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path: root/drivers/dma/tegra20-apb-dma.c
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Diffstat (limited to 'drivers/dma/tegra20-apb-dma.c')
-rw-r--r--drivers/dma/tegra20-apb-dma.c32
1 files changed, 28 insertions, 4 deletions
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 53a8075dcec8..c8f79dcaaee8 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -219,6 +219,13 @@ struct tegra_dma {
void __iomem *base_addr;
const struct tegra_dma_chip_data *chip_data;
+ /*
+ * Counter for managing global pausing of the DMA controller.
+ * Only applicable for devices that don't support individual
+ * channel pausing.
+ */
+ u32 global_pause_count;
+
/* Some register need to be cache before suspend */
u32 reg_gen;
@@ -358,16 +365,32 @@ static void tegra_dma_global_pause(struct tegra_dma_channel *tdc,
struct tegra_dma *tdma = tdc->tdma;
spin_lock(&tdma->global_lock);
- tdma_write(tdma, TEGRA_APBDMA_GENERAL, 0);
- if (wait_for_burst_complete)
- udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
+
+ if (tdc->tdma->global_pause_count == 0) {
+ tdma_write(tdma, TEGRA_APBDMA_GENERAL, 0);
+ if (wait_for_burst_complete)
+ udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
+ }
+
+ tdc->tdma->global_pause_count++;
+
+ spin_unlock(&tdma->global_lock);
}
static void tegra_dma_global_resume(struct tegra_dma_channel *tdc)
{
struct tegra_dma *tdma = tdc->tdma;
- tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
+ spin_lock(&tdma->global_lock);
+
+ if (WARN_ON(tdc->tdma->global_pause_count == 0))
+ goto out;
+
+ if (--tdc->tdma->global_pause_count == 0)
+ tdma_write(tdma, TEGRA_APBDMA_GENERAL,
+ TEGRA_APBDMA_GENERAL_ENABLE);
+
+out:
spin_unlock(&tdma->global_lock);
}
@@ -1407,6 +1430,7 @@ static int tegra_dma_probe(struct platform_device *pdev)
dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
+ tdma->global_pause_count = 0;
tdma->dma_dev.dev = &pdev->dev;
tdma->dma_dev.device_alloc_chan_resources =
tegra_dma_alloc_chan_resources;