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 static int sdw_slave_add(struct sdw_bus *bus,
  18                          struct sdw_slave_id *id, struct fwnode_handle *fwnode)
  19 {
  20         struct sdw_slave *slave;
  21         int ret;
  22
  23         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
  24         if (!slave)
  25                 return -ENOMEM;
  26
  27         /* Initialize data structure */
  28         memcpy(&slave->id, id, sizeof(*id));
  29         slave->dev.parent = bus->dev;
  30         slave->dev.fwnode = fwnode;
  31
  32         if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
  33                 /* name shall be sdw:link:mfg:part:class */
  34                 dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x",
  35                              bus->link_id, id->mfg_id, id->part_id,
  36                              id->class_id);
  37         } else {
  38                 /* name shall be sdw:link:mfg:part:class:unique */
  39                 dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
  40                              bus->link_id, id->mfg_id, id->part_id,
  41                              id->class_id, id->unique_id);
  42         }
  43
  44         slave->dev.release = sdw_slave_release;
  45         slave->dev.bus = &sdw_bus_type;
  46         slave->dev.of_node = of_node_get(to_of_node(fwnode));
  47         slave->bus = bus;
  48         slave->status = SDW_SLAVE_UNATTACHED;
  49         init_completion(&slave->enumeration_complete);
  50         init_completion(&slave->initialization_complete);
  51         slave->dev_num = 0;
  52         init_completion(&slave->probe_complete);
  53         slave->probed = false;
  54
  55         mutex_lock(&bus->bus_lock);
  56         list_add_tail(&slave->node, &bus->slaves);
  57         mutex_unlock(&bus->bus_lock);
  58
  59         ret = device_register(&slave->dev);
  60         if (ret) {
  61                 dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
  62
  63                 /*
  64                  * On err, don't free but drop ref as this will be freed
  65                  * when release method is invoked.
  66                  */
  67                 mutex_lock(&bus->bus_lock);
  68                 list_del(&slave->node);
  69                 mutex_unlock(&bus->bus_lock);
  70                 put_device(&slave->dev);
  71         }
  72         sdw_slave_debugfs_init(slave);
  73
  74         return ret;
  75 }
  76
  77 #if IS_ENABLED(CONFIG_ACPI)
  78
  79 static bool find_slave(struct sdw_bus *bus,
  80                        struct acpi_device *adev,
  81                        struct sdw_slave_id *id)
  82 {
  83         unsigned long long addr;
  84         unsigned int link_id;
  85         acpi_status status;
  86
  87         status = acpi_evaluate_integer(adev->handle,
  88                                        METHOD_NAME__ADR, NULL, &addr);
  89
  90         if (ACPI_FAILURE(status)) {
  91                 dev_err(bus->dev, "_ADR resolution failed: %x\n",
  92                         status);
  93                 return false;
  94         }
  95
  96         /* Extract link id from ADR, Bit 51 to 48 (included) */
  97         link_id = (addr >> 48) & GENMASK(3, 0);
  98
  99         /* Check for link_id match */
 100         if (link_id != bus->link_id)
 101                 return false;
 102
 103         sdw_extract_slave_id(bus, addr, id);
 104
 105         return true;
 106 }
 107
 108 /*
 109  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
 110  * @bus: SDW bus instance
 111  *
 112  * Scans Master ACPI node for SDW child Slave devices and registers it.
 113  */
 114 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 115 {
 116         struct acpi_device *adev, *parent;
 117         struct acpi_device *adev2, *parent2;
 118
 119         parent = ACPI_COMPANION(bus->dev);
 120         if (!parent) {
 121                 dev_err(bus->dev, "Can't find parent for acpi bind\n");
 122                 return -ENODEV;
 123         }
 124
 125         list_for_each_entry(adev, &parent->children, node) {
 126                 struct sdw_slave_id id;
 127                 struct sdw_slave_id id2;
 128                 bool ignore_unique_id = true;
 129
 130                 if (!find_slave(bus, adev, &id))
 131                         continue;
 132
 133                 /* brute-force O(N^2) search for duplicates */
 134                 parent2 = parent;
 135                 list_for_each_entry(adev2, &parent2->children, node) {
 136
 137                         if (adev == adev2)
 138                                 continue;
 139
 140                         if (!find_slave(bus, adev2, &id2))
 141                                 continue;
 142
 143                         if (id.sdw_version != id2.sdw_version ||
 144                             id.mfg_id != id2.mfg_id ||
 145                             id.part_id != id2.part_id ||
 146                             id.class_id != id2.class_id)
 147                                 continue;
 148
 149                         if (id.unique_id != id2.unique_id) {
 150                                 dev_dbg(bus->dev,
 151                                         "Valid unique IDs %x %x for Slave mfg %x part %d\n",
 152                                         id.unique_id, id2.unique_id,
 153                                         id.mfg_id, id.part_id);
 154                                 ignore_unique_id = false;
 155                         } else {
 156                                 dev_err(bus->dev,
 157                                         "Invalid unique IDs %x %x for Slave mfg %x part %d\n",
 158                                         id.unique_id, id2.unique_id,
 159                                         id.mfg_id, id.part_id);
 160                                 return -ENODEV;
 161                         }
 162                 }
 163
 164                 if (ignore_unique_id)
 165                         id.unique_id = SDW_IGNORED_UNIQUE_ID;
 166
 167                 /*
 168                  * don't error check for sdw_slave_add as we want to continue
 169                  * adding Slaves
 170                  */
 171                 sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
 172         }
 173
 174         return 0;
 175 }
 176
 177 #endif
 178
 179 /*
 180  * sdw_of_find_slaves() - Find Slave devices in master device tree node
 181  * @bus: SDW bus instance
 182  *
 183  * Scans Master DT node for SDW child Slave devices and registers it.
 184  */
 185 int sdw_of_find_slaves(struct sdw_bus *bus)
 186 {
 187         struct device *dev = bus->dev;
 188         struct device_node *node;
 189
 190         for_each_child_of_node(bus->dev->of_node, node) {
 191                 int link_id, ret, len;
 192                 unsigned int sdw_version;
 193                 const char *compat = NULL;
 194                 struct sdw_slave_id id;
 195                 const __be32 *addr;
 196
 197                 compat = of_get_property(node, "compatible", NULL);
 198                 if (!compat)
 199                         continue;
 200
 201                 ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
 202                              &id.mfg_id, &id.part_id, &id.class_id);
 203
 204                 if (ret != 4) {
 205                         dev_err(dev, "Invalid compatible string found %s\n",
 206                                 compat);
 207                         continue;
 208                 }
 209
 210                 addr = of_get_property(node, "reg", &len);
 211                 if (!addr || (len < 2 * sizeof(u32))) {
 212                         dev_err(dev, "Invalid Link and Instance ID\n");
 213                         continue;
 214                 }
 215
 216                 link_id = be32_to_cpup(addr++);
 217                 id.unique_id = be32_to_cpup(addr);
 218                 id.sdw_version = sdw_version;
 219
 220                 /* Check for link_id match */
 221                 if (link_id != bus->link_id)
 222                         continue;
 223
 224                 sdw_slave_add(bus, &id, of_fwnode_handle(node));
 225         }
 226
 227         return 0;
 228 }