Re: [PATCH 1/2] spi/bfin_spi: support for multiples of 8bits with hardware CS

[Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>]

On Tue, Jan 11, 2011 at 11:19:07AM -0500, Mike Frysinger wrote:
> From: Bob Liu <lliubbo-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> 
> We can do multiples of 8bit transfers when using the hardware CS and a
> little bit of magic, so make it work.
> 
> Signed-off-by: Bob Liu <lliubbo-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Signed-off-by: Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>

Applied, thanks

g.

> ---
>  drivers/spi/spi_bfin5xx.c |  103 +++++++++++++++++++++++++++++++--------------
>  1 files changed, 71 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
> index 3f22351..e8d68b7 100644
> --- a/drivers/spi/spi_bfin5xx.c
> +++ b/drivers/spi/spi_bfin5xx.c
> @@ -425,6 +425,7 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
>  	struct bfin_spi_slave_data *chip = drv_data->cur_chip;
>  	struct spi_message *msg = drv_data->cur_msg;
>  	int n_bytes = drv_data->n_bytes;
> +	int loop = 0;
>  
>  	/* wait until transfer finished. */
>  	while (!(read_STAT(drv_data) & BIT_STAT_RXS))
> @@ -435,10 +436,15 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
>  		/* last read */
>  		if (drv_data->rx) {
>  			dev_dbg(&drv_data->pdev->dev, "last read\n");
> -			if (n_bytes == 2)
> -				*(u16 *) (drv_data->rx) = read_RDBR(drv_data);
> -			else if (n_bytes == 1)
> -				*(u8 *) (drv_data->rx) = read_RDBR(drv_data);
> +			if (n_bytes % 2) {
> +				u16 *buf = (u16 *)drv_data->rx;
> +				for (loop = 0; loop < n_bytes / 2; loop++)
> +					*buf++ = read_RDBR(drv_data);
> +			} else {
> +				u8 *buf = (u8 *)drv_data->rx;
> +				for (loop = 0; loop < n_bytes; loop++)
> +					*buf++ = read_RDBR(drv_data);
> +			}
>  			drv_data->rx += n_bytes;
>  		}
>  
> @@ -458,29 +464,53 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
>  	if (drv_data->rx && drv_data->tx) {
>  		/* duplex */
>  		dev_dbg(&drv_data->pdev->dev, "duplex: write_TDBR\n");
> -		if (drv_data->n_bytes == 2) {
> -			*(u16 *) (drv_data->rx) = read_RDBR(drv_data);
> -			write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
> -		} else if (drv_data->n_bytes == 1) {
> -			*(u8 *) (drv_data->rx) = read_RDBR(drv_data);
> -			write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
> +		if (n_bytes % 2) {
> +			u16 *buf = (u16 *)drv_data->rx;
> +			u16 *buf2 = (u16 *)drv_data->tx;
> +			for (loop = 0; loop < n_bytes / 2; loop++) {
> +				*buf++ = read_RDBR(drv_data);
> +				write_TDBR(drv_data, *buf2++);
> +			}
> +		} else {
> +			u8 *buf = (u8 *)drv_data->rx;
> +			u8 *buf2 = (u8 *)drv_data->tx;
> +			for (loop = 0; loop < n_bytes; loop++) {
> +				*buf++ = read_RDBR(drv_data);
> +				write_TDBR(drv_data, *buf2++);
> +			}
>  		}
>  	} else if (drv_data->rx) {
>  		/* read */
>  		dev_dbg(&drv_data->pdev->dev, "read: write_TDBR\n");
> -		if (drv_data->n_bytes == 2)
> -			*(u16 *) (drv_data->rx) = read_RDBR(drv_data);
> -		else if (drv_data->n_bytes == 1)
> -			*(u8 *) (drv_data->rx) = read_RDBR(drv_data);
> -		write_TDBR(drv_data, chip->idle_tx_val);
> +		if (n_bytes % 2) {
> +			u16 *buf = (u16 *)drv_data->rx;
> +			for (loop = 0; loop < n_bytes / 2; loop++) {
> +				*buf++ = read_RDBR(drv_data);
> +				write_TDBR(drv_data, chip->idle_tx_val);
> +			}
> +		} else {
> +			u8 *buf = (u8 *)drv_data->rx;
> +			for (loop = 0; loop < n_bytes; loop++) {
> +				*buf++ = read_RDBR(drv_data);
> +				write_TDBR(drv_data, chip->idle_tx_val);
> +			}
> +		}
>  	} else if (drv_data->tx) {
>  		/* write */
>  		dev_dbg(&drv_data->pdev->dev, "write: write_TDBR\n");
> -		bfin_spi_dummy_read(drv_data);
> -		if (drv_data->n_bytes == 2)
> -			write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
> -		else if (drv_data->n_bytes == 1)
> -			write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
> +		if (n_bytes % 2) {
> +			u16 *buf = (u16 *)drv_data->tx;
> +			for (loop = 0; loop < n_bytes / 2; loop++) {
> +				read_RDBR(drv_data);
> +				write_TDBR(drv_data, *buf++);
> +			}
> +		} else {
> +			u8 *buf = (u8 *)drv_data->tx;
> +			for (loop = 0; loop < n_bytes; loop++) {
> +				read_RDBR(drv_data);
> +				write_TDBR(drv_data, *buf++);
> +			}
> +		}
>  	}
>  
>  	if (drv_data->tx)
> @@ -651,16 +681,16 @@ static void bfin_spi_pump_transfers(unsigned long data)
>  
>  	/* Bits per word setup */
>  	bits_per_word = transfer->bits_per_word ? : message->spi->bits_per_word;
> -	if (bits_per_word == 8) {
> -		drv_data->n_bytes = 1;
> -		drv_data->len = transfer->len;
> -		cr_width = 0;
> -		drv_data->ops = &bfin_bfin_spi_transfer_ops_u8;
> -	} else if (bits_per_word == 16) {
> -		drv_data->n_bytes = 2;
> +	if ((bits_per_word > 0) && (bits_per_word % 16 == 0)) {
> +		drv_data->n_bytes = bits_per_word/8;
>  		drv_data->len = (transfer->len) >> 1;
>  		cr_width = BIT_CTL_WORDSIZE;
>  		drv_data->ops = &bfin_bfin_spi_transfer_ops_u16;
> +	} else if ((bits_per_word > 0) && (bits_per_word % 8 == 0)) {
> +		drv_data->n_bytes = bits_per_word/8;
> +		drv_data->len = transfer->len;
> +		cr_width = 0;
> +		drv_data->ops = &bfin_bfin_spi_transfer_ops_u8;
>  	} else {
>  		dev_err(&drv_data->pdev->dev, "transfer: unsupported bits_per_word\n");
>  		message->status = -EINVAL;
> @@ -815,10 +845,19 @@ static void bfin_spi_pump_transfers(unsigned long data)
>  		if (drv_data->tx == NULL)
>  			write_TDBR(drv_data, chip->idle_tx_val);
>  		else {
> -			if (bits_per_word == 8)
> -				write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
> -			else
> -				write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
> +			int loop;
> +			if (bits_per_word % 16 == 0) {
> +				u16 *buf = (u16 *)drv_data->tx;
> +				for (loop = 0; loop < bits_per_word / 16;
> +						loop++) {
> +					write_TDBR(drv_data, *buf++);
> +				}
> +			} else if (bits_per_word % 8 == 0) {
> +				u8 *buf = (u8 *)drv_data->tx;
> +				for (loop = 0; loop < bits_per_word / 8; loop++)
> +					write_TDBR(drv_data, *buf++);
> +			}
> +
>  			drv_data->tx += drv_data->n_bytes;
>  		}
>  
> @@ -1031,7 +1070,7 @@ static int bfin_spi_setup(struct spi_device *spi)
>  		chip->ctl_reg &= bfin_ctl_reg;
>  	}
>  
> -	if (spi->bits_per_word != 8 && spi->bits_per_word != 16) {
> +	if (spi->bits_per_word % 8) {
>  		dev_err(&spi->dev, "%d bits_per_word is not supported\n",
>  				spi->bits_per_word);
>  		goto error;
> -- 
> 1.7.4.rc1
> 

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