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path: root/drivers/soundwire/bus_type.c
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Diffstat (limited to 'drivers/soundwire/bus_type.c')
-rw-r--r--drivers/soundwire/bus_type.c172
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c
new file mode 100644
index 000000000000..8d8dcc68e9a8
--- /dev/null
+++ b/drivers/soundwire/bus_type.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright(c) 2015-17 Intel Corporation.
+
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/pm_domain.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_type.h>
+
+/**
+ * sdw_get_device_id - find the matching SoundWire device id
+ * @slave: SoundWire Slave Device
+ * @drv: SoundWire Slave Driver
+ *
+ * The match is done by comparing the mfg_id and part_id from the
+ * struct sdw_device_id.
+ */
+static const struct sdw_device_id *
+sdw_get_device_id(struct sdw_slave *slave, struct sdw_driver *drv)
+{
+ const struct sdw_device_id *id = drv->id_table;
+
+ while (id && id->mfg_id) {
+ if (slave->id.mfg_id == id->mfg_id &&
+ slave->id.part_id == id->part_id)
+ return id;
+ id++;
+ }
+
+ return NULL;
+}
+
+static int sdw_bus_match(struct device *dev, struct device_driver *ddrv)
+{
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+ struct sdw_driver *drv = drv_to_sdw_driver(ddrv);
+
+ return !!sdw_get_device_id(slave, drv);
+}
+
+int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
+{
+ /* modalias is sdw:m<mfg_id>p<part_id> */
+
+ return snprintf(buf, size, "sdw:m%04Xp%04X\n",
+ slave->id.mfg_id, slave->id.part_id);
+}
+
+static int sdw_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+ char modalias[32];
+
+ sdw_slave_modalias(slave, modalias, sizeof(modalias));
+
+ if (add_uevent_var(env, "MODALIAS=%s", modalias))
+ return -ENOMEM;
+
+ return 0;
+}
+
+struct bus_type sdw_bus_type = {
+ .name = "soundwire",
+ .match = sdw_bus_match,
+ .uevent = sdw_uevent,
+};
+EXPORT_SYMBOL_GPL(sdw_bus_type);
+
+static int sdw_drv_probe(struct device *dev)
+{
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+ struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
+ const struct sdw_device_id *id;
+ int ret;
+
+ id = sdw_get_device_id(slave, drv);
+ if (!id)
+ return -ENODEV;
+
+ /*
+ * attach to power domain but don't turn on (last arg)
+ */
+ ret = dev_pm_domain_attach(dev, false);
+ if (ret != -EPROBE_DEFER) {
+ ret = drv->probe(slave, id);
+ if (ret) {
+ dev_err(dev, "Probe of %s failed: %d\n", drv->name, ret);
+ dev_pm_domain_detach(dev, false);
+ }
+ }
+
+ return ret;
+}
+
+static int sdw_drv_remove(struct device *dev)
+{
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+ struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
+ int ret = 0;
+
+ if (drv->remove)
+ ret = drv->remove(slave);
+
+ dev_pm_domain_detach(dev, false);
+
+ return ret;
+}
+
+static void sdw_drv_shutdown(struct device *dev)
+{
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+ struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
+
+ if (drv->shutdown)
+ drv->shutdown(slave);
+}
+
+/**
+ * __sdw_register_driver() - register a SoundWire Slave driver
+ * @drv: driver to register
+ * @owner: owning module/driver
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
+{
+ drv->driver.bus = &sdw_bus_type;
+
+ if (!drv->probe) {
+ pr_err("driver %s didn't provide SDW probe routine\n",
+ drv->name);
+ return -EINVAL;
+ }
+
+ drv->driver.owner = owner;
+ drv->driver.probe = sdw_drv_probe;
+
+ if (drv->remove)
+ drv->driver.remove = sdw_drv_remove;
+
+ if (drv->shutdown)
+ drv->driver.shutdown = sdw_drv_shutdown;
+
+ return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(__sdw_register_driver);
+
+/**
+ * sdw_unregister_driver() - unregisters the SoundWire Slave driver
+ * @drv: driver to unregister
+ */
+void sdw_unregister_driver(struct sdw_driver *drv)
+{
+ driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(sdw_unregister_driver);
+
+static int __init sdw_bus_init(void)
+{
+ return bus_register(&sdw_bus_type);
+}
+
+static void __exit sdw_bus_exit(void)
+{
+ bus_unregister(&sdw_bus_type);
+}
+
+postcore_initcall(sdw_bus_init);
+module_exit(sdw_bus_exit);
+
+MODULE_DESCRIPTION("SoundWire bus");
+MODULE_LICENSE("GPL v2");