Re: [PATCH v2 14/25] mtd: nand: qcom: add and initialize QPIC DMA resources

[Abhishek Sahu]

On 2017-08-02 14:11, Archit Taneja wrote:
> On 07/19/2017 05:18 PM, Abhishek Sahu wrote:
> > 1. QPIC NAND uses 3 BAM channels: command, data tx and data
> >     rx while EBI2 NAND uses only single ADM channel.
> > 2. CRCI is only required for ADM DMA and its not required for
>
> s/its/it's

 I Will fix this.

> >     QPIC NAND.
> >
> > Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
> > ---
> >   drivers/mtd/nand/qcom_nandc.c | 83 
> > +++++++++++++++++++++++++++++++++----------
> >   1 file changed, 65 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/qcom_nandc.c 
> > b/drivers/mtd/nand/qcom_nandc.c
> > index 6d24630..cb2b245 100644
> > --- a/drivers/mtd/nand/qcom_nandc.c
> > +++ b/drivers/mtd/nand/qcom_nandc.c
> > @@ -250,9 +250,19 @@ struct qcom_nand_controller {
> >   	struct clk *core_clk;
> >   	struct clk *aon_clk;
> >   -	struct dma_chan *chan;
> > -	unsigned int cmd_crci;
> > -	unsigned int data_crci;
> > +	union {
> > +		struct {
> > +			struct dma_chan *tx_chan;
> > +			struct dma_chan *rx_chan;
> > +			struct dma_chan *cmd_chan;
> > +		};
> > +		struct {
> > +			struct dma_chan *chan;
> > +			unsigned int cmd_crci;
> > +			unsigned int data_crci;
> > +		};
> > +	};
>
> Could you put comments here explaining one is for EBI2/ADM
> and other is for QPIC/BAM? It'll improve the readability a
> bit. Otherwise:

 Yes that would be better. I will put the comment.

> Reviewed-by: Archit Taneja <architt@xxxxxxxxxxxxxx>
>
> Thanks,
> Archit
>
> > +
> >   	struct list_head desc_list;
> >     	u8		*data_buffer;
> > @@ -1985,10 +1995,31 @@ static int qcom_nandc_alloc(struct 
> > qcom_nand_controller *nandc)
> >   	if (!nandc->reg_read_buf)
> >   		return -ENOMEM;
> >   -	nandc->chan = dma_request_slave_channel(nandc->dev, "rxtx");
> > -	if (!nandc->chan) {
> > -		dev_err(nandc->dev, "failed to request slave channel\n");
> > -		return -ENODEV;
> > +	if (nandc->props->is_bam) {
> > +		nandc->tx_chan = dma_request_slave_channel(nandc->dev, "tx");
> > +		if (!nandc->tx_chan) {
> > +			dev_err(nandc->dev, "failed to request tx channel\n");
> > +			return -ENODEV;
> > +		}
> > +
> > +		nandc->rx_chan = dma_request_slave_channel(nandc->dev, "rx");
> > +		if (!nandc->rx_chan) {
> > +			dev_err(nandc->dev, "failed to request rx channel\n");
> > +			return -ENODEV;
> > +		}
> > +
> > +		nandc->cmd_chan = dma_request_slave_channel(nandc->dev, "cmd");
> > +		if (!nandc->cmd_chan) {
> > +			dev_err(nandc->dev, "failed to request cmd channel\n");
> > +			return -ENODEV;
> > +		}
> > +	} else {
> > +		nandc->chan = dma_request_slave_channel(nandc->dev, "rxtx");
> > +		if (!nandc->chan) {
> > +			dev_err(nandc->dev,
> > +				"failed to request slave channel\n");
> > +			return -ENODEV;
> > +		}
> >   	}
> >     	INIT_LIST_HEAD(&nandc->desc_list);
> > @@ -2001,7 +2032,19 @@ static int qcom_nandc_alloc(struct 
> > qcom_nand_controller *nandc)
> >     static void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
> >   {
> > -	dma_release_channel(nandc->chan);
> > +	if (nandc->props->is_bam) {
> > +		if (nandc->tx_chan)
> > +			dma_release_channel(nandc->tx_chan);
> > +
> > +		if (nandc->rx_chan)
> > +			dma_release_channel(nandc->rx_chan);
> > +
> > +		if (nandc->cmd_chan)
> > +			dma_release_channel(nandc->cmd_chan);
> > +	} else {
> > +		if (nandc->chan)
> > +			dma_release_channel(nandc->chan);
> > +	}
> >   }
> >     /* one time setup of a few nand controller registers */
> > @@ -2140,16 +2183,20 @@ static int qcom_nandc_parse_dt(struct 
> > platform_device *pdev)
> >   	struct device_node *np = nandc->dev->of_node;
> >   	int ret;
> >   -	ret = of_property_read_u32(np, "qcom,cmd-crci", &nandc->cmd_crci);
> > -	if (ret) {
> > -		dev_err(nandc->dev, "command CRCI unspecified\n");
> > -		return ret;
> > -	}
> > +	if (!nandc->props->is_bam) {
> > +		ret = of_property_read_u32(np, "qcom,cmd-crci",
> > +					   &nandc->cmd_crci);
> > +		if (ret) {
> > +			dev_err(nandc->dev, "command CRCI unspecified\n");
> > +			return ret;
> > +		}
> >   -	ret = of_property_read_u32(np, "qcom,data-crci", 
> > &nandc->data_crci);
> > -	if (ret) {
> > -		dev_err(nandc->dev, "data CRCI unspecified\n");
> > -		return ret;
> > +		ret = of_property_read_u32(np, "qcom,data-crci",
> > +					   &nandc->data_crci);
> > +		if (ret) {
> > +			dev_err(nandc->dev, "data CRCI unspecified\n");
> > +			return ret;
> > +		}
> >   	}
> >     	return 0;
> > @@ -2199,7 +2246,7 @@ static int qcom_nandc_probe(struct 
> > platform_device *pdev)
> >     	ret = qcom_nandc_alloc(nandc);
> >   	if (ret)
> > -		return ret;
> > +		goto err_core_clk;
> >     	ret = clk_prepare_enable(nandc->core_clk);
> >   	if (ret)