ARM: OMAP4: clockdomain/CM code: Update supported transition modes
For OMAP3+ devices, the clock domains (CLKDMs) support one or more of the following transition modes ... NO_SLEEP (0x0) - A clock domain sleep transition is never initiated, irrespective of the hardware conditions. SW_SLEEP (0x1) - A software-forced sleep transition. The transition is initiated when the associated hardware conditions are satisfied SW_WKUP (0x2) - A software-forced clock domain wake-up transition is initiated, irrespective of the hardware conditions. HW_AUTO (0x3) - Hardware-controlled automatic sleep and wake-up transition is initiated by the PRCM module when the associated hardware conditions are satisfied. For OMAP4 devices, SW_SLEEP is equivalent to HW_AUTO and NO_SLEEP is equivalent to SW_WKUP. The only difference between HW_AUTO and SW_SLEEP for OMAP4 devices is that the PRM_IRQSTATUS_MPU.TRANSITION_ST interrupt status is set in case of SW_SLEEP transition, and not set in case of HW_AUTO transition. For OMAP4 devices, all CLKDMs support HW_AUTO and therefore we can place the CLKDMs in the HW_AUTO state instead of the SW_SLEEP mode. Hence, we do not need to use the SW_SLEEP mode. With regard to NO_SLEEP and SW_WKUP it is preferred to use SW_WKUP mode if the CLKDM supports it and so use this mode instead of NO_SLEEP where possible. For a software perspective the above 4 modes are represented by the following flags to indicate what modes are supported by each of the CLKDMs. CLKDM_CAN_DISABLE_AUTO --> NO_SLEEP CLKDM_CAN_ENABLE_AUTO --> HW_AUTO CLKDM_CAN_FORCE_SLEEP --> SW_SLEEP CLKDM_CAN_FORCE_WAKEUP --> SW_WKUP By eliminating the SW_SLEEP mode the the mapping of the flags for OMAP4 devices can becomes ... CLKDM_CAN_DISABLE_AUTO --> NO_SLEEP CLKDM_CAN_ENABLE_AUTO --> HW_AUTO CLKDM_CAN_FORCE_SLEEP --> HW_AUTO CLKDM_CAN_FORCE_WAKEUP --> SW_WKUP Cc: Ming Lei <ming.lei@canonical.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Benoit Cousson <b-cousson@ti.com> Cc: Paul Walmsley <paul@pwsan.com> Cc: Kevin Hilman <khilman@ti.com> Reviewed-by: NBenoit Cousson <b-cousson@ti.com> Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: NJon Hunter <jon-hunter@ti.com> Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Showing
想要评论请 注册 或 登录