[PATCH] mx7ulp: Only enable LDO if it is not already enabled

[Jorge Ramirez-Ortiz, Foundries]

On 17/01/20 16:07:14, Fabio Estevam wrote:
> LDO mode may be already enabled by the ROM and enabling it again
> can cause U-Boot to hang.
> 
> Avoid this problem by only enabling LDO mode if it is initially disabled.
> 
> Reported-by: Jorge Ramirez-Ortiz <jorge at foundries.io>

Tested-by: Jorge Ramirez-Ortiz <jorge at foundries.io>

> Signed-off-by: Fabio Estevam <festevam at gmail.com>
> ---
>  arch/arm/mach-imx/mx7ulp/soc.c | 32 +++++++++++++++++---------------
>  1 file changed, 17 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/mx7ulp/soc.c b/arch/arm/mach-imx/mx7ulp/soc.c
> index 8345b01398..4d84193dec 100644
> --- a/arch/arm/mach-imx/mx7ulp/soc.c
> +++ b/arch/arm/mach-imx/mx7ulp/soc.c
> @@ -117,11 +117,28 @@ void init_wdog(void)
>  	disable_wdog(WDG2_RBASE);
>  }
>  
> +#define PMC0_BASE_ADDR		0x410a1000
> +#define PMC0_CTRL		0x28
> +#define PMC0_CTRL_LDOEN		BIT(31)
> +
> +static bool ldo_mode_is_enabled(void)
> +{
> +	unsigned int reg;
> +
> +	reg = readl(PMC0_BASE_ADDR + PMC0_CTRL);
> +	if (reg & PMC0_CTRL_LDOEN)
> +		return true;
> +	else
> +		return false;
> +}
>  #if defined(CONFIG_LDO_ENABLED_MODE)
>  static void init_ldo_mode(void)
>  {
>  	unsigned int reg;
>  
> +	if (ldo_mode_is_enabled())
> +		return;
> +
>  	/* Set LDOOKDIS */
>  	setbits_le32(PMC0_BASE_ADDR + PMC0_CTRL, PMC0_CTRL_LDOOKDIS);
>  
> @@ -190,21 +207,6 @@ const char *get_imx_type(u32 imxtype)
>  	return "7ULP";
>  }
>  
> -#define PMC0_BASE_ADDR		0x410a1000
> -#define PMC0_CTRL		0x28
> -#define PMC0_CTRL_LDOEN		BIT(31)
> -
> -static bool ldo_mode_is_enabled(void)
> -{
> -	unsigned int reg;
> -
> -	reg = readl(PMC0_BASE_ADDR + PMC0_CTRL);
> -	if (reg & PMC0_CTRL_LDOEN)
> -		return true;
> -	else
> -		return false;
> -}
> -
>  int print_cpuinfo(void)
>  {
>  	u32 cpurev;
> -- 
> 2.17.1
>