[U-Boot] [PATCH 1/2] S3C2440 : PLL Initialization should be SoC specific

Gabriel Huau contact at huau-gabriel.fr
Sun Apr 22 22:55:10 CEST 2012


On Sun, Apr 22, 2012 at 10:30:52PM +0200, Marek Vasut wrote:
> Dear Gabriel Huau,
> 
> > Signed-off-by: Gabriel Huau <contact at huau-gabriel.fr>
> > ---
> >  arch/arm/cpu/arm920t/s3c24x0/timer.c |   36
> > ++++++++++++++++++++++++++++++++++ board/mpl/vcma9/lowlevel_init.S      | 
> >  22 --------------------- board/samsung/smdk2410/smdk2410.c    |   19
> > ------------------
> >  3 files changed, 36 insertions(+), 41 deletions(-)
> > 
> > diff --git a/arch/arm/cpu/arm920t/s3c24x0/timer.c
> > b/arch/arm/cpu/arm920t/s3c24x0/timer.c index d8668be..7ff687c 100644
> > --- a/arch/arm/cpu/arm920t/s3c24x0/timer.c
> > +++ b/arch/arm/cpu/arm920t/s3c24x0/timer.c
> > @@ -37,8 +37,27 @@
> > 
> >  DECLARE_GLOBAL_DATA_PTR;
> > 
> > +#ifdef CONFIG_S3C2440
> > +/*
> > + * PLL/Clock configuration
> > + */
> > +/* FCLK = 405 MHz, HCLK = 101 MHz, PCLK = 50 MHz, UCLK = 48 MHz */
> > +#define CLKDIVN_VAL	7
> > +#define M_MDIV		0x7f
> > +#define M_PDIV		0x2
> > +#define M_SDIV		0x1
> > +
> > +#define U_M_MDIV	0x38
> > +#define U_M_PDIV	0x2
> > +#define U_M_SDIV	0x2
> > +#endif
> 
> So after applying your patch, timer driver won't build for 2410 ?
> 

Yes it will build, This patch is only for s3c2440. I just moved PLL
initialization of s3c2440 board to this file. I don't know if theses
values are correct for s3c2410 too.

> > +
> > +	/* configure MPLL */
> > +	clk_power->mpllcon = ((M_MDIV << 12) + (M_PDIV << 4) + M_SDIV);
> > +
> > +	/* some delay between MPLL and UPLL */
> > +	__udelay(8000);
> > +#endif
> > +
> >  	return 0;
> >  }
> > 
> > diff --git a/board/mpl/vcma9/lowlevel_init.S
> > b/board/mpl/vcma9/lowlevel_init.S index dadaac7..4deb451 100644
> > --- a/board/mpl/vcma9/lowlevel_init.S
> > +++ b/board/mpl/vcma9/lowlevel_init.S
> > @@ -262,28 +262,6 @@ lowlevel_init:
> >  	cmp     r3, r4
> >  	bne     0b
> > 
> > -	/* setup MPLL registers */
> > -	ldr	r1, =CLKBASE
> > -	ldr	r4, =0xFFFFFF
> > -	add	r3, r2, #4		/* r3 points to PLL values */
> > -	str	r4, [r1, #LOCKTIME]
> > -	ldmia	r3, {r4,r5}
> > -	str	r5, [r1, #UPLLCON]	/* writing PLL register */
> > -					/* !! order seems to be important !! */
> > -	/* a little delay */
> > -	ldr	r3, =0x4000
> > -0:
> > -	subs	r3, r3, #1
> > -	bne	0b
> > -
> > -	str	r4, [r1, #MPLLCON]	/* writing PLL register */
> > -					/* !! order seems to be important !! */
> > -	/* a little delay */
> > -	ldr	r3, =0x4000
> > -0:
> > -	subs	r3, r3, #1
> > -	bne	0b
> > -
> >  	/* everything is fine now */
> >  	mov	pc, lr
> > 
> > diff --git a/board/samsung/smdk2410/smdk2410.c
> > b/board/samsung/smdk2410/smdk2410.c index e9ba922..3beb587 100644
> > --- a/board/samsung/smdk2410/smdk2410.c
> > +++ b/board/samsung/smdk2410/smdk2410.c
> > @@ -69,27 +69,8 @@ static inline void pll_delay(unsigned long loops)
> > 
> >  int board_early_init_f(void)
> >  {
> > -	struct s3c24x0_clock_power * const clk_power =
> > -					s3c24x0_get_base_clock_power();
> >  	struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio();
> > 
> > -	/* to reduce PLL lock time, adjust the LOCKTIME register */
> > -	writel(0xFFFFFF, &clk_power->locktime);
> > -
> > -	/* configure MPLL */
> > -	writel((M_MDIV << 12) + (M_PDIV << 4) + M_SDIV,
> > -	       &clk_power->mpllcon);
> > -
> > -	/* some delay between MPLL and UPLL */
> > -	pll_delay(4000);
> > -
> > -	/* configure UPLL */
> > -	writel((U_M_MDIV << 12) + (U_M_PDIV << 4) + U_M_SDIV,
> > -	       &clk_power->upllcon);
> > -
> > -	/* some delay between MPLL and UPLL */
> > -	pll_delay(8000);
> > -
> >  	/* set up the I/O ports */
> >  	writel(0x007FFFFF, &gpio->gpacon);
> >  	writel(0x00044555, &gpio->gpbcon);
> 
> Magic?
> 

I don't maintain theses boards, I just removed PLL initialization
because I moved it. So for magic values in I/O port, we have to contact
the maintainers :).

> Best regards,
> Marek Vasut


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