summaryrefslogtreecommitdiffstats
path: root/firmware/target/arm/imx233/powermgmt-imx233.c
diff options
context:
space:
mode:
authorAmaury Pouly <amaury.pouly@gmail.com>2014-02-04 00:28:26 +0100
committerAmaury Pouly <amaury.pouly@gmail.com>2014-02-10 23:14:25 +0100
commitc043ecf9e144b1bf24edf5a8a9bf3e2cad08b97c (patch)
treea7957294218f59f79649acaeebc821ed4990eddf /firmware/target/arm/imx233/powermgmt-imx233.c
parent61dbeb60b73d771abb86270579e8669fe08586cf (diff)
downloadrockbox-c043ecf9e144b1bf24edf5a8a9bf3e2cad08b97c.tar.gz
rockbox-c043ecf9e144b1bf24edf5a8a9bf3e2cad08b97c.tar.bz2
rockbox-c043ecf9e144b1bf24edf5a8a9bf3e2cad08b97c.zip
imx233: rework early time power init
The current code does hazardous tweaks to the power subsystem: indeed if one boots with USB plugged and some stub powers on the DCDC switch, it will fail. Indeed, a hardware bug prevents from going back to linear regulators (see errata) so we cannot expect to reach a known state (linreg on, dcdc off) on each configuration and in particular, powering down the 4p2 rail in such a configuration will result in a power brownout. This commit works around this issue by not touching the initial power configuration until USB is (un)plugged, which are the best spots to get known states. Change-Id: I8741a3995df8ae61ca1c887a3ecb7903d0ac5136
Diffstat (limited to 'firmware/target/arm/imx233/powermgmt-imx233.c')
-rw-r--r--firmware/target/arm/imx233/powermgmt-imx233.c41
1 files changed, 15 insertions, 26 deletions
diff --git a/firmware/target/arm/imx233/powermgmt-imx233.c b/firmware/target/arm/imx233/powermgmt-imx233.c
index 7a1ea8338e..01d0e3eae1 100644
--- a/firmware/target/arm/imx233/powermgmt-imx233.c
+++ b/firmware/target/arm/imx233/powermgmt-imx233.c
@@ -58,35 +58,13 @@ void imx233_powermgmt_init(void)
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
- /* 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 */
-#endif
-
-#if IMX233_SUBTARGET >= 3700
/* 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);
- /* make sure we are in a known state: disable charger */
- BF_SET(POWER_CHARGE, PWD_BATTCHRG);
-#endif
-#if IMX233_SUBTARGET >= 3780
- /* make sure we are in a known state: disable 4p2 */
- BF_WR(POWER_DCDC4P2, ENABLE_DCDC, 0);
- BF_WR(POWER_DCDC4P2, ENABLE_4P2, 0);
- BF_SET(POWER_5VCTRL, PWD_CHARGE_4P2);
+#else
+ BF_SET(POWER_5VCTRL, LINREG_OFFSET);
#endif
}
@@ -110,6 +88,7 @@ void charging_algorithm_step(void)
#if IMX233_SUBTARGET >= 3780
BF_WR(POWER_DCDC4P2, ENABLE_DCDC, 0);
BF_WR(POWER_DCDC4P2, ENABLE_4P2, 0);
+ BF_WR(POWER_5VCTRL, CHARGE_4P2_ILIMIT, 1);
BF_SET(POWER_5VCTRL, PWD_CHARGE_4P2);
#endif
charge_state = DISCHARGING;
@@ -120,10 +99,14 @@ void charging_algorithm_step(void)
logf("pwrmgmt: discharging -> trickle");
logf("pwrmgmt: begin charging 4p2");
#if IMX233_SUBTARGET >= 3780
- /* 5V has been detected: prepare 4.2V power rail for activation */
+ /* 5V has been detected: prepare 4.2V power rail for activation
+ * WARNING we can reach this situation when starting after Freescale bootloader
+ * or after RoLo in a state where the DCDC is running. In this case,
+ * we must *NOT* disable it or this will shutdown the device. This procedure
+ * is safe: it will never disable the DCDC and will not reduce the charge
+ * limit on the 4P2 rail. */
BF_WR(POWER_DCDC4P2, ENABLE_4P2, 1);
BF_SET(POWER_CHARGE, ENABLE_LOAD);
- BF_WR(POWER_5VCTRL, CHARGE_4P2_ILIMIT, 1);
BF_CLR(POWER_5VCTRL, PWD_CHARGE_4P2);// FIXME: manual error ?
BF_WR(POWER_DCDC4P2, ENABLE_DCDC, 1);
#endif
@@ -147,6 +130,12 @@ void charging_algorithm_step(void)
{
logf("pwrmgmt: enable dcdc and charger");
logf("pwrmgmt: trickle -> charging");
+#if IMX233_SUBTARGET >= 3780
+ /* 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 */
+#endif
+ /* switch to DCDC */
BF_CLR(POWER_5VCTRL, DCDC_XFER);
BF_SET(POWER_5VCTRL, ENABLE_DCDC);
/* enable battery charging */