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         const char *name;
  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         slave->ops = drv->ops;
 102
 103         /*
 104          * attach to power domain but don't turn on (last arg)
 105          */
 106         ret = dev_pm_domain_attach(dev, false);
 107         if (ret)
 108                 return ret;
 109
 110         ret = drv->probe(slave, id);
 111         if (ret) {
 112                 name = drv->name;
 113                 if (!name)
 114                         name = drv->driver.name;
 115                 dev_err(dev, "Probe of %s failed: %d\n", name, ret);
 116                 dev_pm_domain_detach(dev, false);
 117                 return ret;
 118         }
 119
 120         /* device is probed so let's read the properties now */
 121         if (slave->ops && slave->ops->read_prop)
 122                 slave->ops->read_prop(slave);
 123
 124         /* init the sysfs as we have properties now */
 125         ret = sdw_slave_sysfs_init(slave);
 126         if (ret < 0)
 127                 dev_warn(dev, "Slave sysfs init failed:%d\n", ret);
 128
 129         /*
 130          * Check for valid clk_stop_timeout, use DisCo worst case value of
 131          * 300ms
 132          *
 133          * TODO: check the timeouts and driver removal case
 134          */
 135         if (slave->prop.clk_stop_timeout == 0)
 136                 slave->prop.clk_stop_timeout = 300;
 137
 138         slave->bus->clk_stop_timeout = max_t(u32, slave->bus->clk_stop_timeout,
 139                                              slave->prop.clk_stop_timeout);
 140
 141         slave->probed = true;
 142         complete(&slave->probe_complete);
 143
 144         dev_dbg(dev, "probe complete\n");
 145
 146         return 0;
 147 }
 148
 149 static int sdw_drv_remove(struct device *dev)
 150 {
 151         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 152         struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
 153         int ret = 0;
 154
 155         if (drv->remove)
 156                 ret = drv->remove(slave);
 157
 158         dev_pm_domain_detach(dev, false);
 159
 160         return ret;
 161 }
 162
 163 static void sdw_drv_shutdown(struct device *dev)
 164 {
 165         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 166         struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
 167
 168         if (drv->shutdown)
 169                 drv->shutdown(slave);
 170 }
 171
 172 /**
 173  * __sdw_register_driver() - register a SoundWire Slave driver
 174  * @drv: driver to register
 175  * @owner: owning module/driver
 176  *
 177  * Return: zero on success, else a negative error code.
 178  */
 179 int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
 180 {
 181         const char *name;
 182
 183         drv->driver.bus = &sdw_bus_type;
 184
 185         if (!drv->probe) {
 186                 name = drv->name;
 187                 if (!name)
 188                         name = drv->driver.name;
 189
 190                 pr_err("driver %s didn't provide SDW probe routine\n", name);
 191                 return -EINVAL;
 192         }
 193
 194         drv->driver.owner = owner;
 195         drv->driver.probe = sdw_drv_probe;
 196
 197         if (drv->remove)
 198                 drv->driver.remove = sdw_drv_remove;
 199
 200         if (drv->shutdown)
 201                 drv->driver.shutdown = sdw_drv_shutdown;
 202
 203         return driver_register(&drv->driver);
 204 }
 205 EXPORT_SYMBOL_GPL(__sdw_register_driver);
 206
 207 /**
 208  * sdw_unregister_driver() - unregisters the SoundWire Slave driver
 209  * @drv: driver to unregister
 210  */
 211 void sdw_unregister_driver(struct sdw_driver *drv)
 212 {
 213         driver_unregister(&drv->driver);
 214 }
 215 EXPORT_SYMBOL_GPL(sdw_unregister_driver);
 216
 217 static int __init sdw_bus_init(void)
 218 {
 219         sdw_debugfs_init();
 220         return bus_register(&sdw_bus_type);
 221 }
 222
 223 static void __exit sdw_bus_exit(void)
 224 {
 225         sdw_debugfs_exit();
 226         bus_unregister(&sdw_bus_type);
 227 }
 228
 229 postcore_initcall(sdw_bus_init);
 230 module_exit(sdw_bus_exit);
 231
 232 MODULE_DESCRIPTION("SoundWire bus");
 233 MODULE_LICENSE("GPL v2");