usb: pi3usb9281: Allow flexible chip configurations

Previously we supported using a single pi3usb9281 chip, or using two
chips on the same i2c bus behind a mux. Now that we need to support a
third configuration of multiple chips on different busses, it makes
sense to be able to configure the configuration freely at the board
level.

BUG=chrome-os-partner:40920
TEST=Manual on samus_pd. Plug USB charger, verify detection is correct
on both charge ports.
BRANCH=None

Change-Id: I120dcb1c3ceb6f013b92407effcd8cb66e7ffcce
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/276511
Reviewed-by: Alec Berg <alecaberg@chromium.org>

14 files changed, 190 insertions, 126 deletions

diff --git a/board/oak/board.c b/board/oak/board.c
index 1877c7c0c7..2f0373e672 100644
--- a/board/oak/board.c
+++ b/board/oak/board.c
@@ -108,6 +108,24 @@ const struct i2c_port_t i2c_ports[] = {
 
 const unsigned int i2c_ports_used = ARRAY_SIZE(i2c_ports);
 
+struct mutex pericom_mux_lock;
+struct pi3usb9281_config pi3usb9281_chips[] = {
+	{
+		.i2c_port = I2C_PORT_PERICOM,
+		.mux_gpio = GPIO_USB_C_BC12_SEL,
+		.mux_gpio_level = 0,
+		.mux_lock = &pericom_mux_lock,
+	},
+	{
+		.i2c_port = I2C_PORT_PERICOM,
+		.mux_gpio = GPIO_USB_C_BC12_SEL,
+		.mux_gpio_level = 1,
+		.mux_lock = &pericom_mux_lock,
+	},
+};
+BUILD_ASSERT(ARRAY_SIZE(pi3usb9281_chips) ==
+	     CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT);
+
 static int discharging_on_ac;
 
 /**
@@ -185,6 +203,7 @@ static void board_init(void)
 				&charge_none);
 
 		/* Initialize VBUS supplier based on VBUS */
+		/* TODO(crbug.com/498974): Don't do i2c from hook_init. */
 		bc12_status = pi3usb9281_get_charger_status(i);
 		charge_sel = PI3USB9281_CHG_STATUS_ANY(bc12_status) ?
 				&charge_vbus : &charge_none;
diff --git a/board/oak/board.h b/board/oak/board.h
index e00ce7be50..f10c6dabe7 100644
--- a/board/oak/board.h
+++ b/board/oak/board.h
@@ -93,8 +93,7 @@
 /* BC 1.2 charger */
 #define CONFIG_USB_SWITCH_PI3USB30532
 #define CONFIG_USB_SWITCH_PI3USB9281
-#undef CONFIG_USB_SWITCH_PI3USB9281_MUX_GPIO
-#define CONFIG_USB_SWITCH_PI3USB9281_MUX_GPIO GPIO_USB_C_BC12_SEL
+#define CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT 2
 
 #ifndef __ASSEMBLER__
 
@@ -108,6 +107,7 @@
 #define I2C_PORT_MASTER 0
 #define I2C_PORT_BATTERY 0
 #define I2C_PORT_CHARGER 0
+#define I2C_PORT_PERICOM 0
 #define I2C_PORT_PD_MCU 1
 #define I2C_PORT_USB_SWITCH 1
 #define I2C_PORT_TCPC 1
diff --git a/board/oak/ec.tasklist b/board/oak/ec.tasklist
index 35c72c3acf..35b64ed622 100644
--- a/board/oak/ec.tasklist
+++ b/board/oak/ec.tasklist
@@ -26,3 +26,5 @@
 	TASK_NOTEST(KEYSCAN, keyboard_scan_task, NULL, TASK_STACK_SIZE) \
 	TASK_ALWAYS(PD_C0, pd_task, NULL, LARGER_TASK_STACK_SIZE) \
 	TASK_ALWAYS(PD_C1, pd_task, NULL, LARGER_TASK_STACK_SIZE)
+
+/* TODO: Add pericom USB charger tasks */
diff --git a/board/ryu/board.c b/board/ryu/board.c
index 0c15c674b7..348dd55c9f 100644
--- a/board/ryu/board.c
+++ b/board/ryu/board.c
@@ -160,6 +160,15 @@ USB_STREAM_CONFIG(sh_usb,
 		  sh_usb_to_usart,
 		  sh_usart_to_usb)
 
+struct pi3usb9281_config pi3usb9281_chips[] = {
+	{
+		.i2c_port = I2C_PORT_PERICOM,
+		.mux_lock = NULL,
+	}
+};
+BUILD_ASSERT(ARRAY_SIZE(pi3usb9281_chips) ==
+	     CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT);
+
 /* Initialize board. */
 static void board_init(void)
 {
@@ -188,8 +197,6 @@ static void board_init(void)
 
 	/* Enable pericom BC1.2 interrupts. */
 	gpio_enable_interrupt(GPIO_USBC_BC12_INT_L);
-	pi3usb9281_set_interrupt_mask(0, 0xff);
-	pi3usb9281_enable_interrupts(0);
 
 	/*
 	 * Determine recovery mode is requested by the power, volup, and
diff --git a/board/ryu/board.h b/board/ryu/board.h
index 2cc8fa4e61..72cc5f32a8 100644
--- a/board/ryu/board.h
+++ b/board/ryu/board.h
@@ -37,6 +37,7 @@
 #define CONFIG_USB_PD_TCPC
 #define CONFIG_USB_PD_TCPM_STUB
 #define CONFIG_USB_SWITCH_PI3USB9281
+#define CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT 1
 #define CONFIG_USBC_SS_MUX
 #define CONFIG_USBC_VCONN
 #define CONFIG_USBC_VCONN_SWAP
@@ -85,6 +86,7 @@
 #define I2C_PORT_BATTERY I2C_PORT_MASTER
 #define I2C_PORT_LIGHTBAR I2C_PORT_MASTER
 #define I2C_PORT_ACCEL I2C_PORT_MASTER
+#define I2C_PORT_PERICOM I2C_PORT_MASTER
 #define BMM150_I2C_ADDRESS BMM150_ADDR0
 
 /* slave address for host commands */
diff --git a/board/ryu_p4p5/board.c b/board/ryu_p4p5/board.c
index 4ce21be02a..7a333610a1 100644
--- a/board/ryu_p4p5/board.c
+++ b/board/ryu_p4p5/board.c
@@ -158,6 +158,15 @@ USB_STREAM_CONFIG(sh_usb,
 		  sh_usb_to_usart,
 		  sh_usart_to_usb)
 
+struct pi3usb9281_config pi3usb9281_chips[] = {
+	{
+		.i2c_port = I2C_PORT_PERICOM,
+		.mux_lock = NULL,
+	}
+};
+BUILD_ASSERT(ARRAY_SIZE(pi3usb9281_chips) ==
+	     CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT);
+
 /* Initialize board. */
 static void board_init(void)
 {
@@ -186,8 +195,6 @@ static void board_init(void)
 
 	/* Enable pericom BC1.2 interrupts. */
 	gpio_enable_interrupt(GPIO_USBC_BC12_INT_L);
-	pi3usb9281_set_interrupt_mask(0, 0xff);
-	pi3usb9281_enable_interrupts(0);
 
 	/*
 	 * Determine recovery mode is requested by the power, volup, and
diff --git a/board/ryu_p4p5/board.h b/board/ryu_p4p5/board.h
index 4d039b2ea0..93eda6f119 100644
--- a/board/ryu_p4p5/board.h
+++ b/board/ryu_p4p5/board.h
@@ -34,6 +34,7 @@
 #define CONFIG_USB_PD_TCPC
 #define CONFIG_USB_PD_TCPM_STUB
 #define CONFIG_USB_SWITCH_PI3USB9281
+#define CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT 1
 #define CONFIG_USBC_SS_MUX
 #define CONFIG_USBC_VCONN
 #define CONFIG_USBC_VCONN_SWAP
@@ -82,6 +83,7 @@
 #define I2C_PORT_CHARGER I2C_PORT_MASTER
 #define I2C_PORT_BATTERY I2C_PORT_MASTER
 #define I2C_PORT_LIGHTBAR I2C_PORT_MASTER
+#define I2C_PORT_PERICOM I2C_PORT_MASTER
 
 /* slave address for host commands */
 #ifdef HAS_TASK_HOSTCMD
diff --git a/board/samus_pd/board.c b/board/samus_pd/board.c
index eee86c4a8b..161fc135fc 100644
--- a/board/samus_pd/board.c
+++ b/board/samus_pd/board.c
@@ -24,6 +24,7 @@
 #include "system.h"
 #include "task.h"
 #include "usb.h"
+#include "usb_charge.h"
 #include "usb_pd.h"
 #include "util.h"
 
@@ -77,6 +78,24 @@ const struct pwm_t pwm_channels[] = {
 };
 BUILD_ASSERT(ARRAY_SIZE(pwm_channels) == PWM_CH_COUNT);
 
+struct mutex pericom_mux_lock;
+struct pi3usb9281_config pi3usb9281_chips[] = {
+	{
+		.i2c_port = I2C_PORT_PERICOM,
+		.mux_gpio = GPIO_USB_C_BC12_SEL,
+		.mux_gpio_level = 0,
+		.mux_lock = &pericom_mux_lock,
+	},
+	{
+		.i2c_port = I2C_PORT_PERICOM,
+		.mux_gpio = GPIO_USB_C_BC12_SEL,
+		.mux_gpio_level = 1,
+		.mux_lock = &pericom_mux_lock,
+	},
+};
+BUILD_ASSERT(ARRAY_SIZE(pi3usb9281_chips) ==
+	     CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT);
+
 static void pericom_port0_reenable_interrupts(void)
 {
 	CPRINTS("VBUS p0 %d", gpio_get_level(GPIO_USB_C0_VBUS_WAKE));
@@ -309,10 +328,6 @@ static void board_init(void)
 	/* Enable pericom BC1.2 interrupts. */
 	gpio_enable_interrupt(GPIO_USB_C0_BC12_INT_L);
 	gpio_enable_interrupt(GPIO_USB_C1_BC12_INT_L);
-	pi3usb9281_set_interrupt_mask(0, 0xff);
-	pi3usb9281_set_interrupt_mask(1, 0xff);
-	pi3usb9281_enable_interrupts(0);
-	pi3usb9281_enable_interrupts(1);
 
 	/* Determine initial chipset state */
 	if (slp_s5 && slp_s3) {
@@ -555,10 +570,7 @@ int board_set_active_charge_port(int charge_port)
 	int is_real_port = (charge_port >= 0 &&
 			    charge_port < CONFIG_USB_PD_PORT_COUNT);
 	/* check if we are source vbus on that port */
-	int source = gpio_get_level(charge_port == 0 ? GPIO_USB_C0_5V_EN :
-						       GPIO_USB_C1_5V_EN);
-
-	if (is_real_port && source) {
+	if (is_real_port && usb_charger_port_is_sourcing_vbus(charge_port)) {
 		CPRINTS("Skip enable p%d", charge_port);
 		return EC_ERROR_INVAL;
 	}
diff --git a/board/samus_pd/board.h b/board/samus_pd/board.h
index c3dcd49ca0..8e72a259ac 100644
--- a/board/samus_pd/board.h
+++ b/board/samus_pd/board.h
@@ -61,8 +61,7 @@
 #define CONFIG_USB_PD_TCPC
 #define CONFIG_USB_PD_TCPM_STUB
 #define CONFIG_USB_SWITCH_PI3USB9281
-#undef  CONFIG_USB_SWITCH_PI3USB9281_MUX_GPIO
-#define CONFIG_USB_SWITCH_PI3USB9281_MUX_GPIO GPIO_USB_C_BC12_SEL
+#define CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT 2
 #define CONFIG_USBC_SS_MUX_DFP_ONLY
 #define CONFIG_USBC_SS_MUX
 #define CONFIG_USBC_VCONN
@@ -79,6 +78,7 @@
 #define I2C_PORT_MASTER 1
 #define I2C_PORT_SLAVE  0
 #define I2C_PORT_EC I2C_PORT_SLAVE
+#define I2C_PORT_PERICOM I2C_PORT_MASTER
 
 /* slave address for host commands */
 #ifdef HAS_TASK_HOSTCMD
diff --git a/common/usb_charger.c b/common/usb_charger.c
index bb85fc3c7f..b003f415e4 100644
--- a/common/usb_charger.c
+++ b/common/usb_charger.c
@@ -16,6 +16,7 @@
 #include "pi3usb9281.h"
 #include "task.h"
 #include "timer.h"
+#include "usb_charge.h"
 #include "usb_pd.h"
 
 /* Wait after a charger is detected to debounce pin contact order */
@@ -26,24 +27,36 @@
  */
 #define USB_CHG_RESET_DELAY_MS 100
 
+int usb_charger_port_is_sourcing_vbus(int port)
+{
+	if (port == 0)
+		return gpio_get_level(GPIO_USB_C0_5V_EN);
+#if CONFIG_USB_PD_PORT_COUNT >= 2
+	else if (port == 1)
+		return gpio_get_level(GPIO_USB_C1_5V_EN);
+#endif
+	/* Not a valid port */
+	return 0;
+}
+
 void usb_charger_task(void)
 {
 	int port = (task_get_current() == TASK_ID_USB_CHG_P0 ? 0 : 1);
-#if (CONFIG_USB_PD_PORT_COUNT == 1)
-	int vbus_source = GPIO_USB_C0_5V_EN;
-#else
-	int vbus_source = (port == 0 ? GPIO_USB_C0_5V_EN : GPIO_USB_C1_5V_EN);
-#endif
+
 	int device_type, charger_status;
 	struct charge_port_info charge;
 	int type;
+
 	charge.voltage = USB_BC12_CHARGE_VOLTAGE;
 
+	/* Initialize chip and enable interrupts */
+	pi3usb9281_init(port);
+
 	while (1) {
 		/* Read interrupt register to clear on chip */
 		pi3usb9281_get_interrupts(port);
 
-		if (gpio_get_level(vbus_source)) {
+		if (usb_charger_port_is_sourcing_vbus(port)) {
 			/* If we're sourcing VBUS then we're not charging */
 			device_type = charger_status = 0;
 		} else {
diff --git a/driver/pi3usb9281.h b/driver/pi3usb9281.h
index 56b126c1e3..7a23a869b3 100644
--- a/driver/pi3usb9281.h
+++ b/driver/pi3usb9281.h
@@ -56,46 +56,55 @@
 /* Check if charge status has any connection */
 #define PI3USB9281_CHG_STATUS_ANY(x) (((x) & 0x1f) > 1)
 
-/* Read PI3USB9281 register. */
-uint8_t pi3usb9281_read(uint8_t chip_idx, uint8_t reg);
-
-/* Write PI3USB9281 register. */
-int pi3usb9281_write(uint8_t chip_idx, uint8_t reg, uint8_t val);
+/* Define configuration of one pi3usb9281 part */
+struct pi3usb9281_config {
+	/* i2c port that chip resides on */
+	int i2c_port;
+	/* GPIO for chip selection in muxed configuration */
+	enum gpio_signal mux_gpio;
+	/* Logic level of mux_gpio to select chip */
+	int mux_gpio_level;
+	/* Mutex to lock access to mux gpio or NULL if no mux exists */
+	struct mutex *mux_lock;
+};
+
+/* Configuration struct defined at board level */
+extern struct pi3usb9281_config pi3usb9281_chips[];
+
+/* Initialize chip and enable interrupts */
+void pi3usb9281_init(int port);
 
 /* Enable interrupts. */
-int pi3usb9281_enable_interrupts(uint8_t chip_idx);
+int pi3usb9281_enable_interrupts(int port);
 
 /* Disable all interrupts. */
-int pi3usb9281_disable_interrupts(uint8_t chip_idx);
+int pi3usb9281_disable_interrupts(int port);
 
 /* Set interrupt mask. */
-int pi3usb9281_set_interrupt_mask(uint8_t chip_idx, uint8_t mask);
+int pi3usb9281_set_interrupt_mask(int port, uint8_t mask);
 
 /* Get and clear current interrupt status. */
-int pi3usb9281_get_interrupts(uint8_t chip_idx);
-
-/* Get but keep interrupt status. */
-int pi3usb9281_peek_interrupts(uint8_t chip_idx);
+int pi3usb9281_get_interrupts(int port);
 
 /* Get attached device type. */
-int pi3usb9281_get_device_type(uint8_t chip_idx);
+int pi3usb9281_get_device_type(int port);
 
 /* Get attached charger status. */
-int pi3usb9281_get_charger_status(uint8_t chip_idx);
+int pi3usb9281_get_charger_status(int port);
 
 /* Get charger current limit based on device type and charger status. */
 int pi3usb9281_get_ilim(int device_type, int charger_status);
 
 /* Set switch configuration to manual. */
-int pi3usb9281_set_switch_manual(uint8_t chip_idx, int val);
+int pi3usb9281_set_switch_manual(int port, int val);
 
 /* Set bits to enable pins in manual switch register. */
-int pi3usb9281_set_pins(uint8_t chip_idx, uint8_t mask);
+int pi3usb9281_set_pins(int port, uint8_t mask);
 
 /* Set D+/D-/Vbus switches to open or closed/auto-control. */
-int pi3usb9281_set_switches(uint8_t chip_idx, int open);
+int pi3usb9281_set_switches(int port, int open);
 
 /* Reset PI3USB9281. */
-int pi3usb9281_reset(uint8_t chip_idx);
+int pi3usb9281_reset(int port);
 
 #endif /* PI3USB9281_H */
diff --git a/driver/usb_switch_pi3usb9281.c b/driver/usb_switch_pi3usb9281.c
index 1841a9909a..063d7d3983 100644
--- a/driver/usb_switch_pi3usb9281.c
+++ b/driver/usb_switch_pi3usb9281.c
@@ -24,35 +24,34 @@
 /* Delay values */
 #define PI3USB9281_SW_RESET_DELAY 20
 
-#ifdef CONFIG_USB_SWITCH_PI3USB9281_MUX_GPIO
-#define PI3USB9281_COUNT 2
-struct mutex mux_lock;
-static inline void select_chip(uint8_t chip_idx)
+static void select_chip(int port)
 {
-	mutex_lock(&mux_lock);
-	gpio_set_level(CONFIG_USB_SWITCH_PI3USB9281_MUX_GPIO, chip_idx);
+	struct pi3usb9281_config *chip = &pi3usb9281_chips[port];
+	ASSERT(port < CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT);
+
+	if (chip->mux_lock) {
+		mutex_lock(chip->mux_lock);
+		gpio_set_level(chip->mux_gpio, chip->mux_gpio_level);
+	}
 }
 
-static inline void unselect_chip(void)
+static void unselect_chip(int port)
 {
-	/* Just release the mutex, no need to change the mux gpio */
-	mutex_unlock(&mux_lock);
-}
-#else
-#define PI3USB9281_COUNT 1
-#define select_chip(x)
-#define unselect_chip()
-#endif
+	struct pi3usb9281_config *chip = &pi3usb9281_chips[port];
 
-static int saved_interrupts[PI3USB9281_COUNT];
+	if (chip->mux_lock)
+		/* Just release the mutex, no need to change the mux gpio */
+		mutex_unlock(chip->mux_lock);
+}
 
-uint8_t pi3usb9281_read(uint8_t chip_idx, uint8_t reg)
+static uint8_t pi3usb9281_read(int port, uint8_t reg)
 {
+	struct pi3usb9281_config *chip = &pi3usb9281_chips[port];
 	int res, val;
 
-	select_chip(chip_idx);
-	res = i2c_read8(I2C_PORT_MASTER, PI3USB9281_I2C_ADDR, reg, &val);
-	unselect_chip();
+	select_chip(port);
+	res = i2c_read8(chip->i2c_port, PI3USB9281_I2C_ADDR, reg, &val);
+	unselect_chip(port);
 
 	if (res)
 		return 0xee;
@@ -60,13 +59,14 @@ uint8_t pi3usb9281_read(uint8_t chip_idx, uint8_t reg)
 	return val;
 }
 
-int pi3usb9281_write(uint8_t chip_idx, uint8_t reg, uint8_t val)
+static int pi3usb9281_write(int port, uint8_t reg, uint8_t val)
 {
+	struct pi3usb9281_config *chip = &pi3usb9281_chips[port];
 	int res;
 
-	select_chip(chip_idx);
-	res = i2c_write8(I2C_PORT_MASTER, PI3USB9281_I2C_ADDR, reg, val);
-	unselect_chip();
+	select_chip(port);
+	res = i2c_write8(chip->i2c_port, PI3USB9281_I2C_ADDR, reg, val);
+	unselect_chip(port);
 
 	if (res)
 		CPRINTS("PI3USB9281 I2C write failed");
@@ -74,70 +74,68 @@ int pi3usb9281_write(uint8_t chip_idx, uint8_t reg, uint8_t val)
 }
 
 /* Write control register, taking care to correctly set reserved bits. */
-static int pi3usb9281_write_ctrl(uint8_t chip_idx, uint8_t ctrl)
+static int pi3usb9281_write_ctrl(int port, uint8_t ctrl)
 {
-	return pi3usb9281_write(chip_idx, PI3USB9281_REG_CONTROL,
+	return pi3usb9281_write(port, PI3USB9281_REG_CONTROL,
 				(ctrl & PI3USB9281_CTRL_MASK) |
 				PI3USB9281_CTRL_RSVD_1);
 }
 
-int pi3usb9281_enable_interrupts(uint8_t chip_idx)
+void pi3usb9281_init(int port)
 {
-	uint8_t ctrl = pi3usb9281_read(chip_idx, PI3USB9281_REG_CONTROL);
+	uint8_t dev_id;
+
+	dev_id = pi3usb9281_read(port, PI3USB9281_REG_DEV_ID);
+
+	if (dev_id != PI3USB9281_DEV_ID && dev_id != PI3USB9281_DEV_ID_A)
+		CPRINTS("PI3USB9281 invalid ID 0x%02x", dev_id);
+
+	pi3usb9281_set_interrupt_mask(port, 0xff);
+	pi3usb9281_enable_interrupts(port);
+}
+
+
+int pi3usb9281_enable_interrupts(int port)
+{
+	uint8_t ctrl = pi3usb9281_read(port, PI3USB9281_REG_CONTROL);
 
 	if (ctrl == 0xee)
 		return EC_ERROR_UNKNOWN;
 
-	return pi3usb9281_write_ctrl(chip_idx, ctrl & ~PI3USB9281_CTRL_INT_DIS);
+	return pi3usb9281_write_ctrl(port, ctrl & ~PI3USB9281_CTRL_INT_DIS);
 }
 
-int pi3usb9281_disable_interrupts(uint8_t chip_idx)
+int pi3usb9281_disable_interrupts(int port)
 {
-	uint8_t ctrl = pi3usb9281_read(chip_idx, PI3USB9281_REG_CONTROL);
+	uint8_t ctrl = pi3usb9281_read(port, PI3USB9281_REG_CONTROL);
 	int rv;
 
 	if (ctrl == 0xee)
 		return EC_ERROR_UNKNOWN;
 
-	rv = pi3usb9281_write_ctrl(chip_idx, ctrl | PI3USB9281_CTRL_INT_DIS);
-	pi3usb9281_get_interrupts(chip_idx);
+	rv = pi3usb9281_write_ctrl(port, ctrl | PI3USB9281_CTRL_INT_DIS);
+	pi3usb9281_get_interrupts(port);
 	return rv;
 }
 
-int pi3usb9281_set_interrupt_mask(uint8_t chip_idx, uint8_t mask)
+int pi3usb9281_set_interrupt_mask(int port, uint8_t mask)
 {
-	return pi3usb9281_write(chip_idx, PI3USB9281_REG_INT_MASK, ~mask);
+	return pi3usb9281_write(port, PI3USB9281_REG_INT_MASK, ~mask);
 }
 
-int pi3usb9281_get_interrupts(uint8_t chip_idx)
+int pi3usb9281_get_interrupts(int port)
 {
-	int ret = pi3usb9281_peek_interrupts(chip_idx);
-
-	if (chip_idx >= PI3USB9281_COUNT)
-		return EC_ERROR_PARAM1;
-
-	saved_interrupts[chip_idx] = 0;
-	return ret;
-}
-
-int pi3usb9281_peek_interrupts(uint8_t chip_idx)
-{
-	if (chip_idx >= PI3USB9281_COUNT)
-		return EC_ERROR_PARAM1;
-
-	saved_interrupts[chip_idx] |= pi3usb9281_read(chip_idx,
-		PI3USB9281_REG_INT);
-	return saved_interrupts[chip_idx];
+	return pi3usb9281_read(port, PI3USB9281_REG_INT);
 }
 
-int pi3usb9281_get_device_type(uint8_t chip_idx)
+int pi3usb9281_get_device_type(int port)
 {
-	return pi3usb9281_read(chip_idx, PI3USB9281_REG_DEV_TYPE) & 0x77;
+	return pi3usb9281_read(port, PI3USB9281_REG_DEV_TYPE) & 0x77;
 }
 
-int pi3usb9281_get_charger_status(uint8_t chip_idx)
+int pi3usb9281_get_charger_status(int port)
 {
-	return pi3usb9281_read(chip_idx, PI3USB9281_REG_CHG_STATUS) & 0x1f;
+	return pi3usb9281_read(port, PI3USB9281_REG_CHG_STATUS) & 0x1f;
 }
 
 int pi3usb9281_get_ilim(int device_type, int charger_status)
@@ -162,18 +160,18 @@ int pi3usb9281_get_ilim(int device_type, int charger_status)
 	return current_limit_ma;
 }
 
-int pi3usb9281_get_vbus(uint8_t chip_idx)
+int pi3usb9281_get_vbus(int port)
 {
-	int vbus = pi3usb9281_read(chip_idx, PI3USB9281_REG_VBUS);
+	int vbus = pi3usb9281_read(port, PI3USB9281_REG_VBUS);
 	if (vbus == 0xee)
 		return EC_ERROR_UNKNOWN;
 
 	return !!(vbus & 0x2);
 }
 
-int pi3usb9281_reset(uint8_t chip_idx)
+int pi3usb9281_reset(int port)
 {
-	int rv = pi3usb9281_write(chip_idx, PI3USB9281_REG_RESET, 0x1);
+	int rv = pi3usb9281_write(port, PI3USB9281_REG_RESET, 0x1);
 
 	if (!rv)
 		/* Reset takes ~15ms. Wait for 20ms to be safe. */
@@ -182,9 +180,9 @@ int pi3usb9281_reset(uint8_t chip_idx)
 	return rv;
 }
 
-int pi3usb9281_set_switch_manual(uint8_t chip_idx, int val)
+int pi3usb9281_set_switch_manual(int port, int val)
 {
-	uint8_t ctrl = pi3usb9281_read(chip_idx, PI3USB9281_REG_CONTROL);
+	uint8_t ctrl = pi3usb9281_read(port, PI3USB9281_REG_CONTROL);
 
 	if (ctrl == 0xee)
 		return EC_ERROR_UNKNOWN;
@@ -194,17 +192,17 @@ int pi3usb9281_set_switch_manual(uint8_t chip_idx, int val)
 	else
 		ctrl |= PI3USB9281_CTRL_AUTO;
 
-	return pi3usb9281_write_ctrl(chip_idx, ctrl);
+	return pi3usb9281_write_ctrl(port, ctrl);
 }
 
-int pi3usb9281_set_pins(uint8_t chip_idx, uint8_t val)
+int pi3usb9281_set_pins(int port, uint8_t val)
 {
-	return pi3usb9281_write(chip_idx, PI3USB9281_REG_MANUAL, val);
+	return pi3usb9281_write(port, PI3USB9281_REG_MANUAL, val);
 }
 
-int pi3usb9281_set_switches(uint8_t chip_idx, int open)
+int pi3usb9281_set_switches(int port, int open)
 {
-	uint8_t ctrl = pi3usb9281_read(chip_idx, PI3USB9281_REG_CONTROL);
+	uint8_t ctrl = pi3usb9281_read(port, PI3USB9281_REG_CONTROL);
 
 	if (ctrl == 0xee)
 		return EC_ERROR_UNKNOWN;
@@ -214,20 +212,5 @@ int pi3usb9281_set_switches(uint8_t chip_idx, int open)
 	else
 		ctrl |= PI3USB9281_CTRL_SWITCH_AUTO;
 
-	return pi3usb9281_write_ctrl(chip_idx, ctrl);
-}
-
-static void pi3usb9281_init(void)
-{
-	uint8_t dev_id;
-	int i;
-
-	for (i = 0; i < PI3USB9281_COUNT; i++) {
-		dev_id = pi3usb9281_read(i, PI3USB9281_REG_DEV_ID);
-
-		if (dev_id != PI3USB9281_DEV_ID &&
-		    dev_id != PI3USB9281_DEV_ID_A)
-			CPRINTS("PI3USB9281[%d] invalid ID 0x%02x", i, dev_id);
-	}
+	return pi3usb9281_write_ctrl(port, ctrl);
 }
-DECLARE_HOOK(HOOK_INIT, pi3usb9281_init, HOOK_PRIO_LAST);
diff --git a/include/config.h b/include/config.h
index 8ceba6036b..c0c553fd38 100644
--- a/include/config.h
+++ b/include/config.h
@@ -1414,8 +1414,8 @@
 /* Support the Pericom PI3USB9281 I2C USB switch */
 #undef CONFIG_USB_SWITCH_PI3USB9281
 
-/* Select GPIO MUX for Pericom PI3USB9281 I2C USB switch */
-#undef CONFIG_USB_SWITCH_PI3USB9281_MUX_GPIO
+/* Number of Pericom PI3USB9281 chips present in system */
+#undef CONFIG_USB_SWITCH_PI3USB9281_CHIP_COUNT
 
 /*****************************************************************************/
 /* USB GPIO config */
diff --git a/include/usb_charge.h b/include/usb_charge.h
index e67aba482e..f95e69e91d 100644
--- a/include/usb_charge.h
+++ b/include/usb_charge.h
@@ -42,4 +42,12 @@ int usb_charge_set_mode(int usb_port_id, enum usb_charge_mode mode);
  */
 int usb_charge_ports_enabled(void);
 
+/**
+ * Returns true if the passed port is a power source.
+ *
+ * @param port  Port number.
+ * @return      True if port is sourcing vbus.
+ */
+int usb_charger_port_is_sourcing_vbus(int port);
+
 #endif  /* __CROS_EC_USB_CHARGE_H */