dmaengine: dw-axi-dmac: Add support for CV1800B DMA

As the DMA controller on Sophgo CV1800 series SoC only has 8 channels,
the SoC provides a dma multiplexer to reuse the DMA channel. However,
the dma multiplexer also controls the DMA interrupt multiplexer, which
means that the dma multiplexer needs to know the channel number.

Allow the driver to use DMA phandle args as the channel number, so the
DMA multiplexer can route the DMA interrupt correctly.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260120013706.436742-3-inochiama@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index c90a83a3bd2ffacaefefec5e745bcbd12e92c8b5..4d53f077e9d2563b81ffcc55fdb537d88e006809 100644 (file)
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -50,6 +50,7 @@
 #define AXI_DMA_FLAG_HAS_APB_REGS      BIT(0)
 #define AXI_DMA_FLAG_HAS_RESETS                BIT(1)
 #define AXI_DMA_FLAG_USE_CFG2          BIT(2)
+#define AXI_DMA_FLAG_ARG0_AS_CHAN      BIT(3)
 
 static inline void
 axi_dma_iowrite32(struct axi_dma_chip *chip, u32 reg, u32 val)
@@ -1357,16 +1358,27 @@ static int __maybe_unused axi_dma_runtime_resume(struct device *dev)
 static struct dma_chan *dw_axi_dma_of_xlate(struct of_phandle_args *dma_spec,
                                            struct of_dma *ofdma)
 {
+       unsigned int handshake = dma_spec->args[0];
        struct dw_axi_dma *dw = ofdma->of_dma_data;
-       struct axi_dma_chan *chan;
+       struct axi_dma_chan *chan = NULL;
        struct dma_chan *dchan;
 
-       dchan = dma_get_any_slave_channel(&dw->dma);
+       if (dw->hdata->use_handshake_as_channel_number) {
+               if (handshake >= dw->hdata->nr_channels)
+                       return NULL;
+
+               chan = &dw->chan[handshake];
+               dchan = dma_get_slave_channel(&chan->vc.chan);
+       } else {
+               dchan = dma_get_any_slave_channel(&dw->dma);
+       }
+
        if (!dchan)
                return NULL;
 
-       chan = dchan_to_axi_dma_chan(dchan);
-       chan->hw_handshake_num = dma_spec->args[0];
+       if (!chan)
+               chan = dchan_to_axi_dma_chan(dchan);
+       chan->hw_handshake_num = handshake;
        return dchan;
 }
 
@@ -1505,6 +1517,8 @@ static int dw_probe(struct platform_device *pdev)
                        return ret;
        }
 
+       chip->dw->hdata->use_handshake_as_channel_number = !!(flags & AXI_DMA_FLAG_ARG0_AS_CHAN);
+
        chip->dw->hdata->use_cfg2 = !!(flags & AXI_DMA_FLAG_USE_CFG2);
 
        chip->core_clk = devm_clk_get(chip->dev, "core-clk");
@@ -1660,6 +1674,9 @@ static const struct of_device_id dw_dma_of_id_table[] = {
        }, {
                .compatible = "intel,kmb-axi-dma",
                .data = (void *)AXI_DMA_FLAG_HAS_APB_REGS,
+       }, {
+               .compatible = "sophgo,cv1800b-axi-dma",
+               .data = (void *)AXI_DMA_FLAG_ARG0_AS_CHAN,
        }, {
                .compatible = "starfive,jh7110-axi-dma",
                .data = (void *)(AXI_DMA_FLAG_HAS_RESETS | AXI_DMA_FLAG_USE_CFG2),

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
index b842e6a8d90d3db82690b60f2d35fcaf52e7652d..67cc199e24d1fa84d8af52182d25f7b2eec571de 100644 (file)
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
@@ -34,6 +34,7 @@ struct dw_axi_dma_hcfg {
        bool    reg_map_8_channels;
        bool    restrict_axi_burst_len;
        bool    use_cfg2;
+       bool    use_handshake_as_channel_number;
 };
 
 struct axi_dma_chan {