On Wed, Jan 20, 2010 at 7:51 PM, Feng Tang <[email protected]> wrote:
> From aa51023622a3393dc8f412b11e9db2f5fc0334ad Mon Sep 17 00:00:00 2001
> From: Feng Tang <[email protected]>
> Date: Thu, 21 Jan 2010 10:41:10 +0800
> Subject: [PATCH] spi/dw_spi: add a FIFO depth detection
>
> FIFO depth is configurable for each implementation of DW core,
> so add a depth detection for those interface drivers who don't set
> the fifo_len explicitly
>
> Signed-off-by: Feng Tang <[email protected]>
merged
> ---
> drivers/spi/dw_spi.c | 16 ++++++++++++++++
> 1 files changed, 16 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
> index 4e2774c..0e76a6e 100644
> --- a/drivers/spi/dw_spi.c
> +++ b/drivers/spi/dw_spi.c
> @@ -990,6 +990,22 @@ static void spi_hw_init(struct dw_spi *dws)
> spi_mask_intr(dws, 0xff);
> spi_enable_chip(dws, 1);
> flush(dws);
> +
> + /*
> + * Try to detect the FIFO depth if not set by interface driver,
> + * the depth could be from 2 to 256 from HW spec
> + */
> + if (!dws->fifo_len) {
> + u32 fifo;
> + for (fifo = 2; fifo <= 257; fifo++) {
> + dw_writew(dws, txfltr, fifo);
> + if (fifo != dw_readw(dws, txfltr))
> + break;
> + }
> +
> + dws->fifo_len = (fifo == 257) ? 0 : fifo;
> + dw_writew(dws, txfltr, 0);
> + }
> }
>
> int __devinit dw_spi_add_host(struct dw_spi *dws)
> --
> 1.6.0.4
>
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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