On Fri, Sep 03, 2010 at 10:36:54AM +0900, Jassi Brar wrote:
> We can't do without setting channel and bus width to
> same size.
> Inorder to do that, define a new callback to be used
> to do read/write of appropriate widths.
>
> Signed-off-by: Jassi Brar <[email protected]>
> ---
> drivers/spi/spi_s3c64xx.c | 78 +++++++++++++++++++++++++++++++++++++-------
> 1 files changed, 65 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/spi/spi_s3c64xx.c b/drivers/spi/spi_s3c64xx.c
> index 39816bb..8aa9f85 100644
> --- a/drivers/spi/spi_s3c64xx.c
> +++ b/drivers/spi/spi_s3c64xx.c
> @@ -174,12 +174,59 @@ struct s3c64xx_spi_driver_data {
> unsigned state;
> unsigned cur_mode, cur_bpw;
> unsigned cur_speed;
> + void (*do_xfer)(void *ptr, void *fifo, unsigned sz, bool rd);
Looking at the code; it appears that it would be better to have
separate read and write transfer hooks.
> };
>
> static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
> .name = "samsung-spi-dma",
> };
>
> +static void s3c64xx_spi_xfer8(void *ptr, void __iomem *fifo,
> + unsigned len, bool read)
> +{
> + u8 *buf = (u8 *)ptr;
ptr is already a void* which makes this an unnecessary cast.
> + int i = 0;
> +
> + if (read)
> + while (i < len)
> + buf[i++] = readb(fifo);
perhaps ioread8_rep() instead of open-coding? If so, then
ioread*_rep() and iowrite*_rep() can be used in all these cases.
In fact, the 8, 16 and 32 versions have the same signature and so
could possibly be used directly without these hooks.
g.
> + else
> + while (i < len)
> + writeb(buf[i++], fifo);
> +}
> +
> +static void s3c64xx_spi_xfer16(void *ptr, void __iomem *fifo,
> + unsigned len, bool read)
> +{
> + u16 *buf = (u16 *)ptr;
> + int i = 0;
> +
> + len /= 2;
> +
> + if (read)
> + while (i < len)
> + buf[i++] = readw(fifo);
> + else
> + while (i < len)
> + writew(buf[i++], fifo);
> +}
> +
> +static void s3c64xx_spi_xfer32(void *ptr, void __iomem *fifo,
> + unsigned len, bool read)
> +{
> + u32 *buf = (u32 *)ptr;
> + int i = 0;
> +
> + len /= 4;
> +
> + if (read)
> + while (i < len)
> + buf[i++] = readl(fifo);
> + else
> + while (i < len)
> + writel(buf[i++], fifo);
> +}
> +
> static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
> {
> struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
> @@ -260,10 +307,8 @@ static void enable_datapath(struct
> s3c64xx_spi_driver_data *sdd,
> xfer->tx_dma, xfer->len);
> s3c2410_dma_ctrl(sdd->tx_dmach, S3C2410_DMAOP_START);
> } else {
> - unsigned char *buf = (unsigned char *) xfer->tx_buf;
> - int i = 0;
> - while (i < xfer->len)
> - writeb(buf[i++], regs + S3C64XX_SPI_TX_DATA);
> + sdd->do_xfer((void *)xfer->tx_buf,
> + regs + S3C64XX_SPI_TX_DATA, xfer->len, false);
> }
> }
>
> @@ -360,20 +405,14 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data
> *sdd,
> return -EIO;
> }
> } else {
> - unsigned char *buf;
> - int i;
> -
> /* If it was only Tx */
> if (xfer->rx_buf == NULL) {
> sdd->state &= ~TXBUSY;
> return 0;
> }
>
> - i = 0;
> - buf = xfer->rx_buf;
> - while (i < xfer->len)
> - buf[i++] = readb(regs + S3C64XX_SPI_RX_DATA);
> -
> + sdd->do_xfer(xfer->rx_buf,
> + regs + S3C64XX_SPI_RX_DATA, xfer->len, true);
> sdd->state &= ~RXBUSY;
> }
>
> @@ -423,15 +462,20 @@ static void s3c64xx_spi_config(struct
> s3c64xx_spi_driver_data *sdd)
> switch (sdd->cur_bpw) {
> case 32:
> val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
> + val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
> + sdd->do_xfer = s3c64xx_spi_xfer32;
> break;
> case 16:
> val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
> + val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
> + sdd->do_xfer = s3c64xx_spi_xfer16;
> break;
> default:
> val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
> + val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
> + sdd->do_xfer = s3c64xx_spi_xfer8;
> break;
> }
> - val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE; /* Always 8bits wide */
>
> writel(val, regs + S3C64XX_SPI_MODE_CFG);
>
> @@ -610,6 +654,14 @@ static void handle_msg(struct s3c64xx_spi_driver_data
> *sdd,
> bpw = xfer->bits_per_word ? : spi->bits_per_word;
> speed = xfer->speed_hz ? : spi->max_speed_hz;
>
> + if (bpw != 8 && xfer->len % (bpw / 8)) {
> + dev_err(&spi->dev,
> + "Xfer length(%u) not a multiple of word
> size(%u)\n",
> + xfer->len, bpw / 8);
> + status = -EIO;
> + goto out;
> + }
> +
> if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
> sdd->cur_bpw = bpw;
> sdd->cur_speed = speed;
> --
> 1.6.2.5
>
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