RE: [PATCH 08/12] pm: at91: rename file name: pm_slowclock.S -->pm_suspend.S

From: Yang, Wenyou
Date: Sun Jan 25 2015 - 20:26:48 EST


Hi Sylvain,

Thank you for your review.

> -----Original Message-----
> From: Sylvain Rochet [mailto:sylvain.rochet@xxxxxxxxxxxx]
> Sent: Saturday, January 24, 2015 3:17 AM
> To: Yang, Wenyou
> Cc: Ferre, Nicolas; linux@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> alexandre.belloni@xxxxxxxxxxxxxxxxxx; peda@xxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH 08/12] pm: at91: rename file name: pm_slowclock.S --
> >pm_suspend.S
>
> Hello Wenyou,
>
> On Tue, Jan 20, 2015 at 04:17:01PM +0800, Wenyou Yang wrote:
> >
> > diff --git a/arch/arm/mach-at91/pm_suspend.S
> > b/arch/arm/mach-at91/pm_suspend.S new file mode 100644 index
> > 0000000..420e730
> > --- /dev/null
>
>
> > + /* Turn off the main oscillator */
> > + ldr tmp1, [pmc, #AT91_CKGR_MOR]
> > + bic tmp1, tmp1, #AT91_PMC_MOSCEN
>
> at91sam9x5 and probably others need a key here:
> orr tmp1, tmp1, #AT91_PMC_KEY
>
Yes, I am preparing the patches to support other SoCs.

> > + str tmp1, [pmc, #AT91_CKGR_MOR]
>
>
>
> > + /* Wait for interrupt */
> > + mcr p15, 0, tmp1, c7, c0, 4
>
> The linux-3.10-at91 branch uses a different approach which seem necessary for
> newer board, you probably forget to merge the following:
>
> /*
> * Put the processor to enter into Standby mode, wait for interrupt to wakeup */
> .macro _do_wfi
>
> #if defined(CONFIG_CPU_V7)
> dsb
>
> /* Disable the processor clock */
> mov tmp1, #AT91_PMC_PCK
> str tmp1, [pmc, #AT91_PMC_SCDR]
>
> wfi @ Wait For Interrupt
> #else
> mcr p15, 0, tmp1, c7, c0, 4
> #endif
>
> .endm
>
> .text
>
I will send the new patch serials to support it in this week. Thanks.

> ENTRY(at91_slow_clock)
> (...)
> /* Wait for interrupt */
> _do_wfi
> (...)
>
>
>
>
> > + /* Turn on the main oscillator */
> > + ldr tmp1, [pmc, #AT91_CKGR_MOR]
> > + orr tmp1, tmp1, #AT91_PMC_MOSCEN
>
> at91sam9x5 and probably others need a key here:
> orr tmp1, tmp1, #AT91_PMC_KEY
>
> > + str tmp1, [pmc, #AT91_CKGR_MOR]
>
>
>
> What about the following parts which are also in linux-3.10-at91 branch but not in
> this rework, are they necessary ?
Yes, they are necessary, I will send the next patch serial in this week.

>
> sdr_sr_done:
> /* Disable MPDDRC Clock*/
> cmp ddrcid, #0
> beq 2f
> bic tmp2, ddrcid, #0xe0 /* fetch lowest 5 bits */
> mov tmp1, #0x01
> mov tmp1, tmp1, lsl tmp2
>
> tst ddrcid, #0x20 /* > 32 ? */
> beq 1f
> str tmp1, [pmc, #AT91_PMC_PCDR1]
> b 2f
> 1:
> str tmp1, [pmc, #AT91_PMC_PCDR]
> 2:
>
> /* Disable DDR Clock */
> mov tmp1, #AT91_PMC_SYS_DDR
> str tmp1, [pmc, #AT91_PMC_SCDR]
>
>
>
>
> /* Enable MPDDRC Clock*/
> cmp ddrcid, #0
> beq 4f
> bic tmp2, ddrcid, #0xe0 /* fetch lowest 5 bits */
> mov tmp1, #0x01
> mov tmp1, tmp1, lsl tmp2
>
> tst ddrcid, #0x20 /* > 32 ? */
> beq 3f
> str tmp1, [pmc, #AT91_PMC_PCER1]
> b 4f
> 3:
> str tmp1, [pmc, #AT91_PMC_PCER]
> 4:
>
> /* Enable DDR clock */
> mov tmp1, #AT91_PMC_SYS_DDR
> str tmp1, [pmc, #AT91_PMC_SCER]
>
>
>
> Sylvain

Best Regards,
Wenyou Yang