diff options
Diffstat (limited to 'arch/arm')
| -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 a9b38cc..8b6b7c1 100644 --- a/arch/arm/cpu/armv7/mx6/soc.c +++ b/arch/arm/cpu/armv7/mx6/soc.c @@ -376,6 +376,24 @@ static void clear_mmdc_ch_mask(void) writel(0, &mxc_ccm->ccdr); } +static void init_bandgap(void) +{ + struct mxc_ccm_reg *mxc_ccm = (struct mxc_ccm_reg *)CCM_BASE_ADDR; + + /* + * Ensure the bandgap has stabilized. + */ + while (!(readl(&mxc_ccm->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, &mxc_ccm->ana_misc0_set); +} + + #ifdef CONFIG_MX6SX void vadc_power_up(void) { @@ -506,6 +524,12 @@ 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. |