMASK(3, 0);
 106
 107         /* Check for link_id match */
 108         if (link_id != bus->link_id)
 109                 return false;
 110
 111         sdw_extract_slave_id(bus, addr, id);
 112
 113         return true;
 114 }
 115
 116 /*
 117  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
 118  * @bus: SDW bus instance
 119  *
 120  * Scans Master ACPI node for SDW child Slave devices and registers it.
 121  */
 122 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 123 {
 124         struct acpi_device *adev, *parent;
 125         struct acpi_device *adev2, *parent2;
 126
 127         parent = ACPI_COMPANION(bus->dev);
 128         if (!parent) {
 129                 dev_err(bus->dev, "Can't find parent for acpi bind\n");
 130                 return -ENODEV;
 131         }
 132
 133         list_for_each_entry(adev, &parent->children, node) {
 134                 struct sdw_slave_id id;
 135                 struct sdw_slave_id id2;
 136                 bool ignore_unique_id = true;
 137
 138                 if (!find_slave(bus, adev, &id))
 139                         continue;
 140
 141                 /* brute-force O(N^2) search for duplicates */
 142                 parent2 = parent;
 143                 list_for_each_entry(adev2, &parent2->children, node) {
 144
 145                         if (adev == adev2)
 146                                 continue;
 147
 148                         if (!find_slave(bus, adev2, &id2))
 149                                 continue;
 150
 151                         if (id.sdw_version != id2.sdw_version ||
 152                             id.mfg_id != id2.mfg_id ||
 153                             id.part_id != id2.part_id ||
 154                             id.class_id != id2.class_id)
 155                                 continue;
 156
 157                         if (id.unique_id != id2.unique_id) {
 158                                 dev_dbg(bus->dev,
 159                                         "Valid unique IDs %x %x for Slave mfg %x part %d\n",
 160                                         id.unique_id, id2.unique_id,
 161                                         id.mfg_id, id.part_id);
 162                                 ignore_unique_id = false;
 163                         } else {
 164                                 dev_err(bus->dev,
 165                                         "Invalid unique IDs %x %x for Slave mfg %x part %d\n",
 166                                         id.unique_id, id2.unique_id,
 167                                         id.mfg_id, id.part_id);
 168                                 return -ENODEV;
 169                         }
 170                 }
 171
 172                 if (ignore_unique_id)
 173                         id.unique_id = SDW_IGNORED_UNIQUE_ID;
 174
 175                 /*
 176                  * don't error check for sdw_slave_add as we want to continue
 177                  * adding Slaves
 178                  */
 179                 sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
 180         }
 181
 182         return 0;
 183 }
 184
 185 #endif
 186
 187 /*
 188  * sdw_of_find_slaves() - Find Slave devices in master device tree node
 189  * @bus: SDW bus instance
 190  *
 191  * Scans Master DT node for SDW child Slave devices and registers it.
 192  */
 193 int sdw_of_find_slaves(struct sdw_bus *bus)
 194 {
 195         struct device *dev = bus->dev;
 196         struct device_node *node;
 197
 198         for_each_child_of_node(bus->dev->of_node, node) {
 199                 int link_id, ret, len;
 200                 unsigned int sdw_version;
 201                 const char *compat = NULL;
 202                 struct sdw_slave_id id;
 203                 const __be32 *addr;
 204
 205                 compat = of_get_property(node, "compatible", NULL);
 206                 if (!compat)
 207                         continue;
 208
 209                 ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
 210                              &id.mfg_id, &id.part_id, &id.class_id);
 211
 212                 if (ret != 4) {
 213                         dev_err(dev, "Invalid compatible string found %s\n",
 214                                 compat);
 215                         continue;
 216                 }
 217
 218                 addr = of_get_property(node, "reg", &len);
 219                 if (!addr || (len < 2 * sizeof(u32))) {
 220                         dev_err(dev, "Invalid Link and Instance ID\n");
 221                         continue;
 222                 }
 223
 224                 link_id = be32_to_cpup(addr++);
 225                 id.unique_id = be32_to_cpup(addr);
 226                 id.sdw_version = sdw_version;
 227
 228                 /* Check for link_id match */
 229                 if (link_id != bus->link_id)
 230                         continue;
 231
 232                 sdw_slave_add(bus, &id, of_fwnode_handle(node));
 233         }
 234
 235         return 0;
 236 }