Re: [RESEND PATCH] dmaengine: dw-edma: Add Simple Mode Support

[Vinod Koul <vkoul@kernel.org>]

On 23-06-25, 11:47, Devendra K Verma wrote:
> The HDMA IP supports the simple mode (non-linked list).
> In this mode the channel registers are configured to initiate
> a single DMA data transfer. The channel can be configured in
> simple mode via peripheral param of dma_slave_config param.
> 
> Signed-off-by: Devendra K Verma <devverma@amd.com>
> ---
>  drivers/dma/dw-edma/dw-edma-core.c    | 10 +++++
>  drivers/dma/dw-edma/dw-edma-core.h    |  2 +
>  drivers/dma/dw-edma/dw-hdma-v0-core.c | 53 ++++++++++++++++++++++++++-
>  include/linux/dma/edma.h              |  8 ++++
>  4 files changed, 72 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index c2b88cc99e5d..4dafd6554277 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -235,9 +235,19 @@ static int dw_edma_device_config(struct dma_chan *dchan,
>  				 struct dma_slave_config *config)
>  {
>  	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
> +	struct dw_edma_peripheral_config *pconfig = config->peripheral_config;
> +	unsigned long flags;
> +
> +	if (WARN_ON(config->peripheral_config &&
> +		    config->peripheral_size != sizeof(*pconfig)))
> +		return -EINVAL;
>  
> +	spin_lock_irqsave(&chan->vc.lock, flags);
>  	memcpy(&chan->config, config, sizeof(*config));
> +
> +	chan->non_ll_en = pconfig ? pconfig->non_ll_en : false;
>  	chan->configured = true;
> +	spin_unlock_irqrestore(&chan->vc.lock, flags);
>  
>  	return 0;
>  }
> diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
> index 71894b9e0b15..c0266976aa22 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.h
> +++ b/drivers/dma/dw-edma/dw-edma-core.h
> @@ -86,6 +86,8 @@ struct dw_edma_chan {
>  	u8				configured;
>  
>  	struct dma_slave_config		config;
> +
> +	bool				non_ll_en;

why do you need this? What is the decision to use non ll vs ll one?

>  };
>  
>  struct dw_edma_irq {
> diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> index e3f8db4fe909..3237c807a18e 100644
> --- a/drivers/dma/dw-edma/dw-hdma-v0-core.c
> +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> @@ -225,7 +225,7 @@ static void dw_hdma_v0_sync_ll_data(struct dw_edma_chunk *chunk)
>  		readl(chunk->ll_region.vaddr.io);
>  }
>  
> -static void dw_hdma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
> +static void dw_hdma_v0_ll_start(struct dw_edma_chunk *chunk, bool first)
>  {
>  	struct dw_edma_chan *chan = chunk->chan;
>  	struct dw_edma *dw = chan->dw;
> @@ -263,6 +263,57 @@ static void dw_hdma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
>  	SET_CH_32(dw, chan->dir, chan->id, doorbell, HDMA_V0_DOORBELL_START);
>  }
>  
> +static void dw_hdma_v0_non_ll_start(struct dw_edma_chunk *chunk)
> +{
> +	struct dw_edma_chan *chan = chunk->chan;
> +	struct dw_edma *dw = chan->dw;
> +	struct dw_edma_burst *child;
> +	u32 val;
> +
> +	list_for_each_entry(child, &chunk->burst->list, list) {
> +		SET_CH_32(dw, chan->dir, chan->id, ch_en, BIT(0));
> +
> +		/* Source address */
> +		SET_CH_32(dw, chan->dir, chan->id, sar.lsb, lower_32_bits(child->sar));
> +		SET_CH_32(dw, chan->dir, chan->id, sar.msb, upper_32_bits(child->sar));
> +
> +		/* Destination address */
> +		SET_CH_32(dw, chan->dir, chan->id, dar.lsb, lower_32_bits(child->dar));
> +		SET_CH_32(dw, chan->dir, chan->id, dar.msb, upper_32_bits(child->dar));
> +
> +		/* Transfer size */
> +		SET_CH_32(dw, chan->dir, chan->id, transfer_size, child->sz);
> +
> +		/* Interrupt setup */
> +		val = GET_CH_32(dw, chan->dir, chan->id, int_setup) |
> +				HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK |
> +				HDMA_V0_LOCAL_STOP_INT_EN | HDMA_V0_LOCAL_ABORT_INT_EN;
> +
> +		if (!(dw->chip->flags & DW_EDMA_CHIP_LOCAL))
> +			val |= HDMA_V0_REMOTE_STOP_INT_EN | HDMA_V0_REMOTE_ABORT_INT_EN;
> +
> +		SET_CH_32(dw, chan->dir, chan->id, int_setup, val);
> +
> +		/* Channel control setup */
> +		val = GET_CH_32(dw, chan->dir, chan->id, control1);
> +		val &= ~HDMA_V0_LINKLIST_EN;
> +		SET_CH_32(dw, chan->dir, chan->id, control1, val);
> +
> +		/* Ring the doorbell */
> +		SET_CH_32(dw, chan->dir, chan->id, doorbell, HDMA_V0_DOORBELL_START);
> +	}
> +}
> +
> +static void dw_hdma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
> +{
> +	struct dw_edma_chan *chan = chunk->chan;
> +
> +	if (!chan->non_ll_en)
> +		dw_hdma_v0_ll_start(chunk, first);
> +	else
> +		dw_hdma_v0_non_ll_start(chunk);
> +}
> +
>  static void dw_hdma_v0_core_ch_config(struct dw_edma_chan *chan)
>  {
>  	struct dw_edma *dw = chan->dw;
> diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
> index 3080747689f6..82d808013a66 100644
> --- a/include/linux/dma/edma.h
> +++ b/include/linux/dma/edma.h
> @@ -101,6 +101,14 @@ struct dw_edma_chip {
>  	struct dw_edma		*dw;
>  };
>  
> +/**
> + * struct dw_edma_peripheral_config - peripheral spicific configurations
> + * @non_ll_en:		 enable non-linked list mode of operations
> + */
> +struct dw_edma_peripheral_config {
> +	bool			non_ll_en;
> +};
> +
>  /* Export to the platform drivers */
>  #if IS_REACHABLE(CONFIG_DW_EDMA)
>  int dw_edma_probe(struct dw_edma_chip *chip);
> -- 
> 2.43.0

-- 
~Vinod