drivers/soundwire/bus_type.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright(c) 2015-17 Intel Corporation.
   3
   4 #include <linux/module.h>
   5 #include <linux/mod_devicetable.h>
   6 #include <linux/pm_domain.h>
   7 #include <linux/soundwire/sdw.h>
   8 #include <linux/soundwire/sdw_type.h>
   9 #include "bus.h"
  10 #include "irq.h"
  11 #include "sysfs_local.h"
  12
  13 /**
  14  * sdw_get_device_id - find the matching SoundWire device id
  15  * @slave: SoundWire Slave Device
  16  * @drv: SoundWire Slave Driver
  17  *
  18  * The match is done by comparing the mfg_id and part_id from the
  19  * struct sdw_device_id.
  20  */
  21 static const struct sdw_device_id *
  22 sdw_get_device_id(struct sdw_slave *slave, const struct sdw_driver *drv)
  23 {
  24         const struct sdw_device_id *id;
  25
  26         for (id = drv->id_table; id && id->mfg_id; id++)
  27                 if (slave->id.mfg_id == id->mfg_id &&
  28                     slave->id.part_id == id->part_id  &&
  29                     (!id->sdw_version ||
  30                      slave->id.sdw_version == id->sdw_version) &&
  31                     (!id->class_id ||
  32                      slave->id.class_id == id->class_id))
  33                         return id;
  34
  35         return NULL;
  36 }
  37
  38 static int sdw_bus_match(struct device *dev, const struct device_driver *ddrv)
  39 {
  40         struct sdw_slave *slave;
  41         const struct sdw_driver *drv;
  42         int ret = 0;
  43
  44         if (is_sdw_slave(dev)) {
  45                 slave = dev_to_sdw_dev(dev);
  46                 drv = drv_to_sdw_driver(ddrv);
  47
  48                 ret = !!sdw_get_device_id(slave, drv);
  49         }
  50         return ret;
  51 }
  52
  53 int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
  54 {
  55         /* modalias is sdw:m<mfg_id>p<part_id>v<version>c<class_id> */
  56
  57         return snprintf(buf, size, "sdw:m%04Xp%04Xv%02Xc%02X\n",
  58                         slave->id.mfg_id, slave->id.part_id,
  59                         slave->id.sdw_version, slave->id.class_id);
  60 }
  61
  62 int sdw_slave_uevent(const struct device *dev, struct kobj_uevent_env *env)
  63 {
  64         const struct sdw_slave *slave = dev_to_sdw_dev(dev);
  65         char modalias[32];
  66
  67         sdw_slave_modalias(slave, modalias, sizeof(modalias));
  68
  69         if (add_uevent_var(env, "MODALIAS=%s", modalias))
  70                 return -ENOMEM;
  71
  72         return 0;
  73 }
  74
  75 const struct bus_type sdw_bus_type = {
  76         .name = "soundwire",
  77         .match = sdw_bus_match,
  78 };
  79 EXPORT_SYMBOL_GPL(sdw_bus_type);
  80
  81 static int sdw_drv_probe(struct device *dev)
  82 {
  83         struct sdw_slave *slave = dev_to_sdw_dev(dev);
  84         struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
  85         const struct sdw_device_id *id;
  86         int ret;
  87
  88         /*
  89          * fw description is mandatory to bind
  90          */
  91         if (!dev->fwnode)
  92                 return -ENODEV;
  93
  94         if (!IS_ENABLED(CONFIG_ACPI) && !dev->of_node)
  95                 return -ENODEV;
  96
  97         id = sdw_get_device_id(slave, drv);
  98         if (!id)
  99                 return -ENODEV;
 100
 101         /*
 102          * attach to power domain but don't turn on (last arg)
 103          */
 104         ret = dev_pm_domain_attach(dev, false);
 105         if (ret)
 106                 return ret;
 107
 108         ret = drv->probe(slave, id);
 109         if (ret) {
 110                 dev_pm_domain_detach(dev, false);
 111                 return ret;
 112         }
 113
 114         mutex_lock(&slave->sdw_dev_lock);
 115
 116         /* device is probed so let's read the properties now */
 117         if (drv->ops && drv->ops->read_prop)
 118                 drv->ops->read_prop(slave);
 119
 120         if (slave->prop.use_domain_irq)
 121                 sdw_irq_create_mapping(slave);
 122
 123         /* init the dynamic sysfs attributes we need */
 124         ret = sdw_slave_sysfs_dpn_init(slave);
 125         if (ret < 0)
 126                 dev_warn(dev, "failed to initialise sysfs: %d\n", ret);
 127
 128         /*
 129          * Check for valid clk_stop_timeout, use DisCo worst case value of
 130          * 300ms
 131          *
 132          * TODO: check the timeouts and driver removal case
 133          */
 134         if (slave->prop.clk_stop_timeout == 0)
 135                 slave->prop.clk_stop_timeout = 300;
 136
 137         slave->bus->clk_stop_timeout = max_t(u32, slave->bus->clk_stop_timeout,
 138                                              slave->prop.clk_stop_timeout);
 139
 140         slave->probed = true;
 141
 142         /*
 143          * if the probe happened after the bus was started, notify the codec driver
 144          * of the current hardware status to e.g. start the initialization.
 145          * Errors are only logged as warnings to avoid failing the probe.
 146          */
 147         if (drv->ops && drv->ops->update_status) {
 148                 ret = drv->ops->update_status(slave, slave->status);
 149                 if (ret < 0)
 150                         dev_warn(dev, "failed to update status at probe: %d\n", ret);
 151         }
 152
 153         mutex_unlock(&slave->sdw_dev_lock);
 154
 155         dev_dbg(dev, "probe complete\n");
 156
 157         return 0;
 158 }
 159
 160 static int sdw_drv_remove(struct device *dev)
 161 {
 162         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 163         struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
 164         int ret = 0;
 165
 166         mutex_lock(&slave->sdw_dev_lock);
 167
 168         slave->probed = false;
 169
 170         if (slave->prop.use_domain_irq)
 171                 sdw_irq_dispose_mapping(slave);
 172
 173         mutex_unlock(&slave->sdw_dev_lock);
 174
 175         if (drv->remove)
 176                 ret = drv->remove(slave);
 177
 178         dev_pm_domain_detach(dev, false);
 179
 180         return ret;
 181 }
 182
 183 static void sdw_drv_shutdown(struct device *dev)
 184 {
 185         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 186         struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
 187
 188         if (drv->shutdown)
 189                 drv->shutdown(slave);
 190 }
 191
 192 /**
 193  * __sdw_register_driver() - register a SoundWire Slave driver
 194  * @drv: driver to register
 195  * @owner: owning module/driver
 196  *
 197  * Return: zero on success, else a negative error code.
 198  */
 199 int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
 200 {
 201         drv->driver.bus = &sdw_bus_type;
 202
 203         if (!drv->probe) {
 204                 pr_err("driver %s didn't provide SDW probe routine\n",
 205                                 drv->driver.name);
 206                 return -EINVAL;
 207         }
 208
 209         drv->driver.owner = owner;
 210         drv->driver.probe = sdw_drv_probe;
 211         drv->driver.remove = sdw_drv_remove;
 212         drv->driver.shutdown = sdw_drv_shutdown;
 213         drv->driver.dev_groups = sdw_attr_groups;
 214
 215         return driver_register(&drv->driver);
 216 }
 217 EXPORT_SYMBOL_GPL(__sdw_register_driver);
 218
 219 /**
 220  * sdw_unregister_driver() - unregisters the SoundWire Slave driver
 221  * @drv: driver to unregister
 222  */
 223 void sdw_unregister_driver(struct sdw_driver *drv)
 224 {
 225         driver_unregister(&drv->driver);
 226 }
 227 EXPORT_SYMBOL_GPL(sdw_unregister_driver);
 228
 229 static int __init sdw_bus_init(void)
 230 {
 231         sdw_debugfs_init();
 232         return bus_register(&sdw_bus_type);
 233 }
 234
 235 static void __exit sdw_bus_exit(void)
 236 {
 237         sdw_debugfs_exit();
 238         bus_unregister(&sdw_bus_type);
 239 }
 240
 241 postcore_initcall(sdw_bus_init);
 242 module_exit(sdw_bus_exit);
 243
 244 MODULE_DESCRIPTION("SoundWire bus");
 245 MODULE_LICENSE("GPL v2");