Re: [PATCH v4 12/58] dmaengine: hdmac: Split device_control

[Nicolas Ferre]

On 28/10/2014 22:25, Maxime Ripard :
> Split the device_control callback of the Atmel HDMAC driver to make use
> of the newly introduced callbacks, that will eventually be used to retrieve
> slave capabilities.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>

It seems okay:

Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>

Thanks.

> ---
>  drivers/dma/at_hdmac.c | 121 +++++++++++++++++++++++++++++--------------------
>  1 file changed, 73 insertions(+), 48 deletions(-)
> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index ca9dd2613283..86450b3442f2 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -972,11 +972,13 @@ err_out:
>  	return NULL;
>  }
>  
> -static int set_runtime_config(struct dma_chan *chan,
> -			      struct dma_slave_config *sconfig)
> +static int atc_config(struct dma_chan *chan,
> +		      struct dma_slave_config *sconfig)
>  {
>  	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
>  
> +	dev_vdbg(chan2dev(chan), "%s\n", __func__);
> +
>  	/* Check if it is chan is configured for slave transfers */
>  	if (!chan->private)
>  		return -EINVAL;
> @@ -989,9 +991,28 @@ static int set_runtime_config(struct dma_chan *chan,
>  	return 0;
>  }
>  
> +static int atc_pause(struct dma_chan *chan)
> +{
> +	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
> +	struct at_dma		*atdma = to_at_dma(chan->device);
> +	int			chan_id = atchan->chan_common.chan_id;
> +	unsigned long		flags;
>  
> -static int atc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
> -		       unsigned long arg)
> +	LIST_HEAD(list);
> +
> +	dev_vdbg(chan2dev(chan), "%s\n", __func__);
> +
> +	spin_lock_irqsave(&atchan->lock, flags);
> +
> +	dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id));
> +	set_bit(ATC_IS_PAUSED, &atchan->status);
> +
> +	spin_unlock_irqrestore(&atchan->lock, flags);
> +
> +	return 0;
> +}
> +
> +static int atc_resume(struct dma_chan *chan)
>  {
>  	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
>  	struct at_dma		*atdma = to_at_dma(chan->device);
> @@ -1000,60 +1021,61 @@ static int atc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
>  
>  	LIST_HEAD(list);
>  
> -	dev_vdbg(chan2dev(chan), "atc_control (%d)\n", cmd);
> +	dev_vdbg(chan2dev(chan), "%s\n", __func__);
>  
> -	if (cmd == DMA_PAUSE) {
> -		spin_lock_irqsave(&atchan->lock, flags);
> +	if (!atc_chan_is_paused(atchan))
> +		return 0;
>  
> -		dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id));
> -		set_bit(ATC_IS_PAUSED, &atchan->status);
> +	spin_lock_irqsave(&atchan->lock, flags);
>  
> -		spin_unlock_irqrestore(&atchan->lock, flags);
> -	} else if (cmd == DMA_RESUME) {
> -		if (!atc_chan_is_paused(atchan))
> -			return 0;
> +	dma_writel(atdma, CHDR, AT_DMA_RES(chan_id));
> +	clear_bit(ATC_IS_PAUSED, &atchan->status);
>  
> -		spin_lock_irqsave(&atchan->lock, flags);
> +	spin_unlock_irqrestore(&atchan->lock, flags);
>  
> -		dma_writel(atdma, CHDR, AT_DMA_RES(chan_id));
> -		clear_bit(ATC_IS_PAUSED, &atchan->status);
> +	return 0;
> +}
>  
> -		spin_unlock_irqrestore(&atchan->lock, flags);
> -	} else if (cmd == DMA_TERMINATE_ALL) {
> -		struct at_desc	*desc, *_desc;
> -		/*
> -		 * This is only called when something went wrong elsewhere, so
> -		 * we don't really care about the data. Just disable the
> -		 * channel. We still have to poll the channel enable bit due
> -		 * to AHB/HSB limitations.
> -		 */
> -		spin_lock_irqsave(&atchan->lock, flags);
> +static int atc_terminate_all(struct dma_chan *chan)
> +{
> +	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
> +	struct at_dma		*atdma = to_at_dma(chan->device);
> +	int			chan_id = atchan->chan_common.chan_id;
> +	struct at_desc		*desc, *_desc;
> +	unsigned long		flags;
>  
> -		/* disabling channel: must also remove suspend state */
> -		dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask);
> +	LIST_HEAD(list);
>  
> -		/* confirm that this channel is disabled */
> -		while (dma_readl(atdma, CHSR) & atchan->mask)
> -			cpu_relax();
> +	dev_vdbg(chan2dev(chan), "%s\n", __func__);
>  
> -		/* active_list entries will end up before queued entries */
> -		list_splice_init(&atchan->queue, &list);
> -		list_splice_init(&atchan->active_list, &list);
> +	/*
> +	 * This is only called when something went wrong elsewhere, so
> +	 * we don't really care about the data. Just disable the
> +	 * channel. We still have to poll the channel enable bit due
> +	 * to AHB/HSB limitations.
> +	 */
> +	spin_lock_irqsave(&atchan->lock, flags);
>  
> -		/* Flush all pending and queued descriptors */
> -		list_for_each_entry_safe(desc, _desc, &list, desc_node)
> -			atc_chain_complete(atchan, desc);
> +	/* disabling channel: must also remove suspend state */
> +	dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask);
>  
> -		clear_bit(ATC_IS_PAUSED, &atchan->status);
> -		/* if channel dedicated to cyclic operations, free it */
> -		clear_bit(ATC_IS_CYCLIC, &atchan->status);
> +	/* confirm that this channel is disabled */
> +	while (dma_readl(atdma, CHSR) & atchan->mask)
> +		cpu_relax();
>  
> -		spin_unlock_irqrestore(&atchan->lock, flags);
> -	} else if (cmd == DMA_SLAVE_CONFIG) {
> -		return set_runtime_config(chan, (struct dma_slave_config *)arg);
> -	} else {
> -		return -ENXIO;
> -	}
> +	/* active_list entries will end up before queued entries */
> +	list_splice_init(&atchan->queue, &list);
> +	list_splice_init(&atchan->active_list, &list);
> +
> +	/* Flush all pending and queued descriptors */
> +	list_for_each_entry_safe(desc, _desc, &list, desc_node)
> +		atc_chain_complete(atchan, desc);
> +
> +	clear_bit(ATC_IS_PAUSED, &atchan->status);
> +	/* if channel dedicated to cyclic operations, free it */
> +	clear_bit(ATC_IS_CYCLIC, &atchan->status);
> +
> +	spin_unlock_irqrestore(&atchan->lock, flags);
>  
>  	return 0;
>  }
> @@ -1505,7 +1527,10 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  		/* controller can do slave DMA: can trigger cyclic transfers */
>  		dma_cap_set(DMA_CYCLIC, atdma->dma_common.cap_mask);
>  		atdma->dma_common.device_prep_dma_cyclic = atc_prep_dma_cyclic;
> -		atdma->dma_common.device_control = atc_control;
> +		atdma->dma_common.device_config = atc_config;
> +		atdma->dma_common.device_pause = atc_pause;
> +		atdma->dma_common.device_resume = atc_resume;
> +		atdma->dma_common.device_terminate_all = atc_terminate_all;
>  	}
>  
>  	dma_writel(atdma, EN, AT_DMA_ENABLE);
> @@ -1622,7 +1647,7 @@ static void atc_suspend_cyclic(struct at_dma_chan *atchan)
>  	if (!atc_chan_is_paused(atchan)) {
>  		dev_warn(chan2dev(chan),
>  		"cyclic channel not paused, should be done by channel user\n");
> -		atc_control(chan, DMA_PAUSE, 0);
> +		atc_pause(chan);
>  	}
>  
>  	/* now preserve additional data for cyclic operations */
> 


-- 
Nicolas Ferre
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