[U-Boot] [PATCH 4/4] spi: mxc_spi: Fix spi clock glitch durant reset
Stefano Babic
sbabic at denx.de
Fri Nov 16 14:17:26 CET 2012
On 15/11/2012 22:23, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam at freescale.com>
>
> Measuring the spi clock line on a scope shows a 'glitch' during the reset of the
> spi.
>
> Fix this by toggling only the MXC_CSPICTRL_EN bit, so that the clock line becomes
> always stable.
>
> Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
> ---
> drivers/spi/mxc_spi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
> index 4bed4f0..102fca5 100644
> --- a/drivers/spi/mxc_spi.c
> +++ b/drivers/spi/mxc_spi.c
> @@ -140,8 +140,8 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
> reg_ctrl = reg_read(®s->ctrl);
>
> /* Reset spi */
> - reg_write(®s->ctrl, 0);
> - reg_write(®s->ctrl, (reg_ctrl | 0x1));
> + reg_write(®s->ctrl, (reg_ctrl & ~MXC_CSPICTRL_EN));
> + reg_write(®s->ctrl, (reg_ctrl | MXC_CSPICTRL_EN));
>
Right - the enabled was set after clearing the register, but before
setting it.
Acked-by: Stefano Babic <sbabic at denx.de>
Best regards,
Stefano Babic
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