Re: [PATCH 2/3] at91: Support for at91sam9g45: clocks management

[Ben Dooks <ben-linux@fluff.org>]

On Thu, Jun 04, 2009 at 10:48:01AM +0200, Nicolas Ferre wrote:
> Add the at91sam9g45 series support to the AT91 generic clock file.
> This takes care of the particularities of the PMC for this series.
> It also takes advantage of the management by functionalities of
> those PLLs and clocks.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

personally, please don't post between open and subscriber only lists,
this should really only be sent to linux-arm-kernel.

> ---
>  arch/arm/mach-at91/clock.c |   62 ++++++++++++++++++++++++++++++++++++-------
>  1 files changed, 52 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/arm/mach-at91/clock.c b/arch/arm/mach-at91/clock.c
> index bac578f..6396680 100644
> --- a/arch/arm/mach-at91/clock.c
> +++ b/arch/arm/mach-at91/clock.c
> @@ -47,20 +47,25 @@
>   * Chips have some kind of clocks : group them by functionality
>   */
>  #define cpu_has_utmi()		(  cpu_is_at91cap9() \

how does this pass checkpatch? no spaces after (.

> -				|| cpu_is_at91sam9rl())
> +				|| cpu_is_at91sam9rl() \
> +				|| cpu_is_at91sam9g45())
>  
> -#define cpu_has_800M_plla()	(cpu_is_at91sam9g20())
> +#define cpu_has_800M_plla()	(  cpu_is_at91sam9g20() \
> +				|| cpu_is_at91sam9g45())
>  
> -#define cpu_has_pllb()		(!cpu_is_at91sam9rl())
> +#define cpu_has_300M_plla()	(0)
>  
> -#define cpu_has_upll()		(0)
> +#define cpu_has_pllb()		(!(cpu_is_at91sam9rl() \
> +				|| cpu_is_at91sam9g45()))
> +
> +#define cpu_has_upll()		(cpu_is_at91sam9g45())
>  
>  /* USB host HS & FS */
>  #define cpu_has_uhp()		(!cpu_is_at91sam9rl())
>  
>  /* USB device FS only */
> -#define cpu_has_udpfs()		(!cpu_is_at91sam9rl())
> -
> +#define cpu_has_udpfs()		(!(cpu_is_at91sam9rl() \
> +				|| cpu_is_at91sam9g45()))
>  
>  static LIST_HEAD(clocks);
>  static DEFINE_SPINLOCK(clk_lock);
> @@ -133,6 +138,13 @@ static void pmc_uckr_mode(struct clk *clk, int is_on)
>  {
>  	unsigned int uckr = at91_sys_read(AT91_CKGR_UCKR);
>  
> +	if (cpu_is_at91sam9g45()) {
> +		if (is_on)
> +			uckr |= AT91_PMC_BIASEN;
> +		else
> +			uckr &= ~AT91_PMC_BIASEN;
> +	}
> +
>  	if (is_on) {
>  		is_on = AT91_PMC_LOCKU;
>  		at91_sys_write(AT91_CKGR_UCKR, uckr | clk->pmc_mask);
> @@ -310,6 +322,7 @@ long clk_round_rate(struct clk *clk, unsigned long rate)
>  	unsigned long	flags;
>  	unsigned	prescale;
>  	unsigned long	actual;
> +	unsigned long	prev = ULONG_MAX;
>  
>  	if (!clk_is_programmable(clk))
>  		return -EINVAL;
> @@ -317,8 +330,16 @@ long clk_round_rate(struct clk *clk, unsigned long rate)
>  
>  	actual = clk->parent->rate_hz;
>  	for (prescale = 0; prescale < 7; prescale++) {
> -		if (actual && actual <= rate)
> +		if (actual > rate)
> +			prev = actual;
> +
> +		if (actual && actual <= rate) {
> +			if ((prev - rate) < (rate - actual)) {
> +				actual = prev;
> +				prescale--;
> +			}
>  			break;
> +		}
>  		actual >>= 1;
>  	}
>  
> @@ -373,6 +394,10 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
>  		return -EBUSY;
>  	if (!clk_is_primary(parent) || !clk_is_programmable(clk))
>  		return -EINVAL;
> +
> +	if (cpu_is_at91sam9rl() && parent->id == AT91_PMC_CSS_PLLB)
> +		return -EINVAL;
> +
>  	spin_lock_irqsave(&clk_lock, flags);
>  
>  	clk->rate_hz = parent->rate_hz;
> @@ -637,6 +662,7 @@ int __init at91_clock_init(unsigned long main_clock)
>  {
>  	unsigned tmp, freq, mckr;
>  	int i;
> +	int pll_overclock = false;
>  
>  	/*
>  	 * When the bootloader initialized the main oscillator correctly,
> @@ -654,12 +680,25 @@ int __init at91_clock_init(unsigned long main_clock)
>  
>  	/* report if PLLA is more than mildly overclocked */
>  	plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_sys_read(AT91_CKGR_PLLAR));
> -	if ((!cpu_has_800M_plla() && plla.rate_hz > 209000000)
> -	   || (cpu_has_800M_plla() && plla.rate_hz > 800000000))
> +	if (cpu_has_300M_plla()) {
> +		if (plla.rate_hz > 300000000)
> +			pll_overclock = true;
> +	} else if (cpu_has_800M_plla()) {
> +		if (plla.rate_hz > 800000000)
> +			pll_overclock = true;
> +	} else {
> +		if (plla.rate_hz > 209000000)
> +			pll_overclock = true;
> +	}
> +	if (pll_overclock)
>  		pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000);
>  
> +	if (cpu_is_at91sam9g45()) {
> +		mckr = at91_sys_read(AT91_PMC_MCKR);
> +		plla.rate_hz /= (1 << ((mckr & AT91_PMC_PLLADIV2) >> 12));	/* plla divisor by 2 */
> +	}
>  
> -	if (cpu_has_upll() && !cpu_has_pllb()) {
> +	if (!cpu_has_pllb() && cpu_has_upll()) {
>  		/* setup UTMI clock as the fourth primary clock
>  		 * (instead of pllb) */
>  		utmi_clk.type |= CLK_TYPE_PRIMARY;
> @@ -701,6 +740,9 @@ int __init at91_clock_init(unsigned long main_clock)
>  			freq / ((mckr & AT91_PMC_MDIV) >> 7) : freq;	/* mdiv ; (x >> 7) = ((x >> 8) * 2) */
>  		if (mckr & AT91_PMC_PDIV)
>  			freq /= 2;		/* processor clock division */
> +	} else if (cpu_is_at91sam9g45()) {
> +		mck.rate_hz = (mckr & AT91_PMC_MDIV) == AT91SAM9_PMC_MDIV_3 ?
> +			freq / 3 : freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8));	/* mdiv */
>  	} else {
>  		mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8));      /* mdiv */
>  	}

-- 
Ben (ben@fluff.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'