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