hw21, 26: suppress power on with ignition off

power down system in SPL when ignition is not active on a
power-on start.

board/nm/common/da9063.h

@@ -16,17 +16,21 @@
 #define CONFIG_PMIC_I2C_ADDR	0x58	/* Pages 0 and 1, Pages 2 and 3 -> 0x59 */
 
 #define PMIC_REG_STATUS_A		0x01	/* Status of ON_KEY, WAKE, COMP1V2, DVC */
+#define PMIC_REG_STATUS_A_COMP1V2_MASK	0x08
+
 #define PMIC_REG_FAULT_LOG		0x05	/* PMIC fault log register, holding reset reason */
 #define PMIC_FAULT_TWD_ERROR_MASK	0x01	/* Watchdog timeout detected */
 #define PMIC_FAULT_POR_MASK		0x02	/* Startup from No-Power/RTC/Delivery mode */
 
 #define PMIC_REG_EVENT_A		0x06
 #define PMIC_REG_EVENT_RTC_ALARM_MASK	0x02
+#define PMIC_REG_EVENT_RTC_TICK_MASK	0x04
 #define PMIC_REG_EVENT_EVENTS_B_MASK	0x20
 
 #define PMIC_REG_EVENT_B		0x07
 #define PMIC_REG_EVENT_COMP1V2_MASK	0x04
 
+#define PMIC_REG_CONTROL_A      0x0E    /* Control register for power states */
 #define PMIC_REG_CONTROL_D	0x11    /* Control register for blink/watchdog */
 #define PMIC_REG_GPIO14_15	0x1C    /* Configuration of GPIO14/15 (mode, wake) */
 #define PMIC_REG_GPIO_MODE0_7	0x1D	/* Control register for GPIOs 0..7 */

board/nm/nmhw21/board.c

@@ -153,8 +153,10 @@ static int hw_type = -1;
 static char hw_variant_name[64];
 #else
 static int hw_type = -1;
+static uint32_t sys_start_event = 0x0;
 #endif
 
+
 #if !defined(CONFIG_SPL_BUILD)
 static struct ctrl_dev *cdev = (struct ctrl_dev *)CTRL_DEVICE_BASE;
 #endif
@@ -416,27 +418,6 @@ static void pmic_disable_auto_mode(void)
 	}
 }
 
-static void pmic_ignition_gate_on(void)
-{
-	uint8_t val;
-
-	/* Configure GPIO15 to permanent high, so that ignition sense signal is readable */
-
-	(void)da9063_set_reg(PMIC_REG_GPIO14_15, 0xCC);		/* GPIO14/15 = Outputs open drain */
-
-	(void)da9063_get_reg(PMIC_REG_CONFIG_L, &val);		/* Enable pull ups on GPIO14/15 */
-	val |= 0xC0;
-	(void)da9063_set_reg(PMIC_REG_CONFIG_L, val);
-
-	(void)da9063_get_reg(PMIC_REG_CONTROL_D, &val);		/* No blinking, state selected by GPIOxx_MODE */
-	val &= ~0xF8;
-	(void)da9063_set_reg(PMIC_REG_CONTROL_D, val);
-
-	(void)da9063_get_reg(PMIC_REG_GPIO_MODE8_15, &val);	/* Set to GPIO14,15 to high */
-	val |= 0xC0;
-	(void)da9063_set_reg(PMIC_REG_GPIO_MODE8_15, val);
-}
-
 static void init_pmic_spl(void)
 {
 	int bus;
@@ -462,8 +443,6 @@ static void init_pmic_spl(void)
 	(void)da9063_set_reg(PMIC_REG_LDO11_CONT, PMIC_LDOx_EN_MASK);
 	mdelay(2);
 
-	pmic_ignition_gate_on();
-
 	if (hw_type == 21) {
 		/* hw21: trim RTC to compensate +18ppm crystal deviation */
 		(void)da9063_set_reg(PMIC_REG_TRIM_CLDR, (-18*10)/19);
@@ -499,17 +478,18 @@ struct reset_registers {
 #define SE_WATCHDOG  			0x00000010
 #define SE_IGNITION  			0x00000100
 #define SE_RTC_ALARM  			0x00000200
+#define SE_RTC_TICK  			0x00000400
 
 
 static void print_start_reason(uint32_t events)
 {
-	puts("Start Events: ");
+	puts("\nStart Events: ");
 
 	if (events == 0) {
 		puts("-\n");
 	}
 	else {
-		static char buffer[10+11+11+6+1];
+		static char buffer[10+11+11+6+6+1];
 		
 		buffer[0] = 0;
 		if (events & SE_POR)
@@ -520,6 +500,8 @@ static void print_start_reason(uint32_t events)
 			strncat(buffer, "Ignition, ", sizeof(buffer));
 		if (events & SE_RTC_ALARM)
 			strncat(buffer, "RTC, ", sizeof(buffer));
+		if (events & SE_RTC_TICK)
+			strncat(buffer, "Tick, ", sizeof(buffer));
 
 		/* Trim last comma, no 0 len check required, at least one entry is present */
 		buffer[strlen(buffer)-2] = 0;	
@@ -576,6 +558,7 @@ static void check_pmic_reset_reason(unsigned int reset_reason_shm_location)
 	 * Event Register A
 	 * - Event B Activity
 	 * - RTC Alarm
+	 * - RTC Tick
 	 */
 	ret = da9063_get_reg(PMIC_REG_EVENT_A, &state);
 	if ((ret == 0) && (state != 0)) {
@@ -585,6 +568,10 @@ static void check_pmic_reset_reason(unsigned int reset_reason_shm_location)
 			start_event |= SE_RTC_ALARM;
 		}
 
+		if (state & PMIC_REG_EVENT_RTC_TICK_MASK) {
+			start_event |= SE_RTC_TICK;
+		}
+
 		if (state & PMIC_REG_EVENT_EVENTS_B_MASK) {
 			/*
 			 * Event Register B
@@ -599,8 +586,12 @@ static void check_pmic_reset_reason(unsigned int reset_reason_shm_location)
 				}
 			}
 		}
+
+		/* TODO: Should we clear events here or leave them for Linux driver? */
 	}
 
+	sys_start_event = start_event;
+
 	/* Store start events in shared memory region for OS */
 	reset_regs->se_magic = SE_MAGIC;
 	reset_regs->se_events = start_event;
@@ -613,6 +604,107 @@ static void check_pmic_reset_reason(unsigned int reset_reason_shm_location)
 	print_start_reason(reset_regs->se_events);
 }
 
+static void pmic_ignition_gate_on(void)
+{
+	int bus;
+	uint8_t val;
+
+	bus = da9063_claim_i2c_bus();
+
+	/* Configure GPIO15 to permanent high, so that ignition sense signal is readable */
+
+	(void)da9063_set_reg(PMIC_REG_GPIO14_15, 0xCC);		/* GPIO14/15 = Outputs open drain */
+
+	(void)da9063_get_reg(PMIC_REG_CONFIG_L, &val);		/* Enable pull ups on GPIO14/15 */
+	val |= 0xC0;
+	(void)da9063_set_reg(PMIC_REG_CONFIG_L, val);
+
+	(void)da9063_get_reg(PMIC_REG_CONTROL_D, &val);		/* No blinking, state selected by GPIOxx_MODE */
+	val &= ~0xF8;
+	(void)da9063_set_reg(PMIC_REG_CONTROL_D, val);
+
+	(void)da9063_get_reg(PMIC_REG_GPIO_MODE8_15, &val);	/* Set to GPIO14,15 to high */
+	val |= 0xC0;
+	(void)da9063_set_reg(PMIC_REG_GPIO_MODE8_15, val);
+
+	/*
+	 * Comparator input is debounced (10ms), see DA9063 datasheet 5.13.5
+	 * Give enough time to stabilize input reading.
+	 */
+	mdelay(10+10);
+
+	da9063_release_i2c_bus(bus);
+}
+
+static void powerdown(void) 
+{
+	int bus;
+
+	bus = da9063_claim_i2c_bus();
+
+	/* Final call, will not return */
+	da9063_set_reg(PMIC_REG_CONTROL_A, 0x00);
+
+	da9063_release_i2c_bus(bus);
+
+	puts("ERROR: PMIC power down failed\n");
+	for (;;) {}
+}
+
+static void reset(void)
+{
+	/* Code copied from arm v7 lib */
+	udelay (50000);
+
+	disable_interrupts();
+	reset_misc();
+	reset_cpu(0);
+
+	puts("ERROR: Reset failed\n");
+	for (;;) {}
+}
+
+static void stop_if_ignition_is_off(void)
+{
+	uint8_t state = 0x00;
+	int bus;
+	int ret;
+
+	bus = da9063_claim_i2c_bus();
+
+	ret = da9063_get_reg(PMIC_REG_STATUS_A, &state);
+	if (ret == 0) {
+		if ((state & PMIC_REG_STATUS_A_COMP1V2_MASK) == PMIC_REG_STATUS_A_COMP1V2_MASK) {
+			puts("Ignition    : On\n");
+		}
+		else {
+			puts("Ignition    : Off\n");
+			/* 
+			 * Ignition is off, if this is a power-on start, power down
+			 * as this is considered an unwanted system start.
+			 */
+
+			/* 
+			 * There is a chance for a race condition, when ignition is enabled
+			 * between the check above and here. In this case we should just reset
+			 * not power down.
+			 * Although the risk is minimal here due to the very short time interval
+			 * we do the check. The same logic will have to be added in other
+			 * components.
+			 */
+			ret = da9063_get_reg(PMIC_REG_EVENT_B, &state);
+			if ((ret == 0) && ((state & PMIC_REG_EVENT_COMP1V2_MASK) == 0)) {
+				powerdown();
+			}
+			else {
+				reset();
+			}
+		}
+	}
+
+	da9063_release_i2c_bus(bus);
+}
+
 static void init_bd_spl(void)
 {
 	hw_type = 21;	/* Assume hw21, unless BD tells different */
@@ -648,6 +740,17 @@ void am33xx_spl_board_init(void)
 	/* Detect reset/Wakeup reason */
 	check_pmic_reset_reason(RESET_REASON_SHM_LOCATION);
 
+	/* Switch on ignition gate so we can read state later */
+	pmic_ignition_gate_on();
+
+	/* 
+	 * If this is a power-on start, see if ignition is active. 
+	 * If not, power down as this is considered an unwanted system start.
+	 */
+	if (sys_start_event & SE_POR) {
+		stop_if_ignition_is_off();
+	}
+
 	/* Setup PMIC */
 	init_pmic_spl();