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                 return ret;
  73         }
  74         sdw_slave_debugfs_init(slave);
  75
  76         return ret;
  77 }
  78
  79 #if IS_ENABLED(CONFIG_ACPI)
  80
  81 static bool find_slave(struct sdw_bus *bus,
  82                        struct acpi_device *adev,
  83                        struct sdw_slave_id *id)
  84 {
  85         unsigned long long addr;
  86         unsigned int link_id;
  87         acpi_status status;
  88
  89         status = acpi_evaluate_integer(adev->handle,
  90                                        METHOD_NAME__ADR, NULL, &addr);
  91
  92         if (ACPI_FAILURE(status)) {
  93                 dev_err(bus->dev, "_ADR resolution failed: %x\n",
  94                         status);
  95                 return false;
  96         }
  97
  98         /* Extract link id from ADR, Bit 51 to 48 (included) */
  99         link_id = (addr >> 48) & GENMASK(3, 0);
 100
 101         /* Check for link_id match */
 102         if (link_id != bus->link_id)
 103                 return false;
 104
 105         sdw_extract_slave_id(bus, addr, id);
 106
 107         return true;
 108 }
 109
 110 /*
 111  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
 112  * @bus: SDW bus instance
 113  *
 114  * Scans Master ACPI node for SDW child Slave devices and registers it.
 115  */
 116 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 117 {
 118         struct acpi_device *adev, *parent;
 119         struct acpi_device *adev2, *parent2;
 120
 121         parent = ACPI_COMPANION(bus->dev);
 122         if (!parent) {
 123                 dev_err(bus->dev, "Can't find parent for acpi bind\n");
 124                 return -ENODEV;
 125         }
 126
 127         list_for_each_entry(adev, &parent->children, node) {
 128                 struct sdw_slave_id id;
 129                 struct sdw_slave_id id2;
 130                 bool ignore_unique_id = true;
 131
 132                 if (!find_slave(bus, adev, &id))
 133                         continue;
 134
 135                 /* brute-force O(N^2) search for duplicates */
 136                 parent2 = parent;
 137                 list_for_each_entry(adev2, &parent2->children, node) {
 138
 139                         if (adev == adev2)
 140                                 continue;
 141
 142                         if (!find_slave(bus, adev2, &id2))
 143                                 continue;
 144
 145                         if (id.sdw_version != id2.sdw_version ||
 146                             id.mfg_id != id2.mfg_id ||
 147                             id.part_id != id2.part_id ||
 148                             id.class_id != id2.class_id)
 149                                 continue;
 150
 151                         if (id.unique_id != id2.unique_id) {
 152                                 dev_dbg(bus->dev,
 153                                         "Valid unique IDs %x %x for Slave mfg %x part %d\n",
 154                                         id.unique_id, id2.unique_id,
 155                                         id.mfg_id, id.part_id);
 156                                 ignore_unique_id = false;
 157                         } else {
 158                                 dev_err(bus->dev,
 159                                         "Invalid 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                                 return -ENODEV;
 163                         }
 164                 }
 165
 166                 if (ignore_unique_id)
 167                         id.unique_id = SDW_IGNORED_UNIQUE_ID;
 168
 169                 /*
 170                  * don't error check for sdw_slave_add as we want to continue
 171                  * adding Slaves
 172                  */
 173                 sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
 174         }
 175
 176         return 0;
 177 }
 178
 179 #endif
 180
 181 /*
 182  * sdw_of_find_slaves() - Find Slave devices in master device tree node
 183  * @bus: SDW bus instance
 184  *
 185  * Scans Master DT node for SDW child Slave devices and registers it.
 186  */
 187 int sdw_of_find_slaves(struct sdw_bus *bus)
 188 {
 189         struct device *dev = bus->dev;
 190         struct device_node *node;
 191
 192         for_each_child_of_node(bus->dev->of_node, node) {
 193                 int link_id, ret, len;
 194                 unsigned int sdw_version;
 195                 const char *compat = NULL;
 196                 struct sdw_slave_id id;
 197                 const __be32 *addr;
 198
 199                 compat = of_get_property(node, "compatible", NULL);
 200                 if (!compat)
 201                         continue;
 202
 203                 ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
 204                              &id.mfg_id, &id.part_id, &id.class_id);
 205
 206                 if (ret != 4) {
 207                         dev_err(dev, "Invalid compatible string found %s\n",
 208                                 compat);
 209                         continue;
 210                 }
 211
 212                 addr = of_get_property(node, "reg", &len);
 213                 if (!addr || (len < 2 * sizeof(u32))) {
 214                         dev_err(dev, "Invalid Link and Instance ID\n");
 215                         continue;
 216                 }
 217
 218                 link_id = be32_to_cpup(addr++);
 219                 id.unique_id = be32_to_cpup(addr);
 220                 id.sdw_version = sdw_version;
 221
 222                 /* Check for link_id match */
 223                 if (link_id != bus->link_id)
 224                         continue;
 225
 226                 sdw_slave_add(bus, &id, of_fwnode_handle(node));
 227         }
 228
 229         return 0;
 230 }