[PATCH v2 2/2] mx7ulp: Only enable LDO if it is not already enabled

Peng Fan
2020-02-03T12:07:18Z

> Subject: [PATCH v2 2/2] mx7ulp: Only enable LDO if it is not already enabled
>
> 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@foundries.io>
> Signed-off-by: Fabio Estevam <festevam@gmail.com>
> Tested-by: Jorge Ramirez-Ortiz <jorge@foundries.io>

Reviewed-by: Peng Fan <peng.fan@nxp.com>

Just have a question, LDO mode enabled by ROM, this is configured with fuse?

Is there any special configuration need to be done in Linux? I not touch this
part before (:

Thanks,
Peng.

> ---
> Changes since v1:
> - Drop the define changes as they are duplicated (Stefano).
>
> arch/arm/mach-imx/mx7ulp/soc.c | 25 ++++++++++++++-----------
> 1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm/mach-imx/mx7ulp/soc.c
> b/arch/arm/mach-imx/mx7ulp/soc.c index d8d691692c..0d39dab7ea 100644
> --- a/arch/arm/mach-imx/mx7ulp/soc.c
> +++ b/arch/arm/mach-imx/mx7ulp/soc.c
> @@ -118,12 +118,26 @@ void init_wdog(void)
> disable_wdog(WDG2_RBASE);
> }
>
> +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_SPL) || (defined(CONFIG_SPL) &&
> defined(CONFIG_SPL_BUILD)) #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);
>
> @@ -193,17 +207,6 @@ const char *get_imx_type(u32 imxtype)
> return "7ULP";
> }
>
> -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