For some board designs, it might be useful to switch the DC-DC clock source to something else rather the default 24 MHz, e.g. for EMI reasons.

For this, use something like this in your board configuration:

Signed-off-by: Michael Heimpold mhei@heimpold.de Cc: Marek Vasut marex@denx.de Cc: Otavio Salvador otavio@ossystems.com.br Cc: Fabio Estevam fabio.estevam@freescale.com ---

I'm not sure whether the position to set these bits is the best one.

Regards, Michael

arch/arm/cpu/arm926ejs/mxs/spl_power_init.c | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c index 1972de8..410cf0b 100644 --- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c +++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c @@ -260,6 +260,15 @@ static void mxs_src_power_init(void)

debug("SPL: Pre-Configuring power block\n");

+#ifdef CONFIG_SYS_MXS_DCDC_FREQSEL + /* Select clocksource for DC-DC converter */ + clrsetbits_le32(&power_regs->hw_power_misc, + POWER_MISC_FREQSEL_MASK, + CONFIG_SYS_MXS_DCDC_FREQSEL); + setbits_le32(&power_regs->hw_power_misc, + POWER_MISC_SEL_PLLCLK); +#endif + /* Improve efficieny and reduce transient ripple */ writel(POWER_LOOPCTRL_TOGGLE_DIF | POWER_LOOPCTRL_EN_CM_HYST | POWER_LOOPCTRL_EN_DF_HYST, &power_regs->hw_power_loopctrl_set);