[PATCHv3 2/6] ARM: OMAP3 PM: Move IO Daisychain function to omap3 prm file

[t-kristo@ti.com (Tero Kristo)]

On Thu, 2012-03-01 at 12:19 +0530, Rajendra Nayak wrote:
> On Wednesday 29 February 2012 07:56 PM, Tero Kristo wrote:
> > From: Vishwanath BS<vishwanath.bs@ti.com>
> >
> > Since IO Daisychain modifies only PRM registers, it makes sense to move
> > it to PRM File.
> >
> > Signed-off-by: Vishwanath BS<vishwanath.bs@ti.com>
> > Tested-by: Govindraj.R<govindraj.raja@ti.com>
> > Signed-off-by: Tero Kristo<t-kristo@ti.com>
> > ---
> >   arch/arm/mach-omap2/pm34xx.c       |   30 +-----------------------------
> >   arch/arm/mach-omap2/prm2xxx_3xxx.c |   32 ++++++++++++++++++++++++++++++++
> >   arch/arm/mach-omap2/prm2xxx_3xxx.h |   14 ++++++++++++++
> >   3 files changed, 47 insertions(+), 29 deletions(-)
> >
> > diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> > index b0821a8..e97ec3f 100644
> > --- a/arch/arm/mach-omap2/pm34xx.c
> > +++ b/arch/arm/mach-omap2/pm34xx.c
> > @@ -85,34 +85,6 @@ static inline void omap3_per_restore_context(void)
> >   	omap_gpio_restore_context();
> >   }
> >
> > -static void omap3_enable_io_chain(void)
> > -{
> > -	int timeout = 0;
> > -
> > -	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> > -				   PM_WKEN);
> > -	/* Do a readback to assure write has been done */
> > -	omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
> > -
> > -	while (!(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST)&
> > -		 OMAP3430_ST_IO_CHAIN_MASK)) {
> > -		timeout++;
> > -		if (timeout>  1000) {
> > -			pr_err("Wake up daisy chain activation failed.\n");
> > -			return;
> > -		}
> > -	}
> > -	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> > -			PM_WKEN);
> > -
> > -}
> > -
> > -static void omap3_disable_io_chain(void)
> > -{
> > -	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> > -				     PM_WKEN);
> > -}
> > -
> >   static void omap3_core_save_context(void)
> >   {
> >   	omap3_ctrl_save_padconf();
> > @@ -324,7 +296,7 @@ void omap_sram_idle(void)
> >   	     core_next_state<  PWRDM_POWER_ON)) {
> >   		omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD, PM_WKEN);
> >   		if (omap3_has_io_chain_ctrl())
> > -			omap3_enable_io_chain();
> > +			omap3_trigger_io_chain();
> >   	}
> >
> >   	pwrdm_pre_transition();
> > diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c
> > index 9ce7654..fc98781 100644
> > --- a/arch/arm/mach-omap2/prm2xxx_3xxx.c
> > +++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c
> > @@ -301,6 +301,38 @@ void omap3xxx_prm_restore_irqen(u32 *saved_mask)
> >   				OMAP3_PRM_IRQENABLE_MPU_OFFSET);
> >   }
> >
> > +/**
> > + * Maximum time(us) it takes to output the signal WUCLKOUT of the last pad of
> > + * the I/O ring after asserting WUCLKIN high
> > + */
> > +#define MAX_IOPAD_LATCH_TIME 1000
> 
> Since we are changing the implementation to use omap_test_timeout()
> in this patch, it makes sense to make this 100 so we have a max 100us
> delay, similar to what we did on OMAP4.

I didn't change this timeout as I wasn't quite sure what is a safe value
for it. Do you know if 100us is safe for omap3 also in all possible
scenarios?

> 
> > +
> > +/* OMAP3 Daisychain enable sequence */
> > +void omap3_trigger_io_chain(void)
> > +{
> > +	int i = 0;
> > +
> > +	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> > +				   PM_WKEN);
> > +	/* Do a readback to assure write has been done */
> > +	omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
> > +
> > +	omap_test_timeout(((omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST)&
> > +			    OMAP3430_ST_IO_CHAIN_MASK) == 1),
> > +			  MAX_IOPAD_LATCH_TIME, i);
> > +
> > +	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> > +				     PM_WKEN);
> 
> The comment from Djamil should hold good here too. We should wait for
> IO chain status to show 0 here.

Hmm okay, I'll address this also for next version.

-Tero


> 
> > +}
> > +
> 
> regards,
> Rajendra