imx233: rework power management

The current code was spreaded over power and powermgmt which made
it behave strangely, especially since there are relationships
between power management and frequency scaling. The new code makes
sure power management is initialised before frequency scaling
starts. It also makes sure to start from a known state, thus
fixing potential issue when the bootloader stops in a trickle
state where DCDC is improperly configured.

Change-Id: Ibded2e590e108f6c98daa52d2cf1bd28763c8923

1 files changed, 29 insertions, 5 deletions

diff --git a/firmware/target/arm/imx233/powermgmt-imx233.c b/firmware/target/arm/imx233/powermgmt-imx233.c
index 8980124b33..9819406974 100644
--- a/firmware/target/arm/imx233/powermgmt-imx233.c
+++ b/firmware/target/arm/imx233/powermgmt-imx233.c
@@ -44,19 +44,46 @@ int _battery_voltage(void)
     return BF_RD(POWER_BATTMONITOR, BATT_VAL) * 8;
 }
 
-void powermgmt_init_target(void)
+void imx233_powermgmt_init(void)
 {
     imx233_power_set_charge_current(IMX233_CHARGE_CURRENT);
     imx233_power_set_stop_current(IMX233_STOP_CURRENT);
-#if IMX233_SUBTARGET >= 3780
     /* assume that adc_init was called and battery monitoring via LRADC setup */
     BF_WR(POWER_BATTMONITOR, EN_BATADJ, 1);
+#if IMX233_SUBTARGET >= 3700
+    /* setup linear regulator offsets to 25 mV below to prevent contention between
+     * linear regulators and DCDC */
+    BF_WR(POWER_VDDDCTRL, LINREG_OFFSET, 2);
+    BF_WR(POWER_VDDACTRL, LINREG_OFFSET, 2);
+    BF_WR(POWER_VDDIOCTRL, LINREG_OFFSET, 2);
+    /* enable DCDC (more efficient) */
+    BF_SET(POWER_5VCTRL, ENABLE_DCDC);
+    BF_CLR(POWER_5VCTRL, DCDC_XFER);
+#else
+    BF_SET(POWER_5VCTRL, LINREG_OFFSET);
+    BF_SET(POWER_5VCTRL, EN_DCDC1);
+    BF_SET(POWER_5VCTRL, EN_DCDC2);
+#endif
+
+#if IMX233_SUBTARGET >= 3780
+    /* enable a few bits controlling the DC-DC as recommended by Freescale */
+    BF_SET(POWER_LOOPCTRL, TOGGLE_DIF);
+    BF_SET(POWER_LOOPCTRL, EN_CM_HYST);
+    BF_CLR(POWER_LOOPCTRL, EN_RCSCALE);
+    BF_SETV(POWER_LOOPCTRL, EN_RCSCALE, 1);
+    /* adjust arbitration between 4.2 and battery */
+    BF_WR(POWER_DCDC4P2, CMPTRIP, 0); /* 85% */
+    BF_WR(POWER_DCDC4P2, DROPOUT_CTRL, 0xe); /* select greater, 200 mV drop */
     /* make sure we are in a known state: disable charger and 4p2 */
     BF_SET(POWER_CHARGE, PWD_BATTCHRG);
     BF_WR(POWER_DCDC4P2, ENABLE_DCDC, 0);
     BF_WR(POWER_DCDC4P2, ENABLE_4P2, 0);
     BF_SET(POWER_5VCTRL, PWD_CHARGE_4P2);
 #endif
+}
+
+void powermgmt_init_target(void)
+{
     charge_state = DISCHARGING;
 }
 
@@ -106,9 +133,6 @@ void charging_algorithm_step(void)
         {
             logf("pwrmgmt: enable dcdc and charger");
             logf("pwrmgmt: trickle -> charging");
-            /* adjust arbitration between 4.2 and battery */
-            BF_WR(POWER_DCDC4P2, CMPTRIP, 0); /* 85% */
-            BF_WR(POWER_DCDC4P2, DROPOUT_CTRL, 0xe); /* select greater, 200 mV drop */
             BF_CLR(POWER_5VCTRL, DCDC_XFER);
             BF_SET(POWER_5VCTRL, ENABLE_DCDC);
             /* enable battery charging */