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         id = sdw_get_device_id(slave, drv);
  88         if (!id)
  89                 return -ENODEV;
  90
  91         slave->ops = drv->ops;
  92
  93         /*
  94          * attach to power domain but don't turn on (last arg)
  95          */
  96         ret = dev_pm_domain_attach(dev, false);
  97         if (ret)
  98                 return ret;
  99
 100         ret = drv->probe(slave, id);
 101         if (ret) {
 102                 dev_err(dev, "Probe of %s failed: %d\n", drv->name, ret);
 103                 dev_pm_domain_detach(dev, false);
 104                 return ret;
 105         }
 106
 107         /* device is probed so let's read the properties now */
 108         if (slave->ops && slave->ops->read_prop)
 109                 slave->ops->read_prop(slave);
 110
 111         /* init the sysfs as we have properties now */
 112         ret = sdw_slave_sysfs_init(slave);
 113         if (ret < 0)
 114                 dev_warn(dev, "Slave sysfs init failed:%d\n", ret);
 115
 116         /*
 117          * Check for valid clk_stop_timeout, use DisCo worst case value of
 118          * 300ms
 119          *
 120          * TODO: check the timeouts and driver removal case
 121          */
 122         if (slave->prop.clk_stop_timeout == 0)
 123                 slave->prop.clk_stop_timeout = 300;
 124
 125         slave->bus->clk_stop_timeout = max_t(u32, slave->bus->clk_stop_timeout,
 126                                              slave->prop.clk_stop_timeout);
 127
 128         slave->probed = true;
 129         complete(&slave->probe_complete);
 130
 131         dev_dbg(dev, "probe complete\n");
 132
 133         return 0;
 134 }
 135
 136 static int sdw_drv_remove(struct device *dev)
 137 {
 138         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 139         struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
 140         int ret = 0;
 141
 142         if (drv->remove)
 143                 ret = drv->remove(slave);
 144
 145         dev_pm_domain_detach(dev, false);
 146
 147         return ret;
 148 }
 149
 150 static void sdw_drv_shutdown(struct device *dev)
 151 {
 152         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 153         struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
 154
 155         if (drv->shutdown)
 156                 drv->shutdown(slave);
 157 }
 158
 159 /**
 160  * __sdw_register_driver() - register a SoundWire Slave driver
 161  * @drv: driver to register
 162  * @owner: owning module/driver
 163  *
 164  * Return: zero on success, else a negative error code.
 165  */
 166 int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
 167 {
 168         drv->driver.bus = &sdw_bus_type;
 169
 170         if (!drv->probe) {
 171                 pr_err("driver %s didn't provide SDW probe routine\n",
 172                        drv->name);
 173                 return -EINVAL;
 174         }
 175
 176         drv->driver.owner = owner;
 177         drv->driver.probe = sdw_drv_probe;
 178
 179         if (drv->remove)
 180                 drv->driver.remove = sdw_drv_remove;
 181
 182         if (drv->shutdown)
 183                 drv->driver.shutdown = sdw_drv_shutdown;
 184
 185         return driver_register(&drv->driver);
 186 }
 187 EXPORT_SYMBOL_GPL(__sdw_register_driver);
 188
 189 /**
 190  * sdw_unregister_driver() - unregisters the SoundWire Slave driver
 191  * @drv: driver to unregister
 192  */
 193 void sdw_unregister_driver(struct sdw_driver *drv)
 194 {
 195         driver_unregister(&drv->driver);
 196 }
 197 EXPORT_SYMBOL_GPL(sdw_unregister_driver);
 198
 199 static int __init sdw_bus_init(void)
 200 {
 201         sdw_debugfs_init();
 202         return bus_register(&sdw_bus_type);
 203 }
 204
 205 static void __exit sdw_bus_exit(void)
 206 {
 207         sdw_debugfs_exit();
 208         bus_unregister(&sdw_bus_type);
 209 }
 210
 211 postcore_initcall(sdw_bus_init);
 212 module_exit(sdw_bus_exit);
 213
 214 MODULE_DESCRIPTION("SoundWire bus");
 215 MODULE_LICENSE("GPL v2");