[U-Boot] [U-Boot, v1, 4/8] mpc8xxx: set x2 DDR3 refresh rate if SPD config requires it

York Sun
2013-08-13T20:24:22Z

On 07/26/2013 03:02 AM, Valentin Longchamp wrote:
> If the DDR3 module supports industrial temperature range and requires
> the x2 refresh rate for that temp range, the refresh period must be
> 3.9us instead of 7.8 us.
>
> Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
>
> ---
> arch/powerpc/cpu/mpc8xxx/ddr/ddr3_dimm_params.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/powerpc/cpu/mpc8xxx/ddr/ddr3_dimm_params.c b/arch/powerpc/cpu/mpc8xxx/ddr/ddr3_dimm_params.c
> index 3e7c269..603b68b 100644
> --- a/arch/powerpc/cpu/mpc8xxx/ddr/ddr3_dimm_params.c
> +++ b/arch/powerpc/cpu/mpc8xxx/ddr/ddr3_dimm_params.c
> @@ -320,6 +320,8 @@ ddr_compute_dimm_parameters(const ddr3_spd_eeprom_t *spd,
> * = 3.9 us at ext temperature range
> */
> pdimm->refresh_rate_ps = 7800000;
> + if ((spd->therm_ref_opt & 0x1) && !(spd->therm_ref_opt & 0x2))
> + pdimm->refresh_rate_ps = 3900000;
>
> /*
> * min four active window delay time
>

Has this been verified on a board?

This looks half-way done. If the module supports extended temperature
range, the MR2 should be adjusted to fit the module.

York