Re: [PATCH 3/6] OMAP3: Add runtime check for OMAP35x

[Kevin Hilman <khilman@deeprootsystems.com>]

"Premi, Sanjeev" <premi@ti.com> writes:

>> -----Original Message-----
>> From: Tony Lindgren [mailto:tony@atomide.com] 
>> Sent: Thursday, August 06, 2009 5:20 PM
>> To: Premi, Sanjeev
>> Cc: linux-omap@vger.kernel.org
>> Subject: Re: [PATCH 3/6] OMAP3: Add runtime check for OMAP35x
>> 
>> * Premi, Sanjeev <premi@ti.com> [090806 14:34]:
>> >  
>> > > -----Original Message-----
>> > > From: Tony Lindgren [mailto:tony@atomide.com] 
>> > > Sent: Thursday, August 06, 2009 4:34 PM
>> > > To: Premi, Sanjeev
>> > > Cc: linux-omap@vger.kernel.org
>> > > Subject: Re: [PATCH 3/6] OMAP3: Add runtime check for OMAP35x
>> > > 
>> > > Hi,
>> > > 
>> > > * Sanjeev Premi <premi@ti.com> [090806 13:36]:
>> > > > Added runtime check via omap2_set_globals_35xx().
>> > > > 
>> > > > Parts of this patch have been derived from an earlier
>> > > > earlier patch submitted by Tony Lindgren <tony@atomide.com>
>> > > > 
>> > > >  [1] http://marc.info/?l=linux-omap&m=123301852702797&w=2
>> > > >  [2] http://marc.info/?l=linux-omap&m=123334055822212&w=2
>> > > > 
>> > > > Signed-off-by: Sanjeev Premi <premi@ti.com>
>> > > > ---
>> > > >  arch/arm/mach-omap2/id.c                 |  115 
>> > > ++++++++++++++++++++++++------
>> > > >  arch/arm/plat-omap/common.c              |   18 +++++-
>> > > >  arch/arm/plat-omap/include/mach/common.h |    1 +
>> > > >  arch/arm/plat-omap/include/mach/cpu.h    |   64 
>> ++++++++++++++++-
>> > > >  4 files changed, 173 insertions(+), 25 deletions(-)
>> > > > 
>> > > > diff --git a/arch/arm/mach-omap2/id.c b/arch/arm/mach-omap2/id.c
>> > > > index a98201c..06770aa 100644
>> > > > --- a/arch/arm/mach-omap2/id.c
>> > > > +++ b/arch/arm/mach-omap2/id.c
>> > > > @@ -28,6 +28,14 @@
>> > > >  static struct omap_chip_id omap_chip;
>> > > >  static unsigned int omap_revision;
>> > > >  
>> > > > +/* The new OMAP35x devices have assymetric names - 
>> > > OMAP3505 and OMAP3517.
>> > > > + * It is not possible to define a common macro to 
>> identify them.
>> > > > + *
>> > > > + * A quick way is to separate them across 
>> 'generations' as below.
>> > > > + */
>> > > > +#define OMAP35XX_G1	0x1	/* Applies to 3503, 
>> > > 3515, 3525 and 3530 */
>> > > > +#define OMAP35XX_G2	0x2	/* Applies to 3505 and 3517 */
>> > > > +
>> > > >  
>> > > >  unsigned int omap_rev(void)
>> > > >  {
>> > > > @@ -155,12 +163,71 @@ void __init omap24xx_check_revision(void)
>> > > >  	pr_info("\n");
>> > > >  }
>> > > >  
>> > > > +static void __init omap34xx_set_revision(u8 rev, char 
>> *rev_name)
>> > > > +{
>> > > > +	switch (rev) {
>> > > > +	case 0:
>> > > > +		omap_revision = OMAP3430_REV_ES2_0;
>> > > > +		strcat(rev_name, "ES2.0");
>> > > > +		break;
>> > > > +	case 2:
>> > > > +		omap_revision = OMAP3430_REV_ES2_1;
>> > > > +		strcat(rev_name, "ES2.1");
>> > > > +		break;
>> > > > +	case 3:
>> > > > +		omap_revision = OMAP3430_REV_ES3_0;
>> > > > +		strcat(rev_name, "ES3.0");
>> > > > +		break;
>> > > > +	case 4:
>> > > > +		omap_revision = OMAP3430_REV_ES3_1;
>> > > > +		strcat(rev_name, "ES3.1");
>> > > > +		break;
>> > > > +	default:
>> > > > +		/* Use the latest known revision as default */
>> > > > +		omap_revision = OMAP3430_REV_ES3_1;
>> > > > +		strcat(rev_name, "Unknown revision");
>> > > > +	}
>> > > > +}
>> > > > +
>> > > > +static void __init omap35xx_set_revision(u8 rev, u8 gen, 
>> > > char *rev_name)
>> > > > +{
>> > > > +	omap_revision = OMAP35XX_CLASS ;
>> > > > +
>> > > > +	if (gen == OMAP35XX_G1) {
>> > > > +		switch (rev) {
>> > > > +		case 0:	/* Take care of some older boards */
>> > > > +		case 1:
>> > > > +			omap_revision |= OMAP35XX_MASK_ES2_0;
>> > > > +			strcat(rev_name, "ES2.0");
>> > > > +			break;
>> > > > +		case 2:
>> > > > +			omap_revision |= OMAP35XX_MASK_ES2_1;
>> > > > +			strcat(rev_name, "ES2.1");
>> > > > +			break;
>> > > > +		case 3:
>> > > > +			omap_revision |= OMAP35XX_MASK_ES3_0;
>> > > > +			strcat(rev_name, "ES3.0");
>> > > > +			break;
>> > > > +		case 4:
>> > > > +			omap_revision |= OMAP35XX_MASK_ES3_1;
>> > > > +			strcat(rev_name, "ES3.1");
>> > > > +			break;
>> > > > +		default:
>> > > > +			/* Use the latest known 
>> revision as default */
>> > > > +			omap_revision |= OMAP35XX_MASK_ES3_0;
>> > > > +			strcat(rev_name, "Unknown revision");
>> > > > +		}
>> > > > +	} else {
>> > > > +		strcat(rev_name, "ES1.0");
>> > > > +	}
>> > > > +}
>> > > > +
>> > > 
>> > > To me it looks like you're checking the exact same cores as 
>> > > we already do
>> > > for 34xx. That is, (idcode >> 28) & 0xff for both 34xx and 
>> > > 35xx. So basically
>> > > they have the same omap cores.
>> > 
>> > No, the cores in OMAP3505 and OMAP3517 are very different.
>> > I have listed major differences in PATCH 2/6.
>> > 
>> > These devices differ in following areas:
>> >  - Power management capabilities
>> >    (Only 1 power domain, 1 OPP, etc.)
>> >  - EMIF4 instead of SDRC
>> >  - Support for DDR2
>> >  - EMAC
>> >  - USB
>> >  - HECC
>> 
>> Sure, but from compiler flags and io point of view they can still
>> be treated as 34xx.
>> 
>> How about just add the individual type detection for 35xx processors,
>> and then have something like this:
>> 
>> #define cpu_is_omap35xx()	(cpu_is_omap34xx() && 
>> (cpu_is_omap3510() || \
>> 					cpu_is_omap3520() || 
>> cpu_is_omap3530())
>> 
>> That should pretty much shrink this patch series down to 
>> about 50 lines or
>> so of code.
>
> Okay, I will try this. Just not sure if some of the differences
> in OMAP3530 and OMAP3430 can be detected.
>
> Will submit a patch soon.


IMO, we should not be using cpu_is_* for detecting the differences
between 34xx and 35xx, but rather we could query the features like
you're doing in PATCH 4/6.

Adding conditionals like

  if (omap3_has_iva2())
     ...

and

  if (omap3_has_sgx()) 
     ...

rather than having a long list of cpu_is checks that have to be changed
each time a new SoC comes out.

Kevin