[PATCH] net/libertas: make SPI interface big endian aware

[Andrey Yurovsky]

On Fri, May 22, 2009 at 7:14 AM, Sebastian Andrzej Siewior
<bigeasy at linutronix.de> wrote:
> The comment (which I remove) says that the translation is done SPI routines.
> IMHO this can't work because the SPI driver does not know whether the incomming
> bytes are part of the registers/bytes which need to be flipped or part of
> packet data which has to remain untouched.
> While adding le helpers I also removed spu_write_u32() which has no users.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
> ---
>  drivers/net/wireless/libertas/if_spi.c |   34 +++++++++++++++----------------
>  1 files changed, 16 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/wireless/libertas/if_spi.c b/drivers/net/wireless/libertas/if_spi.c
> index 07311e7..8cf5d65 100644
> --- a/drivers/net/wireless/libertas/if_spi.c
> +++ b/drivers/net/wireless/libertas/if_spi.c
> @@ -119,9 +119,6 @@ static struct chip_ident chip_id_to_device_name[] = {
>  * First we have to put a SPU register name on the bus. Then we can
>  * either read from or write to that register.
>  *
> - * For 16-bit transactions, byte order on the bus is big-endian.
> - * We don't have to worry about that here, though.
> - * The translation takes place in the SPI routines.
>  */
>
>  static void spu_transaction_init(struct if_spi_card *card)
> @@ -147,7 +144,7 @@ static void spu_transaction_finish(struct if_spi_card *card)
>  static int spu_write(struct if_spi_card *card, u16 reg, const u8 *buf, int len)
>  {
>        int err = 0;
> -       u16 reg_out = reg | IF_SPI_WRITE_OPERATION_MASK;
> +       u16 reg_out = cpu_to_le16(reg | IF_SPI_WRITE_OPERATION_MASK);
>
>        /* You must give an even number of bytes to the SPU, even if it
>         * doesn't care about the last one.  */
> @@ -169,16 +166,10 @@ out:
>
>  static inline int spu_write_u16(struct if_spi_card *card, u16 reg, u16 val)
>  {
> -       return spu_write(card, reg, (u8 *)&val, sizeof(u16));
> -}
> +       u16 buff;
>
> -static inline int spu_write_u32(struct if_spi_card *card, u16 reg, u32 val)
> -{
> -       /* The lower 16 bits are written first. */
> -       u16 out[2];
> -       out[0] = val & 0xffff;
> -       out[1] = (val & 0xffff0000) >> 16;
> -       return spu_write(card, reg, (u8 *)&out, sizeof(u32));
> +       buff = cpu_to_le16(val);
> +       return spu_write(card, reg, (u8 *)&buff, sizeof(u16));
>  }
>
>  static inline int spu_reg_is_port_reg(u16 reg)
> @@ -198,7 +189,7 @@ static int spu_read(struct if_spi_card *card, u16 reg, u8 *buf, int len)
>        unsigned int i, delay;
>        int err = 0;
>        u16 zero = 0;
> -       u16 reg_out = reg | IF_SPI_READ_OPERATION_MASK;
> +       u16 reg_out = cpu_to_le16(reg | IF_SPI_READ_OPERATION_MASK);
>
>        /* You must take an even number of bytes from the SPU, even if you
>         * don't care about the last one.  */
> @@ -236,18 +227,25 @@ out:
>  /* Read 16 bits from an SPI register */
>  static inline int spu_read_u16(struct if_spi_card *card, u16 reg, u16 *val)
>  {
> -       return spu_read(card, reg, (u8 *)val, sizeof(u16));
> +       u16 buf;
> +       int ret;
> +
> +       ret = spu_read(card, reg, (u8 *)&buf, sizeof(buf));
> +       if (ret == 0)
> +               *val = le16_to_cpup(&buf);
> +       return ret;
>  }
>
>  /* Read 32 bits from an SPI register.
>  * The low 16 bits are read first. */
>  static int spu_read_u32(struct if_spi_card *card, u16 reg, u32 *val)
>  {
> -       u16 buf[2];
> +       u32 buf;
>        int err;
> -       err = spu_read(card, reg, (u8 *)buf, sizeof(u32));
> +
> +       err = spu_read(card, reg, (u8 *)&buf, sizeof(buf));
>        if (!err)
> -               *val = buf[0] | (buf[1] << 16);
> +               *val = le32_to_cpup(&buf);
>        return err;
>  }
>
> --
> 1.6.2.4
>
>

Thanks Sebastian, that cleans things up and works on my Blackfin
system.  Please CC the linux-wireless mailing list
(linux-wireless at vger.kernel.org) and you can add:

Tested-by: Andrey Yurovsky <andrey at cozybit.com>

  -Andrey