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Revision 6048a3dd2371c58611ea0ab8b306f8f1469399ae authored by Cory Maccarrone on 19 January 2010, 10:22:45 UTC, committed by Samuel Ortiz on 07 March 2010, 21:17:09 UTC 
mfd: Add HTCPLD driver
 
This change introduces a driver for the HTC PLD chip found
on some smartphones, such as the HTC Wizard and HTC Herald.
It works through the I2C bus and acts as a GPIO extender.
Specifically:

 * it can have several sub-devices, each with its own I2C
   address
 * Each sub-device provides 8 output and 8 input pins
 * The chip attaches to one GPIO to signal when any of the
   input GPIOs change -- at which point all chips must be
   scanned for changes

This driver implements the GPIOs throught the kernel's
GPIO and IRQ framework.  This allows any GPIO-servicing
drivers to operate on htcpld pins, such as the gpio-keys
and gpio-leds drivers.

Signed-off-by: Cory Maccarrone <darkstar6262@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
1 parent 08ff6f2
Raw File
ac97_bus.c 
/*
 * Linux driver model AC97 bus interface
 *
 * Author:	Nicolas Pitre
 * Created:	Jan 14, 2005
 * Copyright:	(C) MontaVista Software Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/string.h>
#include <sound/ac97_codec.h>

/*
 * Let drivers decide whether they want to support given codec from their
 * probe method.  Drivers have direct access to the struct snd_ac97 structure and may
 * decide based on the id field amongst other things.
 */
static int ac97_bus_match(struct device *dev, struct device_driver *drv)
{
	return 1;
}

#ifdef CONFIG_PM
static int ac97_bus_suspend(struct device *dev, pm_message_t state)
{
	int ret = 0;

	if (dev->driver && dev->driver->suspend)
		ret = dev->driver->suspend(dev, state);

	return ret;
}

static int ac97_bus_resume(struct device *dev)
{
	int ret = 0;

	if (dev->driver && dev->driver->resume)
		ret = dev->driver->resume(dev);

	return ret;
}
#endif /* CONFIG_PM */

struct bus_type ac97_bus_type = {
	.name		= "ac97",
	.match		= ac97_bus_match,
#ifdef CONFIG_PM
	.suspend	= ac97_bus_suspend,
	.resume		= ac97_bus_resume,
#endif /* CONFIG_PM */
};

static int __init ac97_bus_init(void)
{
	return bus_register(&ac97_bus_type);
}

subsys_initcall(ac97_bus_init);

static void __exit ac97_bus_exit(void)
{
	bus_unregister(&ac97_bus_type);
}

module_exit(ac97_bus_exit);

EXPORT_SYMBOL(ac97_bus_type);

MODULE_LICENSE("GPL");
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