fw/abb/twl3025: Add function to query PWON state

This allows us to detect power button presses on the Pirelli
DP-L10 and the Huawei GTM900-B module. Polling will only be
activated once the power button has been pressed and we received
the interrupt. The goal is to reduce the required amount of
TWL3025 register accesses to a minimum.

Change-Id: I31be61c8089173aed616abd1ede6c4cf5c9b6770

2 files changed, 30 insertions, 0 deletions

diff --git a/src/target/firmware/abb/twl3025.c b/src/target/firmware/abb/twl3025.c
index e4fcf4f0..ad2b01f9 100644
--- a/src/target/firmware/abb/twl3025.c
+++ b/src/target/firmware/abb/twl3025.c
@@ -60,8 +60,15 @@ const uint16_t twl3025_default_ramp[16] = {
 	ABB_RAMP_VAL( 0,  0),
 };
 
+typedef enum pwon_state {
+	PWON_IDLE,
+	PWON_DETECTED,
+	PWON_REPORTED,
+} pwon_state_t;
+
 struct twl3025 {
 	uint8_t page;
+	pwon_state_t pwon;
 };
 static struct twl3025 twl3025_state;
 
@@ -106,6 +113,8 @@ static void twl3025_irq(enum irq_nr nr)
 	case IRQ_EXTERNAL: // charger in/out, pwrbtn, adc done
 		src = twl3025_reg_read(ITSTATREG);
 //		printd("itstatreg 0x%02x\n", src);
+		if ((src & 0x04) && twl3025_state.pwon == PWON_IDLE)
+			twl3025_state.pwon = PWON_DETECTED;
 		if (src & 0x08)
 			handle_charger();
 		if (src & 0x20)
@@ -127,6 +136,7 @@ void twl3025_init(void)
 	twl3025_clk13m(1);
 	twl3025_reg_write(AFCCTLADD, 0x01);	/* AFCCK(1:0) must not be zero! */
 	twl3025_unit_enable(TWL3025_UNIT_AFC, 1);
+	twl3025_state.pwon = PWON_IDLE;
 
 	irq_register_handler(IRQ_EXTERNAL, &twl3025_irq);
 	irq_config(IRQ_EXTERNAL, 0, 0, 0);
@@ -185,6 +195,24 @@ static void twl3025_wait_ibic_access(void)
 	delay_ms(1);
 }
 
+int twl3025_get_pwon(void)
+{
+	switch (twl3025_state.pwon) {
+	case PWON_DETECTED:
+		twl3025_state.pwon = PWON_REPORTED;
+		break;
+	case PWON_REPORTED:
+		if (twl3025_reg_read(VRPCSTS) & 0x10)
+			twl3025_state.pwon = PWON_IDLE;
+		break;
+	case PWON_IDLE:
+	default:
+		break;
+	}
+
+	return (twl3025_state.pwon != PWON_IDLE);
+}
+
 void twl3025_power_off(void)
 {
 	unsigned long flags;
diff --git a/src/target/firmware/include/abb/twl3025.h b/src/target/firmware/include/abb/twl3025.h
index 36406449..938a4252 100755
--- a/src/target/firmware/include/abb/twl3025.h
+++ b/src/target/firmware/include/abb/twl3025.h
@@ -144,6 +144,8 @@ void twl3025_init(void);
 void twl3025_reg_write(uint8_t reg, uint16_t data);
 uint16_t twl3025_reg_read(uint8_t reg);
 
+int twl3025_get_pwon(void);
+
 void twl3025_power_off(void);
 
 void twl3025_clk13m(int enable);