Enable the DMA clock when allocating channel and disable clock when freeing channels.
Signed-off-by: Laxman Dewangan <[email protected]> --- Changes from V1 to V2: - Enable/disable clock when allocating/freeing channels. - rewrite the description to reflect change. drivers/dma/tegra20-apb-dma.c | 18 +++++++++++++++++- 1 files changed, 17 insertions(+), 1 deletions(-) diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index d52dbc6..24acd71 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -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]; -- 1.7.1.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
