[U-Boot] [PATCH v2] i.MX28: Check if we are using a valid VBUS for power initialization

[Otavio Salvador]

Signed-off-by: Otavio Salvador <otavio at ossystems.com.br>
---
Changes in v2:
- add comments
- fix when we have vbus OR vdd5v
- improve patch short description

 arch/arm/cpu/arm926ejs/mx28/spl_power_init.c |   26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/mx28/spl_power_init.c b/arch/arm/cpu/arm926ejs/mx28/spl_power_init.c
index 4b09b0c..fdf810c 100644
--- a/arch/arm/cpu/arm926ejs/mx28/spl_power_init.c
+++ b/arch/arm/cpu/arm926ejs/mx28/spl_power_init.c
@@ -564,6 +564,15 @@ void mx28_batt_boot(void)
 		0x8 << POWER_5VCTRL_CHARGE_4P2_ILIMIT_OFFSET);
 }
 
+static int mx28_valid_vbus(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	/* iMX23 uses POWER_STS_VBUSVALID_STATUS at same offset */
+	return readl(&power_regs->hw_power_sts) & POWER_STS_VBUSVALID0_STATUS;
+}
+
 void mx28_handle_5v_conflict(void)
 {
 	struct mx28_power_regs *power_regs =
@@ -577,14 +586,19 @@ void mx28_handle_5v_conflict(void)
 		tmp = readl(&power_regs->hw_power_sts);
 
 		if (tmp & POWER_STS_VDDIO_BO) {
+			/*
+			 * VDDIO has a brownout, then the VDD5V_GT_VDDIO becomes
+			 * unreliable
+			 */
 			mx28_powerdown();
 			break;
 		}
 
-		if (tmp & POWER_STS_VDD5V_GT_VDDIO) {
+		if (mx28_valid_vbus() || (tmp & POWER_STS_VDD5V_GT_VDDIO)) {
 			mx28_boot_valid_5v();
 			break;
 		} else {
+			/* Neither 5v sees 5v so we power down */
 			mx28_powerdown();
 			break;
 		}
@@ -601,17 +615,15 @@ void mx28_5v_boot(void)
 	struct mx28_power_regs *power_regs =
 		(struct mx28_power_regs *)MXS_POWER_BASE;
 
-	/*
-	 * NOTE: In original IMX-Bootlets, this also checks for VBUSVALID,
-	 * but their implementation always returns 1 so we omit it here.
-	 */
-	if (readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO) {
+	if (mx28_valid_vbus() &&
+		(readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO)) {
 		mx28_boot_valid_5v();
 		return;
 	}
 
 	early_delay(1000);
-	if (readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO) {
+	if (mx28_valid_vbus() &&
+		(readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO)) {
 		mx28_boot_valid_5v();
 		return;
 	}
-- 
1.7.10.4