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