* Tero Kristo <t-kristo@xxxxxx> [140412 02:01]:
> On 04/11/2014 02:47 AM, Tony Lindgren wrote:>
> > @@ -282,6 +283,7 @@ void omap_sram_idle(void)
> >
> > /* CORE */
> > if (core_next_state < PWRDM_POWER_ON) {
> > + omap3_vc_set_pmic_signaling(core_next_state);
> > if (core_next_state == PWRDM_POWER_OFF) {
> > omap3_core_save_context();
> > omap3_cm_save_context();
>
> I think this implementation is sub-optimal, as it only scales
> voltages if core is entering idle state. MPU only idle is possible,
> however you do not scale voltages in this case.
Hmm that's same as PWRDM_POWER_RET? That's working too.
Or do you have something else in mind that I'm not aware
of?
> > @@ -220,6 +220,78 @@ static inline u32 omap_usec_to_32k(u32 usec)
> > return DIV_ROUND_UP_ULL(32768ULL * (u64)usec, 1000000ULL);
> > }
> >
> > +void omap3_vc_set_pmic_signaling(int core_next_state)
> > +{
> > + u32 voltctrl;
> > +
> > + voltctrl = omap2_prm_read_mod_reg(OMAP3430_GR_MOD,
> > + OMAP3_PRM_VOLTCTRL_OFFSET);
>
> Just a note here, I am currently working on trying to get rid of all
> the direct prm_read/write calls outside PRCM drivers, this and rest
> should use voltdm->read/write.
OK, sounds like you already have a patch for that in your
3.14-rc4-cm-prm-driver-wip branch?
Let's do the fixes first, then it's going to be a lot easier for
us to test the rest of the PRMC changes.
> > + /*
> > + * By default let's use I2C4 signaling for retention idle
> > + * and sys_off_mode pin signaling for off idle. This way we
> > + * have sys_clk_req pin go down for retention and both
> > + * sys_clk_req and sys_off_mode pins will go down for off
> > + * idle. And we can also scale voltages to zero for off-idle.
> > + * Note that no actual voltage scaling will happen unless the
> > + * board specific twl4030 PMIC scripts are loaded.
> > + */
> > + val = omap2_prm_read_mod_reg(OMAP3430_GR_MOD,
> > + OMAP3_PRM_VOLTCTRL_OFFSET);
>
> Why not use the I2C4 signalling for off-mode? This way the voltages
> can be scaled to 0.6V even without any board specific scripts.
Using I2C4 works too, we're just missing a place to set
and clear OMAP3430_PRM_VOLTCTRL_SEL_OFF bit currently. Sounds
like eventually we should allow changing it dynamically somewhere.
But for now, SEL_OFF should be enabled as it allows debugging PM
by looking at the sys_clkreq and sys_off_mode pins no matter if
there are board specific scripts or not. The sys_off_mode won't
toggle if things are configured to use I2C4, which is confusing.
Regards,
Tony
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