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, 9 insertions, 3 deletions

diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c
index 5d17e09cb625..ce28c1e22825 100644
--- a/drivers/dma/shdma.c
+++ b/drivers/dma/shdma.c
@@ -580,12 +580,16 @@ static struct dma_async_tx_descriptor *sh_dmae_prep_slave_sg(
                                direction, flags);
 }
 
-static void sh_dmae_terminate_all(struct dma_chan *chan)
+static int sh_dmae_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd)
 {
         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
 
+        /* Only supports DMA_TERMINATE_ALL */
+        if (cmd != DMA_TERMINATE_ALL)
+                return -ENXIO;
+
         if (!chan)
-                return;
+                return -EINVAL;
 
         dmae_halt(sh_chan);
 
@@ -601,6 +605,8 @@ static void sh_dmae_terminate_all(struct dma_chan *chan)
         spin_unlock_bh(&sh_chan->desc_lock);
 
         sh_dmae_chan_ld_cleanup(sh_chan, true);
+
+        return 0;
 }
 
 static dma_async_tx_callback __ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
@@ -1029,7 +1035,7 @@ static int __init sh_dmae_probe(struct platform_device *pdev)
 
         /* Compulsory for DMA_SLAVE fields */
         shdev->common.device_prep_slave_sg = sh_dmae_prep_slave_sg;
-        shdev->common.device_terminate_all = sh_dmae_terminate_all;
+        shdev->common.device_control = sh_dmae_control;
 
         shdev->common.dev = &pdev->dev;
         /* Default transfer size of 32 bytes requires 32-byte alignment */