[U-Boot] [v3 PATCH 0/3] Add support for booting mx28 boards without a battery

[U-Boot] [v3 PATCH 0/3] Add support for booting mx28 boards without a battery

[Graeme Russ]

This series adds support for booting mx28 based boards which do not
include a battery as per Freescale application note AN4199

Patch 1 adds SPL debug output to help track down where early init
of the power block and SDRAM fails (define DEBUG and
CONFIG_SPL_SERIAL_SUPPORT in order to enable)

Patch 2 (which implements booting without a battery) is based on a patch
submitted to the Freescale community forums by Damien Gotfroi (define
CONFIG_SYS_MXS_VDD5V_ONLY to enable)

Patch 3 adds a useful halt upon completion of SPL in the case that the
board is booted in JTAG mode. If SPL debug is enabled, 'Waiting for JTAG
user' will be printed to the console when SPL has completed

Changes in v2
 - Dropped patch which adds Reachtech G2C1 board in order to allow the
   'no battery' functionality to be mainlined as soon as possible
 - Removed the patch which moved the PLL power up from spl_power_init.c
   to spl_mem_init.c - This patch will be considered in future rework
   of the power block and SDRAM initialisation code

Changes in v3
 - Clarified commit message for patch 2
 - Used explicit define in patch 2 (define == 0x00, so no functional
   change)
 - Removed extra blank line from patch #3


Graeme Russ (3):
  arm: mxs: Add debug outputs and comments to mxs SPL source files
  arm: mxs: Enable booting of mx28 without battery
  arm: mxs: Add 'Wait for JTAG user' if booted in JTAG mode

 arch/arm/cpu/arm926ejs/mxs/spl_boot.c       |   6 ++
 arch/arm/cpu/arm926ejs/mxs/spl_lradc_init.c |  13 +++-
 arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c   |  18 +++++
 arch/arm/cpu/arm926ejs/mxs/spl_power_init.c | 110 ++++++++++++++++++++++++++--
 arch/arm/include/asm/arch-mxs/sys_proto.h   |  17 +++++
 5 files changed, 157 insertions(+), 7 deletions(-)

-- 
1.9.3

[U-Boot] [v3 PATCH 1/3] arm: mxs: Add debug outputs and comments to mxs SPL source files

[Graeme Russ]

It is difficult to track down fail to boot issues in the mxs SPL.
Implement the following to make it easier:
 - Add debug outputs to allow tracing of SPL progress in order to track
where failure to boot occurs. DEUBUG and CONFIG_SPL_SERIAL_SUPPORT must
be defined to enable debug output in SPL
 - Add TODO comments where it is not clear if the code is doing what it
is meant to be doing, even tough the board boots properly (these comments
refer to existing code, not to any code added by this patch)

Signed-off-by: Graeme Russ <gruss@tss-engineering.com>
---

Changes in v2
 - Add missing newlines
 - Add commit message

Changed in v3
 - None

---
 arch/arm/cpu/arm926ejs/mxs/spl_boot.c       |   1 +
 arch/arm/cpu/arm926ejs/mxs/spl_lradc_init.c |  13 +++-
 arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c   |  18 +++++
 arch/arm/cpu/arm926ejs/mxs/spl_power_init.c | 100 +++++++++++++++++++++++++++-
 4 files changed, 127 insertions(+), 5 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
index d29b9aa..2a5f817 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
@@ -147,6 +147,7 @@ void mxs_common_spl_init(const uint32_t arg, const uint32_t *resptr,
 	mxs_iomux_setup_multiple_pads(iomux_setup, iomux_size);
 
 	mxs_spl_console_init();
+	debug("SPL: Serial Console Initialised\n");
 
 	mxs_power_init();
 
diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_lradc_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_lradc_init.c
index cdfcddd..96bd32f 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_lradc_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_lradc_init.c
@@ -18,6 +18,8 @@ void mxs_lradc_init(void)
 {
 	struct mxs_lradc_regs *regs = (struct mxs_lradc_regs *)MXS_LRADC_BASE;
 
+	debug("SPL: Initialisating LRADC\n");
+
 	writel(LRADC_CTRL0_SFTRST, &regs->hw_lradc_ctrl0_clr);
 	writel(LRADC_CTRL0_CLKGATE, &regs->hw_lradc_ctrl0_clr);
 	writel(LRADC_CTRL0_ONCHIP_GROUNDREF, &regs->hw_lradc_ctrl0_clr);
@@ -37,9 +39,15 @@ void mxs_lradc_enable_batt_measurement(void)
 {
 	struct mxs_lradc_regs *regs = (struct mxs_lradc_regs *)MXS_LRADC_BASE;
 
+	debug("SPL: Enabling LRADC battery measurement\n");
+
 	/* Check if the channel is present at all. */
-	if (!(readl(&regs->hw_lradc_status) & LRADC_STATUS_CHANNEL7_PRESENT))
+	if (!(readl(&regs->hw_lradc_status) & LRADC_STATUS_CHANNEL7_PRESENT)) {
+		debug("SPL: LRADC channel 7 is not present - aborting\n");
 		return;
+	}
+
+	debug("SPL: LRADC channel 7 is present - configuring\n");
 
 	writel(LRADC_CTRL1_LRADC7_IRQ_EN, &regs->hw_lradc_ctrl1_clr);
 	writel(LRADC_CTRL1_LRADC7_IRQ, &regs->hw_lradc_ctrl1_clr);
@@ -65,6 +73,7 @@ void mxs_lradc_enable_batt_measurement(void)
 		100, &regs->hw_lradc_delay3);
 
 	writel(0xffffffff, &regs->hw_lradc_ch7_clr);
-
 	writel(LRADC_DELAY_KICK, &regs->hw_lradc_delay3_set);
+
+	debug("SPL: LRADC channel 7 configuration complete\n");
 }
diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c
index 97ef67d..a744e5d 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c
@@ -92,6 +92,7 @@ static uint32_t dram_vals[] = {
 
 __weak void mxs_adjust_memory_params(uint32_t *dram_vals)
 {
+	debug("SPL: Using default SDRAM parameters\n");
 }
 
 #ifdef CONFIG_MX28
@@ -99,8 +100,10 @@ static void initialize_dram_values(void)
 {
 	int i;
 
+	debug("SPL: Setting mx28 board specific SDRAM parameters\n");
 	mxs_adjust_memory_params(dram_vals);
 
+	debug("SPL: Applying SDRAM parameters\n");
 	for (i = 0; i < ARRAY_SIZE(dram_vals); i++)
 		writel(dram_vals[i], MXS_DRAM_BASE + (4 * i));
 }
@@ -109,6 +112,7 @@ static void initialize_dram_values(void)
 {
 	int i;
 
+	debug("SPL: Setting mx23 board specific SDRAM parameters\n");
 	mxs_adjust_memory_params(dram_vals);
 
 	/*
@@ -120,6 +124,7 @@ static void initialize_dram_values(void)
 	 * HW_DRAM_CTL8 is setup as the last element.
 	 * So skip the initialization of these HW_DRAM_CTL registers.
 	 */
+	debug("SPL: Applying SDRAM parameters\n");
 	for (i = 0; i < ARRAY_SIZE(dram_vals); i++) {
 		if (i == 8 || i == 27 || i == 28 || i == 35)
 			continue;
@@ -146,6 +151,8 @@ static void mxs_mem_init_clock(void)
 	const unsigned char divider = 21;
 #endif
 
+	debug("SPL: Initialising FRAC0\n");
+
 	/* Gate EMI clock */
 	writeb(CLKCTRL_FRAC_CLKGATE,
 		&clkctrl_regs->hw_clkctrl_frac0_set[CLKCTRL_FRAC0_EMI]);
@@ -170,6 +177,7 @@ static void mxs_mem_init_clock(void)
 		&clkctrl_regs->hw_clkctrl_clkseq_clr);
 
 	early_delay(10000);
+	debug("SPL: FRAC0 Initialised\n");
 }
 
 static void mxs_mem_setup_cpu_and_hbus(void)
@@ -177,6 +185,8 @@ static void mxs_mem_setup_cpu_and_hbus(void)
 	struct mxs_clkctrl_regs *clkctrl_regs =
 		(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
 
+	debug("SPL: Setting CPU and HBUS clock frequencies\n");
+
 	/* Set fractional divider for ref_cpu to 480 * 18 / 19 = 454MHz
 	 * and ungate CPU clock */
 	writeb(19 & CLKCTRL_FRAC_FRAC_MASK,
@@ -209,6 +219,8 @@ static void mxs_mem_setup_vdda(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Configuring VDDA\n");
+
 	writel((0xc << POWER_VDDACTRL_TRG_OFFSET) |
 		(0x7 << POWER_VDDACTRL_BO_OFFSET_OFFSET) |
 		POWER_VDDACTRL_LINREG_OFFSET_1STEPS_BELOW,
@@ -240,6 +252,8 @@ static void mx23_mem_setup_vddmem(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Setting mx23 VDDMEM\n");
+
 	/* We must wait before and after disabling the current limiter! */
 	early_delay(10000);
 
@@ -252,6 +266,8 @@ static void mx23_mem_setup_vddmem(void)
 
 static void mx23_mem_init(void)
 {
+	debug("SPL: Initialising mx23 SDRAM Controller\n");
+
 	/*
 	 * Reset/ungate the EMI block. This is essential, otherwise the system
 	 * suffers from memory instability. This thing is mx23 specific and is
@@ -297,6 +313,8 @@ static void mx28_mem_init(void)
 	struct mxs_pinctrl_regs *pinctrl_regs =
 		(struct mxs_pinctrl_regs *)MXS_PINCTRL_BASE;
 
+	debug("SPL: Initialising mx28 SDRAM Controller\n");
+
 	/* Set DDR2 mode */
 	writel(PINCTRL_EMI_DS_CTRL_DDR_MODE_DDR2,
 		&pinctrl_regs->hw_pinctrl_emi_ds_ctrl_set);
diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
index 1c54ab7..7fb734e 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
@@ -26,6 +26,8 @@ static void mxs_power_clock2xtal(void)
 	struct mxs_clkctrl_regs *clkctrl_regs =
 		(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
 
+	debug("SPL: Switching CPU clock to 24MHz XTAL\n");
+
 	/* Set XTAL as CPU reference clock */
 	writel(CLKCTRL_CLKSEQ_BYPASS_CPU,
 		&clkctrl_regs->hw_clkctrl_clkseq_set);
@@ -43,9 +45,23 @@ static void mxs_power_clock2pll(void)
 	struct mxs_clkctrl_regs *clkctrl_regs =
 		(struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
 
+	debug("SPL: Switching CPU core clock source to PLL\n");
+
+	/*
+	 * TODO: Are we really? It looks like we turn on PLL0, but we then
+	 * set the CLKCTRL_CLKSEQ_BYPASS_CPU bit of the (which was already
+	 * set by mxs_power_clock2xtal()). Clearing this bit here seems to
+	 * introduce some instability (causing the CPU core to hang). Maybe
+	 * we aren't giving PLL0 enough time to stabilise?
+	 */
 	setbits_le32(&clkctrl_regs->hw_clkctrl_pll0ctrl0,
 			CLKCTRL_PLL0CTRL0_POWER);
 	early_delay(100);
+
+	/*
+	 * TODO: Should the PLL0 FORCE_LOCK bit be set here followed be a
+	 * wait on the PLL0 LOCK bit?
+	 */
 	setbits_le32(&clkctrl_regs->hw_clkctrl_clkseq,
 			CLKCTRL_CLKSEQ_BYPASS_CPU);
 }
@@ -62,6 +78,8 @@ static void mxs_power_set_auto_restart(void)
 	struct mxs_rtc_regs *rtc_regs =
 		(struct mxs_rtc_regs *)MXS_RTC_BASE;
 
+	debug("SPL: Setting auto-restart bit\n");
+
 	writel(RTC_CTRL_SFTRST, &rtc_regs->hw_rtc_ctrl_clr);
 	while (readl(&rtc_regs->hw_rtc_ctrl) & RTC_CTRL_SFTRST)
 		;
@@ -101,14 +119,17 @@ static void mxs_power_set_linreg(void)
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
 	/* Set linear regulator 25mV below switching converter */
+	debug("SPL: Setting VDDD 25mV below DC-DC converters\n");
 	clrsetbits_le32(&power_regs->hw_power_vdddctrl,
 			POWER_VDDDCTRL_LINREG_OFFSET_MASK,
 			POWER_VDDDCTRL_LINREG_OFFSET_1STEPS_BELOW);
 
+	debug("SPL: Setting VDDA 25mV below DC-DC converters\n");
 	clrsetbits_le32(&power_regs->hw_power_vddactrl,
 			POWER_VDDACTRL_LINREG_OFFSET_MASK,
 			POWER_VDDACTRL_LINREG_OFFSET_1STEPS_BELOW);
 
+	debug("SPL: Setting VDDIO 25mV below DC-DC converters\n");
 	clrsetbits_le32(&power_regs->hw_power_vddioctrl,
 			POWER_VDDIOCTRL_LINREG_OFFSET_MASK,
 			POWER_VDDIOCTRL_LINREG_OFFSET_1STEPS_BELOW);
@@ -127,6 +148,8 @@ static int mxs_get_batt_volt(void)
 	volt &= POWER_BATTMONITOR_BATT_VAL_MASK;
 	volt >>= POWER_BATTMONITOR_BATT_VAL_OFFSET;
 	volt *= 8;
+
+	debug("SPL: Battery Voltage = %dmV\n", volt);
 	return volt;
 }
 
@@ -154,8 +177,10 @@ static int mxs_is_batt_good(void)
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 	uint32_t volt = mxs_get_batt_volt();
 
-	if ((volt >= 2400) && (volt <= 4300))
+	if ((volt >= 2400) && (volt <= 4300)) {
+		debug("SPL: Battery is good\n");
 		return 1;
+	}
 
 	clrsetbits_le32(&power_regs->hw_power_5vctrl,
 		POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK,
@@ -175,16 +200,21 @@ static int mxs_is_batt_good(void)
 
 	volt = mxs_get_batt_volt();
 
-	if (volt >= 3500)
+	if (volt >= 3500) {
+		debug("SPL: Battery Voltage too high\n");
 		return 0;
+	}
 
-	if (volt >= 2400)
+	if (volt >= 2400) {
+		debug("SPL: Battery is good\n");
 		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);
 
+	debug("SPL: Battery Voltage too low\n");
 	return 0;
 }
 
@@ -203,6 +233,7 @@ static void mxs_power_setup_5v_detect(void)
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
 	/* Start 5V detection */
+	debug("SPL: Starting 5V input detection comparator\n");
 	clrsetbits_le32(&power_regs->hw_power_5vctrl,
 			POWER_5VCTRL_VBUSVALID_TRSH_MASK,
 			POWER_5VCTRL_VBUSVALID_TRSH_4V4 |
@@ -220,6 +251,8 @@ static void mxs_src_power_init(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Pre-Configuring power block\n");
+
 	/* 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);
@@ -257,6 +290,8 @@ static void mxs_power_init_4p2_params(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Configuring common 4P2 regulator params\n");
+
 	/* Setup 4P2 parameters */
 	clrsetbits_le32(&power_regs->hw_power_dcdc4p2,
 		POWER_DCDC4P2_CMPTRIP_MASK | POWER_DCDC4P2_TRG_MASK,
@@ -289,6 +324,8 @@ static void mxs_enable_4p2_dcdc_input(int xfer)
 	uint32_t tmp, vbus_thresh, vbus_5vdetect, pwd_bo;
 	uint32_t prev_5v_brnout, prev_5v_droop;
 
+	debug("SPL: %s 4P2 DC-DC Input\n", xfer ? "Enabling" : "Disabling");
+
 	prev_5v_brnout = readl(&power_regs->hw_power_5vctrl) &
 				POWER_5VCTRL_PWDN_5VBRNOUT;
 	prev_5v_droop = readl(&power_regs->hw_power_ctrl) &
@@ -390,6 +427,8 @@ static void mxs_power_init_4p2_regulator(void)
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 	uint32_t tmp, tmp2;
 
+	debug("SPL: Enabling 4P2 regulator\n");
+
 	setbits_le32(&power_regs->hw_power_dcdc4p2, POWER_DCDC4P2_ENABLE_4P2);
 
 	writel(POWER_CHARGE_ENABLE_LOAD, &power_regs->hw_power_charge_set);
@@ -407,6 +446,7 @@ static void mxs_power_init_4p2_regulator(void)
 	 * gradually to avoid large inrush current from the 5V cable which can
 	 * cause transients/problems
 	 */
+	debug("SPL: Charging 4P2 capacitor\n");
 	mxs_enable_4p2_dcdc_input(0);
 
 	if (readl(&power_regs->hw_power_ctrl) & POWER_CTRL_VBUS_VALID_IRQ) {
@@ -420,6 +460,8 @@ static void mxs_power_init_4p2_regulator(void)
 			POWER_DCDC4P2_ENABLE_DCDC);
 		writel(POWER_5VCTRL_PWD_CHARGE_4P2_MASK,
 			&power_regs->hw_power_5vctrl_set);
+
+		debug("SPL: Unable to recover from mx23 errata 5837\n");
 		hang();
 	}
 
@@ -433,6 +475,7 @@ static void mxs_power_init_4p2_regulator(void)
 	 * current limit until the brownout status is false or until we've
 	 * reached our maximum defined 4p2 current limit.
 	 */
+	debug("SPL: Setting 4P2 brownout level\n");
 	clrsetbits_le32(&power_regs->hw_power_dcdc4p2,
 			POWER_DCDC4P2_BO_MASK,
 			22 << POWER_DCDC4P2_BO_OFFSET);	/* 4.15V */
@@ -479,8 +522,11 @@ static void mxs_power_init_dcdc_4p2_source(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Switching DC-DC converters to 4P2\n");
+
 	if (!(readl(&power_regs->hw_power_dcdc4p2) &
 		POWER_DCDC4P2_ENABLE_DCDC)) {
+		debug("SPL: Already switched - aborting\n");
 		hang();
 	}
 
@@ -509,6 +555,8 @@ static void mxs_power_enable_4p2(void)
 	uint32_t vdddctrl, vddactrl, vddioctrl;
 	uint32_t tmp;
 
+	debug("SPL: Powering up 4P2 regulator\n");
+
 	vdddctrl = readl(&power_regs->hw_power_vdddctrl);
 	vddactrl = readl(&power_regs->hw_power_vddactrl);
 	vddioctrl = readl(&power_regs->hw_power_vddioctrl);
@@ -559,6 +607,8 @@ static void mxs_power_enable_4p2(void)
 	if (tmp)
 		writel(POWER_CHARGE_ENABLE_LOAD,
 			&power_regs->hw_power_charge_clr);
+
+	debug("SPL: 4P2 regulator powered-up\n");
 }
 
 /**
@@ -574,6 +624,8 @@ static void mxs_boot_valid_5v(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Booting from 5V supply\n");
+
 	/*
 	 * Use VBUSVALID level instead of VDD5V_GT_VDDIO level to trigger a 5V
 	 * disconnect event. FIXME
@@ -601,6 +653,9 @@ static void mxs_powerdown(void)
 {
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
+
+	debug("Powering Down\n");
+
 	writel(POWER_RESET_UNLOCK_KEY, &power_regs->hw_power_reset);
 	writel(POWER_RESET_UNLOCK_KEY | POWER_RESET_PWD_OFF,
 		&power_regs->hw_power_reset);
@@ -617,6 +672,8 @@ static void mxs_batt_boot(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Configuring power block to boot from battery\n");
+
 	clrbits_le32(&power_regs->hw_power_5vctrl, POWER_5VCTRL_PWDN_5VBRNOUT);
 	clrbits_le32(&power_regs->hw_power_5vctrl, POWER_5VCTRL_ENABLE_DCDC);
 
@@ -672,6 +729,8 @@ static void mxs_handle_5v_conflict(void)
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 	uint32_t tmp;
 
+	debug("SPL: Resolving 5V conflict\n");
+
 	setbits_le32(&power_regs->hw_power_vddioctrl,
 			POWER_VDDIOCTRL_BO_OFFSET_MASK);
 
@@ -683,19 +742,27 @@ static void mxs_handle_5v_conflict(void)
 			 * VDDIO has a brownout, then the VDD5V_GT_VDDIO becomes
 			 * unreliable
 			 */
+			debug("SPL: VDDIO has a brownout\n");
 			mxs_powerdown();
 			break;
 		}
 
 		if (tmp & POWER_STS_VDD5V_GT_VDDIO) {
+			debug("SPL: POWER_STS_VDD5V_GT_VDDIO is set\n");
 			mxs_boot_valid_5v();
 			break;
 		} else {
+			debug("SPL: POWER_STS_VDD5V_GT_VDDIO is not set\n");
 			mxs_powerdown();
 			break;
 		}
 
+		/*
+		 * TODO: I can't see this being reached. We'll either
+		 * powerdown or boot from a stable 5V supply.
+		 */
 		if (tmp & POWER_STS_PSWITCH_MASK) {
+			debug("SPL: POWER_STS_PSWITCH_MASK is set\n");
 			mxs_batt_boot();
 			break;
 		}
@@ -713,21 +780,26 @@ static void mxs_5v_boot(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Configuring power block to boot from 5V input\n");
+
 	/*
 	 * 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) {
+		debug("SPL: 5V VDD good\n");
 		mxs_boot_valid_5v();
 		return;
 	}
 
 	early_delay(1000);
 	if (readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO) {
+		debug("SPL: 5V VDD good (after delay)\n");
 		mxs_boot_valid_5v();
 		return;
 	}
 
+	debug("SPL: 5V VDD not good\n");
 	mxs_handle_5v_conflict();
 }
 
@@ -742,6 +814,8 @@ static void mxs_init_batt_bo(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Initialising battery brown-out level to 3.0V\n");
+
 	/* Brownout at 3V */
 	clrsetbits_le32(&power_regs->hw_power_battmonitor,
 		POWER_BATTMONITOR_BRWNOUT_LVL_MASK,
@@ -762,6 +836,8 @@ static void mxs_switch_vddd_to_dcdc_source(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Switching VDDD to DC-DC converters\n");
+
 	clrsetbits_le32(&power_regs->hw_power_vdddctrl,
 		POWER_VDDDCTRL_LINREG_OFFSET_MASK,
 		POWER_VDDDCTRL_LINREG_OFFSET_1STEPS_BELOW);
@@ -788,6 +864,8 @@ static void mxs_power_configure_power_source(void)
 	struct mxs_lradc_regs *lradc_regs =
 		(struct mxs_lradc_regs *)MXS_LRADC_BASE;
 
+	debug("SPL: Configuring power source\n");
+
 	mxs_src_power_init();
 
 	if (readl(&power_regs->hw_power_sts) & POWER_STS_VDD5V_GT_VDDIO) {
@@ -811,6 +889,10 @@ static void mxs_power_configure_power_source(void)
 		mxs_batt_boot();
 	}
 
+	/*
+	 * TODO: Do not switch CPU clock to PLL if we are VDD5V is sourced
+	 * from USB VBUS
+	 */
 	mxs_power_clock2pll();
 
 	mxs_init_batt_bo();
@@ -819,6 +901,7 @@ static void mxs_power_configure_power_source(void)
 
 #ifdef CONFIG_MX23
 	/* Fire up the VDDMEM LinReg now that we're all set. */
+	debug("SPL: Enabling mx23 VDDMEM linear regulator\n");
 	writel(POWER_VDDMEMCTRL_ENABLE_LINREG | POWER_VDDMEMCTRL_ENABLE_ILIMIT,
 		&power_regs->hw_power_vddmemctrl);
 #endif
@@ -838,6 +921,8 @@ static void mxs_enable_output_rail_protection(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Enabling output rail protection\n");
+
 	writel(POWER_CTRL_VDDD_BO_IRQ | POWER_CTRL_VDDA_BO_IRQ |
 		POWER_CTRL_VDDIO_BO_IRQ, &power_regs->hw_power_ctrl_clr);
 
@@ -1077,6 +1162,8 @@ static void mxs_power_set_vddx(const struct mxs_vddx_cfg *cfg,
  */
 static void mxs_setup_batt_detect(void)
 {
+	debug("SPL: Starting battery voltage measurement logic\n");
+
 	mxs_lradc_init();
 	mxs_lradc_enable_batt_measurement();
 	early_delay(10);
@@ -1111,6 +1198,8 @@ void mxs_power_init(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Initialising Power Block\n");
+
 	mxs_ungate_power();
 
 	mxs_power_clock2xtal();
@@ -1123,9 +1212,13 @@ void mxs_power_init(void)
 	mxs_power_configure_power_source();
 	mxs_enable_output_rail_protection();
 
+	debug("SPL: Setting VDDIO to 3V3 (brownout @ 3v15)\n");
 	mxs_power_set_vddx(&mxs_vddio_cfg, 3300, 3150);
+
+	debug("SPL: Setting VDDD to 1V5 (brownout @ 1v0)\n");
 	mxs_power_set_vddx(&mxs_vddd_cfg, 1500, 1000);
 #ifdef CONFIG_MX23
+	debug("SPL: Setting mx23 VDDMEM to 2V5 (brownout @ 1v7)\n");
 	mxs_power_set_vddx(&mxs_vddmem_cfg, 2500, 1700);
 #endif
 	writel(POWER_CTRL_VDDD_BO_IRQ | POWER_CTRL_VDDA_BO_IRQ |
@@ -1150,6 +1243,7 @@ void mxs_power_wait_pswitch(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	debug("SPL: Waiting for power switch input\n");
 	while (!(readl(&power_regs->hw_power_sts) & POWER_STS_PSWITCH_MASK))
 		;
 }
-- 
1.9.3

[U-Boot] [v3 PATCH 2/3] arm: mxs: Enable booting of mx28 without battery

[Graeme Russ]

Section 4.1.2 of Freescale Application Note AN4199 describes the
configuration required to operate the mx28 from a 5V source without a
battery.

This patch changes the behaviour of the dropout control of the DC-DC
converter (refer to section 11.12.9 of the mx28 Application Processor
Reference Manual - Document Number: MCIMX28RM, Rev 2, 08/2013) to the
following:
 - Always use 4P2 Linear Regulator if CONFIG_SYS_MXS_VDD5V_ONLY is defined
 - Switch between 4P2 Linear Regulator and Battery, using whichever has
   the highest voltage if CONFIG_SYS_MXS_VDD5V_ONLY isnot set (this is
   the same as the pre-patch behaviour)

Signed-off-by: Graeme Russ <gruss@tss-engineering.com>
Signed-off-by: Damien Gotfroi <dgotfroi@greenwatch.be>
---

Changes in v2
 - Implemented Damien Gotfroi's simplified version

Changes in v3
 - Updated commit message
 - Explicitly use POWER_DCDC4P2_DROPOUT_CTRL_SRC_4P2 for the
   DCDC4P2_DROPOUT_CONFIG define (it is 0x0 so it make no functional
   difference)

---
 arch/arm/cpu/arm926ejs/mxs/spl_power_init.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
index 7fb734e..c342217 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
@@ -14,6 +14,13 @@
 
 #include "mxs_init.h"
 
+#ifdef CONFIG_SYS_MXS_VDD5V_ONLY
+#define DCDC4P2_DROPOUT_CONFIG	POWER_DCDC4P2_DROPOUT_CTRL_100MV | \
+				POWER_DCDC4P2_DROPOUT_CTRL_SRC_4P2
+#else
+#define DCDC4P2_DROPOUT_CONFIG	POWER_DCDC4P2_DROPOUT_CTRL_100MV | \
+				POWER_DCDC4P2_DROPOUT_CTRL_SRC_SEL
+#endif
 /**
  * mxs_power_clock2xtal() - Switch CPU core clock source to 24MHz XTAL
  *
@@ -303,8 +310,7 @@ static void mxs_power_init_4p2_params(void)
 
 	clrsetbits_le32(&power_regs->hw_power_dcdc4p2,
 		POWER_DCDC4P2_DROPOUT_CTRL_MASK,
-		POWER_DCDC4P2_DROPOUT_CTRL_100MV |
-		POWER_DCDC4P2_DROPOUT_CTRL_SRC_SEL);
+		DCDC4P2_DROPOUT_CONFIG);
 
 	clrsetbits_le32(&power_regs->hw_power_5vctrl,
 		POWER_5VCTRL_CHARGE_4P2_ILIMIT_MASK,
-- 
1.9.3

[U-Boot] [v3 PATCH 3/3] arm: mxs: Add 'Wait for JTAG user' if booted in JTAG mode

[Graeme Russ]

When booting in JTAG mode, there is no way to use soft break-points, and
no way of knowing when SPL has finished executing (so the user can issue
a 'halt' command to load u-boot.bin for example)

Add a debug output and simple loop to stop execution at the completion of
the SPL initialisation as a pseudo break-point when booting in JTAG mode

Signed-off-by: Graeme Russ <gruss@tss-engineering.com>
---

Changes in v2
 - Added and used boot mode #defines

Changes in v3
 - Removed extra new-line

---
 arch/arm/cpu/arm926ejs/mxs/spl_boot.c     |  5 +++++
 arch/arm/include/asm/arch-mxs/sys_proto.h | 17 +++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
index 2a5f817..d7956e5 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
@@ -157,6 +157,11 @@ void mxs_common_spl_init(const uint32_t arg, const uint32_t *resptr,
 	data->boot_mode_idx = bootmode;
 
 	mxs_power_wait_pswitch();
+
+	if (mxs_boot_modes[data->boot_mode_idx].boot_pads == MXS_BM_JTAG) {
+		debug("SPL: Waiting for JTAG user\n");
+		asm volatile ("x: b x");
+	}
 }
 
 /* Support aparatus */
diff --git a/arch/arm/include/asm/arch-mxs/sys_proto.h b/arch/arm/include/asm/arch-mxs/sys_proto.h
index 062f3de..4678723 100644
--- a/arch/arm/include/asm/arch-mxs/sys_proto.h
+++ b/arch/arm/include/asm/arch-mxs/sys_proto.h
@@ -74,6 +74,23 @@ static const struct mxs_pair mxs_boot_modes[] = {
 #endif
 };
 
+#define MXS_BM_USB			0x00
+#define MXS_BM_I2C_MASTER_3V3		0x01
+#define MXS_BM_I2C_MASTER_1V8		0x11
+#define MXS_BM_SPI2_MASTER_3V3_NOR	0x02
+#define MXS_BM_SPI2_MASTER_1V8_NOR	0x12
+#define MXS_BM_SPI3_MASTER_3V3_NOR	0x03
+#define MXS_BM_SPI3_MASTER_1V8_NOR	0x13
+#define MXS_BM_NAND_3V3			0x04
+#define MXS_BM_NAND_1V8			0x14
+#define MXS_BM_JTAG			0x06
+#define MXS_BM_SPI3_MASTER_3V3_EEPROM	0x08
+#define MXS_BM_SPI3_MASTER_1V8_EEPROM	0x18
+#define MXS_BM_SDMMC0_3V3		0x09
+#define MXS_BM_SDMMC0_1V8		0x19
+#define MXS_BM_SDMMC1_3V3		0x0a
+#define MXS_BM_SDMMC1_1V8		0x1a
+
 struct mxs_spl_data {
 	uint8_t		boot_mode_idx;
 	uint32_t	mem_dram_size;
-- 
1.9.3

[U-Boot] [v3 PATCH 1/3] arm: mxs: Add debug outputs and comments to mxs SPL source files

[Stefano Babic]

On 25/01/2015 02:07, Graeme Russ wrote:
> It is difficult to track down fail to boot issues in the mxs SPL.
> Implement the following to make it easier:
>  - Add debug outputs to allow tracing of SPL progress in order to track
> where failure to boot occurs. DEUBUG and CONFIG_SPL_SERIAL_SUPPORT must
> be defined to enable debug output in SPL
>  - Add TODO comments where it is not clear if the code is doing what it
> is meant to be doing, even tough the board boots properly (these comments
> refer to existing code, not to any code added by this patch)
> 
> Signed-off-by: Graeme Russ <gruss@tss-engineering.com>
> ---

Applied to u-boot-imx, thanks !

Best regards,
Stefano Babic


-- 
=====================================================================
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================

[U-Boot] [v3 PATCH 2/3] arm: mxs: Enable booting of mx28 without battery

[Stefano Babic]

On 25/01/2015 02:07, Graeme Russ wrote:
> Section 4.1.2 of Freescale Application Note AN4199 describes the
> configuration required to operate the mx28 from a 5V source without a
> battery.
> 
> This patch changes the behaviour of the dropout control of the DC-DC
> converter (refer to section 11.12.9 of the mx28 Application Processor
> Reference Manual - Document Number: MCIMX28RM, Rev 2, 08/2013) to the
> following:
>  - Always use 4P2 Linear Regulator if CONFIG_SYS_MXS_VDD5V_ONLY is defined
>  - Switch between 4P2 Linear Regulator and Battery, using whichever has
>    the highest voltage if CONFIG_SYS_MXS_VDD5V_ONLY isnot set (this is
>    the same as the pre-patch behaviour)
> 
> Signed-off-by: Graeme Russ <gruss@tss-engineering.com>
> Signed-off-by: Damien Gotfroi <dgotfroi@greenwatch.be>
> ---
> 
> Changes in v2
>  - Implemented Damien Gotfroi's simplified version
> 
> Changes in v3
>  - Updated commit message
>  - Explicitly use POWER_DCDC4P2_DROPOUT_CTRL_SRC_4P2 for the
>    DCDC4P2_DROPOUT_CONFIG define (it is 0x0 so it make no functional
>    difference)
> 
> ---

Applied to u-boot-imx, thanks !

Best regards,
Stefano Babic


-- 
=====================================================================
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================

[U-Boot] [v3 PATCH 3/3] arm: mxs: Add 'Wait for JTAG user' if booted in JTAG mode

[Stefano Babic]

On 25/01/2015 02:07, Graeme Russ wrote:
> When booting in JTAG mode, there is no way to use soft break-points, and
> no way of knowing when SPL has finished executing (so the user can issue
> a 'halt' command to load u-boot.bin for example)
> 
> Add a debug output and simple loop to stop execution at the completion of
> the SPL initialisation as a pseudo break-point when booting in JTAG mode
> 
> Signed-off-by: Graeme Russ <gruss@tss-engineering.com>
> ---


Applied to u-boot-imx, thanks !

Best regards,
Stefano Babic


-- 
=====================================================================
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================