diff options
author | Alexandru Ardelean <alexandru.ardelean@analog.com> | 2020-08-25 18:19:50 +0300 |
---|---|---|
committer | Vinod Koul <vkoul@kernel.org> | 2020-08-25 21:07:11 +0530 |
commit | 78a2f92e4c4a3b775add7f99d04f8acf2fcb48d7 (patch) | |
tree | a4c2cc20cf88d1d67497b50b0a3826cfa22a84d0 /drivers/dma | |
parent | 3061a65c1b3dbcad0d6c03e4edc606698cfa05d2 (diff) |
dmaengine: axi-dmac: add support for reading bus attributes from registers
Starting with core version 4.3.a the DMA bus attributes can (and should) be
read from the INTERFACE_DESCRIPTION (0x10) register.
For older core versions, this will still need to be provided from the
device-tree.
The bus-type values are identical to the ones stored in the device-trees,
so we just need to read them. Bus-width values are stored in log2 values,
so we just need to use them as shift values to make them equivalent to the
current format.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20200825151950.57605-7-alexandru.ardelean@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r-- | drivers/dma/dma-axi-dmac.c | 66 |
1 files changed, 63 insertions, 3 deletions
diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c index 7ee56ae60093..25442a437879 100644 --- a/drivers/dma/dma-axi-dmac.c +++ b/drivers/dma/dma-axi-dmac.c @@ -6,6 +6,7 @@ * Author: Lars-Peter Clausen <lars@metafoo.de> */ +#include <linux/bitfield.h> #include <linux/clk.h> #include <linux/device.h> #include <linux/dma-mapping.h> @@ -45,6 +46,16 @@ * there is no address than can or needs to be configured for the device side. */ +#define AXI_DMAC_REG_INTERFACE_DESC 0x10 +#define AXI_DMAC_DMA_SRC_TYPE_MSK GENMASK(13, 12) +#define AXI_DMAC_DMA_SRC_TYPE_GET(x) FIELD_GET(AXI_DMAC_DMA_SRC_TYPE_MSK, x) +#define AXI_DMAC_DMA_SRC_WIDTH_MSK GENMASK(11, 8) +#define AXI_DMAC_DMA_SRC_WIDTH_GET(x) FIELD_GET(AXI_DMAC_DMA_SRC_WIDTH_MSK, x) +#define AXI_DMAC_DMA_DST_TYPE_MSK GENMASK(5, 4) +#define AXI_DMAC_DMA_DST_TYPE_GET(x) FIELD_GET(AXI_DMAC_DMA_DST_TYPE_MSK, x) +#define AXI_DMAC_DMA_DST_WIDTH_MSK GENMASK(3, 0) +#define AXI_DMAC_DMA_DST_WIDTH_GET(x) FIELD_GET(AXI_DMAC_DMA_DST_WIDTH_MSK, x) + #define AXI_DMAC_REG_IRQ_MASK 0x80 #define AXI_DMAC_REG_IRQ_PENDING 0x84 #define AXI_DMAC_REG_IRQ_SOURCE 0x88 @@ -801,6 +812,51 @@ static int axi_dmac_parse_dt(struct device *dev, struct axi_dmac *dmac) return 0; } +static int axi_dmac_read_chan_config(struct device *dev, struct axi_dmac *dmac) +{ + struct axi_dmac_chan *chan = &dmac->chan; + unsigned int val, desc; + + desc = axi_dmac_read(dmac, AXI_DMAC_REG_INTERFACE_DESC); + if (desc == 0) { + dev_err(dev, "DMA interface register reads zero\n"); + return -EFAULT; + } + + val = AXI_DMAC_DMA_SRC_TYPE_GET(desc); + if (val > AXI_DMAC_BUS_TYPE_FIFO) { + dev_err(dev, "Invalid source bus type read: %d\n", val); + return -EINVAL; + } + chan->src_type = val; + + val = AXI_DMAC_DMA_DST_TYPE_GET(desc); + if (val > AXI_DMAC_BUS_TYPE_FIFO) { + dev_err(dev, "Invalid destination bus type read: %d\n", val); + return -EINVAL; + } + chan->dest_type = val; + + val = AXI_DMAC_DMA_SRC_WIDTH_GET(desc); + if (val == 0) { + dev_err(dev, "Source bus width is zero\n"); + return -EINVAL; + } + /* widths are stored in log2 */ + chan->src_width = 1 << val; + + val = AXI_DMAC_DMA_DST_WIDTH_GET(desc); + if (val == 0) { + dev_err(dev, "Destination bus width is zero\n"); + return -EINVAL; + } + chan->dest_width = 1 << val; + + axi_dmac_adjust_chan_params(chan); + + return 0; +} + static int axi_dmac_detect_caps(struct axi_dmac *dmac, unsigned int version) { struct axi_dmac_chan *chan = &dmac->chan; @@ -880,7 +936,13 @@ static int axi_dmac_probe(struct platform_device *pdev) if (ret < 0) return ret; - ret = axi_dmac_parse_dt(&pdev->dev, dmac); + version = axi_dmac_read(dmac, ADI_AXI_REG_VERSION); + + if (version >= ADI_AXI_PCORE_VER(4, 3, 'a')) + ret = axi_dmac_read_chan_config(&pdev->dev, dmac); + else + ret = axi_dmac_parse_dt(&pdev->dev, dmac); + if (ret < 0) goto err_clk_disable; @@ -912,8 +974,6 @@ static int axi_dmac_probe(struct platform_device *pdev) dmac->chan.vchan.desc_free = axi_dmac_desc_free; vchan_init(&dmac->chan.vchan, dma_dev); - version = axi_dmac_read(dmac, ADI_AXI_REG_VERSION); - ret = axi_dmac_detect_caps(dmac, version); if (ret) goto err_clk_disable; |