nigel@nigel:/usr/src/build-2.6.22-rc6$ grep RTC .config
# CONFIG_RTC is not set
# CONFIG_GEN_RTC is not set
CONFIG_HPET_RTC_IRQ=y
CONFIG_RTC_LIB=y
CONFIG_RTC_CLASS=y
CONFIG_RTC_HCTOSYS=y
CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
CONFIG_RTC_DEBUG=y
# RTC interfaces
CONFIG_RTC_INTF_SYSFS=y
CONFIG_RTC_INTF_PROC=y
CONFIG_RTC_INTF_DEV=y
CONFIG_RTC_INTF_DEV_UIE_EMUL=y
# CONFIG_RTC_DRV_TEST is not set
# I2C RTC drivers
# SPI RTC drivers
# Platform RTC drivers
CONFIG_RTC_DRV_CMOS=y
# CONFIG_RTC_DRV_DS1553 is not set
# CONFIG_RTC_DRV_DS1742 is not set
# CONFIG_RTC_DRV_M48T86 is not set
# CONFIG_RTC_DRV_V3020 is not set
# on-CPU RTC drivers
nigel@nigel:/usr/src/build-2.6.22-rc6$