[PATCH 6/7] spi/s3c64xx: Add support DMA engine API
Grant Likely
grant.likely at secretlab.ca
Mon Jul 4 12:42:51 EDT 2011
On Mon, Jul 04, 2011 at 09:18:34PM +0900, Kukjin Kim wrote:
> From: Boojin Kim <boojin.kim at samsung.com>
>
> 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 | 234 +++++++++++++++++++++++++++++++++++++--------
> 1 files changed, 194 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/spi/spi_s3c64xx.c b/drivers/spi/spi_s3c64xx.c
> index 795828b..848487b 100644
> --- a/drivers/spi/spi_s3c64xx.c
> +++ b/drivers/spi/spi_s3c64xx.c
> @@ -26,6 +26,10 @@
> #include <linux/dma-mapping.h>
> #include <linux/platform_device.h>
> #include <linux/spi/spi.h>
> +#if defined(CONFIG_DMADEV_PL330)
> +#include <linux/dmaengine.h>
> +#include <linux/amba/pl330.h>
> +#endif
Is the #if protection really needed here?
>
> #include <mach/dma.h>
> #include <plat/s3c64xx-spi.h>
> @@ -174,11 +178,19 @@ struct s3c64xx_spi_driver_data {
> unsigned state;
> unsigned cur_mode, cur_bpw;
> unsigned cur_speed;
> +#if defined(CONFIG_DMADEV_PL330)
> + struct dma_chan *rx_chan;
> + struct dma_chan *tx_chan;
> + struct dma_async_tx_descriptor *rx_desc;
> + struct dma_async_tx_descriptor *tx_desc;
> +#endif
> };
>
> +#if !defined(CONFIG_DMADEV_PL330)
> static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
> .name = "samsung-spi-dma",
> };
> +#endif
>
> static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
> {
> @@ -229,6 +241,80 @@ static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
> writel(val, regs + S3C64XX_SPI_CH_CFG);
> }
>
> +#if defined(CONFIG_DMADEV_PL330)
> +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);
> +}
> +#else
> +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);
> +}
> +#endif
> +
> static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
> struct spi_device *spi,
> struct spi_transfer *xfer, int dma_mode)
> @@ -236,6 +322,11 @@ 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;
> +#if defined(CONFIG_DMADEV_PL330)
> + struct dma_slave_config slave_config;
> + struct scatterlist tx_sg;
> + struct scatterlist rx_sg;
> +#endif
>
> modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
> modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
> @@ -261,10 +352,34 @@ 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;
> +#if defined(CONFIG_DMADEV_PL330)
> + memset(&slave_config, 0, sizeof(slave_config));
> + slave_config.direction = DMA_TO_DEVICE;
> + slave_config.src_addr = xfer->tx_dma;
> + slave_config.dst_addr =
> + sdd->sfr_start + S3C64XX_SPI_TX_DATA;
> + slave_config.dst_addr_width = sdd->cur_bpw / 8;
> + dmaengine_slave_config(sdd->tx_chan, &slave_config);
> +
> + sg_init_table(&tx_sg, 1);
> + sg_set_page(&tx_sg, pfn_to_page(PFN_DOWN(xfer->tx_dma)),
> + xfer->len, offset_in_page(xfer->tx_dma));
> + sg_dma_len(&tx_sg) = xfer->len;
> + sg_dma_address(&tx_sg) = xfer->tx_dma;
> + sdd->tx_desc =
> + sdd->tx_chan->device->device_prep_slave_sg(
> + sdd->tx_chan, &tx_sg, 1, DMA_TO_DEVICE,
> + DMA_PREP_INTERRUPT);
> + sdd->tx_desc->callback = s3c64xx_spi_dma_txcb;
> + sdd->tx_desc->callback_param = sdd;
> + dmaengine_submit(sdd->tx_desc);
> + dma_async_issue_pending(sdd->tx_chan);
> +#else
> 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);
> +#endif
Hmmm, this is not pretty. The driver behaviour is entirely different depending on if CONFIG_DMADEV_PL330 is enabled? When we get to multiplatform kernels, is this going to break on some hardware?
> } else {
> switch (sdd->cur_bpw) {
> case 32:
> @@ -296,10 +411,33 @@ 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);
> +#if defined(CONFIG_DMADEV_PL330)
> + slave_config.direction = DMA_FROM_DEVICE;
> + slave_config.dst_addr = xfer->rx_dma;
> + slave_config.src_addr =
> + sdd->sfr_start + S3C64XX_SPI_RX_DATA;
> + slave_config.src_addr_width = sdd->cur_bpw / 8;
> + dmaengine_slave_config(sdd->rx_chan, &slave_config);
> +
> + sg_init_table(&rx_sg, 1);
> + sg_set_page(&rx_sg, pfn_to_page(PFN_DOWN(xfer->rx_dma)),
> + xfer->len, offset_in_page(xfer->rx_dma));
> + sg_dma_len(&rx_sg) = xfer->len;
> + sg_dma_address(&rx_sg) = xfer->rx_dma;
> + sdd->rx_desc =
> + sdd->rx_chan->device->device_prep_slave_sg(
> + sdd->rx_chan, &rx_sg, 1, DMA_FROM_DEVICE,
> + DMA_PREP_INTERRUPT);
> + sdd->rx_desc->callback = s3c64xx_spi_dma_rxcb;
> + sdd->rx_desc->callback_param = sdd;
> + dmaengine_submit(sdd->rx_desc);
> + dma_async_issue_pending(sdd->rx_chan);
> +#else
> 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);
> +#endif
> }
> }
>
> @@ -485,46 +623,6 @@ 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,
> @@ -699,12 +797,20 @@ static void handle_msg(struct s3c64xx_spi_driver_data *sdd,
> if (use_dma) {
> if (xfer->tx_buf != NULL
> && (sdd->state & TXBUSY))
> +#if defined(CONFIG_DMADEV_PL330)
> + dmaengine_terminate_all(sdd->tx_chan);
> +#else
> s3c2410_dma_ctrl(sdd->tx_dmach,
> S3C2410_DMAOP_FLUSH);
> +#endif
> if (xfer->rx_buf != NULL
> && (sdd->state & RXBUSY))
> +#if defined(CONFIG_DMADEV_PL330)
> + dmaengine_terminate_all(sdd->rx_chan);
> +#else
> s3c2410_dma_ctrl(sdd->rx_dmach,
> S3C2410_DMAOP_FLUSH);
> +#endif
> }
>
> goto out;
> @@ -742,8 +848,50 @@ out:
> msg->complete(msg->context);
> }
>
> +#if defined(CONFIG_DMADEV_PL330)
> +static bool rxfilter(struct dma_chan *chan, void *param)
> +{
> + struct s3c64xx_spi_driver_data *sdd
> + = (struct s3c64xx_spi_driver_data *)param;
> + struct dma_pl330_peri *peri = (struct dma_pl330_peri *)chan->private;
> +
> + if (peri->peri_id != sdd->rx_dmach)
> + return false;
> +
> + return true;
> +}
> +static bool txfilter(struct dma_chan *chan, void *param)
> +{
> + struct s3c64xx_spi_driver_data *sdd
> + = (struct s3c64xx_spi_driver_data *)param;
> + struct dma_pl330_peri *peri = (struct dma_pl330_peri *)chan->private;
> +
> + if (peri->peri_id != sdd->tx_dmach)
> + return false;
> +
> + return true;
> +}
> +#endif
> +
> static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
> {
> +#if defined(CONFIG_DMADEV_PL330)
> + dma_cap_mask_t mask;
> + dma_cap_zero(mask);
> + dma_cap_set(DMA_SLAVE, mask);
> + sdd->rx_chan =
> + dma_request_channel(mask, rxfilter, (void *)sdd);
> + if (!sdd->rx_chan) {
> + dev_err(&sdd->pdev->dev, "cannot get RxDMA\n");
> + return 0;
> + }
> + sdd->tx_chan =
> + dma_request_channel(mask, txfilter, (void *)sdd);
> + if (!sdd->tx_chan) {
> + dev_err(&sdd->pdev->dev, "cannot get TxDMA\n");
> + return 0;
> + }
> +#else
> if (s3c2410_dma_request(sdd->rx_dmach,
> &s3c64xx_spi_dma_client, NULL) < 0) {
> dev_err(&sdd->pdev->dev, "cannot get RxDMA\n");
> @@ -762,6 +910,7 @@ static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
> 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);
> +#endif
>
> return 1;
> }
> @@ -802,8 +951,13 @@ static void s3c64xx_spi_work(struct work_struct *work)
> spin_unlock_irqrestore(&sdd->lock, flags);
>
> /* Free DMA channels */
> +#if defined(CONFIG_DMADEV_PL330)
> + dma_release_channel(sdd->tx_chan);
> + dma_release_channel(sdd->rx_chan);
> +#else
> s3c2410_dma_free(sdd->tx_dmach, &s3c64xx_spi_dma_client);
> s3c2410_dma_free(sdd->rx_dmach, &s3c64xx_spi_dma_client);
> +#endif
Wow. A lot of #ifdefs here. It does not look multiplatform friendly
at all. Are the s3c2410_dma functions obsolete when DMADEV_PL330 is
selected? If so, can they be removed entirely, or are they required
to support certain hardware?
g.
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