/*
*********************************************************************************************************
* SYSTEM PWM ENTER STANDBY MODE
*
* Description: enter standby mode.
*
* Arguments : none
*
* Returns : none;
*********************************************************************************************************
*/
static void standby(void)
{
/* gating off dram clock */
standby_clk_dramgating(0);
/* switch cpu clock to HOSC, and disable pll */
standby_clk_core2hosc();
standby_clk_plldisable();
/* backup voltages */
dcdc2 = standby_get_voltage(POWER_VOL_DCDC2);
dcdc3 = standby_get_voltage(POWER_VOL_DCDC3);
/* adjust voltage */
standby_set_voltage(POWER_VOL_DCDC3, STANDBY_DCDC3_VOL);
standby_set_voltage(POWER_VOL_DCDC2, STANDBY_DCDC2_VOL);
/* set clock division cpu:axi:ahb:apb = 2:2:2:1 */
standby_clk_getdiv(&clk_div);
tmp_clk_div.axi_div = 0;
tmp_clk_div.ahb_div = 0;
tmp_clk_div.apb_div = 0;
standby_clk_setdiv(&tmp_clk_div);
/* swtich apb1 to losc */
standby_clk_apb2losc();
standby_mdelay(10);
/* switch cpu to 32k */
standby_clk_core2losc();
#if(ALLOW_DISABLE_HOSC)
// disable HOSC, and disable LDO
standby_clk_hoscdisable();
standby_clk_ldodisable();
#endif
/* cpu enter sleep, wait wakeup by interrupt */
asm("WFI");
#if(ALLOW_DISABLE_HOSC)
/* enable LDO, enable HOSC */
standby_clk_ldoenable();
/* delay 1ms for power be stable */
standby_delay(1);
standby_clk_hoscenable();
standby_delay(1);
#endif
/* swtich apb1 to hosc */
standby_clk_apb2hosc();
/* switch clock to hosc */
standby_clk_core2hosc();
/* restore clock division */
standby_clk_setdiv(&clk_div);
/* check system wakeup event */
pm_info.standby_para.event = 0;
pm_info.standby_para.event |= standby_query_int(INT_SOURCE_EXTNMI)? 0:SUSPEND_WAKEUP_SRC_EXINT;
pm_info.standby_para.event |= standby_query_int(INT_SOURCE_USB0)? 0:SUSPEND_WAKEUP_SRC_USB;
pm_info.standby_para.event |= standby_query_int(INT_SOURCE_LRADC)? 0:SUSPEND_WAKEUP_SRC_KEY;
pm_info.standby_para.event |= standby_query_int(INT_SOURCE_IR0)? 0:SUSPEND_WAKEUP_SRC_IR;
pm_info.standby_para.event |= standby_query_int(INT_SOURCE_ALARM)? 0:SUSPEND_WAKEUP_SRC_ALARM;
pm_info.standby_para.event |= standby_query_int(INT_SOURCE_TIMER0)? 0:SUSPEND_WAKEUP_SRC_TIMEOFF;
/* restore voltage for exit standby */
standby_set_voltage(POWER_VOL_DCDC2, dcdc2);
standby_set_voltage(POWER_VOL_DCDC3, dcdc3);
standby_mdelay(10);
/* enable pll */
standby_clk_pllenable();
standby_mdelay(10);
/* switch cpu clock to core pll */
standby_clk_core2pll();
standby_mdelay(10);
/* gating on dram clock */
standby_clk_dramgating(1);
return;
}
