On Wed, Jun 20, 2018 at 4:43 PM, Radhey Shyam Pandey <radheys@xxxxxxxxxx> wrote: >> -----Original Message----- >> From: dmaengine-owner@xxxxxxxxxxxxxxx [mailto:dmaengine- >> owner@xxxxxxxxxxxxxxx] On Behalf Of Andrea Merello >> Sent: Wednesday, June 20, 2018 2:07 PM >> To: vkoul@xxxxxxxxxx; dan.j.williams@xxxxxxxxx; Michal Simek >> <michals@xxxxxxxxxx>; Appana Durga Kedareswara Rao >> <appanad@xxxxxxxxxx>; dmaengine@xxxxxxxxxxxxxxx >> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; >> Andrea Merello <andrea.merello@xxxxxxxxx> >> Subject: [PATCH 5/6] dmaengine: xilinx_dma: autodetect whether the HW >> supports scatter-gather >> >> The HW can be either direct-access or scatter-gather version. These are >> SW incompatible. >> >> The driver can handle both version: a DT property was used to >> tell the driver whether to assume the HW is is scatter-gather mode. >> >> This patch makes the driver to autodetect this information. The DT >> property is not required anymore. >> >> Signed-off-by: Andrea Merello <andrea.merello@xxxxxxxxx> >> --- >> drivers/dma/xilinx/xilinx_dma.c | 12 ++++++++---- >> 1 file changed, 8 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c >> index bdbc8ba9092a..8c6e818e596f 100644 >> --- a/drivers/dma/xilinx/xilinx_dma.c >> +++ b/drivers/dma/xilinx/xilinx_dma.c >> @@ -86,6 +86,7 @@ >> #define XILINX_DMA_DMASR_DMA_DEC_ERR BIT(6) >> #define XILINX_DMA_DMASR_DMA_SLAVE_ERR BIT(5) >> #define XILINX_DMA_DMASR_DMA_INT_ERR BIT(4) >> +#define XILINX_DMA_DMASR_SG_MASK BIT(3) >> #define XILINX_DMA_DMASR_IDLE BIT(1) >> #define XILINX_DMA_DMASR_HALTED BIT(0) >> #define XILINX_DMA_DMASR_DELAY_MASK GENMASK(31, 24) >> @@ -407,7 +408,6 @@ struct xilinx_dma_config { >> * @dev: Device Structure >> * @common: DMA device structure >> * @chan: Driver specific DMA channel >> - * @has_sg: Specifies whether Scatter-Gather is present or not >> * @mcdma: Specifies whether Multi-Channel is present or not >> * @flush_on_fsync: Flush on frame sync >> * @ext_addr: Indicates 64 bit addressing is supported by dma device >> @@ -426,7 +426,6 @@ struct xilinx_dma_device { >> struct device *dev; >> struct dma_device common; >> struct xilinx_dma_chan >> *chan[XILINX_DMA_MAX_CHANS_PER_DEVICE]; >> - bool has_sg; >> bool mcdma; >> u32 flush_on_fsync; >> bool ext_addr; >> @@ -2391,7 +2390,6 @@ static int xilinx_dma_chan_probe(struct >> xilinx_dma_device *xdev, >> >> chan->dev = xdev->dev; >> chan->xdev = xdev; >> - chan->has_sg = xdev->has_sg; >> chan->desc_pendingcount = 0x0; >> chan->ext_addr = xdev->ext_addr; >> /* This variable ensures that descriptors are not >> @@ -2488,6 +2486,13 @@ static int xilinx_dma_chan_probe(struct >> xilinx_dma_device *xdev, >> chan->stop_transfer = xilinx_dma_stop_transfer; >> } >> >> + /* check if SG is enabled */ >> + if (dma_ctrl_read(chan, XILINX_DMA_REG_DMASR) & >> + XILINX_DMA_DMASR_SG_MASK) > I think SGIncld mask is only applicable for AXI DMA and CDMA IP. > For VDMA IP this bit is reserved. OK. I can make it conditional wrt the IP type. As far as I can see VDMA IP has not the two (SG vs no-SG) variant at all, so all should be still OK. > . >> + chan->has_sg = true; >> + dev_dbg(chan->dev, "ch %d: SG %s\n", chan->id, >> + chan->has_sg ? "enabled" : "disabled"); >> + >> /* Initialize the tasklet */ >> tasklet_init(&chan->tasklet, xilinx_dma_do_tasklet, >> (unsigned long)chan); >> @@ -2626,7 +2631,6 @@ static int xilinx_dma_probe(struct platform_device >> *pdev) >> return PTR_ERR(xdev->regs); >> >> /* Retrieve the DMA engine properties from the device tree */ >> - > Unrelated change Oops.. Sorry. > >> if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) { >> xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma"); >> err = of_property_read_u32(node, "xlnx,lengthregwidth", >> -- >> 2.17.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe dmaengine" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
