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dma: tegra: enable/disable dma clock

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Enable the DMA clock when allocating channel and
disable clock when freeing channels.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
This commit is contained in:
Laxman Dewangan 2012-07-20 13:31:08 +05:30 committed by Vinod Koul
parent f986ffedd7
commit ffc493062c
1 changed files with 17 additions and 1 deletions
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18
drivers/dma/tegra20-apb-dma.c
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@ -1119,15 +1119,21 @@ struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma *tdma = tdc->tdma;
int ret;
dma_cookie_init(&tdc->dma_chan);
tdc->config_init = false;
return 0;
ret = clk_prepare_enable(tdma->dma_clk);
if (ret < 0)
dev_err(tdc2dev(tdc), "clk_prepare_enable failed: %d\n", ret);
return ret;
}
static void tegra_dma_free_chan_resources(struct dma_chan *dc)
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma *tdma = tdc->tdma;
struct tegra_dma_desc *dma_desc;
struct tegra_dma_sg_req *sg_req;
@ -1163,6 +1169,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
list_del(&sg_req->node);
kfree(sg_req);
}
clk_disable_unprepare(tdma->dma_clk);
}
/* Tegra20 specific DMA controller information */
@ -1255,6 +1262,13 @@ static int __devinit tegra_dma_probe(struct platform_device *pdev)
}
}
/* Enable clock before accessing registers */
ret = clk_prepare_enable(tdma->dma_clk);
if (ret < 0) {
dev_err(&pdev->dev, "clk_prepare_enable failed: %d\n", ret);
goto err_pm_disable;
}
/* Reset DMA controller */
tegra_periph_reset_assert(tdma->dma_clk);
udelay(2);
@ -1265,6 +1279,8 @@ static int __devinit tegra_dma_probe(struct platform_device *pdev)
tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
clk_disable_unprepare(tdma->dma_clk);
INIT_LIST_HEAD(&tdma->dma_dev.channels);
for (i = 0; i < cdata->nr_channels; i++) {
struct tegra_dma_channel *tdc = &tdma->channels[i];