dmaengine: dw-axi-dmac: add burst_trans_len support.

Different peripherals may require different burst_trans_len.
Some ALSA devices may require BURST_TRANS_LEN_16, but this
parameter may not work properly on some peripherals (spi, etc.).

This patch will allow BURST_TRANS_LEN to be passed in from DTS.

    dmas = <&dma hs_nu burst_trans_len>

    burst_trans_len:
    <-1> defalut
    <0>  BURST_TRANS_LEN_1
    <1>  BURST_TRANS_LEN_4    /*defalut value*/
    <2>  BURST_TRANS_LEN_8
    <3>  BURST_TRANS_LEN_16
    <4>  BURST_TRANS_LEN_32
    <5>  BURST_TRANS_LEN_64
    <6>  BURST_TRANS_LEN_128
    <7>  BURST_TRANS_LEN_256

Signed-off-by: samin <samin.guo@starfivetech.com>

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 6136844..48e42ca 100644 (file)
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -658,6 +658,7 @@ static int dw_axi_dma_set_hw_desc(struct axi_dma_chan *chan,
        size_t block_ts;
        u32 ctllo, ctlhi;
        u32 burst_len;
+       u32 burst_trans_len;
 
        axi_block_ts = chan->chip->dw->hdata->block_size[chan->id];
 
@@ -721,8 +722,14 @@ static int dw_axi_dma_set_hw_desc(struct axi_dma_chan *chan,
 
        hw_desc->lli->block_ts_lo = cpu_to_le32(block_ts - 1);
 
-       ctllo |= DWAXIDMAC_BURST_TRANS_LEN_4 << CH_CTL_L_DST_MSIZE_POS |
-                DWAXIDMAC_BURST_TRANS_LEN_4 << CH_CTL_L_SRC_MSIZE_POS;
+       if (chan->fixed_burst_trans_len == true)
+               burst_trans_len = chan->burst_trans_len;
+       else
+               burst_trans_len = DWAXIDMAC_BURST_TRANS_LEN_4;
+
+       ctllo |= burst_trans_len << CH_CTL_L_DST_MSIZE_POS |
+                burst_trans_len << CH_CTL_L_SRC_MSIZE_POS;
+
        hw_desc->lli->ctl_lo = cpu_to_le32(ctllo);
 
        set_desc_src_master(hw_desc);
@@ -1316,6 +1323,13 @@ static struct dma_chan *dw_axi_dma_of_xlate(struct of_phandle_args *dma_spec,
 
        chan = dchan_to_axi_dma_chan(dchan);
        chan->hw_handshake_num = dma_spec->args[0];
+
+       /*some per may need fixed-burst_trans_len*/
+       if (dma_spec->args_count == 2  && dma_spec->args[1] > 0) {
+               chan->fixed_burst_trans_len = true;
+               chan->burst_trans_len = dma_spec->args[1];
+       }
+
        return dchan;
 }
 

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
index 6589eee..8d92ba2 100644 (file)
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
@@ -66,6 +66,7 @@ struct axi_dma_chan {
        void __iomem                    *chan_regs;
        u8                              id;
        u8                              hw_handshake_num;
+       s8                              burst_trans_len;
        atomic_t                        descs_allocated;
 
        struct dma_pool                 *desc_pool;
@@ -74,6 +75,7 @@ struct axi_dma_chan {
        struct axi_dma_desc             *desc;
        struct dma_slave_config         config;
        enum dma_transfer_direction     direction;
+       bool                            fixed_burst_trans_len;
        bool                            cyclic;
        /* these other elements are all protected by vc.lock */
        bool                            is_paused;