Re: [PATCH 1/7] mmc_spi: allow setting of spi mode 3

[David Brownell <david-b@pacbell.net>]

On Wednesday 11 March 2009, Wolfgang Mües wrote:
> From: Wolfgang Muees <wolfgang.mues@auerswald.de>
> 
> o allow the platform data structures to specify spi mode 3
>   (if there is a pullup on the clock line or the spi hardware
>    is not able to serve spi mode 0).
> 
> Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de>

Acked-by: David Brownell <dbrownell@users.sourceforge.net>


> ---
> This is one of a line of patches to enhance the usability of
> the mmc spi host port driver from "don't work with most SD cards"
> to "work with nearly all SD cards" (including those ugly cards
> with non-byte-aligned responses). 



>   
> diff -uprN 2_6_29_rc7_backported/drivers/mmc/host/mmc_spi.c 2_6_29_rc7_patch1_spi_mode_3/drivers/mmc/host/mmc_spi.c
> --- 2_6_29_rc7_backported/drivers/mmc/host/mmc_spi.c	2009-03-04 02:05:22.000000000 +0100
> +++ 2_6_29_rc7_patch1_spi_mode_3/drivers/mmc/host/mmc_spi.c	2009-03-11 12:58:47.000000000 +0100
> @@ -1204,10 +1204,12 @@ static int mmc_spi_probe(struct spi_devi
>  
>  	/* MMC and SD specs only seem to care that sampling is on the
>  	 * rising edge ... meaning SPI modes 0 or 3.  So either SPI mode
> -	 * should be legit.  We'll use mode 0 since it seems to be a
> -	 * bit less troublesome on some hardware ... unclear why.
> +	 * should be legit.  We'll use mode 0 since the steady state is 0,
> +	 * which is appropriate for hotplugging, unless the platform data
> +	 * specify mode 3 (if hardware is not compatible to mode 0).
>  	 */
> -	spi->mode = SPI_MODE_0;
> +	if (spi->mode != SPI_MODE_3)
> +		spi->mode = SPI_MODE_0;
>  	spi->bits_per_word = 8;
>  
>  	status = spi_setup(spi);
> 
> ---
> regards
> 
> i. A. Wolfgang Mües
> -- 
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