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/at_hdmac.c b/drivers/dma/at_hdmac.c
index efc1a61ca231..f9143cf9e50a 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -759,13 +759,17 @@ err_desc_get:
         return NULL;
 }
 
-static void atc_terminate_all(struct dma_chan *chan)
+static int atc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd)
 {
         struct at_dma_chan      *atchan = to_at_dma_chan(chan);
         struct at_dma           *atdma = to_at_dma(chan->device);
         struct at_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
@@ -789,6 +793,8 @@ static void atc_terminate_all(struct dma_chan *chan)
         /* Flush all pending and queued descriptors */
         list_for_each_entry_safe(desc, _desc, &list, desc_node)
                 atc_chain_complete(atchan, desc);
+
+        return 0;
 }
 
 /**
@@ -1091,7 +1097,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
 
         if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)) {
                 atdma->dma_common.device_prep_slave_sg = atc_prep_slave_sg;
-                atdma->dma_common.device_terminate_all = atc_terminate_all;
+                atdma->dma_common.device_control = atc_control;
         }
 
         dma_writel(atdma, EN, AT_DMA_ENABLE);