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path: root/drivers/dma/ep93xx_dma.c
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Diffstat (limited to 'drivers/dma/ep93xx_dma.c')
-rw-r--r--drivers/dma/ep93xx_dma.c39
1 files changed, 35 insertions, 4 deletions
diff --git a/drivers/dma/ep93xx_dma.c b/drivers/dma/ep93xx_dma.c
index d37e8dda8079..ec240592f5c8 100644
--- a/drivers/dma/ep93xx_dma.c
+++ b/drivers/dma/ep93xx_dma.c
@@ -201,6 +201,7 @@ struct ep93xx_dma_engine {
struct dma_device dma_dev;
bool m2m;
int (*hw_setup)(struct ep93xx_dma_chan *);
+ void (*hw_synchronize)(struct ep93xx_dma_chan *);
void (*hw_shutdown)(struct ep93xx_dma_chan *);
void (*hw_submit)(struct ep93xx_dma_chan *);
int (*hw_interrupt)(struct ep93xx_dma_chan *);
@@ -323,6 +324,8 @@ static int m2p_hw_setup(struct ep93xx_dma_chan *edmac)
| M2P_CONTROL_ENABLE;
m2p_set_control(edmac, control);
+ edmac->buffer = 0;
+
return 0;
}
@@ -331,21 +334,27 @@ static inline u32 m2p_channel_state(struct ep93xx_dma_chan *edmac)
return (readl(edmac->regs + M2P_STATUS) >> 4) & 0x3;
}
-static void m2p_hw_shutdown(struct ep93xx_dma_chan *edmac)
+static void m2p_hw_synchronize(struct ep93xx_dma_chan *edmac)
{
+ unsigned long flags;
u32 control;
+ spin_lock_irqsave(&edmac->lock, flags);
control = readl(edmac->regs + M2P_CONTROL);
control &= ~(M2P_CONTROL_STALLINT | M2P_CONTROL_NFBINT);
m2p_set_control(edmac, control);
+ spin_unlock_irqrestore(&edmac->lock, flags);
while (m2p_channel_state(edmac) >= M2P_STATE_ON)
- cpu_relax();
+ schedule();
+}
+static void m2p_hw_shutdown(struct ep93xx_dma_chan *edmac)
+{
m2p_set_control(edmac, 0);
- while (m2p_channel_state(edmac) == M2P_STATE_STALL)
- cpu_relax();
+ while (m2p_channel_state(edmac) != M2P_STATE_IDLE)
+ dev_warn(chan2dev(edmac), "M2P: Not yet IDLE\n");
}
static void m2p_fill_desc(struct ep93xx_dma_chan *edmac)
@@ -1161,6 +1170,26 @@ fail:
}
/**
+ * ep93xx_dma_synchronize - Synchronizes the termination of transfers to the
+ * current context.
+ * @chan: channel
+ *
+ * Synchronizes the DMA channel termination to the current context. When this
+ * function returns it is guaranteed that all transfers for previously issued
+ * descriptors have stopped and and it is safe to free the memory associated
+ * with them. Furthermore it is guaranteed that all complete callback functions
+ * for a previously submitted descriptor have finished running and it is safe to
+ * free resources accessed from within the complete callbacks.
+ */
+static void ep93xx_dma_synchronize(struct dma_chan *chan)
+{
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
+
+ if (edmac->edma->hw_synchronize)
+ edmac->edma->hw_synchronize(edmac);
+}
+
+/**
* ep93xx_dma_terminate_all - terminate all transactions
* @chan: channel
*
@@ -1323,6 +1352,7 @@ static int __init ep93xx_dma_probe(struct platform_device *pdev)
dma_dev->device_prep_slave_sg = ep93xx_dma_prep_slave_sg;
dma_dev->device_prep_dma_cyclic = ep93xx_dma_prep_dma_cyclic;
dma_dev->device_config = ep93xx_dma_slave_config;
+ dma_dev->device_synchronize = ep93xx_dma_synchronize;
dma_dev->device_terminate_all = ep93xx_dma_terminate_all;
dma_dev->device_issue_pending = ep93xx_dma_issue_pending;
dma_dev->device_tx_status = ep93xx_dma_tx_status;
@@ -1340,6 +1370,7 @@ static int __init ep93xx_dma_probe(struct platform_device *pdev)
} else {
dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
+ edma->hw_synchronize = m2p_hw_synchronize;
edma->hw_setup = m2p_hw_setup;
edma->hw_shutdown = m2p_hw_shutdown;
edma->hw_submit = m2p_hw_submit;