Commit 4cb865de authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx 

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (33 commits)
  x86: poll waiting for I/OAT DMA channel status
  maintainers: add dma engine tree details
  dmaengine: add TODO items for future work on dma drivers
  dmaengine: Add API documentation for slave dma usage
  dmaengine/dw_dmac: Update maintainer-ship
  dmaengine: move link order
  dmaengine/dw_dmac: implement pause and resume in dwc_control
  dmaengine/dw_dmac: Replace spin_lock* with irqsave variants and enable submission from callback
  dmaengine/dw_dmac: Divide one sg to many desc, if sg len is greater than DWC_MAX_COUNT
  dmaengine/dw_dmac: set residue as total len in dwc_tx_status if status is !DMA_SUCCESS
  dmaengine/dw_dmac: don't call callback routine in case dmaengine_terminate_all() is called
  dmaengine: at_hdmac: pause: no need to wait for FIFO empty
  pch_dma: modify pci device table definition
  pch_dma: Support new device ML7223 IOH
  pch_dma: Support I2S for ML7213 IOH
  pch_dma: Fix DMA setting issue
  pch_dma: modify for checkpatch
  pch_dma: fix dma direction issue for ML7213 IOH video-in
  dmaengine: at_hdmac: use descriptor chaining help function
  dmaengine: at_hdmac: implement pause and resume in atc_control
  ...

Fix up trivial conflict in drivers/dma/dw_dmac.c
parents 55f08e1b 19d78a61

Documentation/dmaengine.txt

+96 −1
Original line number Original line Diff line number Diff line 
See Documentation/crypto/async-tx-api.txt
 
			DMA Engine API Guide

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



		 Vinod Koul <vinod dot koul at intel.com>



NOTE: For DMA Engine usage in async_tx please see:

	Documentation/crypto/async-tx-api.txt





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

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



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.



Interface:

struct dma_chan *dma_request_channel(dma_cap_mask_t mask,

		dma_filter_fn filter_fn,

		void *filter_param);

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.



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.



Interface:

int dmaengine_slave_config(struct dma_chan *chan,

					  struct dma_slave_config *config)



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.



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,

		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 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.

Interface:

void dma_async_issue_pending(struct dma_chan *chan);



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



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

MAINTAINERS

+9 −0
Original line number Original line Diff line number Diff line
@@ -2178,6 +2178,8 @@ M: Dan Williams <dan.j.williams@intel.com> 
S:	Supported

S:	Supported

F:	drivers/dma/

F:	drivers/dma/

F:	include/linux/dma*

F:	include/linux/dma*

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx.git

T:	git git://git.infradead.org/users/vkoul/slave-dma.git (slave-dma)





DME1737 HARDWARE MONITOR DRIVER

DME1737 HARDWARE MONITOR DRIVER

M:	Juerg Haefliger <juergh@gmail.com>

M:	Juerg Haefliger <juergh@gmail.com>
@@ -5451,6 +5453,13 @@ L: linux-serial@vger.kernel.org 
S:	Maintained

S:	Maintained

F:	drivers/tty/serial

F:	drivers/tty/serial





SYNOPSYS DESIGNWARE DMAC DRIVER

M:	Viresh Kumar <viresh.kumar@st.com>

S:	Maintained

F:	include/linux/dw_dmac.h

F:	drivers/dma/dw_dmac_regs.h

F:	drivers/dma/dw_dmac.c



TIMEKEEPING, NTP

TIMEKEEPING, NTP

M:	John Stultz <johnstul@us.ibm.com>

M:	John Stultz <johnstul@us.ibm.com>

M:	Thomas Gleixner <tglx@linutronix.de>

M:	Thomas Gleixner <tglx@linutronix.de>

drivers/Makefile

+3 −1
Original line number Original line Diff line number Diff line
@@ -17,6 +17,9 @@ obj-$(CONFIG_SFI) += sfi/ 
# was used and do nothing if so

# was used and do nothing if so

obj-$(CONFIG_PNP)		+= pnp/

obj-$(CONFIG_PNP)		+= pnp/

obj-$(CONFIG_ARM_AMBA)		+= amba/

obj-$(CONFIG_ARM_AMBA)		+= amba/

# Many drivers will want to use DMA so this has to be made available

# really early.

obj-$(CONFIG_DMA_ENGINE)	+= dma/





obj-$(CONFIG_VIRTIO)		+= virtio/

obj-$(CONFIG_VIRTIO)		+= virtio/

obj-$(CONFIG_XEN)		+= xen/

obj-$(CONFIG_XEN)		+= xen/
@@ -92,7 +95,6 @@ obj-$(CONFIG_EISA) += eisa/ 
obj-y				+= lguest/

obj-y				+= lguest/

obj-$(CONFIG_CPU_FREQ)		+= cpufreq/

obj-$(CONFIG_CPU_FREQ)		+= cpufreq/

obj-$(CONFIG_CPU_IDLE)		+= cpuidle/

obj-$(CONFIG_CPU_IDLE)		+= cpuidle/

obj-$(CONFIG_DMA_ENGINE)	+= dma/

obj-$(CONFIG_MMC)		+= mmc/

obj-$(CONFIG_MMC)		+= mmc/

obj-$(CONFIG_MEMSTICK)		+= memstick/

obj-$(CONFIG_MEMSTICK)		+= memstick/

obj-y				+= leds/

obj-y				+= leds/

drivers/dma/Kconfig

+7 −5
Original line number Original line Diff line number Diff line
@@ -200,16 +200,18 @@ config PL330_DMA 
	  platform_data for a dma-pl330 device.

	  platform_data for a dma-pl330 device.





config PCH_DMA

config PCH_DMA

	tristate "Intel EG20T PCH / OKI SEMICONDUCTOR ML7213 IOH DMA support"

	tristate "Intel EG20T PCH / OKI Semi IOH(ML7213/ML7223) DMA support"

	depends on PCI && X86

	depends on PCI && X86

	select DMA_ENGINE

	select DMA_ENGINE

	help

	help

	  Enable support for Intel EG20T PCH DMA engine.

	  Enable support for Intel EG20T PCH DMA engine.





	  This driver also can be used for OKI SEMICONDUCTOR ML7213 IOH(Input/

	  This driver also can be used for OKI SEMICONDUCTOR IOH(Input/

	  Output Hub) which is for IVI(In-Vehicle Infotainment) use.

	  Output Hub), ML7213 and ML7223.

	  ML7213 is companion chip for Intel Atom E6xx series.

	  ML7213 IOH is for IVI(In-Vehicle Infotainment) use and ML7223 IOH is

	  ML7213 is completely compatible for Intel EG20T PCH.

	  for MP(Media Phone) use.

	  ML7213/ML7223 is companion chip for Intel Atom E6xx series.

	  ML7213/ML7223 is completely compatible for Intel EG20T PCH.





config IMX_SDMA

config IMX_SDMA

	tristate "i.MX SDMA support"

	tristate "i.MX SDMA support"

drivers/dma/TODO

0 → 100644
+14 −0
Original line number Original line Diff line number Diff line 
TODO for slave dma



1. Move remaining drivers to use new slave interface

2. Remove old slave pointer machansim

3. Make issue_pending to start the transaction in below drivers

	- mpc512x_dma

	- imx-dma

	- imx-sdma

	- mxs-dma.c

	- dw_dmac

	- intel_mid_dma

	- ste_dma40

4. Check other subsystems for dma drivers and merge/move to dmaengine

5. Remove dma_slave_config's dma direction.

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