Commit Graph

8 Commits

Author SHA1 Message Date
Ed Blake
56d355e6f5 dmaengine: img-mdc: Add runtime PM
Add runtime PM support to disable the clock when the h/w is not in use.
The existing clock_prepare_enable is removed from probe() as the clock
is no longer permanently enabled.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-10-16 12:15:39 +05:30
Ed Blake
fd9f22ae15 dmaengine: img-mdc: Add suspend / resume handling
Add suspend / resume handling using suspend_late and resume_early, and
check that all channels are idle before suspending.

DMA drivers should use suspend_late / resume_early to ensure that all
DMA client devices are suspended before the DMA device itself, and that
client devices are resumed after the DMA device. This avoids suspending
the DMA device while transactions are still active.

It is the responsibility of client drivers to terminate all DMA
transactions in their suspend handlers, so there should be no active
transactions by the time suspend_late is called.

There's no need to save and restore registers for MDC during suspend /
resume, as all transactions will be terminated as a result of the
suspend, and all required registers are programmed anyway at the start
of any new transactions following resume.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-10-16 12:15:30 +05:30
Vinod Koul
e5a6b3d5de dmaengine: img-mdc: remove unused ‘prev_phys’
In mdc_prep_dma_memcpy(), mdc_prep_dma_cyclic() and mdc_prep_slave_sg()
variable ‘prev_phys’ is initialized but never used, which
leads to warning with W=1

drivers/dma/img-mdc-dma.c: In function ‘mdc_prep_dma_memcpy’:
drivers/dma/img-mdc-dma.c:295:24: warning: variable ‘prev_phys’ set but not used [-Wunused-but-set-variable]
  dma_addr_t curr_phys, prev_phys;

drivers/dma/img-mdc-dma.c: In function ‘mdc_prep_dma_cyclic’:
drivers/dma/img-mdc-dma.c:378:24: warning: variable ‘prev_phys’ set but not used [-Wunused-but-set-variable]
  dma_addr_t curr_phys, prev_phys;

drivers/dma/img-mdc-dma.c: In function ‘mdc_prep_slave_sg’:
drivers/dma/img-mdc-dma.c:461:24: warning: variable ‘prev_phys’ set but not
used [-Wunused-but-set-variable]
  dma_addr_t curr_phys, prev_phys;

So remove it.

Cc: Damien.Horsley <Damien.Horsley@imgtec.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-12-12 22:25:22 +05:30
LABBE Corentin
32e80820de dmaengine: img-mdc: fix a possible NULL dereference
of_match_device could return NULL, and so cause a NULL pointer
dereference later at line 850:
mdma->soc = match->data;

For fixing this problem, we use of_device_get_match_data(), this will
simplify the code a little by using a standard function for
getting the match data.

This was reported by coverity (CID 1324134)

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-08-22 11:57:49 +05:30
Damien.Horsley
0c328de771 dmaengine: mdc: Correct terminate_all handling
Use of the CANCEL bit in mdc_terminate_all creates an
additional 'command done' to appear in the registers (in
addition to an interrupt).

In addition, there is a potential race between
mdc_terminate_all and the irq handler if a transfer
completes at the same time as the terminate all (presently
this results in an inappropriate warning).

To handle these issues, any outstanding 'command done'
events are cleared during mdc_terminate_all and the irq
handler takes no action when there are no new 'command done'
events.

Signed-off-by: Damien.Horsley <Damien.Horsley@imgtec.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-18 11:12:29 +05:30
Lars-Peter Clausen
9ff68186ea dmaengine: img-mdc: Remove unnecessary synchronize_irq() before devm_free_irq()
Calling synchronize_irq() right before devm_free_irq() is quite useless. On
one hand the IRQ can easily fire again before devm_free_irq() is entered,
on the other hand devm_free_irq() itself calls synchronize_irq() internally
(in a race condition free way), before any state associated with the IRQ is
freed.

Patch was generated using the following semantic patch:
// <smpl>
@@
expression irq, dev;
@@
-synchronize_irq(irq);
 devm_free_irq(dev, irq, ...);
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05 15:56:42 +05:30
Vinod Koul
f265958a6b dmaengine: img-mdc: remove device_alloc_chan_resources handler
Now that device_alloc_chan_resources handler in not mandatory, remove dummy
implementations

Acked-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-03-18 22:44:58 +05:30
Andrew Bresticker
5689ba7fd9 dmaengine: Add driver for IMG MDC
Add support for the IMG Multi-threaded DMA Controller (MDC) found on
certain IMG SoCs.  Currently this driver supports the variant present
on the MIPS-based Pistachio SoC.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-02-04 18:13:32 -08:00