Re: [PATCH] libertas/sdio: set ECSI and SCSI bits for 1-bit transfers

[Alagu Sankar Vellaichamy <alagusankar@gmail.com>]

SCSI is read-only.  We ideally should be checking this bit and then
set the ECSI accordingly, rather than setting both ECSI and SCSI.

- Alagu Sankar

On Tue, Mar 30, 2010 at 11:08 PM, Daniel Mack <daniel@caiaq.de> wrote:
> When operating in 1-bit mode, SDAT1 is used as dedicated interrupt line.
> However, the 8686 will only drive this line when the ECSI and SCSI bits
> are set in the CCCR_IF register.
>
> Thanks to Alagu Sankar for pointing me in the right direction.
>
> Signed-off-by: Daniel Mack <daniel@caiaq.de>
> Cc: Alagu Sankar <alagusankar@embwise.com>
> Cc: Volker Ernst <volker.ernst@txtr.com>
> Cc: Dan Williams <dcbw@redhat.com>
> Cc: John W. Linville <linville@tuxdriver.com>
> Cc: Holger Schurig <hs4233@mail.mn-solutions.de>
> Cc: Bing Zhao <bzhao@marvell.com>
> Cc: libertas-dev@lists.infradead.org
> Cc: linux-wireless@vger.kernel.org
> Cc: linux-mmc@vger.kernel.org
> ---
>  drivers/net/wireless/libertas/if_sdio.c |   24 ++++++++++++++++++++++++
>  include/linux/mmc/sdio.h                |    2 ++
>  2 files changed, 26 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c
> index 7a73f62..d3170f2 100644
> --- a/drivers/net/wireless/libertas/if_sdio.c
> +++ b/drivers/net/wireless/libertas/if_sdio.c
> @@ -34,6 +34,8 @@
>  #include <linux/mmc/card.h>
>  #include <linux/mmc/sdio_func.h>
>  #include <linux/mmc/sdio_ids.h>
> +#include <linux/mmc/sdio.h>
> +#include <linux/mmc/host.h>
>
>  #include "host.h"
>  #include "decl.h"
> @@ -942,6 +944,7 @@ static int if_sdio_probe(struct sdio_func *func,
>        int ret, i;
>        unsigned int model;
>        struct if_sdio_packet *packet;
> +       struct mmc_host *host = func->card->host;
>
>        lbs_deb_enter(LBS_DEB_SDIO);
>
> @@ -1022,6 +1025,27 @@ static int if_sdio_probe(struct sdio_func *func,
>        if (ret)
>                goto disable;
>
> +       /* For 1-bit transfers, we need to enable the interrupt flags in
> +        * the CCCR register. Temporarily set the function number to 0
> +        * for that. */
> +       if ((host->caps & MMC_CAP_SDIO_IRQ) &&
> +           (host->ios.bus_width == MMC_BUS_WIDTH_1)) {
> +               unsigned int num = func->num;
> +               u8 reg;
> +
> +               func->num = 0;
> +               reg = sdio_readb(func, SDIO_CCCR_IF, &ret);
> +               if (ret)
> +                       goto release_int;
> +
> +               reg |= SDIO_BUS_ECSI | SDIO_BUS_SCSI;
> +               sdio_writeb(func, reg, SDIO_CCCR_IF, &ret);
> +               if (ret)
> +                       goto release_int;
> +
> +               func->num = num;
> +       }
> +
>        card->ioport = sdio_readb(func, IF_SDIO_IOPORT, &ret);
>        if (ret)
>                goto release_int;
> diff --git a/include/linux/mmc/sdio.h b/include/linux/mmc/sdio.h
> index 0ebaef5..329a8fa 100644
> --- a/include/linux/mmc/sdio.h
> +++ b/include/linux/mmc/sdio.h
> @@ -94,6 +94,8 @@
>
>  #define  SDIO_BUS_WIDTH_1BIT   0x00
>  #define  SDIO_BUS_WIDTH_4BIT   0x02
> +#define  SDIO_BUS_ECSI         0x20    /* Enable continuous SPI interrupt */
> +#define  SDIO_BUS_SCSI         0x40    /* Support continuous SPI interrupt */
>
>  #define  SDIO_BUS_ASYNC_INT    0x20
>
> --
> 1.7.0
>
>