On Friday, December 11, 2015 at 12:05:36 AM, Michael Heimpold wrote: > 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.
Can you elaborate on this ? Also, is there gonna be a user for this? > For this, override the mxs_power_setup_dcdc_clocksource function > in your board support files. > > Example: > void mxs_power_setup_dcdc_clocksource(void) > { > mxs_power_select_dcdc_clocksource(POWER_MISC_FREQSEL_20MHZ); > } > > Signed-off-by: Michael Heimpold <m...@heimpold.de> > Cc: Marek Vasut <ma...@denx.de> > Cc: Otavio Salvador <ota...@ossystems.com.br> > Cc: Fabio Estevam <fabio.este...@freescale.com> > --- > > Changes in v2: > - use a weak function approach instead of ifdef'ery as suggested > by Marek Vasut > > arch/arm/cpu/arm926ejs/mxs/spl_power_init.c | 31 > +++++++++++++++++++++++++++++ arch/arm/include/asm/arch-mxs/sys_proto.h > | 2 ++ > 2 files changed, 33 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..64e215c > 100644 > --- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c > +++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c > @@ -248,6 +248,36 @@ static void mxs_power_setup_5v_detect(void) > } > > /** > + * mxs_power_switch_dcdc_clocksource() - Switch PLL clock for DC-DC > converters + * > + * This function configures and then enables an alternative PLL clock > source + * for the DC-DC converters. > + */ > +void mxs_power_select_dcdc_clocksource(uint32_t freqsel) > +{ > + struct mxs_power_regs *power_regs = > + (struct mxs_power_regs *)MXS_POWER_BASE; > + > + /* Select clocksource for DC-DC converters */ > + clrsetbits_le32(&power_regs->hw_power_misc, > + POWER_MISC_FREQSEL_MASK, > + freqsel); > + setbits_le32(&power_regs->hw_power_misc, > + POWER_MISC_SEL_PLLCLK); > +} > + > +/** > + * mxs_power_setup_dcdc_clocksource() Please make sure this is compatible with kerneldoc. > + * Normally, there is no need to switch DC-DC clocksource. However, boards > + * can implement this function when required. > + */ > +__weak void mxs_power_setup_dcdc_clocksource(void) > +{ > + debug("SPL: Using default DC-DC clocksource\n"); > +} > + > +/** > * mxs_src_power_init() - Preconfigure the power block > * > * This function configures reasonable values for the DC-DC control loop > @@ -872,6 +902,7 @@ static void mxs_power_configure_power_source(void) > > debug("SPL: Configuring power source\n"); > > + mxs_power_setup_dcdc_clocksource(); > mxs_src_power_init(); > > if (readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO) { > diff --git a/arch/arm/include/asm/arch-mxs/sys_proto.h > b/arch/arm/include/asm/arch-mxs/sys_proto.h index 20ff101..4160e43 100644 > --- a/arch/arm/include/asm/arch-mxs/sys_proto.h > +++ b/arch/arm/include/asm/arch-mxs/sys_proto.h > @@ -25,6 +25,8 @@ int mxsmmc_initialize(bd_t *bis, int id, int (*wp)(int), > int (*cd)(int)); void mxs_common_spl_init(const uint32_t arg, const > uint32_t *resptr, const iomux_cfg_t *iomux_setup, > const unsigned int iomux_size); > + > +void mxs_power_select_dcdc_clocksource(uint32_t freqsel); This function does not need to be exported if it's __weak I believe. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot