DMAENGINE: generic slave control v2

Convert the device_terminate_all() operation on the
DMA engine to a generic device_control() operation
which can now optionally support also pausing and
resuming DMA on a certain channel. Implemented for the
COH 901 318 DMAC as an example.

[dan.j.williams@intel.com: update for timberdale]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Li Yang <leoli@freescale.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index d28369f7afd..8a6b85f6117 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -781,13 +781,17 @@ err_desc_get:
         return NULL;
 }
 
-static void dwc_terminate_all(struct dma_chan *chan)
+static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd)
 {
         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
         struct dw_dma           *dw = to_dw_dma(chan->device);
         struct dw_desc          *desc, *_desc;
         LIST_HEAD(list);
 
+        /* Only supports DMA_TERMINATE_ALL */
+        if (cmd != DMA_TERMINATE_ALL)
+                return -ENXIO;
+
         /*
          * This is only called when something went wrong elsewhere, so
          * we don't really care about the data. Just disable the
@@ -810,6 +814,8 @@ static void dwc_terminate_all(struct dma_chan *chan)
         /* Flush all pending and queued descriptors */
         list_for_each_entry_safe(desc, _desc, &list, desc_node)
                 dwc_descriptor_complete(dwc, desc);
+
+        return 0;
 }
 
 static enum dma_status
@@ -1338,7 +1344,7 @@ static int __init dw_probe(struct platform_device *pdev)
         dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
 
         dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
-        dw->dma.device_terminate_all = dwc_terminate_all;
+        dw->dma.device_control = dwc_control;
 
         dw->dma.device_is_tx_complete = dwc_is_tx_complete;
         dw->dma.device_issue_pending = dwc_issue_pending;