975c947e75
By setting the MODALIAS variable in uevents, userspace helpers will be enabled to load modules via the module alias associated with a device. This information is required to automatically load HDA codec drivers instead of having to explicitly request the various modules in the HDA core code. [Note that currently the legacy HDA controller driver tries to bind codec modules manually. It's for supporting the fallback generic drivers. This new udev modalias support was added rather for ASoC HDA ext drivers, since this addition itself won't hurt the legacy HDA -- tiwai] [Use the common helper function to generate the modalias -- tiwai] Signed-off-by: Thierry Reding <treding@nvidia.com> Reviewed-by: Vinod Koul <vinod.koul@intel.com> Tested-by: Subhransu S Prusty <subhransu.s.prusty@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
97 lines
2.1 KiB
C
97 lines
2.1 KiB
C
/*
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* HD-audio bus
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*/
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/export.h>
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#include <sound/hdaudio.h>
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MODULE_DESCRIPTION("HD-audio bus");
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MODULE_LICENSE("GPL");
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/**
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* hdac_get_device_id - gets the hdac device id entry
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* @hdev: HD-audio core device
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* @drv: HD-audio codec driver
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*
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* Compares the hdac device vendor_id and revision_id to the hdac_device
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* driver id_table and returns the matching device id entry.
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*/
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const struct hda_device_id *
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hdac_get_device_id(struct hdac_device *hdev, struct hdac_driver *drv)
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{
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if (drv->id_table) {
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const struct hda_device_id *id = drv->id_table;
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while (id->vendor_id) {
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if (hdev->vendor_id == id->vendor_id &&
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(!id->rev_id || id->rev_id == hdev->revision_id))
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return id;
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id++;
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}
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(hdac_get_device_id);
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static int hdac_codec_match(struct hdac_device *dev, struct hdac_driver *drv)
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{
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if (hdac_get_device_id(dev, drv))
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return 1;
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else
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return 0;
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}
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static int hda_bus_match(struct device *dev, struct device_driver *drv)
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{
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struct hdac_device *hdev = dev_to_hdac_dev(dev);
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struct hdac_driver *hdrv = drv_to_hdac_driver(drv);
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if (hdev->type != hdrv->type)
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return 0;
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/*
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* if driver provided a match function use that otherwise we will
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* use hdac_codec_match function
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*/
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if (hdrv->match)
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return hdrv->match(hdev, hdrv);
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else
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return hdac_codec_match(hdev, hdrv);
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return 1;
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}
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static int hda_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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char modalias[32];
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snd_hdac_codec_modalias(dev_to_hdac_dev(dev), modalias,
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sizeof(modalias));
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if (add_uevent_var(env, "MODALIAS=%s", modalias))
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return -ENOMEM;
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return 0;
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}
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struct bus_type snd_hda_bus_type = {
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.name = "hdaudio",
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.match = hda_bus_match,
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.uevent = hda_uevent,
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};
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EXPORT_SYMBOL_GPL(snd_hda_bus_type);
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static int __init hda_bus_init(void)
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{
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return bus_register(&snd_hda_bus_type);
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}
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static void __exit hda_bus_exit(void)
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{
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bus_unregister(&snd_hda_bus_type);
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}
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subsys_initcall(hda_bus_init);
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module_exit(hda_bus_exit);
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