[PATCH v3 RESEND] ARM: imx: pllv1: Fix PLL calculation for i.MX27

[Shawn Guo]

On Sat, Nov 30, 2013 at 09:08:19AM +0400, Alexander Shiyan wrote:
> MFN bit 9 on i.MX27 has a different meaning than in other SOCs. This
> is a just sign bit. This patch makes different calculation for i.MX27.
> 
> Signed-off-by: Alexander Shiyan <shc_work at mail.ru>

Sascha,

Do you have any comment on the patch?  Or can I get your Ack on it?

Shawn

> ---
>  arch/arm/mach-imx/clk-pllv1.c | 23 +++++++++++++++++++----
>  1 file changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/clk-pllv1.c b/arch/arm/mach-imx/clk-pllv1.c
> index c1eaee3..d21d14c 100644
> --- a/arch/arm/mach-imx/clk-pllv1.c
> +++ b/arch/arm/mach-imx/clk-pllv1.c
> @@ -18,6 +18,11 @@
>   *
>   * PLL clock version 1, found on i.MX1/21/25/27/31/35
>   */
> +
> +#define MFN_BITS	(10)
> +#define MFN_SIGN	(BIT(MFN_BITS - 1))
> +#define MFN_MASK	(MFN_SIGN - 1)
> +
>  struct clk_pllv1 {
>  	struct clk_hw	hw;
>  	void __iomem	*base;
> @@ -25,6 +30,11 @@ struct clk_pllv1 {
>  
>  #define to_clk_pllv1(clk) (container_of(clk, struct clk_pllv1, clk))
>  
> +static inline bool mfn_is_negative(unsigned int mfn)
> +{
> +	return !cpu_is_mx1() && !cpu_is_mx21() && (mfn & MFN_SIGN);
> +}
> +
>  static unsigned long clk_pllv1_recalc_rate(struct clk_hw *hw,
>  		unsigned long parent_rate)
>  {
> @@ -58,10 +68,15 @@ static unsigned long clk_pllv1_recalc_rate(struct clk_hw *hw,
>  
>  	/*
>  	 * On all i.MXs except i.MX1 and i.MX21 mfn is a 10bit
> -	 * 2's complements number
> +	 * 2's complements number.
> +	 * On i.MX27 the bit 9 is the sign bit.
>  	 */
> -	if (!cpu_is_mx1() && !cpu_is_mx21() && mfn >= 0x200)
> -		mfn_abs = 0x400 - mfn;
> +	if (mfn_is_negative(mfn)) {
> +		if (cpu_is_mx27())
> +			mfn_abs = mfn & MFN_MASK;
> +		else
> +			mfn_abs = BIT(MFN_BITS) - mfn;
> +	}
>  
>  	rate = parent_rate * 2;
>  	rate /= pd + 1;
> @@ -70,7 +85,7 @@ static unsigned long clk_pllv1_recalc_rate(struct clk_hw *hw,
>  
>  	do_div(ll, mfd + 1);
>  
> -	if (!cpu_is_mx1() && !cpu_is_mx21() && mfn >= 0x200)
> +	if (mfn_is_negative(mfn))
>  		ll = -ll;
>  
>  	ll = (rate * mfi) + ll;
> -- 
> 1.8.3.2
>