imx233: add new power debug screen

This screen allows to put the device in a special mode where:
- charging is disabled
- device only draws power from 5V (thus battery is untouched)
This is useful to measure the device consumption by measuring directly
the usb power consumption.

Change-Id: I2716ced0a5bb33c3c9a2607f2d17a0ce02f5689c

firmware/target/arm/imx233/debug-imx233.c

@@ -26,6 +26,7 @@
 #include "lcd.h"
 #include "font.h"
 #include "adc.h"
+#include "usb.h"
 #include "power-imx233.h"
 #include "clkctrl-imx233.h"
 #include "powermgmt-imx233.h"
@@ -45,6 +46,7 @@
 
 #include "regs/usbphy.h"
 #include "regs/timrot.h"
+#include "regs/power.h"
 
 #define ACT_NONE    0
 #define ACT_CANCEL  1
@@ -418,6 +420,91 @@ bool dbg_hw_info_powermgmt(void)
     }
 }
 
+bool dbg_hw_info_power2(void)
+{
+    lcd_setfont(FONT_SYSFIXED);
+    bool holding_select = false;
+    int select_hold_time = 0;
+
+    while(1)
+    {
+        int button = my_get_action(HZ / 10);
+        if(button == ACT_NEXT || button == ACT_PREV)
+        {
+            lcd_setfont(FONT_UI);
+            return true;
+        }
+        else if(button == ACT_CANCEL)
+        {
+            lcd_setfont(FONT_UI);
+            return false;
+        }
+
+        button = my_get_status();
+        if(button == ACT_OK && !holding_select)
+        {
+            holding_select = true;
+            select_hold_time = current_tick;
+        }
+        else if(button != ACT_OK && holding_select)
+        {
+            holding_select = false;
+        }
+
+        /* disable feature if unsafe: we need 4.2 and dcdc fully operational */
+        bool feat_safe = usb_detect() == USB_INSERTED && BF_RD(POWER_DCDC4P2, ENABLE_DCDC)
+            && BF_RD(POWER_DCDC4P2, ENABLE_4P2) && BF_RD(POWER_5VCTRL, ENABLE_DCDC)
+            && !BF_RD(POWER_5VCTRL, PWD_CHARGE_4P2);
+        bool batt_disabled = (BF_RD(POWER_DCDC4P2, DROPOUT_CTRL) == 0xc);
+        if(holding_select && TIME_AFTER(current_tick, select_hold_time + HZ))
+        {
+            if(batt_disabled)
+            {
+                BF_CLR(POWER_CHARGE, PWD_BATTCHRG); /* enable charger again */
+                BF_WR(POWER_DCDC4P2, DROPOUT_CTRL(0xe)); /* select greater, 200 mV drop */
+            }
+            else if(feat_safe)
+            {
+                BF_WR(POWER_DCDC4P2, DROPOUT_CTRL(0xc)); /* always select 4.2, 200 mV drop */
+                BF_SET(POWER_CHARGE, PWD_BATTCHRG); /* disable charger */
+            }
+            holding_select = false;
+            /* return to the beginning of the loop to gather more information
+             * about HW state before displaying it */
+            continue;
+        }
+
+        lcd_clear_display();
+        if(!batt_disabled)
+        {
+            lcd_putsf(0, 0, "Hold select for 1 sec");
+            lcd_putsf(0, 1, "to disable battery");
+            lcd_putsf(0, 1, "and battery charger.");
+            lcd_putsf(0, 2, "The device will run");
+            lcd_putsf(0, 3, "entirely from USB.");
+            lcd_putsf(0, 5, "WARNING");
+            lcd_putsf(0, 6, "This is a debug");
+            lcd_putsf(0, 7, "feature !");
+            if(!feat_safe)
+            {
+                lcd_putsf(0, 9, "NOTE: unavailable");
+                lcd_putsf(0, 10, "Plug USB to enable.");
+            }
+        }
+        else
+        {
+            lcd_putsf(0, 0, "Battery is DISABLED.");
+            lcd_putsf(0, 1, "Hold select for 1 sec");
+            lcd_putsf(0, 2, "to renable battery.");
+            lcd_putsf(0, 4, "WARNING");
+            lcd_putsf(0, 5, "Do not unplug USB !");
+        }
+
+        lcd_update();
+        yield();
+    }
+}
+
 bool dbg_hw_info_rtc(void)
 {
     lcd_setfont(FONT_SYSFIXED);
@@ -1105,6 +1192,7 @@ static struct
     {"dma", dbg_hw_info_dma},
     {"lradc", dbg_hw_info_lradc},
     {"power", dbg_hw_info_power},
+    {"power2", dbg_hw_info_power2},
     {"powermgmt", dbg_hw_info_powermgmt},
     {"rtc", dbg_hw_info_rtc},
     {"dcp", dbg_hw_info_dcp},