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[media] dmaengine: ipu-idmac: add support for the DMA_PAUSE control

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To support multi-size buffers in the mx3_camera V4L2 driver we have to be
able to stop DMA on a channel without releasing descriptors and completely
halting the hardware. Use the DMA_PAUSE control to implement this mode.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Guennadi Liakhovetski 2011-08-25 13:26:53 -03:00 committed by Mauro Carvalho Chehab
parent 2d86401c2c
commit 1d3564d91f
1 changed files with 42 additions and 23 deletions
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65
drivers/dma/ipu/ipu_idmac.c
View file

@ -1307,6 +1307,7 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id)
ipu_submit_buffer(ichan, descnew, sgnew, ichan->active_buffer) < 0) {
callback = descnew->txd.callback;
callback_param = descnew->txd.callback_param;
list_del_init(&descnew->list);
spin_unlock(&ichan->lock);
if (callback)
callback(callback_param);
@ -1428,39 +1429,58 @@ 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);
struct ipu *ipu = to_ipu(idmac);
struct list_head *list, *tmp;
unsigned long flags;
int i;
/* Only supports DMA_TERMINATE_ALL */
if (cmd != DMA_TERMINATE_ALL)
return -ENXIO;
switch (cmd) {
case DMA_PAUSE:
spin_lock_irqsave(&ipu->lock, flags);
ipu_ic_disable_task(ipu, chan->chan_id);
ipu_disable_channel(idmac, ichan,
ichan->status >= IPU_CHANNEL_ENABLED);
/* Return all descriptors into "prepared" state */
list_for_each_safe(list, tmp, &ichan->queue)
list_del_init(list);
tasklet_disable(&to_ipu(idmac)->tasklet);
ichan->sg[0] = NULL;
ichan->sg[1] = NULL;
/* ichan->queue is modified in ISR, have to spinlock */
spin_lock_irqsave(&ichan->lock, flags);
list_splice_init(&ichan->queue, &ichan->free_list);
spin_unlock_irqrestore(&ipu->lock, flags);
if (ichan->desc)
for (i = 0; i < ichan->n_tx_desc; i++) {
struct idmac_tx_desc *desc = ichan->desc + i;
if (list_empty(&desc->list))
/* Descriptor was prepared, but not submitted */
list_add(&desc->list, &ichan->free_list);
ichan->status = IPU_CHANNEL_INITIALIZED;
break;
case DMA_TERMINATE_ALL:
ipu_disable_channel(idmac, ichan,
ichan->status >= IPU_CHANNEL_ENABLED);
async_tx_clear_ack(&desc->txd);
}
tasklet_disable(&ipu->tasklet);
ichan->sg[0] = NULL;
ichan->sg[1] = NULL;
spin_unlock_irqrestore(&ichan->lock, flags);
/* ichan->queue is modified in ISR, have to spinlock */
spin_lock_irqsave(&ichan->lock, flags);
list_splice_init(&ichan->queue, &ichan->free_list);
tasklet_enable(&to_ipu(idmac)->tasklet);
if (ichan->desc)
for (i = 0; i < ichan->n_tx_desc; i++) {
struct idmac_tx_desc *desc = ichan->desc + i;
if (list_empty(&desc->list))
/* Descriptor was prepared, but not submitted */
list_add(&desc->list, &ichan->free_list);
ichan->status = IPU_CHANNEL_INITIALIZED;
async_tx_clear_ack(&desc->txd);
}
ichan->sg[0] = NULL;
ichan->sg[1] = NULL;
spin_unlock_irqrestore(&ichan->lock, flags);
tasklet_enable(&ipu->tasklet);
ichan->status = IPU_CHANNEL_INITIALIZED;
break;
default:
return -ENOSYS;
}
return 0;
}
@ -1663,7 +1683,6 @@ static void __exit ipu_idmac_exit(struct ipu *ipu)
struct idmac_channel *ichan = ipu->channel + i;
idmac_control(&ichan->dma_chan, DMA_TERMINATE_ALL, 0);
idmac_prep_slave_sg(&ichan->dma_chan, NULL, 0, DMA_NONE, 0);
}
dma_async_device_unregister(&idmac->dma);