spring: Distinguish Apple Chargersstabilize-bluetooth-smart

This uses D+/D- voltage to distinguish different Apple chargers.

BUG=chrome-os-partner:14319
TEST=Manual on Spring
BRANCH=none

Change-Id: I50075d466f6e6b1adf613748cf433d7f43c04bfe
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/42850
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

3 files changed, 61 insertions, 18 deletions

diff --git a/board/spring/usb_charging.c b/board/spring/usb_charging.c
index b919ec851b..e1b9029bcb 100644
--- a/board/spring/usb_charging.c
+++ b/board/spring/usb_charging.c
@@ -5,11 +5,13 @@
 
 /* USB charging control for spring board */
 
+#include "adc.h"
 #include "board.h"
 #include "console.h"
 #include "gpio.h"
 #include "lp5562.h"
 #include "registers.h"
+#include "stm32_adc.h"
 #include "task.h"
 #include "timer.h"
 #include "tsu6721.h"
@@ -27,13 +29,19 @@
 
 /* PWM controlled current limit */
 #define I_LIMIT_500MA   85
-#define I_LIMIT_1000MA  70
+#define I_LIMIT_1000MA  75
 #define I_LIMIT_1500MA  50
 #define I_LIMIT_2000MA  35
+#define I_LIMIT_2400MA  25
 #define I_LIMIT_3000MA  0
 
 static enum ilim_config current_ilim_config = ILIM_CONFIG_MANUAL_OFF;
 
+static const int apple_charger_type[4] = {I_LIMIT_500MA,
+					  I_LIMIT_1000MA,
+					  I_LIMIT_2000MA,
+					  I_LIMIT_2400MA};
+
 static void board_ilim_use_gpio(void)
 {
 	/* Disable counter */
@@ -107,6 +115,31 @@ void board_ilim_config(enum ilim_config config)
 	}
 }
 
+/* Returns Apple charger current limit */
+static int board_apple_charger_current(void)
+{
+	int vp, vn;
+	int type = 0;
+	int data[ADC_CH_COUNT];
+
+	/* TODO(victoryang): Handle potential race condition. */
+	tsu6721_disable_interrupts();
+	tsu6721_mux(TSU6721_MUX_USB);
+	/* Wait 20ms for signal to stablize */
+	msleep(20);
+	adc_read_all_channels(data);
+	vp = data[ADC_CH_USB_DP_SNS];
+	vn = data[ADC_CH_USB_DN_SNS];
+	tsu6721_mux(TSU6721_MUX_AUTO);
+	tsu6721_enable_interrupts();
+	if (vp > 1200)
+		type |= 0x2;
+	if (vn > 1200)
+		type |= 0x1;
+
+	return apple_charger_type[type];
+}
+
 void board_pwm_duty_cycle(int percent)
 {
 	if (current_ilim_config != ILIM_CONFIG_PWM)
@@ -143,8 +176,7 @@ static void usb_device_change(int dev_type)
 		if (dev_type & TSU6721_TYPE_CHG12)
 			current_limit = I_LIMIT_3000MA;
 		else if (dev_type & TSU6721_TYPE_APPLE_CHG) {
-			/* TODO: Distinguish 1A/2A chargers. */
-			current_limit = I_LIMIT_1000MA;
+			current_limit = board_apple_charger_current();
 		} else if ((dev_type & TSU6721_TYPE_CDP) ||
 			   (dev_type & TSU6721_TYPE_DCP))
 			current_limit = I_LIMIT_1500MA;
@@ -154,6 +186,7 @@ static void usb_device_change(int dev_type)
 		/* Turns on battery LED */
 		lp5562_poweron();
 	} else {
+		board_ilim_config(ILIM_CONFIG_MANUAL_ON);
 		lp5562_poweroff();
 	}
 
diff --git a/common/tsu6721.c b/common/tsu6721.c
index ba6d3ad4b0..8ea369c463 100644
--- a/common/tsu6721.c
+++ b/common/tsu6721.c
@@ -45,20 +45,24 @@ void tsu6721_write(uint8_t reg, uint8_t val)
 		CPRINTF("[%T TSU6721 I2C write failed]\n");
 }
 
-void tsu6721_enable_interrupts(int mask)
+void tsu6721_enable_interrupts(void)
 {
 	int ctrl = tsu6721_read(TSU6721_REG_CONTROL);
-	tsu6721_write(TSU6721_REG_INT_MASK1, (~mask) & 0xff);
-	tsu6721_write(TSU6721_REG_INT_MASK2, ((~mask) >> 8) & 0xff);
 	tsu6721_write(TSU6721_REG_CONTROL, ctrl & 0x1e);
 }
 
-void tsu6721_disable_interrupt(void)
+void tsu6721_disable_interrupts(void)
 {
 	int ctrl = tsu6721_read(TSU6721_REG_CONTROL);
 	tsu6721_write(TSU6721_REG_CONTROL, ctrl | 0x1);
 }
 
+void tsu6721_set_interrupt_mask(uint16_t mask)
+{
+	tsu6721_write(TSU6721_REG_INT_MASK1, (~mask) & 0xff);
+	tsu6721_write(TSU6721_REG_INT_MASK2, ((~mask) >> 8) & 0xff);
+}
+
 int tsu6721_get_interrupts(void)
 {
 	return (tsu6721_read(TSU6721_REG_INT1) << 8) |
@@ -89,7 +93,7 @@ int tsu6721_mux(enum tsu6721_mux sel)
 		return EC_ERROR_INVAL;
 	}
 
-	if (sel == TSU6721_MUX_NONE) {
+	if (sel == TSU6721_MUX_AUTO) {
 		tsu6721_write(TSU6721_REG_CONTROL, ctrl | TSU6721_CTRL_AUTO);
 	} else {
 		tsu6721_write(TSU6721_REG_MANUAL1, sel);
@@ -114,10 +118,11 @@ void tsu6721_init(void)
 	settings = (settings & ~0x38);
 	tsu6721_write(TSU6721_REG_TIMER, settings);
 
-	tsu6721_enable_interrupts(TSU6721_INT_ATTACH |
-				  TSU6721_INT_DETACH |
-				  TSU6721_INT_ADC_CHANGE |
-				  TSU6721_INT_VBUS);
+	tsu6721_set_interrupt_mask(TSU6721_INT_ATTACH |
+				   TSU6721_INT_DETACH |
+				   TSU6721_INT_ADC_CHANGE |
+				   TSU6721_INT_VBUS);
+	tsu6721_enable_interrupts();
 }
 /*
  * TODO(vpalatin): using the I2C early in the HOOK_INIT
@@ -165,7 +170,7 @@ static int command_usbmux(int argc, char **argv)
 		} else if (!strcasecmp(argv[1], "uart2")) {
 			tsu6721_mux(TSU6721_MUX_AUDIO);
 		} else if (!strcasecmp(argv[1], "auto")) {
-			tsu6721_mux(TSU6721_MUX_NONE);
+			tsu6721_mux(TSU6721_MUX_AUTO);
 		} else { /* read one register */
 			ccprintf("Invalid mux value: %s\n", argv[1]);
 			return EC_ERROR_INVAL;
@@ -191,7 +196,7 @@ static int usb_command_mux(struct host_cmd_handler_args *args)
 		return EC_RES_ACCESS_DENIED;
 
 	/* Safety check */
-	if (p->mux != TSU6721_MUX_NONE &&
+	if (p->mux != TSU6721_MUX_AUTO &&
 	    p->mux != TSU6721_MUX_USB &&
 	    p->mux != TSU6721_MUX_UART &&
 	    p->mux != TSU6721_MUX_AUDIO)
diff --git a/include/tsu6721.h b/include/tsu6721.h
index f1101acf06..66bf5b6a33 100644
--- a/include/tsu6721.h
+++ b/include/tsu6721.h
@@ -32,7 +32,7 @@
 #define TSU6721_CTRL_AUTO     (1 << 2)
 
 enum tsu6721_mux {
-	TSU6721_MUX_NONE  = 0x00,
+	TSU6721_MUX_AUTO  = 0x00,
 	TSU6721_MUX_USB   = 0x24,
 	TSU6721_MUX_AUDIO = 0x48,
 	TSU6721_MUX_UART  = 0x6C,
@@ -81,13 +81,15 @@ uint8_t tsu6721_read(uint8_t reg);
 /* Write TSU6721 register. */
 void tsu6721_write(uint8_t reg, uint8_t val);
 
-/* Enable interrupt(s). The parameter 'mask' can be one or a combination of
- * TSU6721_INT_* */
-void tsu6721_enable_interrupts(int mask);
+/* Enable interrupts. */
+void tsu6721_enable_interrupts(void);
 
 /* Disable all interrupts. */
 void tsu6721_disable_interrupts(void);
 
+/* Set interrupt mask. */
+void tsu6721_set_interrupt_mask(uint16_t mask);
+
 /* Get and clear current interrupt status. Return value is a combination of
  * TSU6721_INT_* */
 int tsu6721_get_interrupts(void);
@@ -96,4 +98,7 @@ int tsu6721_get_interrupts(void);
  * TSU6721_TYPE_* */
 int tsu6721_get_device_type(void);
 
+/* Control TSU6721 mux. */
+int tsu6721_mux(enum tsu6721_mux sel);
+
 #endif /* TSU6721_H */