0ca06a00e2
AC97 Codec,PCI drivers I've made the review changes and as requested I've pasted the RFC by Nicolas below:- 'I would like to know what people think of the following patch. It allows for a codec on an AC97 bus to be shared with other drivers which are completely unrelated to audio. It registers a new bus type, and whenever a codec instance is created then a device for it is also registered with the driver model using that bus type. This allows, for example, to use the extra features of the UCB1400 like the touchscreen interface and the additional GPIOs and ADCs available on that chip for battery monitoring. I have a working UCB1400 touchscreen driver here that simply registers with the driver model happily working alongside with audio features using this.' Changes over RFC:- o Now matches codec name within codec group. o Added ac97_dev_release() to stop kernel complaining about no release method for device. o Added 'config SND_AC97_BUS' to sound/pci/Kconfig and moved 'config SND_AC97_CODEC' out with the PCI=n statement. o module is now called snd-ac97-bus Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com> Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
80 lines
1.8 KiB
C
80 lines
1.8 KiB
C
/*
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* Linux driver model AC97 bus interface
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*
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* Author: Nicolas Pitre
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* Created: Jan 14, 2005
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* Copyright: (C) MontaVista Software Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/string.h>
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/*
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* Codec families have names seperated by commas, so we search for an
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* individual codec name within the family string.
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*/
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static int ac97_bus_match(struct device *dev, struct device_driver *drv)
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{
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return (strstr(dev->bus_id, drv->name) != NULL);
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}
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static int ac97_bus_suspend(struct device *dev, pm_message_t state)
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{
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int ret = 0;
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if (dev->driver && dev->driver->suspend) {
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ret = dev->driver->suspend(dev, state, SUSPEND_DISABLE);
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if (ret == 0)
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ret = dev->driver->suspend(dev, state, SUSPEND_SAVE_STATE);
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if (ret == 0)
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ret = dev->driver->suspend(dev, state, SUSPEND_POWER_DOWN);
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}
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return ret;
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}
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static int ac97_bus_resume(struct device *dev)
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{
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int ret = 0;
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if (dev->driver && dev->driver->resume) {
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ret = dev->driver->resume(dev, RESUME_POWER_ON);
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if (ret == 0)
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ret = dev->driver->resume(dev, RESUME_RESTORE_STATE);
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if (ret == 0)
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ret = dev->driver->resume(dev, RESUME_ENABLE);
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}
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return ret;
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}
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struct bus_type ac97_bus_type = {
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.name = "ac97",
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.match = ac97_bus_match,
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.suspend = ac97_bus_suspend,
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.resume = ac97_bus_resume,
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};
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static int __init ac97_bus_init(void)
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{
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return bus_register(&ac97_bus_type);
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}
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subsys_initcall(ac97_bus_init);
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static void __exit ac97_bus_exit(void)
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{
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bus_unregister(&ac97_bus_type);
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}
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module_exit(ac97_bus_exit);
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EXPORT_SYMBOL(ac97_bus_type);
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MODULE_LICENSE("GPL");
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