i.MX28: Move SPL to arch/arm/cpu/arm926ejs/mx28

This moves SPL to common location so it can be reused by multiple boards. Also,
this commit adjusts M28 SoM to avoid breakage due to the move.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
Cc: Stefano Babic <sbabic@denx.de>

1 files changed, 913 insertions, 0 deletions

diff --git a/arch/arm/cpu/arm926ejs/mx28/spl_power_init.c b/arch/arm/cpu/arm926ejs/mx28/spl_power_init.c
new file mode 100644
index 00000000000..a4dc2a31b7b
--- /dev/null
+++ b/arch/arm/cpu/arm926ejs/mx28/spl_power_init.c
@@ -0,0 +1,913 @@
+/*
+ * Freescale i.MX28 Boot PMIC init
+ *
+ * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
+ * on behalf of DENX Software Engineering GmbH
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <config.h>
+#include <asm/io.h>
+#include <asm/arch/imx-regs.h>
+
+#include "mx28_init.h"
+
+void mx28_power_clock2xtal(void)
+{
+	struct mx28_clkctrl_regs *clkctrl_regs =
+		(struct mx28_clkctrl_regs *)MXS_CLKCTRL_BASE;
+
+	/* Set XTAL as CPU reference clock */
+	writel(CLKCTRL_CLKSEQ_BYPASS_CPU,
+		&clkctrl_regs->hw_clkctrl_clkseq_set);
+}
+
+void mx28_power_clock2pll(void)
+{
+	struct mx28_clkctrl_regs *clkctrl_regs =
+		(struct mx28_clkctrl_regs *)MXS_CLKCTRL_BASE;
+
+	writel(CLKCTRL_PLL0CTRL0_POWER,
+		&clkctrl_regs->hw_clkctrl_pll0ctrl0_set);
+	early_delay(100);
+	writel(CLKCTRL_CLKSEQ_BYPASS_CPU,
+		&clkctrl_regs->hw_clkctrl_clkseq_clr);
+}
+
+void mx28_power_clear_auto_restart(void)
+{
+	struct mx28_rtc_regs *rtc_regs =
+		(struct mx28_rtc_regs *)MXS_RTC_BASE;
+
+	writel(RTC_CTRL_SFTRST, &rtc_regs->hw_rtc_ctrl_clr);
+	while (readl(&rtc_regs->hw_rtc_ctrl) & RTC_CTRL_SFTRST)
+		;
+
+	writel(RTC_CTRL_CLKGATE, &rtc_regs->hw_rtc_ctrl_clr);
+	while (readl(&rtc_regs->hw_rtc_ctrl) & RTC_CTRL_CLKGATE)
+		;
+
+	/*
+	 * Due to the hardware design bug of mx28 EVK-A
+	 * we need to set the AUTO_RESTART bit.
+	 */
+	if (readl(&rtc_regs->hw_rtc_persistent0) & RTC_PERSISTENT0_AUTO_RESTART)
+		return;
+
+	while (readl(&rtc_regs->hw_rtc_stat) & RTC_STAT_NEW_REGS_MASK)
+		;
+
+	setbits_le32(&rtc_regs->hw_rtc_persistent0,
+			RTC_PERSISTENT0_AUTO_RESTART);
+	writel(RTC_CTRL_FORCE_UPDATE, &rtc_regs->hw_rtc_ctrl_set);
+	writel(RTC_CTRL_FORCE_UPDATE, &rtc_regs->hw_rtc_ctrl_clr);
+	while (readl(&rtc_regs->hw_rtc_stat) & RTC_STAT_NEW_REGS_MASK)
+		;
+	while (readl(&rtc_regs->hw_rtc_stat) & RTC_STAT_STALE_REGS_MASK)
+		;
+}
+
+void mx28_power_set_linreg(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	/* Set linear regulator 25mV below switching converter */
+	clrsetbits_le32(&power_regs->hw_power_vdddctrl,
+			POWER_VDDDCTRL_LINREG_OFFSET_MASK,
+			POWER_VDDDCTRL_LINREG_OFFSET_1STEPS_BELOW);
+
+	clrsetbits_le32(&power_regs->hw_power_vddactrl,
+			POWER_VDDACTRL_LINREG_OFFSET_MASK,
+			POWER_VDDACTRL_LINREG_OFFSET_1STEPS_BELOW);
+
+	clrsetbits_le32(&power_regs->hw_power_vddioctrl,
+			POWER_VDDIOCTRL_LINREG_OFFSET_MASK,
+			POWER_VDDIOCTRL_LINREG_OFFSET_1STEPS_BELOW);
+}
+
+void mx28_power_setup_5v_detect(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	/* Start 5V detection */
+	clrsetbits_le32(&power_regs->hw_power_5vctrl,
+			POWER_5VCTRL_VBUSVALID_TRSH_MASK,
+			POWER_5VCTRL_VBUSVALID_TRSH_4V4 |
+			POWER_5VCTRL_PWRUP_VBUS_CMPS);
+}
+
+void mx28_src_power_init(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	/* Improve efficieny and reduce transient ripple */
+	writel(POWER_LOOPCTRL_TOGGLE_DIF | POWER_LOOPCTRL_EN_CM_HYST |
+		POWER_LOOPCTRL_EN_DF_HYST, &power_regs->hw_power_loopctrl_set);
+
+	clrsetbits_le32(&power_regs->hw_power_dclimits,
+			POWER_DCLIMITS_POSLIMIT_BUCK_MASK,
+			0x30 << POWER_DCLIMITS_POSLIMIT_BUCK_OFFSET);
+
+	setbits_le32(&power_regs->hw_power_battmonitor,
+			POWER_BATTMONITOR_EN_BATADJ);
+
+	/* Increase the RCSCALE level for quick DCDC response to dynamic load */
+	clrsetbits_le32(&power_regs->hw_power_loopctrl,
+			POWER_LOOPCTRL_EN_RCSCALE_MASK,
+			POWER_LOOPCTRL_RCSCALE_THRESH |
+			POWER_LOOPCTRL_EN_RCSCALE_8X);
+
+	clrsetbits_le32(&power_regs->hw_power_minpwr,
+			POWER_MINPWR_HALFFETS, POWER_MINPWR_DOUBLE_FETS);
+
+	/* 5V to battery handoff ... FIXME */
+	setbits_le32(&power_regs->hw_power_5vctrl, POWER_5VCTRL_DCDC_XFER);
+	early_delay(30);
+	clrbits_le32(&power_regs->hw_power_5vctrl, POWER_5VCTRL_DCDC_XFER);
+}
+
+void mx28_power_init_4p2_params(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	/* Setup 4P2 parameters */
+	clrsetbits_le32(&power_regs->hw_power_dcdc4p2,
+		POWER_DCDC4P2_CMPTRIP_MASK | POWER_DCDC4P2_TRG_MASK,
+		POWER_DCDC4P2_TRG_4V2 | (31 << POWER_DCDC4P2_CMPTRIP_OFFSET));
+
+	clrsetbits_le32(&power_regs->hw_power_5vctrl,
+		POWER_5VCTRL_HEADROOM_ADJ_MASK,
+		0x4 << POWER_5VCTRL_HEADROOM_ADJ_OFFSET);
+
+	clrsetbits_le32(&power_regs->hw_power_dcdc4p2,
+		POWER_DCDC4P2_DROPOUT_CTRL_MASK,
+		POWER_DCDC4P2_DROPOUT_CTRL_100MV |
+		POWER_DCDC4P2_DROPOUT_CTRL_SRC_SEL);
+
+	clrsetbits_le32(&power_regs->hw_power_5vctrl,
+		POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK,
+		0x3f << POWER_5VCTRL_CHARGE_4P2_ILIMIT_OFFSET);
+}
+
+void mx28_enable_4p2_dcdc_input(int xfer)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t tmp, vbus_thresh, vbus_5vdetect, pwd_bo;
+	uint32_t prev_5v_brnout, prev_5v_droop;
+
+	prev_5v_brnout = readl(&power_regs->hw_power_5vctrl) &
+				POWER_5VCTRL_PWDN_5VBRNOUT;
+	prev_5v_droop = readl(&power_regs->hw_power_ctrl) &
+				POWER_CTRL_ENIRQ_VDD5V_DROOP;
+
+	clrbits_le32(&power_regs->hw_power_5vctrl, POWER_5VCTRL_PWDN_5VBRNOUT);
+	writel(POWER_RESET_UNLOCK_KEY | POWER_RESET_PWD_OFF,
+		&power_regs->hw_power_reset);
+
+	clrbits_le32(&power_regs->hw_power_ctrl, POWER_CTRL_ENIRQ_VDD5V_DROOP);
+
+	if (xfer && (readl(&power_regs->hw_power_5vctrl) &
+			POWER_5VCTRL_ENABLE_DCDC)) {
+		return;
+	}
+
+	/*
+	 * Recording orignal values that will be modified temporarlily
+	 * to handle a chip bug. See chip errata for CQ ENGR00115837
+	 */
+	tmp = readl(&power_regs->hw_power_5vctrl);
+	vbus_thresh = tmp & POWER_5VCTRL_VBUSVALID_TRSH_MASK;
+	vbus_5vdetect = tmp & POWER_5VCTRL_VBUSVALID_5VDETECT;
+
+	pwd_bo = readl(&power_regs->hw_power_minpwr) & POWER_MINPWR_PWD_BO;
+
+	/*
+	 * Disable mechanisms that get erroneously tripped by when setting
+	 * the DCDC4P2 EN_DCDC
+	 */
+	clrbits_le32(&power_regs->hw_power_5vctrl,
+		POWER_5VCTRL_VBUSVALID_5VDETECT |
+		POWER_5VCTRL_VBUSVALID_TRSH_MASK);
+
+	writel(POWER_MINPWR_PWD_BO, &power_regs->hw_power_minpwr_set);
+
+	if (xfer) {
+		setbits_le32(&power_regs->hw_power_5vctrl,
+				POWER_5VCTRL_DCDC_XFER);
+		early_delay(20);
+		clrbits_le32(&power_regs->hw_power_5vctrl,
+				POWER_5VCTRL_DCDC_XFER);
+
+		setbits_le32(&power_regs->hw_power_5vctrl,
+				POWER_5VCTRL_ENABLE_DCDC);
+	} else {
+		setbits_le32(&power_regs->hw_power_dcdc4p2,
+				POWER_DCDC4P2_ENABLE_DCDC);
+	}
+
+	early_delay(25);
+
+	clrsetbits_le32(&power_regs->hw_power_5vctrl,
+			POWER_5VCTRL_VBUSVALID_TRSH_MASK, vbus_thresh);
+
+	if (vbus_5vdetect)
+		writel(vbus_5vdetect, &power_regs->hw_power_5vctrl_set);
+
+	if (!pwd_bo)
+		clrbits_le32(&power_regs->hw_power_minpwr, POWER_MINPWR_PWD_BO);
+
+	while (readl(&power_regs->hw_power_ctrl) & POWER_CTRL_VBUS_VALID_IRQ)
+		clrbits_le32(&power_regs->hw_power_ctrl,
+				POWER_CTRL_VBUS_VALID_IRQ);
+
+	if (prev_5v_brnout) {
+		writel(POWER_5VCTRL_PWDN_5VBRNOUT,
+			&power_regs->hw_power_5vctrl_set);
+		writel(POWER_RESET_UNLOCK_KEY,
+			&power_regs->hw_power_reset);
+	} else {
+		writel(POWER_5VCTRL_PWDN_5VBRNOUT,
+			&power_regs->hw_power_5vctrl_clr);
+		writel(POWER_RESET_UNLOCK_KEY | POWER_RESET_PWD_OFF,
+			&power_regs->hw_power_reset);
+	}
+
+	while (readl(&power_regs->hw_power_ctrl) & POWER_CTRL_VDD5V_DROOP_IRQ)
+		clrbits_le32(&power_regs->hw_power_ctrl,
+				POWER_CTRL_VDD5V_DROOP_IRQ);
+
+	if (prev_5v_droop)
+		clrbits_le32(&power_regs->hw_power_ctrl,
+				POWER_CTRL_ENIRQ_VDD5V_DROOP);
+	else
+		setbits_le32(&power_regs->hw_power_ctrl,
+				POWER_CTRL_ENIRQ_VDD5V_DROOP);
+}
+
+void mx28_power_init_4p2_regulator(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t tmp, tmp2;
+
+	setbits_le32(&power_regs->hw_power_dcdc4p2, POWER_DCDC4P2_ENABLE_4P2);
+
+	writel(POWER_CHARGE_ENABLE_LOAD, &power_regs->hw_power_charge_set);
+
+	writel(POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK,
+		&power_regs->hw_power_5vctrl_clr);
+	clrbits_le32(&power_regs->hw_power_dcdc4p2, POWER_DCDC4P2_TRG_MASK);
+
+	/* Power up the 4p2 rail and logic/control */
+	writel(POWER_5VCTRL_PWD_CHARGE_4P2_MASK,
+		&power_regs->hw_power_5vctrl_clr);
+
+	/*
+	 * Start charging up the 4p2 capacitor. We ramp of this charge
+	 * gradually to avoid large inrush current from the 5V cable which can
+	 * cause transients/problems
+	 */
+	mx28_enable_4p2_dcdc_input(0);
+
+	if (readl(&power_regs->hw_power_ctrl) & POWER_CTRL_VBUS_VALID_IRQ) {
+		/*
+		 * If we arrived here, we were unable to recover from mx23 chip
+		 * errata 5837. 4P2 is disabled and sufficient battery power is
+		 * not present. Exiting to not enable DCDC power during 5V
+		 * connected state.
+		 */
+		clrbits_le32(&power_regs->hw_power_dcdc4p2,
+			POWER_DCDC4P2_ENABLE_DCDC);
+		writel(POWER_5VCTRL_PWD_CHARGE_4P2_MASK,
+			&power_regs->hw_power_5vctrl_set);
+		hang();
+	}
+
+	/*
+	 * Here we set the 4p2 brownout level to something very close to 4.2V.
+	 * We then check the brownout status. If the brownout status is false,
+	 * the voltage is already close to the target voltage of 4.2V so we
+	 * can go ahead and set the 4P2 current limit to our max target limit.
+	 * If the brownout status is true, we need to ramp us the current limit
+	 * so that we don't cause large inrush current issues. We step up the
+	 * current limit until the brownout status is false or until we've
+	 * reached our maximum defined 4p2 current limit.
+	 */
+	clrsetbits_le32(&power_regs->hw_power_dcdc4p2,
+			POWER_DCDC4P2_BO_MASK,
+			22 << POWER_DCDC4P2_BO_OFFSET);	/* 4.15V */
+
+	if (!(readl(&power_regs->hw_power_sts) & POWER_STS_DCDC_4P2_BO)) {
+		setbits_le32(&power_regs->hw_power_5vctrl,
+			0x3f << POWER_5VCTRL_CHARGE_4P2_ILIMIT_OFFSET);
+	} else {
+		tmp = (readl(&power_regs->hw_power_5vctrl) &
+			POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK) >>
+			POWER_5VCTRL_CHARGE_4P2_ILIMIT_OFFSET;
+		while (tmp < 0x3f) {
+			if (!(readl(&power_regs->hw_power_sts) &
+					POWER_STS_DCDC_4P2_BO)) {
+				tmp = readl(&power_regs->hw_power_5vctrl);
+				tmp |= POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK;
+				early_delay(100);
+				writel(tmp, &power_regs->hw_power_5vctrl);
+				break;
+			} else {
+				tmp++;
+				tmp2 = readl(&power_regs->hw_power_5vctrl);
+				tmp2 &= ~POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK;
+				tmp2 |= tmp <<
+					POWER_5VCTRL_CHARGE_4P2_ILIMIT_OFFSET;
+				writel(tmp2, &power_regs->hw_power_5vctrl);
+				early_delay(100);
+			}
+		}
+	}
+
+	clrbits_le32(&power_regs->hw_power_dcdc4p2, POWER_DCDC4P2_BO_MASK);
+	writel(POWER_CTRL_DCDC4P2_BO_IRQ, &power_regs->hw_power_ctrl_clr);
+}
+
+void mx28_power_init_dcdc_4p2_source(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	if (!(readl(&power_regs->hw_power_dcdc4p2) &
+		POWER_DCDC4P2_ENABLE_DCDC)) {
+		hang();
+	}
+
+	mx28_enable_4p2_dcdc_input(1);
+
+	if (readl(&power_regs->hw_power_ctrl) & POWER_CTRL_VBUS_VALID_IRQ) {
+		clrbits_le32(&power_regs->hw_power_dcdc4p2,
+			POWER_DCDC4P2_ENABLE_DCDC);
+		writel(POWER_5VCTRL_ENABLE_DCDC,
+			&power_regs->hw_power_5vctrl_clr);
+		writel(POWER_5VCTRL_PWD_CHARGE_4P2_MASK,
+			&power_regs->hw_power_5vctrl_set);
+	}
+}
+
+void mx28_power_enable_4p2(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t vdddctrl, vddactrl, vddioctrl;
+	uint32_t tmp;
+
+	vdddctrl = readl(&power_regs->hw_power_vdddctrl);
+	vddactrl = readl(&power_regs->hw_power_vddactrl);
+	vddioctrl = readl(&power_regs->hw_power_vddioctrl);
+
+	setbits_le32(&power_regs->hw_power_vdddctrl,
+		POWER_VDDDCTRL_DISABLE_FET | POWER_VDDDCTRL_ENABLE_LINREG |
+		POWER_VDDDCTRL_PWDN_BRNOUT);
+
+	setbits_le32(&power_regs->hw_power_vddactrl,
+		POWER_VDDACTRL_DISABLE_FET | POWER_VDDACTRL_ENABLE_LINREG |
+		POWER_VDDACTRL_PWDN_BRNOUT);
+
+	setbits_le32(&power_regs->hw_power_vddioctrl,
+		POWER_VDDIOCTRL_DISABLE_FET | POWER_VDDIOCTRL_PWDN_BRNOUT);
+
+	mx28_power_init_4p2_params();
+	mx28_power_init_4p2_regulator();
+
+	/* Shutdown battery (none present) */
+	clrbits_le32(&power_regs->hw_power_dcdc4p2, POWER_DCDC4P2_BO_MASK);
+	writel(POWER_CTRL_DCDC4P2_BO_IRQ, &power_regs->hw_power_ctrl_clr);
+	writel(POWER_CTRL_ENIRQ_DCDC4P2_BO, &power_regs->hw_power_ctrl_clr);
+
+	mx28_power_init_dcdc_4p2_source();
+
+	writel(vdddctrl, &power_regs->hw_power_vdddctrl);
+	early_delay(20);
+	writel(vddactrl, &power_regs->hw_power_vddactrl);
+	early_delay(20);
+	writel(vddioctrl, &power_regs->hw_power_vddioctrl);
+
+	/*
+	 * Check if FET is enabled on either powerout and if so,
+	 * disable load.
+	 */
+	tmp = 0;
+	tmp |= !(readl(&power_regs->hw_power_vdddctrl) &
+			POWER_VDDDCTRL_DISABLE_FET);
+	tmp |= !(readl(&power_regs->hw_power_vddactrl) &
+			POWER_VDDACTRL_DISABLE_FET);
+	tmp |= !(readl(&power_regs->hw_power_vddioctrl) &
+			POWER_VDDIOCTRL_DISABLE_FET);
+	if (tmp)
+		writel(POWER_CHARGE_ENABLE_LOAD,
+			&power_regs->hw_power_charge_clr);
+}
+
+void mx28_boot_valid_5v(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	/*
+	 * Use VBUSVALID level instead of VDD5V_GT_VDDIO level to trigger a 5V
+	 * disconnect event. FIXME
+	 */
+	writel(POWER_5VCTRL_VBUSVALID_5VDETECT,
+		&power_regs->hw_power_5vctrl_set);
+
+	/* Configure polarity to check for 5V disconnection. */
+	writel(POWER_CTRL_POLARITY_VBUSVALID |
+		POWER_CTRL_POLARITY_VDD5V_GT_VDDIO,
+		&power_regs->hw_power_ctrl_clr);
+
+	writel(POWER_CTRL_VBUS_VALID_IRQ | POWER_CTRL_VDD5V_GT_VDDIO_IRQ,
+		&power_regs->hw_power_ctrl_clr);
+
+	mx28_power_enable_4p2();
+}
+
+void mx28_powerdown(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	writel(POWER_RESET_UNLOCK_KEY, &power_regs->hw_power_reset);
+	writel(POWER_RESET_UNLOCK_KEY | POWER_RESET_PWD_OFF,
+		&power_regs->hw_power_reset);
+}
+
+void mx28_handle_5v_conflict(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t tmp;
+
+	setbits_le32(&power_regs->hw_power_vddioctrl,
+			POWER_VDDIOCTRL_BO_OFFSET_MASK);
+
+	for (;;) {
+		tmp = readl(&power_regs->hw_power_sts);
+
+		if (tmp & POWER_STS_VDDIO_BO) {
+			mx28_powerdown();
+			break;
+		}
+
+		if (tmp & POWER_STS_VDD5V_GT_VDDIO) {
+			mx28_boot_valid_5v();
+			break;
+		} else {
+			mx28_powerdown();
+			break;
+		}
+	}
+}
+
+int mx28_get_batt_volt(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t volt = readl(&power_regs->hw_power_battmonitor);
+	volt &= POWER_BATTMONITOR_BATT_VAL_MASK;
+	volt >>= POWER_BATTMONITOR_BATT_VAL_OFFSET;
+	volt *= 8;
+	return volt;
+}
+
+int mx28_is_batt_ready(void)
+{
+	return (mx28_get_batt_volt() >= 3600);
+}
+
+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) {
+		mx28_boot_valid_5v();
+		return;
+	}
+
+	early_delay(1000);
+	if (readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO) {
+		mx28_boot_valid_5v();
+		return;
+	}
+
+	mx28_handle_5v_conflict();
+}
+
+void mx28_init_batt_bo(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	/* Brownout at 3V */
+	clrsetbits_le32(&power_regs->hw_power_battmonitor,
+		POWER_BATTMONITOR_BRWNOUT_LVL_MASK,
+		15 << POWER_BATTMONITOR_BRWNOUT_LVL_OFFSET);
+
+	writel(POWER_CTRL_BATT_BO_IRQ, &power_regs->hw_power_ctrl_clr);
+	writel(POWER_CTRL_ENIRQ_BATT_BO, &power_regs->hw_power_ctrl_clr);
+}
+
+void mx28_switch_vddd_to_dcdc_source(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	clrsetbits_le32(&power_regs->hw_power_vdddctrl,
+		POWER_VDDDCTRL_LINREG_OFFSET_MASK,
+		POWER_VDDDCTRL_LINREG_OFFSET_1STEPS_BELOW);
+
+	clrbits_le32(&power_regs->hw_power_vdddctrl,
+		POWER_VDDDCTRL_DISABLE_FET | POWER_VDDDCTRL_ENABLE_LINREG |
+		POWER_VDDDCTRL_DISABLE_STEPPING);
+}
+
+int mx28_is_batt_good(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t volt;
+
+	volt = readl(&power_regs->hw_power_battmonitor);
+	volt &= POWER_BATTMONITOR_BATT_VAL_MASK;
+	volt >>= POWER_BATTMONITOR_BATT_VAL_OFFSET;
+	volt *= 8;
+
+	if ((volt >= 2400) && (volt <= 4300))
+		return 1;
+
+	clrsetbits_le32(&power_regs->hw_power_5vctrl,
+		POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK,
+		0x3 << POWER_5VCTRL_CHARGE_4P2_ILIMIT_OFFSET);
+	writel(POWER_5VCTRL_PWD_CHARGE_4P2_MASK,
+		&power_regs->hw_power_5vctrl_clr);
+
+	clrsetbits_le32(&power_regs->hw_power_charge,
+		POWER_CHARGE_STOP_ILIMIT_MASK | POWER_CHARGE_BATTCHRG_I_MASK,
+		POWER_CHARGE_STOP_ILIMIT_10MA | 0x3);
+
+	writel(POWER_CHARGE_PWD_BATTCHRG, &power_regs->hw_power_charge_clr);
+	writel(POWER_5VCTRL_PWD_CHARGE_4P2_MASK,
+		&power_regs->hw_power_5vctrl_clr);
+
+	early_delay(500000);
+
+	volt = readl(&power_regs->hw_power_battmonitor);
+	volt &= POWER_BATTMONITOR_BATT_VAL_MASK;
+	volt >>= POWER_BATTMONITOR_BATT_VAL_OFFSET;
+	volt *= 8;
+
+	if (volt >= 3500)
+		return 0;
+
+	if (volt >= 2400)
+		return 1;
+
+	writel(POWER_CHARGE_STOP_ILIMIT_MASK | POWER_CHARGE_BATTCHRG_I_MASK,
+		&power_regs->hw_power_charge_clr);
+	writel(POWER_CHARGE_PWD_BATTCHRG, &power_regs->hw_power_charge_set);
+
+	return 0;
+}
+
+void mx28_power_configure_power_source(void)
+{
+	mx28_src_power_init();
+
+	mx28_5v_boot();
+	mx28_power_clock2pll();
+
+	mx28_init_batt_bo();
+	mx28_switch_vddd_to_dcdc_source();
+}
+
+void mx28_enable_output_rail_protection(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	writel(POWER_CTRL_VDDD_BO_IRQ | POWER_CTRL_VDDA_BO_IRQ |
+		POWER_CTRL_VDDIO_BO_IRQ, &power_regs->hw_power_ctrl_clr);
+
+	setbits_le32(&power_regs->hw_power_vdddctrl,
+			POWER_VDDDCTRL_PWDN_BRNOUT);
+
+	setbits_le32(&power_regs->hw_power_vddactrl,
+			POWER_VDDACTRL_PWDN_BRNOUT);
+
+	setbits_le32(&power_regs->hw_power_vddioctrl,
+			POWER_VDDIOCTRL_PWDN_BRNOUT);
+}
+
+int mx28_get_vddio_power_source_off(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t tmp;
+
+	if (readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO) {
+		tmp = readl(&power_regs->hw_power_vddioctrl);
+		if (tmp & POWER_VDDIOCTRL_DISABLE_FET) {
+			if ((tmp & POWER_VDDIOCTRL_LINREG_OFFSET_MASK) ==
+				POWER_VDDDCTRL_LINREG_OFFSET_0STEPS) {
+				return 1;
+			}
+		}
+
+		if (!(readl(&power_regs->hw_power_5vctrl) &
+			POWER_5VCTRL_ENABLE_DCDC)) {
+			if ((tmp & POWER_VDDIOCTRL_LINREG_OFFSET_MASK) ==
+				POWER_VDDDCTRL_LINREG_OFFSET_0STEPS) {
+				return 1;
+			}
+		}
+	}
+
+	return 0;
+
+}
+
+int mx28_get_vddd_power_source_off(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t tmp;
+
+	tmp = readl(&power_regs->hw_power_vdddctrl);
+	if (tmp & POWER_VDDDCTRL_DISABLE_FET) {
+		if ((tmp & POWER_VDDDCTRL_LINREG_OFFSET_MASK) ==
+			POWER_VDDDCTRL_LINREG_OFFSET_0STEPS) {
+			return 1;
+		}
+	}
+
+	if (readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO) {
+		if (!(readl(&power_regs->hw_power_5vctrl) &
+			POWER_5VCTRL_ENABLE_DCDC)) {
+			return 1;
+		}
+	}
+
+	if (!(tmp & POWER_VDDDCTRL_ENABLE_LINREG)) {
+		if ((tmp & POWER_VDDDCTRL_LINREG_OFFSET_MASK) ==
+			POWER_VDDDCTRL_LINREG_OFFSET_1STEPS_BELOW) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+void mx28_power_set_vddio(uint32_t new_target, uint32_t new_brownout)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t cur_target, diff, bo_int = 0;
+	uint32_t powered_by_linreg = 0;
+
+	new_brownout = new_target - new_brownout;
+
+	cur_target = readl(&power_regs->hw_power_vddioctrl);
+	cur_target &= POWER_VDDIOCTRL_TRG_MASK;
+	cur_target *= 50;	/* 50 mV step*/
+	cur_target += 2800;	/* 2800 mV lowest */
+
+	powered_by_linreg = mx28_get_vddio_power_source_off();
+	if (new_target > cur_target) {
+
+		if (powered_by_linreg) {
+			bo_int = readl(&power_regs->hw_power_vddioctrl);
+			clrbits_le32(&power_regs->hw_power_vddioctrl,
+					POWER_CTRL_ENIRQ_VDDIO_BO);
+		}
+
+		setbits_le32(&power_regs->hw_power_vddioctrl,
+				POWER_VDDIOCTRL_BO_OFFSET_MASK);
+		do {
+			if (new_target - cur_target > 100)
+				diff = cur_target + 100;
+			else
+				diff = new_target;
+
+			diff -= 2800;
+			diff /= 50;
+
+			clrsetbits_le32(&power_regs->hw_power_vddioctrl,
+				POWER_VDDIOCTRL_TRG_MASK, diff);
+
+			if (powered_by_linreg)
+				early_delay(1500);
+			else {
+				while (!(readl(&power_regs->hw_power_sts) &
+					POWER_STS_DC_OK))
+					;
+
+			}
+
+			cur_target = readl(&power_regs->hw_power_vddioctrl);
+			cur_target &= POWER_VDDIOCTRL_TRG_MASK;
+			cur_target *= 50;	/* 50 mV step*/
+			cur_target += 2800;	/* 2800 mV lowest */
+		} while (new_target > cur_target);
+
+		if (powered_by_linreg) {
+			writel(POWER_CTRL_VDDIO_BO_IRQ,
+				&power_regs->hw_power_ctrl_clr);
+			if (bo_int & POWER_CTRL_ENIRQ_VDDIO_BO)
+				setbits_le32(&power_regs->hw_power_vddioctrl,
+						POWER_CTRL_ENIRQ_VDDIO_BO);
+		}
+	} else {
+		do {
+			if (cur_target - new_target > 100)
+				diff = cur_target - 100;
+			else
+				diff = new_target;
+
+			diff -= 2800;
+			diff /= 50;
+
+			clrsetbits_le32(&power_regs->hw_power_vddioctrl,
+				POWER_VDDIOCTRL_TRG_MASK, diff);
+
+			if (powered_by_linreg)
+				early_delay(1500);
+			else {
+				while (!(readl(&power_regs->hw_power_sts) &
+					POWER_STS_DC_OK))
+					;
+
+			}
+
+			cur_target = readl(&power_regs->hw_power_vddioctrl);
+			cur_target &= POWER_VDDIOCTRL_TRG_MASK;
+			cur_target *= 50;	/* 50 mV step*/
+			cur_target += 2800;	/* 2800 mV lowest */
+		} while (new_target < cur_target);
+	}
+
+	clrsetbits_le32(&power_regs->hw_power_vddioctrl,
+			POWER_VDDDCTRL_BO_OFFSET_MASK,
+			new_brownout << POWER_VDDDCTRL_BO_OFFSET_OFFSET);
+}
+
+void mx28_power_set_vddd(uint32_t new_target, uint32_t new_brownout)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+	uint32_t cur_target, diff, bo_int = 0;
+	uint32_t powered_by_linreg = 0;
+
+	new_brownout = new_target - new_brownout;
+
+	cur_target = readl(&power_regs->hw_power_vdddctrl);
+	cur_target &= POWER_VDDDCTRL_TRG_MASK;
+	cur_target *= 25;	/* 25 mV step*/
+	cur_target += 800;	/* 800 mV lowest */
+
+	powered_by_linreg = mx28_get_vddd_power_source_off();
+	if (new_target > cur_target) {
+		if (powered_by_linreg) {
+			bo_int = readl(&power_regs->hw_power_vdddctrl);
+			clrbits_le32(&power_regs->hw_power_vdddctrl,
+					POWER_CTRL_ENIRQ_VDDD_BO);
+		}
+
+		setbits_le32(&power_regs->hw_power_vdddctrl,
+				POWER_VDDDCTRL_BO_OFFSET_MASK);
+
+		do {
+			if (new_target - cur_target > 100)
+				diff = cur_target + 100;
+			else
+				diff = new_target;
+
+			diff -= 800;
+			diff /= 25;
+
+			clrsetbits_le32(&power_regs->hw_power_vdddctrl,
+				POWER_VDDDCTRL_TRG_MASK, diff);
+
+			if (powered_by_linreg)
+				early_delay(1500);
+			else {
+				while (!(readl(&power_regs->hw_power_sts) &
+					POWER_STS_DC_OK))
+					;
+
+			}
+
+			cur_target = readl(&power_regs->hw_power_vdddctrl);
+			cur_target &= POWER_VDDDCTRL_TRG_MASK;
+			cur_target *= 25;	/* 25 mV step*/
+			cur_target += 800;	/* 800 mV lowest */
+		} while (new_target > cur_target);
+
+		if (powered_by_linreg) {
+			writel(POWER_CTRL_VDDD_BO_IRQ,
+				&power_regs->hw_power_ctrl_clr);
+			if (bo_int & POWER_CTRL_ENIRQ_VDDD_BO)
+				setbits_le32(&power_regs->hw_power_vdddctrl,
+						POWER_CTRL_ENIRQ_VDDD_BO);
+		}
+	} else {
+		do {
+			if (cur_target - new_target > 100)
+				diff = cur_target - 100;
+			else
+				diff = new_target;
+
+			diff -= 800;
+			diff /= 25;
+
+			clrsetbits_le32(&power_regs->hw_power_vdddctrl,
+					POWER_VDDDCTRL_TRG_MASK, diff);
+
+			if (powered_by_linreg)
+				early_delay(1500);
+			else {
+				while (!(readl(&power_regs->hw_power_sts) &
+					POWER_STS_DC_OK))
+					;
+
+			}
+
+			cur_target = readl(&power_regs->hw_power_vdddctrl);
+			cur_target &= POWER_VDDDCTRL_TRG_MASK;
+			cur_target *= 25;	/* 25 mV step*/
+			cur_target += 800;	/* 800 mV lowest */
+		} while (new_target < cur_target);
+	}
+
+	clrsetbits_le32(&power_regs->hw_power_vdddctrl,
+			POWER_VDDDCTRL_BO_OFFSET_MASK,
+			new_brownout << POWER_VDDDCTRL_BO_OFFSET_OFFSET);
+}
+
+void mx28_power_init(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	mx28_power_clock2xtal();
+	mx28_power_clear_auto_restart();
+	mx28_power_set_linreg();
+	mx28_power_setup_5v_detect();
+	mx28_power_configure_power_source();
+	mx28_enable_output_rail_protection();
+
+	mx28_power_set_vddio(3300, 3150);
+
+	mx28_power_set_vddd(1350, 1200);
+
+	writel(POWER_CTRL_VDDD_BO_IRQ | POWER_CTRL_VDDA_BO_IRQ |
+		POWER_CTRL_VDDIO_BO_IRQ | POWER_CTRL_VDD5V_DROOP_IRQ |
+		POWER_CTRL_VBUS_VALID_IRQ | POWER_CTRL_BATT_BO_IRQ |
+		POWER_CTRL_DCDC4P2_BO_IRQ, &power_regs->hw_power_ctrl_clr);
+
+	writel(POWER_5VCTRL_PWDN_5VBRNOUT, &power_regs->hw_power_5vctrl_set);
+
+	early_delay(1000);
+}
+
+#ifdef	CONFIG_SPL_MX28_PSWITCH_WAIT
+void mx28_power_wait_pswitch(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	while (!(readl(&power_regs->hw_power_sts) & POWER_STS_PSWITCH_MASK))
+		;
+}
+#endif