[PATCH v6 2/2] dma: Add Xilinx AXI Video Direct Memory Access Engine driver support
From: Srikanth Thokala <hidden>
Date: 2014-03-24 09:00:23
Also in:
lkml
Hi Jassi, Thanks for the Acked-by. On Mon, Mar 24, 2014 at 11:50 AM, Jassi Brar [off-list ref] wrote:
On Tue, Mar 18, 2014 at 12:36 AM, Srikanth Thokala [off-list ref] wrote:quoted
+ +/** + * xilinx_vdma_prep_slave_sg - prepare a descriptor for a DMA_SLAVE transactionShould be xilinx_vdma_dma_prep_interleaved here.
Ok, I will correct it. Thanks.
quoted
+/** + * xilinx_vdma_channel_set_config - Configure VDMA channel + * Run-time configuration for Axi VDMA, supports: + * . halt the channel + * . configure interrupt coalescing and inter-packet delay threshold + * . start/stop parking + * . enable genlock + * + * @dchan: DMA channel + * @cfg: VDMA device configuration pointer + * + * Return: '0' on success and failure value on error + */ +int xilinx_vdma_channel_set_config(struct dma_chan *dchan, + struct xilinx_vdma_config *cfg) +{ + struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan); + u32 dmacr; + + if (cfg->reset) + return xilinx_vdma_chan_reset(chan); + + dmacr = vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR); + + chan->config.frm_dly = cfg->frm_dly; + chan->config.park = cfg->park; + + /* genlock settings */ + chan->config.gen_lock = cfg->gen_lock; + chan->config.master = cfg->master; + + if (cfg->gen_lock && chan->genlock) { + dmacr |= XILINX_VDMA_DMACR_GENLOCK_EN; + dmacr |= cfg->master << XILINX_VDMA_DMACR_MASTER_SHIFT; + } + + chan->config.frm_cnt_en = cfg->frm_cnt_en; + if (cfg->park) + chan->config.park_frm = cfg->park_frm; + else + chan->config.park_frm = -1; + + chan->config.coalesc = cfg->coalesc; + chan->config.delay = cfg->delay; + + if (cfg->coalesc <= XILINX_VDMA_DMACR_FRAME_COUNT_MAX) { + dmacr |= cfg->coalesc << XILINX_VDMA_DMACR_FRAME_COUNT_SHIFT; + chan->config.coalesc = cfg->coalesc; + } + + if (cfg->delay <= XILINX_VDMA_DMACR_DELAY_MAX) { + dmacr |= cfg->delay << XILINX_VDMA_DMACR_DELAY_SHIFT; + chan->config.delay = cfg->delay; + } + + /* FSync Source selection */ + dmacr &= ~XILINX_VDMA_DMACR_FSYNCSRC_MASK; + dmacr |= cfg->ext_fsync << XILINX_VDMA_DMACR_FSYNCSRC_SHIFT; + + vdma_ctrl_write(chan, XILINX_VDMA_REG_DMACR, dmacr); + + return 0; +} +EXPORT_SYMBOL(xilinx_vdma_channel_set_config); +Bypassing the DMAEngine api doesn't seem very neat. Is there currently any client driver that /changes/ this configuration between channel requests? If no, then simply get the configuration from DT node and avoid this api.
This change is recently suggested by Lars in the following patch series, "dma: Remove comment about embedding dma_slave_config into custom structs" Thanks, Srikanth
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