[alsa-devel] [PATCH v2 3/3] arm: mxs: disable clock-gates when setting saif-clocks

[Uwe Kleine-König]

On Wed, Sep 07, 2011 at 09:57:38PM +0800, Dong Aisheng wrote:
> From: Wolfram Sang <w.sang at pengutronix.de>
> 
> New divides should only be written when gates are off.
> 
> Reported-by: Dong Aisheng <b29396 at freescale.com>
> Signed-off-by: Wolfram Sang <w.sang at pengutronix.de>
> 
> ---
> Changes since v1:
>  * Fix author name. It should be Wolfram Sang. :)
> 
> BTW, i did a minus change based on wolfram's patch or the saif will
> not work.
> 
> Change
> +       __raw_writel(clkgate, CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs##_SET); \
> to
> +       __raw_writel(reg & ~clkgate,					\
> 			CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs);		\
IMHO this is worth to be noted in the commit log.

> It seemed HW_CLKCTRL_##rs##_SET did not work well.
> (i did not find HW_CLKCTRL_SAIFx_SET in spec).
> ---
>  arch/arm/mach-mxs/clock-mx28.c        |    7 +++++--
>  arch/arm/mach-mxs/regs-clkctrl-mx28.h |    2 ++
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/mach-mxs/clock-mx28.c b/arch/arm/mach-mxs/clock-mx28.c
> index 33cc2ff..c9d0548 100644
> --- a/arch/arm/mach-mxs/clock-mx28.c
> +++ b/arch/arm/mach-mxs/clock-mx28.c
> @@ -476,7 +476,7 @@ _CLK_SET_RATE1(xbus_clk, XBUS)
>  static int name##_set_rate(struct clk *clk, unsigned long rate)		\
>  {									\
>  	u16 div;							\
> -	u32 reg;							\
> +	u32 reg, clkgate;						\
>  	u64 lrate;							\
>  	unsigned long parent_rate;					\
>  	int i;								\
> @@ -493,7 +493,8 @@ static int name##_set_rate(struct clk *clk, unsigned long rate)		\
>  		return -EINVAL;						\
>  									\
>  	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs);		\
> -	reg &= ~BM_CLKCTRL_##rs##_DIV;					\
> +	clkgate = reg & BM_CLKCTRL_##rs##_CLKGATE;			\
> +	reg &= ~(BM_CLKCTRL_##rs##_DIV | BM_CLKCTRL_##rs##_CLKGATE);	\
>  	reg |= div << BP_CLKCTRL_##rs##_DIV;				\
>  	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs);		\
>  									\
> @@ -506,6 +507,8 @@ static int name##_set_rate(struct clk *clk, unsigned long rate)		\
>  		return -ETIMEDOUT;					\
>  	}								\
>  									\
> +	__raw_writel(reg & ~clkgate,					\
> +			CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs);		\
>  	return 0;							\
>  }
>  
> diff --git a/arch/arm/mach-mxs/regs-clkctrl-mx28.h b/arch/arm/mach-mxs/regs-clkctrl-mx28.h
> index 7d1b061..08749b3 100644
> --- a/arch/arm/mach-mxs/regs-clkctrl-mx28.h
> +++ b/arch/arm/mach-mxs/regs-clkctrl-mx28.h
> @@ -285,6 +285,7 @@
>  		(((v) << 0) & BM_CLKCTRL_EMI_DIV_EMI)
>  
>  #define HW_CLKCTRL_SAIF0	(0x00000100)
> +#define HW_CLKCTRL_SAIF0_SET	(0x00000104)
Is this still needed?

>  
>  #define BP_CLKCTRL_SAIF0_CLKGATE	31
>  #define BM_CLKCTRL_SAIF0_CLKGATE	0x80000000
> @@ -296,6 +297,7 @@
>  		(((v) << 0) & BM_CLKCTRL_SAIF0_DIV)
>  
>  #define HW_CLKCTRL_SAIF1	(0x00000110)
> +#define HW_CLKCTRL_SAIF1_SET	(0x00000114)
>  
>  #define BP_CLKCTRL_SAIF1_CLKGATE	31
>  #define BM_CLKCTRL_SAIF1_CLKGATE	0x80000000

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
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