arm: mxs: Add debug outputs and comments to mxs SPL source files

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>

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
index cd43070c6059bb0b35c1bfe057c6a2718829405b..aa0be982c82e79b2164b7eed08d42a84cc116f29 100644 (file)
--- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
@@ -324,6 +324,8 @@ static void mxs_src_power_init(void)
 {
        debug("SPL: Pre-Configuring power block\n");
 
+       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);
@@ -368,6 +370,8 @@ static void mxs_power_init_4p2_params(void)
 {
        debug("SPL: Configuring common 4P2 regulator params\n");
 
+       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,
@@ -592,6 +596,8 @@ static void mxs_power_init_dcdc_4p2_source(void)
 {
        debug("SPL: Switching DC-DC converters to 4P2\n");
 
+       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");
@@ -689,6 +695,8 @@ static void mxs_boot_valid_5v(void)
 {
        debug("SPL: Booting from 5V supply\n");
 
+       debug("SPL: Booting from 5V supply\n");
+
        /*
         * Use VBUSVALID level instead of VDD5V_GT_VDDIO level to trigger a 5V
         * disconnect event. FIXME
@@ -731,6 +739,8 @@ static void mxs_batt_boot(void)
 {
        debug("SPL: Configuring power block to boot from battery\n");
 
+       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);
 
@@ -834,6 +844,8 @@ static void mxs_5v_boot(void)
 {
        debug("SPL: Configuring power block to boot from 5V input\n");
 
+       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.
@@ -895,6 +907,8 @@ static void mxs_init_batt_bo(void)
 {
        debug("SPL: Initialising battery brown-out level to 3.0V\n");
 
+       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,
@@ -914,6 +928,8 @@ static void mxs_switch_vddd_to_dcdc_source(void)
 {
        debug("SPL: Switching VDDD to DC-DC converters\n");
 
+       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);
@@ -995,6 +1011,8 @@ static void mxs_enable_output_rail_protection(void)
 {
        debug("SPL: Enabling output rail protection\n");
 
+       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);
 
@@ -1335,6 +1353,8 @@ void mxs_power_init(void)
 {
        debug("SPL: Initialising Power Block\n");
 
+       debug("SPL: Initialising Power Block\n");
+
        mxs_ungate_power();
 
        mxs_power_clock2xtal();