diff options
Diffstat (limited to 'arch/arm/cpu/armv7/mx6/soc.c')
| -rw-r--r-- | arch/arm/cpu/armv7/mx6/soc.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c index e599a12..df4e824 100644 --- a/arch/arm/cpu/armv7/mx6/soc.c +++ b/arch/arm/cpu/armv7/mx6/soc.c @@ -255,6 +255,23 @@ static void clear_mmdc_ch_mask(void) writel(0, &mxc_ccm->ccdr); } +static void init_bandgap(void) +{ + struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR; + /* + * Ensure the bandgap has stabilized. + */ + while (!(readl(&anatop->ana_misc0) & 0x80)) + ; + /* + * For best noise performance of the analog blocks using the + * outputs of the bandgap, the reftop_selfbiasoff bit should + * be set. + */ + writel(BM_ANADIG_ANA_MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_set); +} + + #ifdef CONFIG_MX6SL static void set_preclk_from_osc(void) { @@ -275,6 +292,13 @@ int arch_cpu_init(void) clear_mmdc_ch_mask(); /* + * Disable self-bias circuit in the analog bandap. + * The self-bias circuit is used by the bandgap during startup. + * This bit should be set after the bandgap has initialized. + */ + init_bandgap(); + + /* * When low freq boot is enabled, ROM will not set AHB * freq, so we need to ensure AHB freq is 132MHz in such * scenario. |