On 8/30/10, Steve Chen <schen at mvista.com> wrote:
> On Sat, Aug 28, 2010 at 8:26 AM, Sumesh Kaana <sumeshkkn at hotmail.com> wrote:
> > I am trying to mount SD-Card over SPI on our custom DM6467 board. davinci
> > spi controller driver and mmc over spi drver are selected in the menuconfig.
> > i am using davinci-PSP.03-XX-00-37 kernel.
> >
> > I have also edited board initialization file to probe the MMC card under SPI
> > as below:
> >
> >
> >
> > static struct spi_board_info dm646x_spi_info[] __initconst = {
> >
> > #ifdef CONFIG_MMC_SPI
> >
> > {
> >
> > .modalias = "mmc_spi",
> >
> > .max_speed_hz = (750 * 1000 ), /* max spi clock (SCK)
> > speed in HZ */
> >
> > .bus_num = 0,
> >
> > .chip_select = 0, /* CS0 */
> >
> > .mode = SPI_MODE_0,
> >
> > },
> >
> > #endif
> >
> >
> >
> > The kernel boots with following log
> >
> ...
> > mmc0: Minimum clock frequency too high for identification mode
> ...
>
> Have you tried lower the clock frequency?
The initial card identification should be done at 400kHz. If that is
successful, the following commands can be sent at your maximum rate.
M