Commit Graph

4 Commits

Author SHA1 Message Date
Olof Johansson
3a5e23cf9e Merge tag 'davinci-for-v3.16/edma' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci into next/drivers
Merge "DaVinci EDMA clean-up for v3.16" from Sekhar Nori:

This series makes edma use configuration information available within
the IP instead of reading it from platform data or DT. Some other useful
clean-ups are included too.

* tag 'davinci-for-v3.16/edma' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci: (34 commits)
  ARM: edma: Remove redundant/unused parameters from edma_soc_info
  ARM: davinci: Remove redundant/unused parameters for edma
  ARM: dts: am4372: Remove obsolete properties from edma node
  ARM: dts: am33xx: Remove obsolete properties from edma node
  dt/bindings: ti,edma: Remove redundant properties from documentation
  ARM: edma: Get IP configuration from HW (number of channels, tc, etc)
  ARM: edma: Save number of regions from pdata to struct edma
  ARM: edma: Remove num_cc member from struct edma
  ARM: edma: Remove queue_tc_mapping data from edma_soc_info
  ARM: davinci: Remove eDMA3 queue_tc_mapping data from edma_soc_info
  ARM: edma: Do not change TC -> Queue mapping, leave it to default.
  ARM: edma: Take the number of tc from edma_soc_info (pdata)
  ARM: edma: No need to clean the pdata in edma_of_parse_dt()
  ARM: edma: Clean up and simplify the code around irq request
  dmaengine: edma: update DMA memcpy to use new param element
  dmaengine: edma: Document variables used for residue accounting
  dmaengine: edma: Provide granular accounting
  dmaengine: edma: Make reading the position of active channels work
  dmaengine: edma: Store transfer data in edma_desc and edma_pset
  dmaengine: edma: Create private pset struct
  ...

Signed-off-by: Olof Johansson <olof@lixom.net>
2014-05-26 14:59:05 -07:00
Peter Ujfalusi
efc24e1480 dt/bindings: ti,edma: Remove redundant properties from documentation
From CCCFG register of eDMA3 we can get all the needed information for the
driver about the IP:
Number of channels: NUM_DMACH
Number of regions: NUM_REGN
Number of slots (PaRAM sets): NUM_PAENTRY
Number of TC/EQ: NUM_EVQUE

The ti,edma-regions; ti,edma-slots and dma-channels in DT are
redundant since the very same information can be obtained from the HW.
The mentioned properties are deprecated.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
2014-05-22 14:55:19 +05:30
Thomas Gleixner
cf7eb97911 ARM: common: edma: Fix xbar mapping
This is another great example of trainwreck engineering:

commit 2646a0e529 (ARM: edma: Add EDMA crossbar event mux support)
added support for using EDMA on peripherals which have no direct EDMA
event mapping.

The code compiles and does not explode in your face, but that's it.

1) Reading an u16 array from an u32 device tree array simply does not
   work. Even if the function is named "edma_of_read_u32_to_s16_array".

   It merily calls of_property_read_u16_array. So the resulting 16bit
   array will have every other entry = 0.

2) The DT entry for the xbar registers related to xbar has length 0x10
   instead of the real length: 0xfd0 - 0xf90 = 0x40.

   Not a real problem as it does not cross a page boundary, but
   wrong nevertheless.

3) But none of this matters as the mapping never happens:

   After reading nonsense edma_of_read_u32_to_s16_array() invalidates
   the first array entry pair, so nobody can ever notice the
   braindamage by immediate explosion.

Seems the QA criteria for this code was solely not to explode when
someone adds edma-xbar-event-map entries to the DT. Goal achieved,
congratulations!

Not really helpful if someone wants to use edma on a device which
requires a xbar mapping.

Fix the issues by:

- annotating the device tree entry with "/bits/ 16" as documented in
  the of_property_read_u16_array kernel doc

- make the size of the xbar register mapping correct

- invalidating the end of the array and not the start

This convoluted mess wants to be completely rewritten as there is no
point to keep the xbar_chan array memory and the iomapping of the xbar
regs around forever. Marking the xbar mapped channels as used should
be done right there.

But that's a different issue and this patch is small enough to make it
work and allows a simple backport for stable.

Cc: stable@vger.kernel.org # v3.12+
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
2014-04-29 19:33:49 +05:30
Matt Porter
bf3156dde3 dmaengine: edma: Add TI EDMA device tree binding
The binding definition is based on the generic DMA controller
binding.

Joel:
* Droped reserved and queue DT entries from Documentation
for now from the original patch series (v10)
* Included properties in Documentation and clarified DMA properties (V11)
* Made ti,hwmod option
* Clarified DMA entries

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Matt Porter <mporter@ti.com>
Signed-off-by: Joel A Fernandes <joelagnel@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
2013-06-24 14:02:02 +05:30