[PATCH V4 12/14] spi/s3c64xx: Add support DMA engine API

Boojin Kim boojin.kim at samsung.com
Tue Jul 26 05:31:17 EDT 2011


Vinod Koul Wrote:
> Sent: Monday, July 25, 2011 8:17 PM
> To: Boojin Kim
> Cc: vinod.koul at intel.com; linux-arm-kernel at lists.infradead.org; linux-
> samsung-soc at vger.kernel.org; Kukjin Kim; Jassi Brar; Grant Likely;
> Mark Brown; Dan Williams
> Subject: Re: [PATCH V4 12/14] spi/s3c64xx: Add support DMA engine API
>
> On Mon, 2011-07-25 at 10:28 +0900, Boojin Kim wrote:
> > This patch adds to support DMA generic API to transfer raw
> > SPI data. Basiclly the spi driver uses DMA generic API if
> > architecture supports it. Otherwise, uses Samsung specific
> > S3C-PL330 APIs.
> >
> > Signed-off-by: Boojin Kim <boojin.kim at samsung.com>
> > Cc: Grant Likely <grant.likely at secretlab.ca>
> > Signed-off-by: Kukjin Kim <kgene.kim at samsung.com>
> > ---
> >  drivers/spi/spi_s3c64xx.c |  141 ++++++++++++++++++++++-------------
> ----------
> >  1 files changed, 69 insertions(+), 72 deletions(-)
> >
> > diff --git a/drivers/spi/spi_s3c64xx.c b/drivers/spi/spi_s3c64xx.c
> > index 8945e20..a4cf76a 100644
> > --- a/drivers/spi/spi_s3c64xx.c
> > +++ b/drivers/spi/spi_s3c64xx.c
> > @@ -172,6 +172,9 @@ struct s3c64xx_spi_driver_data {
> >  	unsigned                        state;
> >  	unsigned                        cur_mode, cur_bpw;
> >  	unsigned                        cur_speed;
> > +	unsigned			rx_ch;
> > +	unsigned			tx_ch;
> > +	struct samsung_dma_ops		*ops;
> >  };
> >
> >  static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
> > @@ -227,6 +230,38 @@ static void flush_fifo(struct
> s3c64xx_spi_driver_data *sdd)
> >  	writel(val, regs + S3C64XX_SPI_CH_CFG);
> >  }
> >
> > +static void s3c64xx_spi_dma_rxcb(void *data)
> > +{
> > +	struct s3c64xx_spi_driver_data *sdd
> > +		= (struct s3c64xx_spi_driver_data *)data;
> > +	unsigned long flags;
> > +
> > +	spin_lock_irqsave(&sdd->lock, flags);
> > +
> > +	sdd->state &= ~RXBUSY;
> > +	/* If the other done */
> > +	if (!(sdd->state & TXBUSY))
> > +		complete(&sdd->xfer_completion);
> > +
> > +	spin_unlock_irqrestore(&sdd->lock, flags);
> > +}
> > +
> > +static void s3c64xx_spi_dma_txcb(void *data)
> > +{
> > +	struct s3c64xx_spi_driver_data *sdd
> > +		= (struct s3c64xx_spi_driver_data *)data;
> > +	unsigned long flags;
> > +
> > +	spin_lock_irqsave(&sdd->lock, flags);
> > +
> > +	sdd->state &= ~TXBUSY;
> > +	/* If the other done */
> > +	if (!(sdd->state & RXBUSY))
> > +		complete(&sdd->xfer_completion);
> > +
> > +	spin_unlock_irqrestore(&sdd->lock, flags);
> > +}
> I don't see much diff in these two functions and you should be able to
> use a generic one which takes care of both TX and RX, does your
> callback
> data know if the channel is for TX or RX? If not then a helper to do
> above should take care well and making code simpler
I'm very agree with you.
But, I think it isn't deeply related to this patch series. So, I wish to make 
and submit it after this patch series is finished.

>
> > +
> >  static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
> >  				struct spi_device *spi,
> >  				struct spi_transfer *xfer, int dma_mode)
> > @@ -234,6 +269,7 @@ static void enable_datapath(struct
> s3c64xx_spi_driver_data *sdd,
> >  	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
> >  	void __iomem *regs = sdd->regs;
> >  	u32 modecfg, chcfg;
> > +	struct samsung_dma_prep_info info;
> >
> >  	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
> >  	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON |
> S3C64XX_SPI_MODE_RXDMA_ON);
> > @@ -259,10 +295,14 @@ static void enable_datapath(struct
> s3c64xx_spi_driver_data *sdd,
> >  		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
> >  		if (dma_mode) {
> >  			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
> > -			s3c2410_dma_config(sdd->tx_dmach, sdd->cur_bpw / 8);
> > -			s3c2410_dma_enqueue(sdd->tx_dmach, (void *)sdd,
> > -						xfer->tx_dma, xfer->len);
> > -			s3c2410_dma_ctrl(sdd->tx_dmach,
> S3C2410_DMAOP_START);
> > +			info.cap = DMA_SLAVE;
> > +			info.direction = DMA_TO_DEVICE;
> > +			info.buf = xfer->tx_dma;
> > +			info.len = xfer->len;
> > +			info.fp = s3c64xx_spi_dma_txcb;
> > +			info.fp_param = sdd;
> > +			sdd->ops->prepare(sdd->tx_ch, &info);
> > +			sdd->ops->trigger(sdd->tx_ch);
> >  		} else {
> >  			switch (sdd->cur_bpw) {
> >  			case 32:
> > @@ -294,10 +334,14 @@ static void enable_datapath(struct
> s3c64xx_spi_driver_data *sdd,
> >  			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
> >  					| S3C64XX_SPI_PACKET_CNT_EN,
> >  					regs + S3C64XX_SPI_PACKET_CNT);
> > -			s3c2410_dma_config(sdd->rx_dmach, sdd->cur_bpw / 8);
> > -			s3c2410_dma_enqueue(sdd->rx_dmach, (void *)sdd,
> > -						xfer->rx_dma, xfer->len);
> > -			s3c2410_dma_ctrl(sdd->rx_dmach,
> S3C2410_DMAOP_START);
> > +			info.cap = DMA_SLAVE;
> > +			info.direction = DMA_FROM_DEVICE;
> > +			info.buf = xfer->rx_dma;
> > +			info.len = xfer->len;
> > +			info.fp = s3c64xx_spi_dma_rxcb;
> > +			info.fp_param = sdd;
> > +			sdd->ops->prepare(sdd->rx_ch, &info);
> > +			sdd->ops->trigger(sdd->rx_ch);
> >  		}
> >  	}
> >
> > @@ -483,46 +527,6 @@ static void s3c64xx_spi_config(struct
> s3c64xx_spi_driver_data *sdd)
> >  	}
> >  }
> >
> > -static void s3c64xx_spi_dma_rxcb(struct s3c2410_dma_chan *chan,
> void *buf_id,
> > -				 int size, enum s3c2410_dma_buffresult res)
> > -{
> > -	struct s3c64xx_spi_driver_data *sdd = buf_id;
> > -	unsigned long flags;
> > -
> > -	spin_lock_irqsave(&sdd->lock, flags);
> > -
> > -	if (res == S3C2410_RES_OK)
> > -		sdd->state &= ~RXBUSY;
> > -	else
> > -		dev_err(&sdd->pdev->dev, "DmaAbrtRx-%d\n", size);
> > -
> > -	/* If the other done */
> > -	if (!(sdd->state & TXBUSY))
> > -		complete(&sdd->xfer_completion);
> > -
> > -	spin_unlock_irqrestore(&sdd->lock, flags);
> > -}
> > -
> > -static void s3c64xx_spi_dma_txcb(struct s3c2410_dma_chan *chan,
> void *buf_id,
> > -				 int size, enum s3c2410_dma_buffresult res)
> > -{
> > -	struct s3c64xx_spi_driver_data *sdd = buf_id;
> > -	unsigned long flags;
> > -
> > -	spin_lock_irqsave(&sdd->lock, flags);
> > -
> > -	if (res == S3C2410_RES_OK)
> > -		sdd->state &= ~TXBUSY;
> > -	else
> > -		dev_err(&sdd->pdev->dev, "DmaAbrtTx-%d \n", size);
> > -
> > -	/* If the other done */
> > -	if (!(sdd->state & RXBUSY))
> > -		complete(&sdd->xfer_completion);
> > -
> > -	spin_unlock_irqrestore(&sdd->lock, flags);
> > -}
> > -
> >  #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
> >
> >  static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd,
> > @@ -697,12 +701,10 @@ static void handle_msg(struct
> s3c64xx_spi_driver_data *sdd,
> >  			if (use_dma) {
> >  				if (xfer->tx_buf != NULL
> >  						&& (sdd->state & TXBUSY))
> > -					s3c2410_dma_ctrl(sdd->tx_dmach,
> > -							S3C2410_DMAOP_FLUSH);
> > +					sdd->ops->stop(sdd->tx_ch);
> >  				if (xfer->rx_buf != NULL
> >  						&& (sdd->state & RXBUSY))
> > -					s3c2410_dma_ctrl(sdd->rx_dmach,
> > -							S3C2410_DMAOP_FLUSH);
> > +					sdd->ops->stop(sdd->rx_ch);
> >  			}
> >
> >  			goto out;
> > @@ -742,24 +744,19 @@ out:
> >
> >  static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
> >  {
> > -	if (s3c2410_dma_request(sdd->rx_dmach,
> > -					&s3c64xx_spi_dma_client, NULL) < 0) {
> > -		dev_err(&sdd->pdev->dev, "cannot get RxDMA\n");
> > -		return 0;
> > -	}
> > -	s3c2410_dma_set_buffdone_fn(sdd->rx_dmach, s3c64xx_spi_dma_rxcb);
> > -	s3c2410_dma_devconfig(sdd->rx_dmach, S3C2410_DMASRC_HW,
> > -					sdd->sfr_start + S3C64XX_SPI_RX_DATA);
> > -
> > -	if (s3c2410_dma_request(sdd->tx_dmach,
> > -					&s3c64xx_spi_dma_client, NULL) < 0) {
> > -		dev_err(&sdd->pdev->dev, "cannot get TxDMA\n");
> > -		s3c2410_dma_free(sdd->rx_dmach, &s3c64xx_spi_dma_client);
> > -		return 0;
> > -	}
> > -	s3c2410_dma_set_buffdone_fn(sdd->tx_dmach, s3c64xx_spi_dma_txcb);
> > -	s3c2410_dma_devconfig(sdd->tx_dmach, S3C2410_DMASRC_MEM,
> > -					sdd->sfr_start + S3C64XX_SPI_TX_DATA);
> > +
> > +	struct samsung_dma_info info;
> > +	sdd->ops = samsung_dma_get_ops();
> > +
> > +	info.cap = DMA_SLAVE;
> > +	info.client = &s3c64xx_spi_dma_client;
> > +	info.direction = DMA_FROM_DEVICE;
> > +	info.fifo = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
> > +	info.width = sdd->cur_bpw / 8;
> > +	sdd->rx_ch = sdd->ops->request(sdd->rx_dmach, &info);
> > +	info.direction = DMA_TO_DEVICE;
> > +	info.fifo = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
> > +	sdd->tx_ch = sdd->ops->request(sdd->tx_dmach, &info);
> >
> >  	return 1;
> >  }
> > @@ -800,8 +797,8 @@ static void s3c64xx_spi_work(struct work_struct
> *work)
> >  	spin_unlock_irqrestore(&sdd->lock, flags);
> >
> >  	/* Free DMA channels */
> > -	s3c2410_dma_free(sdd->tx_dmach, &s3c64xx_spi_dma_client);
> > -	s3c2410_dma_free(sdd->rx_dmach, &s3c64xx_spi_dma_client);
> > +	sdd->ops->release(sdd->rx_ch, &s3c64xx_spi_dma_client);
> > +	sdd->ops->release(sdd->tx_ch, &s3c64xx_spi_dma_client);
> >  }
> >
> >  static int s3c64xx_spi_transfer(struct spi_device *spi,
>
> --
> ~Vinod Koul
> Intel Corp.





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