Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6

		multiple) files based on the record size of the underlying

		persistent storage until at least this amount is reached.

		Default is 10 Kbytes.

		Pstore only supports one backend at a time. If multiple

		backends are available, the preferred backend may be

		set by passing the pstore.backend= argument to the kernel at

		boot time.

Below is a guide to device driver writers on how to use the Slave-DMA API of the

DMA Engine. This is applicable only for slave DMA usage only.

The slave DMA usage consists of following steps

The slave DMA usage consists of following steps:

1. Allocate a DMA slave channel

2. Set slave and controller specific parameters

3. Get a descriptor for transaction

4. Submit the transaction and wait for callback notification

4. Submit the transaction

5. Issue pending requests and wait for callback notification

1. Allocate a DMA slave channel

Channel allocation is slightly different in the slave DMA context, client

drivers typically need a channel from a particular DMA controller only and even

in some cases a specific channel is desired. To request a channel

dma_request_channel() API is used.

   Channel allocation is slightly different in the slave DMA context,

   client drivers typically need a channel from a particular DMA

   controller only and even in some cases a specific channel is desired.

   To request a channel dma_request_channel() API is used.

   Interface:

	struct dma_chan *dma_request_channel(dma_cap_mask_t mask,

   where dma_filter_fn is defined as:

	typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);

When the optional 'filter_fn' parameter is set to NULL dma_request_channel

simply returns the first channel that satisfies the capability mask.  Otherwise,

when the mask parameter is insufficient for specifying the necessary channel,

the filter_fn routine can be used to disposition the available channels in the

system. The filter_fn routine is called once for each free channel in the

system.  Upon seeing a suitable channel filter_fn returns DMA_ACK which flags

that channel to be the return value from dma_request_channel.  A channel

allocated via this interface is exclusive to the caller, until

dma_release_channel() is called.

   The 'filter_fn' parameter is optional, but highly recommended for

   slave and cyclic channels as they typically need to obtain a specific

   DMA channel.

   When the optional 'filter_fn' parameter is NULL, dma_request_channel()

   simply returns the first channel that satisfies the capability mask.

   Otherwise, the 'filter_fn' routine will be called once for each free

   channel which has a capability in 'mask'.  'filter_fn' is expected to

   return 'true' when the desired DMA channel is found.

   A channel allocated via this interface is exclusive to the caller,

   until dma_release_channel() is called.

2. Set slave and controller specific parameters

Next step is always to pass some specific information to the DMA driver. Most of

the generic information which a slave DMA can use is in struct dma_slave_config.

It allows the clients to specify DMA direction, DMA addresses, bus widths, DMA

burst lengths etc. If some DMA controllers have more parameters to be sent then

they should try to embed struct dma_slave_config in their controller specific

structure. That gives flexibility to client to pass more parameters, if

required.

   Next step is always to pass some specific information to the DMA

   driver.  Most of the generic information which a slave DMA can use

   is in struct dma_slave_config.  This allows the clients to specify

   DMA direction, DMA addresses, bus widths, DMA burst lengths etc

   for the peripheral.

   If some DMA controllers have more parameters to be sent then they

   should try to embed struct dma_slave_config in their controller

   specific structure. That gives flexibility to client to pass more

   parameters, if required.

   Interface:

	int dmaengine_slave_config(struct dma_chan *chan,

				  struct dma_slave_config *config)

   Please see the dma_slave_config structure definition in dmaengine.h

   for a detailed explaination of the struct members.  Please note

   that the 'direction' member will be going away as it duplicates the

   direction given in the prepare call.

3. Get a descriptor for transaction

   For slave usage the various modes of slave transfers supported by the

   DMA-engine are:

   slave_sg	- DMA a list of scatter gather buffers from/to a peripheral

   dma_cyclic	- Perform a cyclic DMA operation from/to a peripheral till the

		  operation is explicitly stopped.

The non NULL return of this transfer API represents a "descriptor" for the given

transaction.

   A non-NULL return of this transfer API represents a "descriptor" for

   the given transaction.

   Interface:

struct dma_async_tx_descriptor *(*chan->device->device_prep_dma_sg)(

		struct dma_chan *chan,

		struct scatterlist *dst_sg, unsigned int dst_nents,

		struct scatterlist *src_sg, unsigned int src_nents,

	struct dma_async_tx_descriptor *(*chan->device->device_prep_slave_sg)(

		struct dma_chan *chan, struct scatterlist *sgl,

		unsigned int sg_len, enum dma_data_direction direction,

		unsigned long flags);

	struct dma_async_tx_descriptor *(*chan->device->device_prep_dma_cyclic)(

		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,

		size_t period_len, enum dma_data_direction direction);

4. Submit the transaction and wait for callback notification

To schedule the transaction to be scheduled by dma device, the "descriptor"

returned in above (3) needs to be submitted.

To tell the dma driver that a transaction is ready to be serviced, the

descriptor->submit() callback needs to be invoked. This chains the descriptor to

the pending queue.

   The peripheral driver is expected to have mapped the scatterlist for

   the DMA operation prior to calling device_prep_slave_sg, and must

   keep the scatterlist mapped until the DMA operation has completed.

   The scatterlist must be mapped using the DMA struct device.  So,

   normal setup should look like this:

	nr_sg = dma_map_sg(chan->device->dev, sgl, sg_len);

	if (nr_sg == 0)

		/* error */

	desc = chan->device->device_prep_slave_sg(chan, sgl, nr_sg,

			direction, flags);

   Once a descriptor has been obtained, the callback information can be

   added and the descriptor must then be submitted.  Some DMA engine

   drivers may hold a spinlock between a successful preparation and

   submission so it is important that these two operations are closely

   paired.

   Note:

	Although the async_tx API specifies that completion callback

	routines cannot submit any new operations, this is not the

	case for slave/cyclic DMA.

	For slave DMA, the subsequent transaction may not be available

	for submission prior to callback function being invoked, so

	slave DMA callbacks are permitted to prepare and submit a new

	transaction.

	For cyclic DMA, a callback function may wish to terminate the

	DMA via dmaengine_terminate_all().

	Therefore, it is important that DMA engine drivers drop any

	locks before calling the callback function which may cause a

	deadlock.

	Note that callbacks will always be invoked from the DMA

	engines tasklet, never from interrupt context.

4. Submit the transaction

   Once the descriptor has been prepared and the callback information

   added, it must be placed on the DMA engine drivers pending queue.

   Interface:

	dma_cookie_t dmaengine_submit(struct dma_async_tx_descriptor *desc)

   This returns a cookie can be used to check the progress of DMA engine

   activity via other DMA engine calls not covered in this document.

   dmaengine_submit() will not start the DMA operation, it merely adds

   it to the pending queue.  For this, see step 5, dma_async_issue_pending.

5. Issue pending DMA requests and wait for callback notification

   The transactions in the pending queue can be activated by calling the

issue_pending API. If channel is idle then the first transaction in queue is

started and subsequent ones queued up.

On completion of the DMA operation the next in queue is submitted and a tasklet

triggered. The tasklet would then call the client driver completion callback

routine for notification, if set.

   issue_pending API. If channel is idle then the first transaction in

   queue is started and subsequent ones queued up.

   On completion of each DMA operation, the next in queue is started and

   a tasklet triggered. The tasklet will then call the client driver

   completion callback routine for notification, if set.

   Interface:

	void dma_async_issue_pending(struct dma_chan *chan);

==============================================================================

Further APIs:

1. int dmaengine_terminate_all(struct dma_chan *chan)

   This causes all activity for the DMA channel to be stopped, and may

   discard data in the DMA FIFO which hasn't been fully transferred.

   No callback functions will be called for any incomplete transfers.

2. int dmaengine_pause(struct dma_chan *chan)

   This pauses activity on the DMA channel without data loss.

3. int dmaengine_resume(struct dma_chan *chan)

   Resume a previously paused DMA channel.  It is invalid to resume a

   channel which is not currently paused.

4. enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,

        dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used)

   This can be used to check the status of the channel.  Please see

   the documentation in include/linux/dmaengine.h for a more complete

   description of this API.

   This can be used in conjunction with dma_async_is_complete() and

   the cookie returned from 'descriptor->submit()' to check for

   completion of a specific DMA transaction.

Additional usage notes for dma driver writers

1/ Although DMA engine specifies that completion callback routines cannot submit

any new operations, but typically for slave DMA subsequent transaction may not

be available for submit prior to callback routine being called. This requirement

is not a requirement for DMA-slave devices. But they should take care to drop

the spin-lock they might be holding before calling the callback routine

   Note:

	Not all DMA engine drivers can return reliable information for

	a running DMA channel.  It is recommended that DMA engine users

	pause or stop (via dmaengine_terminate_all) the channel before

	using this API.

			[HW,MOUSE] Controls Logitech smartscroll autorepeat.

			0 = disabled, 1 = enabled (default).

	pstore.backend=	Specify the name of the pstore backend to use

	pt.		[PARIDE]

			See Documentation/blockdev/paride.txt.

	select GENERIC_PENDING_IRQ if SMP

	select IRQ_PER_CPU

	select GENERIC_IRQ_SHOW

	select ARCH_WANT_OPTIONAL_GPIOLIB

	default y

	help

	  The Itanium Processor Family is Intel's 64-bit successor to

config HAVE_SETUP_PER_CPU_AREA

	def_bool y

config GENERIC_GPIO

	def_bool y

config DMI

	bool

	default y

/*

 * Generic GPIO API implementation for IA-64.

 *

 * A stright copy of that for PowerPC which was:

 *

 * Copyright (c) 2007-2008  MontaVista Software, Inc.

 *

 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>

 *

 * 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.

 */

#ifndef _ASM_IA64_GPIO_H

#define _ASM_IA64_GPIO_H

#include <linux/errno.h>

#include <asm-generic/gpio.h>

#ifdef CONFIG_GPIOLIB

/*

 * We don't (yet) implement inlined/rapid versions for on-chip gpios.

 * Just call gpiolib.

 */

static inline int gpio_get_value(unsigned int gpio)

{

	return __gpio_get_value(gpio);

}

static inline void gpio_set_value(unsigned int gpio, int value)

{

	__gpio_set_value(gpio, value);

}

static inline int gpio_cansleep(unsigned int gpio)

{

	return __gpio_cansleep(gpio);

}

static inline int gpio_to_irq(unsigned int gpio)

{

	return __gpio_to_irq(gpio);

}

static inline int irq_to_gpio(unsigned int irq)

{

	return -EINVAL;

}

#endif /* CONFIG_GPIOLIB */

#endif /* _ASM_IA64_GPIO_H */