[PATCH 2/2] ARM: imx: add speed grading check for i.mx6 soc

[Shawn Guo]

On Wed, Feb 12, 2014 at 03:56:17PM +0800, Anson Huang wrote:
> The fuse map of speed_grading[1:0] defines the max speed
> of ARM, see below the definition:
> 
> 2b'11: 1200000000Hz;
> 2b'10: 996000000Hz;
> 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
> 2b'00: 792000000Hz;
> 
> Need to remove all illegal setpoints according to fuse
> map.
> 
> Signed-off-by: Anson Huang <b20788 at freescale.com>
> ---
>  arch/arm/mach-imx/mach-imx6q.c |   22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
> index f9cbbf9..ad9da1f 100644
> --- a/arch/arm/mach-imx/mach-imx6q.c
> +++ b/arch/arm/mach-imx/mach-imx6q.c
> @@ -219,8 +219,10 @@ static void __init imx6q_init_machine(void)
>  #define OCOTP_CFG3			0x440
>  #define OCOTP_CFG3_SPEED_SHIFT		16
>  #define OCOTP_CFG3_SPEED_1P2GHZ		0x3
> +#define OCOTP_CFG3_SPEED_996MHZ		0x2
> +#define OCOTP_CFG3_SPEED_852MHZ		0x1
>  
> -static void __init imx6q_opp_check_1p2ghz(struct device *cpu_dev)
> +static void __init imx6q_opp_check_speed_grading(struct device *cpu_dev)
>  {
>  	struct device_node *np;
>  	void __iomem *base;
> @@ -238,11 +240,27 @@ static void __init imx6q_opp_check_1p2ghz(struct device *cpu_dev)
>  		goto put_node;
>  	}
>  
> +	/*
> +	 * SPEED_GRADING[1:0] defines the max speed of ARM:
> +	 * 2b'11: 1200000000Hz;
> +	 * 2b'10: 996000000Hz;
> +	 * 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
> +	 * 2b'00: 792000000Hz;
> +	 * We need to set the max speed of ARM according to fuse map.
> +	 */
>  	val = readl_relaxed(base + OCOTP_CFG3);
>  	val >>= OCOTP_CFG3_SPEED_SHIFT;

	val &= 0x3;

Then you do not need to do it in every if-clause below.

>  	if ((val & 0x3) != OCOTP_CFG3_SPEED_1P2GHZ)
>  		if (dev_pm_opp_disable(cpu_dev, 1200000000))
>  			pr_warn("failed to disable 1.2 GHz OPP\n");
> +	if ((val & 0x3) < OCOTP_CFG3_SPEED_996MHZ)
> +		if (dev_pm_opp_disable(cpu_dev, 996000000))
> +			pr_warn("failed to disable 996 MHz OPP\n");
> +	if (cpu_is_imx6q()) {
> +		if ((val & 0x3) != OCOTP_CFG3_SPEED_852MHZ)

	if (cpu_is_imx6q() && val != OCOTP_CFG3_SPEED_852MHZ)

Shawn

> +			if (dev_pm_opp_disable(cpu_dev, 852000000))
> +				pr_warn("failed to disable 852 MHz OPP\n");
> +	}
>  
>  put_node:
>  	of_node_put(np);
> @@ -268,7 +286,7 @@ static void __init imx6q_opp_init(void)
>  		goto put_node;
>  	}
>  
> -	imx6q_opp_check_1p2ghz(cpu_dev);
> +	imx6q_opp_check_speed_grading(cpu_dev);
>  
>  put_node:
>  	of_node_put(np);
> -- 
> 1.7.9.5
> 
>