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, 15 insertions, 6 deletions

diff --git a/drivers/dma/ipu/ipu_idmac.c b/drivers/dma/ipu/ipu_idmac.c
index 2a446397c884..39e7fb2a90e3 100644
--- a/drivers/dma/ipu/ipu_idmac.c
+++ b/drivers/dma/ipu/ipu_idmac.c
@@ -1472,13 +1472,17 @@ static void idmac_issue_pending(struct dma_chan *chan)
          */
 }
 
-static void __idmac_terminate_all(struct dma_chan *chan)
+static int __idmac_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd)
 {
         struct idmac_channel *ichan = to_idmac_chan(chan);
         struct idmac *idmac = to_idmac(chan->device);
         unsigned long flags;
         int i;
 
+        /* Only supports DMA_TERMINATE_ALL */
+        if (cmd != DMA_TERMINATE_ALL)
+                return -ENXIO;
+
         ipu_disable_channel(idmac, ichan,
                             ichan->status >= IPU_CHANNEL_ENABLED);
 
@@ -1505,17 +1509,22 @@ static void __idmac_terminate_all(struct dma_chan *chan)
         tasklet_enable(&to_ipu(idmac)->tasklet);
 
         ichan->status = IPU_CHANNEL_INITIALIZED;
+
+        return 0;
 }
 
-static void idmac_terminate_all(struct dma_chan *chan)
+static int idmac_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd)
 {
         struct idmac_channel *ichan = to_idmac_chan(chan);
+        int ret;
 
         mutex_lock(&ichan->chan_mutex);
 
-        __idmac_terminate_all(chan);
+        ret = __idmac_control(chan, cmd);
 
         mutex_unlock(&ichan->chan_mutex);
+
+        return ret;
 }
 
 #ifdef DEBUG
@@ -1607,7 +1616,7 @@ static void idmac_free_chan_resources(struct dma_chan *chan)
 
         mutex_lock(&ichan->chan_mutex);
 
-        __idmac_terminate_all(chan);
+        __idmac_control(chan, DMA_TERMINATE_ALL);
 
         if (ichan->status > IPU_CHANNEL_FREE) {
 #ifdef DEBUG
@@ -1669,7 +1678,7 @@ static int __init ipu_idmac_init(struct ipu *ipu)
 
         /* Compulsory for DMA_SLAVE fields */
         dma->device_prep_slave_sg               = idmac_prep_slave_sg;
-        dma->device_terminate_all               = idmac_terminate_all;
+        dma->device_control                     = idmac_control;
 
         INIT_LIST_HEAD(&dma->channels);
         for (i = 0; i < IPU_CHANNELS_NUM; i++) {
@@ -1703,7 +1712,7 @@ static void __exit ipu_idmac_exit(struct ipu *ipu)
         for (i = 0; i < IPU_CHANNELS_NUM; i++) {
                 struct idmac_channel *ichan = ipu->channel + i;
 
-                idmac_terminate_all(&ichan->dma_chan);
+                idmac_control(&ichan->dma_chan, DMA_TERMINATE_ALL);
                 idmac_prep_slave_sg(&ichan->dma_chan, NULL, 0, DMA_NONE, 0);
         }