Roger Quadros <ext-roger.quadros@xxxxxxxxx> writes:
> As per errata 1.142, on EMU/HS devices, SDRC_POWER should be programmed
> for automatic self-refresh before transition to OFF mode.
> In the current implementation this is done in omap3_scratchpad_contents()
> which is wrong, since this is the value that will be restored while
> resuming from OFF mode and not while transitioning to it.
>
> This patch implements the workaround in the correct way as per errata.
>
> Signed-off-by: Roger Quadros <ext-roger.quadros@xxxxxxxxx>
This looks right to me.
Rajendra, Kalle, any comments? since you were the originators of
the original patch.
Kevin
> ---
> arch/arm/mach-omap2/control.c | 16 ++--------------
> arch/arm/mach-omap2/pm34xx.c | 20 ++++++++++++++------
> 2 files changed, 16 insertions(+), 20 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
> index a7159a9..0a563c8 100644
> --- a/arch/arm/mach-omap2/control.c
> +++ b/arch/arm/mach-omap2/control.c
> @@ -272,20 +272,8 @@ void omap3_save_scratchpad_contents(void)
> (sdrc_read_reg(SDRC_ERR_TYPE) & 0xFFFF);
> sdrc_block_contents.dll_a_ctrl = sdrc_read_reg(SDRC_DLLA_CTRL);
> sdrc_block_contents.dll_b_ctrl = 0x0;
> - /*
> - * Due to a OMAP3 errata (1.142), on EMU/HS devices SRDC should
> - * be programed to issue automatic self refresh on timeout
> - * of AUTO_CNT = 1 prior to any transition to OFF mode.
> - */
> - if ((omap_type() != OMAP2_DEVICE_TYPE_GP)
> - && (omap_rev() >= OMAP3430_REV_ES3_0))
> - sdrc_block_contents.power = (sdrc_read_reg(SDRC_POWER) &
> - ~(SDRC_POWER_AUTOCOUNT_MASK|
> - SDRC_POWER_CLKCTRL_MASK)) |
> - (1 << SDRC_POWER_AUTOCOUNT_SHIFT) |
> - SDRC_SELF_REFRESH_ON_AUTOCOUNT;
> - else
> - sdrc_block_contents.power = sdrc_read_reg(SDRC_POWER);
> +
> + sdrc_block_contents.power = sdrc_read_reg(SDRC_POWER);
>
> sdrc_block_contents.cs_0 = 0x0;
> sdrc_block_contents.mcfg_0 = sdrc_read_reg(SDRC_MCFG_0);
> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> index 14f10bc..eb3c9e5 100644
> --- a/arch/arm/mach-omap2/pm34xx.c
> +++ b/arch/arm/mach-omap2/pm34xx.c
> @@ -405,15 +405,23 @@ void omap_sram_idle(void)
> }
>
> /*
> - * On EMU/HS devices ROM code restores a SRDC value
> - * from scratchpad which has automatic self refresh on timeout
> - * of AUTO_CNT = 1 enabled. This takes care of errata 1.142.
> - * Hence store/restore the SDRC_POWER register here.
> - */
> + * Due to a OMAP3 errata (1.142), on EMU/HS devices SRDC should
> + * be programed to issue automatic self refresh on timeout
> + * of AUTO_CNT = 1 prior to any transition to OFF mode.
> + */
> +
> if (omap_rev() >= OMAP3430_REV_ES3_0 &&
> omap_type() != OMAP2_DEVICE_TYPE_GP &&
> - core_next_state == PWRDM_POWER_OFF)
> + core_next_state == PWRDM_POWER_OFF) {
> +
> sdrc_pwr = sdrc_read_reg(SDRC_POWER);
> + sdrc_write_reg((sdrc_pwr &
> + ~(SDRC_POWER_AUTOCOUNT_MASK|
> + SDRC_POWER_CLKCTRL_MASK)) |
> + (1 << SDRC_POWER_AUTOCOUNT_SHIFT) |
> + SDRC_SELF_REFRESH_ON_AUTOCOUNT,
> + SDRC_POWER);
> + }
>
> if (regset_save_on_suspend)
> pm_dbg_regset_save(1);
> --
> 1.6.0.4
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