diff options
Diffstat (limited to 'drivers/dma/tegra210-adma.c')
| -rw-r--r-- | drivers/dma/tegra210-adma.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c index 115ee10f067c..f26c458d584e 100644 --- a/drivers/dma/tegra210-adma.c +++ b/drivers/dma/tegra210-adma.c @@ -30,6 +30,7 @@ #define ADMA_CH_CMD 0x00 #define ADMA_CH_STATUS 0x0c #define ADMA_CH_STATUS_XFER_EN BIT(0) +#define ADMA_CH_STATUS_XFER_PAUSED BIT(1) #define ADMA_CH_INT_STATUS 0x10 #define ADMA_CH_INT_STATUS_XFER_DONE BIT(0) @@ -41,6 +42,7 @@ #define ADMA_CH_CTRL_DIR_MEM2AHUB 4 #define ADMA_CH_CTRL_MODE_CONTINUOUS (2 << 8) #define ADMA_CH_CTRL_FLOWCTRL_EN BIT(1) +#define ADMA_CH_CTRL_XFER_PAUSE_SHIFT 0 #define ADMA_CH_CONFIG 0x28 #define ADMA_CH_CONFIG_SRC_BUF(val) (((val) & 0x7) << 28) @@ -67,6 +69,8 @@ #define ADMA_GLOBAL_CMD 0x00 #define ADMA_GLOBAL_SOFT_RESET 0x04 +#define TEGRA_ADMA_BURST_COMPLETE_TIME 20 + #define ADMA_CH_FIFO_CTRL_DEFAULT (ADMA_CH_FIFO_CTRL_OVRFW_THRES(1) | \ ADMA_CH_FIFO_CTRL_STARV_THRES(1)) @@ -437,6 +441,51 @@ static void tegra_adma_issue_pending(struct dma_chan *dc) spin_unlock_irqrestore(&tdc->vc.lock, flags); } +static bool tegra_adma_is_paused(struct tegra_adma_chan *tdc) +{ + u32 csts; + + csts = tdma_ch_read(tdc, ADMA_CH_STATUS); + csts &= ADMA_CH_STATUS_XFER_PAUSED; + + return csts ? true : false; +} + +static int tegra_adma_pause(struct dma_chan *dc) +{ + struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc); + struct tegra_adma_desc *desc = tdc->desc; + struct tegra_adma_chan_regs *ch_regs = &desc->ch_regs; + int dcnt = 10; + + ch_regs->ctrl = tdma_ch_read(tdc, ADMA_CH_CTRL); + ch_regs->ctrl |= (1 << ADMA_CH_CTRL_XFER_PAUSE_SHIFT); + tdma_ch_write(tdc, ADMA_CH_CTRL, ch_regs->ctrl); + + while (dcnt-- && !tegra_adma_is_paused(tdc)) + udelay(TEGRA_ADMA_BURST_COMPLETE_TIME); + + if (dcnt < 0) { + dev_err(tdc2dev(tdc), "unable to pause DMA channel\n"); + return -EBUSY; + } + + return 0; +} + +static int tegra_adma_resume(struct dma_chan *dc) +{ + struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc); + struct tegra_adma_desc *desc = tdc->desc; + struct tegra_adma_chan_regs *ch_regs = &desc->ch_regs; + + ch_regs->ctrl = tdma_ch_read(tdc, ADMA_CH_CTRL); + ch_regs->ctrl &= ~(1 << ADMA_CH_CTRL_XFER_PAUSE_SHIFT); + tdma_ch_write(tdc, ADMA_CH_CTRL, ch_regs->ctrl); + + return 0; +} + static int tegra_adma_terminate_all(struct dma_chan *dc) { struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc); @@ -798,6 +847,8 @@ static int tegra_adma_probe(struct platform_device *pdev) tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT; + tdma->dma_dev.device_pause = tegra_adma_pause; + tdma->dma_dev.device_resume = tegra_adma_resume; ret = dma_async_device_register(&tdma->dma_dev); if (ret < 0) { |