servo_v4p1: improve I/O expander implementation

Remove servo_v4p1 custom ioex implementations for TCA64xxA modules.
Enable I/O expander module and move from custom interface to
generic one.

Due to the lack of flash in RW section, IOEX is not available there and
required 'board_id_det' function is stubbed using raw i2c functions.
This results in IOEX and DAC functions available only in RO section,
so their initialization functions are moved to RO-only init.

BUG=b:168385201
BRANCH=main
TEST=Connect to servo's console and execute 'ioexget' command.
     All IOEX pins' states should be printed in terminal.
     Pin TCA_GPIO_DBG_LED_K_ODL should change as LED is blinking.
TEST=Connect to servo's console. Plug USB-C charger to servo power
     port. 'ioexget' command should display EN_PP5000_ALT_3P3 value
     as 1. Execute 'ioexset EN_PP5000_ALT_3P3 0' command.
     Unplug fast the servo charger. Servo should be fully operational
     without any sign of reboot.

Signed-off-by: Michał Barnaś <mb@semihalf.com>
Change-Id: Iff98b37746a95d6a59954507ab18defac65d6329
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2700297
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

11 files changed, 190 insertions, 413 deletions

diff --git a/board/servo_v4p1/board.c b/board/servo_v4p1/board.c
index 79a8a20fe6..7d92c603c8 100644
--- a/board/servo_v4p1/board.c
+++ b/board/servo_v4p1/board.c
@@ -12,6 +12,7 @@
 #include "console.h"
 #include "dacs.h"
 #include <driver/gl3590.h>
+#include "driver/ioexpander/tca64xxa.h"
 #include "ec_version.h"
 #include "fusb302b.h"
 #include "gpio.h"
@@ -425,24 +426,25 @@ static void board_init(void)
 	/* Delay DUT hub to avoid brownout. */
 	usleep(MSEC);
 
-	init_ioexpanders();
-	CPRINTS("Board ID is %d", board_id_det());
-
-	vbus_dischrg_en(0);
-
-	init_dacs();
 	init_pi3usb9201();
 
 	/* Clear BBRAM, we don't want any PD state carried over on reset. */
 	system_set_bbram(SYSTEM_BBRAM_IDX_PD0, 0);
 	system_set_bbram(SYSTEM_BBRAM_IDX_PD1, 0);
 
-	/* Bring atmel part out of reset */
-	atmel_reset_l(1);
-
 #ifdef SECTION_IS_RO
+	init_ioexpanders();
+	CPRINTS("Board ID is %d", board_id_det());
+
+	init_dacs();
+	init_uservo_port();
+	init_pathsel();
 	init_ina231s();
 	init_fusb302b(1);
+	vbus_dischrg_en(0);
+
+	/* Bring atmel part out of reset */
+	atmel_reset_l(1);
 
 	/*
 	 * Get data about available input power. Defer this check, since we need
@@ -474,6 +476,8 @@ static void board_init(void)
 
 	/* Start SuzyQ detection */
 	start_ccd_meas_sbu_cycle();
+#else /* SECTION_IS_RO */
+	CPRINTS("Board ID is %d", board_id_det());
 #endif /* SECTION_IS_RO */
 }
 DECLARE_HOOK(HOOK_INIT, board_init, HOOK_PRIO_DEFAULT);
@@ -499,4 +503,20 @@ void tick_event(void)
 	}
 }
 DECLARE_HOOK(HOOK_TICK, tick_event, HOOK_PRIO_DEFAULT);
+
+struct ioexpander_config_t ioex_config[] = {
+	[0] = {
+		.drv = &tca64xxa_ioexpander_drv,
+		.i2c_host_port = TCA6416A_PORT,
+		.i2c_slave_addr = TCA6416A_ADDR,
+		.flags = TCA64XXA_FLAG_VER_TCA6416A
+	},
+	[1] = {
+		.drv = &tca64xxa_ioexpander_drv,
+		.i2c_host_port = TCA6424A_PORT,
+		.i2c_slave_addr = TCA6424A_ADDR,
+		.flags = TCA64XXA_FLAG_VER_TCA6424A
+	}
+};
+
 #endif /* SECTION_IS_RO */
diff --git a/board/servo_v4p1/board.h b/board/servo_v4p1/board.h
index 98a5fcc6a1..273014f15b 100644
--- a/board/servo_v4p1/board.h
+++ b/board/servo_v4p1/board.h
@@ -24,6 +24,14 @@
 #define DUT 1
 
 /*
+ * IO expanders I2C addresses and ports
+ */
+#define TCA6416A_PORT 1
+#define TCA6416A_ADDR 0x21
+#define TCA6424A_PORT 1
+#define TCA6424A_ADDR 0x23
+
+/*
  * Flash layout: we redefine the sections offsets and sizes as we want to
  * include a pstate region, and will use RO/RW regions of different sizes.
  * RO has size 92K and usb_updater along with the majority of code is placed
@@ -140,6 +148,14 @@
 /* Enable console recasting of GPIO type. */
 #define CONFIG_CMD_GPIO_EXTENDED
 
+/* Enable I/O expander */
+#ifdef SECTION_IS_RO
+#define CONFIG_IO_EXPANDER
+#define CONFIG_IO_EXPANDER_SUPPORT_GET_PORT
+#define CONFIG_IO_EXPANDER_TCA64XXA
+#define CONFIG_IO_EXPANDER_PORT_COUNT 2
+#endif
+
 /* This is not actually an EC so disable some features. */
 #undef CONFIG_WATCHDOG_HELP
 #undef CONFIG_LID_SWITCH
diff --git a/board/servo_v4p1/build.mk b/board/servo_v4p1/build.mk
index 3433b808cd..872b4d4281 100644
--- a/board/servo_v4p1/build.mk
+++ b/board/servo_v4p1/build.mk
@@ -14,7 +14,7 @@ CHIP_VARIANT:=stm32f07x
 test-list-y=
 
 # These files are compiled into RO and RW
-board-y=board.o tca6416a.o tca6424a.o
+board-y=board.o
 board-y+=ioexpanders.o
 board-y+=dacs.o
 board-y+=pi3usb9201.o
diff --git a/board/servo_v4p1/dacs.c b/board/servo_v4p1/dacs.c
index b5c62bb438..d042836a2b 100644
--- a/board/servo_v4p1/dacs.c
+++ b/board/servo_v4p1/dacs.c
@@ -101,6 +101,7 @@ int write_dac(enum dac_t dac, uint16_t value)
 	return EC_SUCCESS;
 }
 
+#ifdef SECION_IS_RO
 static int cmd_cc_dac(int argc, char *argv[])
 {
 	uint8_t dac;
@@ -136,3 +137,4 @@ static int cmd_cc_dac(int argc, char *argv[])
 DECLARE_CONSOLE_COMMAND(cc_dac, cmd_cc_dac,
 			"dac <\"on\"|\"off\"|mv>",
 			"Set Servo v4.1 CC dacs");
+#endif
diff --git a/board/servo_v4p1/gpio.inc b/board/servo_v4p1/gpio.inc
index 52a689c03f..070aa90098 100644
--- a/board/servo_v4p1/gpio.inc
+++ b/board/servo_v4p1/gpio.inc
@@ -65,6 +65,53 @@ GPIO(USB_DUT_TX_CLKIN,        PIN(B, 13), GPIO_INPUT)
 GPIO(MASTER_I2C_SCL,		PIN(B, 10), GPIO_INPUT)
 GPIO(MASTER_I2C_SDA,		PIN(B, 11), GPIO_INPUT)
 
+/* IOEX */
+#ifdef SECTION_IS_RO
+
+IOEX(SBU_UART_SEL, 		EXPIN(0, 0, 0), GPIO_OUT_LOW)
+IOEX(ATMEL_RESET_L, 		EXPIN(0, 0, 1), GPIO_OUT_LOW)
+IOEX(SBU_FLIP_SEL, 		EXPIN(0, 0, 2), GPIO_OUT_HIGH)
+IOEX(USB3_A0_MUX_SEL, 		EXPIN(0, 0, 3), GPIO_OUT_HIGH)
+IOEX(USB3_A0_MUX_EN_L, 		EXPIN(0, 0, 4), GPIO_OUT_LOW)
+IOEX(USB3_A0_PWR_EN, 		EXPIN(0, 0, 5), GPIO_OUT_LOW)
+IOEX(UART_18_SEL, 		EXPIN(0, 0, 6), GPIO_OUT_LOW)
+IOEX(USERVO_POWER_EN, 		EXPIN(0, 0, 7), GPIO_OUT_LOW)
+IOEX(USERVO_FASTBOOT_MUX_SEL, 	EXPIN(0, 1, 0), GPIO_OUT_LOW)
+IOEX(USB3_A1_PWR_EN, 		EXPIN(0, 1, 1), GPIO_OUT_LOW)
+IOEX(USB3_A1_MUX_SEL, 		EXPIN(0, 1, 2), GPIO_OUT_HIGH)
+IOEX(BOARD_ID_DET0, 		EXPIN(0, 1, 3), GPIO_INPUT)
+IOEX(BOARD_ID_DET1, 		EXPIN(0, 1, 4), GPIO_INPUT)
+IOEX(BOARD_ID_DET2, 		EXPIN(0, 1, 5), GPIO_INPUT)
+IOEX(VBUS_DISCHRG_EN, 		EXPIN(0, 1, 6), GPIO_OUT_LOW)
+IOEX(DONGLE_DET, 		EXPIN(0, 1, 7), GPIO_INPUT)
+
+IOEX(EN_PP5000_ALT_3P3, 	EXPIN(1, 0, 0), GPIO_OUT_LOW)
+IOEX(EN_PP3300_ETH, 		EXPIN(1, 0, 1), GPIO_OUT_HIGH)
+IOEX(EN_PP3300_DP, 		EXPIN(1, 0, 2), GPIO_OUT_HIGH)
+IOEX(FAULT_CLEAR_CC, 		EXPIN(1, 0, 3), GPIO_OUT_LOW)
+IOEX(EN_VOUT_BUF_CC1, 		EXPIN(1, 0, 4), GPIO_OUT_LOW)
+IOEX(EN_VOUT_BUF_CC2, 		EXPIN(1, 0, 5), GPIO_OUT_LOW)
+IOEX(DUT_CHG_EN, 		EXPIN(1, 0, 6), GPIO_OUT_LOW)
+IOEX(HOST_OR_CHG_CTL, 		EXPIN(1, 0, 7), GPIO_OUT_LOW)
+IOEX(USERVO_FAULT_L, 		EXPIN(1, 1, 0), GPIO_INPUT)
+IOEX(USB3_A0_FAULT_L, 		EXPIN(1, 1, 1), GPIO_INPUT)
+IOEX(USB3_A1_FAULT_L, 		EXPIN(1, 1, 2), GPIO_INPUT)
+IOEX(USB_DUTCHG_FLT_ODL, 	EXPIN(1, 1, 3), GPIO_INPUT)
+IOEX(PP3300_DP_FAULT_L, 	EXPIN(1, 1, 4), GPIO_INPUT)
+IOEX(DAC_BUF1_LATCH_FAULT_L, 	EXPIN(1, 1, 5), GPIO_INPUT)
+IOEX(DAC_BUF2_LATCH_FAULT_L, 	EXPIN(1, 1, 6), GPIO_INPUT)
+IOEX(PP5000_SRC_SEL, 		EXPIN(1, 1, 7), GPIO_INPUT)
+IOEX(HOST_CHRG_DET, 		EXPIN(1, 2, 0), GPIO_INPUT)
+IOEX(USBH_PWRDN_L, 		EXPIN(1, 2, 1), GPIO_OUT_HIGH)
+IOEX(ATMEL_SS,			EXPIN(1, 2, 2), GPIO_INPUT)
+IOEX(ATMEL_SCLK,		EXPIN(1, 2, 3), GPIO_INPUT)
+IOEX(ATMEL_MOSI,		EXPIN(1, 2, 4), GPIO_INPUT)
+IOEX(ATMEL_MISO,		EXPIN(1, 2, 5), GPIO_INPUT)
+IOEX(SYS_PWR_IRQ_ODL, 		EXPIN(1, 2, 6), GPIO_INPUT)
+IOEX(TCA_GPIO_DBG_LED_K_ODL, 	EXPIN(1, 2, 7), GPIO_OUT_LOW)
+
+#endif
+
 /* Unimplemented signals since we are not an EC */
 UNIMPLEMENTED(ENTERING_RW)
 UNIMPLEMENTED(WP_L)
diff --git a/board/servo_v4p1/ioexpanders.c b/board/servo_v4p1/ioexpanders.c
index 6be5ed26ba..50690321fd 100644
--- a/board/servo_v4p1/ioexpanders.c
+++ b/board/servo_v4p1/ioexpanders.c
@@ -5,125 +5,23 @@
 
 #include "hooks.h"
 #include "i2c.h"
+#include "ioexpander.h"
 #include "ioexpanders.h"
-#include "tca6416a.h"
-#include "tca6424a.h"
 
 /******************************************************************************
  * Initialize IOExpanders.
  */
 
+static enum servo_board_id board_id_val = BOARD_ID_UNSET;
+
+#ifdef SECTION_IS_RO
+
 static int dut_chg_en_state;
 static int bc12_charger;
 
-static enum servo_board_id board_id_val = BOARD_ID_UNSET;
-
 /* Enable all ioexpander outputs. */
 int init_ioexpanders(void)
 {
-	int ret;
-
-	/*
-	 * Init TCA6416A, PORT 0
-	 * NAME                      | DIR | Initial setting
-	 * -------------------------------------------------
-	 * BIT-0 (SBU_UART_SEL)      | O   | 0
-	 * BIT-1 (ATMEL_RESET_L)     | O   | 0
-	 * BIT-2 (SBU_FLIP_SEL)      | O   | 1
-	 * BIT-3 (USB3_A0_MUX_SEL)   | O   | 0
-	 * BIT-4 (USB3_A0_MUX_EN_L)  | O   | 0
-	 * BIT-5 (USB3_A0_PWR_EN)    | O   | 0
-	 * BIT-6 (UART_18_SEL)       | O   | 0
-	 * BIT-7 (USERVO_POWER_EN)   | O   | 0
-	 */
-	ret = tca6416a_write_byte(1, TCA6416A_OUT_PORT_0, 0x04);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	ret = tca6416a_write_byte(1, TCA6416A_DIR_PORT_0, 0x00);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	/*
-	 * Init TCA6416A, PORT 1
-	 * NAME                            | DIR | Initial setting
-	 * -------------------------------------------------------
-	 * BIT-0 (USERVO_FASTBOOT_MUX_SEL) | O   | 0
-	 * BIT-1 (USB3_A1_PWR_EN)          | O   | 0
-	 * BIT-2 (USB3_A1_MUX_SEL)         | O   | 0
-	 * BIT-3 (BOARD_ID)                | I   | x
-	 * BIT-4 (BOARD ID)                | I   | x
-	 * BIT-5 (BOARD_ID)                | I   | x
-	 * BIT-6 (VBUS_DISCHRG_EN)         | O   | 0
-	 * BIT-7 (DONGLE_DET)              | I   | x
-	 */
-	ret = tca6416a_write_byte(1, TCA6416A_OUT_PORT_1, 0x0);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	ret = tca6416a_write_byte(1, TCA6416A_DIR_PORT_1, 0xb8);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	/*
-	 * Init TCA6424A, PORT 0
-	 * NAME                      | DIR | Initial setting
-	 * -------------------------------------------------
-	 * BIT-0 (EN_PP5000_ALT_3P3) | O   | 0
-	 * BIT-1 (EN_PP3300_ETH)     | O   | 1
-	 * BIT-2 (EN_PP3300_DP)      | O   | 0
-	 * BIT-3 (FAULT_CLEAR_CC)    | O   | 0
-	 * BIT-4 (EN_VOUT_BUF_CC1)   | O   | 0
-	 * BIT-5 (EN_VOUT_BUF_CC2)   | O   | 0
-	 * BIT-6 (DUT_CHG_EN)        | O   | 0
-	 * BIT-7 (HOST_OR_CHG_CTL)   | O   | 0
-	 */
-	ret = tca6424a_write_byte(1, TCA6424A_OUT_PORT_0, 0x02);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	ret = tca6424a_write_byte(1, TCA6424A_DIR_PORT_0, 0x00);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	/*
-	 * Init TCA6424A, PORT 1
-	 * NAME                           | DIR | Initial setting
-	 * ------------------------------------------------------
-	 * BIT-0 (USERVO_FAULT_L)         | I   | x
-	 * BIT-1 (USB3_A0_FAULT_L)        | I   | x
-	 * BIT-2 (USB3_A1_FAULT_L)        | I   | x
-	 * BIT-3 (USB_DUTCHG_FLT_ODL)     | I   | x
-	 * BIT-4 (PP3300_DP_FAULT_L)      | I   | x
-	 * BIT-5 (DAC_BUF1_LATCH_FAULT_L) | I   | x
-	 * BIT-6 (DAC_BUF2_LATCH_FAULT_L) | I   | x
-	 * BIT-7 (PP5000_SRC_SEL)         | I   | x
-	 */
-	ret = tca6424a_write_byte(1, TCA6424A_DIR_PORT_1, 0xff);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	/*
-	 * Init TCA6424A, PORT 2
-	 * NAME                      | DIR | Initial setting
-	 * ------------------------------------------------
-	 * BIT-0 (HOST_CHRG_DET)     | I   | x
-	 * BIT-1 (USBH_PWRDN_L)      | O   | 1
-	 * BIT-2 (UNUSED)            | I   | x
-	 * BIT-3 (UNUSED)            | I   | x
-	 * BIT-4 (UNUSED)            | I   | x
-	 * BIT-5 (UNUSED)            | I   | x
-	 * BIT-6 (SYS_PWR_IRQ_ODL)   | I   | x
-	 * BIT-7 (DBG_LED_K_ODL)     | O   | 0
-	 */
-	ret = tca6424a_write_byte(1, TCA6424A_OUT_PORT_2, 0x02);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	ret = tca6424a_write_byte(1, TCA6424A_DIR_PORT_2, 0x7d);
-	if (ret != EC_SUCCESS)
-		return ret;
-
 	/* Clear any faults and other IRQs*/
 	read_faults();
 	read_irqs();
@@ -133,7 +31,7 @@ int init_ioexpanders(void)
 	 * notifies about event on both low and high levels, while notification
 	 * should happen only when state has changed.
 	 */
-	bc12_charger = get_host_chrg_det();
+	ioex_get_level(IOEX_HOST_CHRG_DET, &bc12_charger);
 
 	return EC_SUCCESS;
 }
@@ -172,11 +70,11 @@ static void ioexpanders_irq(void)
 		ccprintf("off DAC1 to clear the fault\n");
 	}
 
-	if (((irqs & HOST_CHRG_DET) != bc12_charger) &&
+	if ((!!(irqs & HOST_CHRG_DET) != bc12_charger) &&
 	    (board_id_det() <= BOARD_ID_REV1)) {
 		ccprintf("BC1.2 charger %s\n", (irqs & HOST_CHRG_DET) ?
 			 "plugged" : "unplugged");
-		bc12_charger = irqs & HOST_CHRG_DET;
+		bc12_charger = !!(irqs & HOST_CHRG_DET);
 	}
 
 	if (!(irqs & SYS_PWR_IRQ_ODL))
@@ -192,118 +90,125 @@ int irq_ioexpanders(void)
 
 inline int sbu_uart_sel(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_0, 0, en);
+	return ioex_set_level(IOEX_SBU_UART_SEL, en);
 }
 
 inline int atmel_reset_l(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_0, 1, en);
+	return ioex_set_level(IOEX_ATMEL_RESET_L, en);
 }
 
 inline int sbu_flip_sel(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_0, 2, en);
+	return ioex_set_level(IOEX_SBU_FLIP_SEL, en);
 }
 
 inline int usb3_a0_mux_sel(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_0, 3, en);
+	return ioex_set_level(IOEX_USB3_A0_MUX_SEL, en);
 }
 
 inline int usb3_a0_mux_en_l(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_0, 4, en);
+	return ioex_set_level(IOEX_USB3_A0_MUX_EN_L, en);
 }
 
 inline int ec_usb3_a0_pwr_en(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_0, 5, en);
+	return ioex_set_level(IOEX_USB3_A0_PWR_EN, en);
 }
 
 inline int uart_18_sel(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_0, 6, en);
+	return ioex_set_level(IOEX_UART_18_SEL, en);
 }
 
 inline int ec_uservo_power_en(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_0, 7, en);
+	return ioex_set_level(IOEX_USERVO_POWER_EN, en);
 }
 
 inline int uservo_fastboot_mux_sel(enum uservo_fastboot_mux_sel_t sel)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_1, 0, sel);
+	return ioex_set_level(IOEX_USERVO_FASTBOOT_MUX_SEL, (int)sel);
 }
 
 inline int ec_usb3_a1_pwr_en(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_1, 1, en);
+	return ioex_set_level(IOEX_USB3_A1_PWR_EN, en);
 }
 
 inline int usb3_a1_mux_sel(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_1, 2, en);
+	return ioex_set_level(IOEX_USB3_A1_MUX_SEL, en);
 }
 
 inline int board_id_det(void)
 {
-	int id;
 	if (board_id_val == BOARD_ID_UNSET) {
+		int id;
+
 		/* Cache board ID at init */
-		id = tca6416a_read_byte(1, TCA6416A_IN_PORT_1);
-		if (id < 0)
+		if (ioex_get_port(IOEX_GET_INFO(IOEX_BOARD_ID_DET0)->ioex,
+		    IOEX_GET_INFO(IOEX_BOARD_ID_DET0)->port,
+		    &id))
 			return id;
-		board_id_val = id;
+
+		/* Board ID consists of bits 5, 4, and 3 */
+		board_id_val = (id >> BOARD_ID_DET_OFFSET) & BOARD_ID_DET_MASK;
 	}
 
-	/* Board ID consists of bits 5, 4, and 3 */
-	return (board_id_val >> 3) & 0x7;
+	return board_id_val;
 }
 
 inline int dongle_det(void)
 {
-	return tca6416a_read_bit(1, TCA6416A_IN_PORT_1, 7);
+	int val;
+	ioex_get_level(IOEX_DONGLE_DET, &val);
+	return val;
 }
 
 inline int get_host_chrg_det(void)
 {
-	return tca6424a_read_bit(1, TCA6424A_IN_PORT_2, 0);
+	int val;
+	ioex_get_level(IOEX_HOST_CHRG_DET, &val);
+	return val;
 }
 
 inline int en_pp5000_alt_3p3(int en)
 {
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_0, 0, en);
+	return ioex_set_level(IOEX_EN_PP5000_ALT_3P3, en);
 }
 
 inline int en_pp3300_eth(int en)
 {
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_0, 1, en);
+	return ioex_set_level(IOEX_EN_PP3300_ETH, en);
 }
 
 inline int en_pp3300_dp(int en)
 {
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_0, 2, en);
+	return ioex_set_level(IOEX_EN_PP3300_DP, en);
 }
 
 inline int fault_clear_cc(int en)
 {
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_0, 3, en);
+	return ioex_set_level(IOEX_FAULT_CLEAR_CC, en);
 }
 
 inline int en_vout_buf_cc1(int en)
 {
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_0, 4, en);
+	return ioex_set_level(IOEX_EN_VOUT_BUF_CC1, en);
 }
 
 inline int en_vout_buf_cc2(int en)
 {
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_0, 5, en);
+	return ioex_set_level(IOEX_EN_VOUT_BUF_CC2, en);
 }
 
 int dut_chg_en(int en)
 {
 	dut_chg_en_state = en;
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_0, 6, en);
+	return ioex_set_level(IOEX_DUT_CHG_EN, en);
 }
 
 int get_dut_chg_en(void)
@@ -313,30 +218,74 @@ int get_dut_chg_en(void)
 
 inline int host_or_chg_ctl(int en)
 {
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_0, 7, en);
+	return ioex_set_level(IOEX_HOST_OR_CHG_CTL, en);
 }
 
 inline int read_faults(void)
 {
-	return tca6424a_read_byte(1, TCA6424A_IN_PORT_1);
+	int val;
+
+	ioex_get_port(IOEX_GET_INFO(IOEX_USERVO_FAULT_L)->ioex,
+		      IOEX_GET_INFO(IOEX_USERVO_FAULT_L)->port,
+		      &val);
+
+	return val;
 }
 
 inline int read_irqs(void)
 {
-	return tca6424a_read_byte(1, TCA6424A_IN_PORT_2);
+	int val;
+
+	ioex_get_port(IOEX_GET_INFO(IOEX_SYS_PWR_IRQ_ODL)->ioex,
+		      IOEX_GET_INFO(IOEX_SYS_PWR_IRQ_ODL)->port,
+		      &val);
+
+	return val;
 }
 
 inline int vbus_dischrg_en(int en)
 {
-	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_1, 6, en);
+	return ioex_set_level(IOEX_VBUS_DISCHRG_EN, en);
 }
 
 inline int usbh_pwrdn_l(int en)
 {
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_2, 1, en);
+	return ioex_set_level(IOEX_USBH_PWRDN_L, en);
 }
 
 inline int tca_gpio_dbg_led_k_odl(int en)
 {
-	return tca6424a_write_bit(1, TCA6424A_OUT_PORT_2, 7, !en);
+	return ioex_set_level(IOEX_TCA_GPIO_DBG_LED_K_ODL, !en);
+}
+
+#else /* SECTION_IS_RO */
+
+/*
+ * Due to lack of flash in RW section, it is not possible to use IOEX subsystem
+ * in it. Instead, RO section uses IOEX, and RW implements only required
+ * function with raw i2c operation. This function is required by 'version'
+ * console command and should work without any special initialization.
+ */
+inline int board_id_det(void)
+{
+	if (board_id_val == BOARD_ID_UNSET) {
+		int id;
+		int res;
+
+		/* Cache board ID at init */
+		res = i2c_read8(TCA6416A_PORT,
+				TCA6416A_ADDR,
+				BOARD_ID_DET_PORT,
+				&id);
+		if (res != EC_SUCCESS)
+			return res;
+
+		/* Board ID consists of bits 5, 4, and 3 */
+		board_id_val = (id >> BOARD_ID_DET_OFFSET) & BOARD_ID_DET_MASK;
+	}
+
+	/* Board ID consists of bits 5, 4, and 3 */
+	return board_id_val;
 }
+
+#endif /* SECTION_IS_RO */
diff --git a/board/servo_v4p1/ioexpanders.h b/board/servo_v4p1/ioexpanders.h
index e6b44a9d45..6565992857 100644
--- a/board/servo_v4p1/ioexpanders.h
+++ b/board/servo_v4p1/ioexpanders.h
@@ -6,6 +6,10 @@
 #ifndef __CROS_EC_IOEXPANDERS_H
 #define __CROS_EC_IOEXPANDERS_H
 
+#define BOARD_ID_DET_MASK 0x7
+#define BOARD_ID_DET_OFFSET 3
+#define BOARD_ID_DET_PORT 1
+
 enum uservo_fastboot_mux_sel_t {
 	MUX_SEL_USERVO = 0,
 	MUX_SEL_FASTBOOT = 1
diff --git a/board/servo_v4p1/tca6416a.c b/board/servo_v4p1/tca6416a.c
deleted file mode 100644
index d776ad86fe..0000000000
--- a/board/servo_v4p1/tca6416a.c
+++ /dev/null
@@ -1,63 +0,0 @@
-/* Copyright 2020 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "i2c.h"
-#include "tca6416a.h"
-
-int tca6416a_write_bit(int port, enum tca6416a_bank bank, uint8_t bit, int val)
-{
-	int tmp;
-	int ret;
-
-	/* Read output port register */
-	ret = i2c_read8(port, TCA6416A_ADDR_FLAGS, bank, &tmp);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	if (val)
-		tmp |= BIT(bit);
-	else
-		tmp &= ~BIT(bit);
-
-	/* Write back modified output port register */
-	ret = i2c_write8(port, TCA6416A_ADDR_FLAGS, bank, tmp);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	return EC_SUCCESS;
-}
-
-int tca6416a_write_byte(int port, enum tca6416a_bank bank, uint8_t val)
-{
-	int ret;
-
-	ret = i2c_write8(port, TCA6416A_ADDR_FLAGS, bank, val);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	return EC_SUCCESS;
-}
-
-int tca6416a_read_byte(int port, enum tca6416a_bank bank)
-{
-	int tmp;
-
-	if (i2c_read8(port, TCA6416A_ADDR_FLAGS, bank, &tmp) != EC_SUCCESS)
-		return -1;
-
-	return tmp;
-}
-
-int tca6416a_read_bit(int port, enum tca6416a_bank bank, uint8_t bit)
-{
-	int tmp;
-	int mask = 1 << bit;
-
-	/* Read input port register */
-	if (i2c_read8(port, TCA6416A_ADDR_FLAGS, bank, &tmp) != EC_SUCCESS)
-		return -1;
-
-	return (tmp & mask) >> bit;
-}
diff --git a/board/servo_v4p1/tca6416a.h b/board/servo_v4p1/tca6416a.h
deleted file mode 100644
index 5255059d99..0000000000
--- a/board/servo_v4p1/tca6416a.h
+++ /dev/null
@@ -1,66 +0,0 @@
-/* Copyright 2020 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef __CROS_EC_IOEXPANDER_TCA6416A_H
-#define __CROS_EC_IOEXPANDER_TCA6416A_H
-
-#include <stdint.h>
-
-#define TCA6416A_ADDR_FLAGS 0x21
-
-enum tca6416a_bank {
-	TCA6416A_IN_PORT_0  = 0x0,
-	TCA6416A_IN_PORT_1  = 0x1,
-	TCA6416A_OUT_PORT_0 = 0x2,
-	TCA6416A_OUT_PORT_1 = 0x3,
-	TCA6416A_DIR_PORT_0 = 0x6,
-	TCA6416A_DIR_PORT_1 = 0x7,
-};
-
-/*
- * Set a bit in the supplied bank
- *
- * @param port  The I2C port of TCA6416A.
- * @param bank  The bank the bit belongs to.
- * @param bit   The index of the bit to set.
- * @param val   The value to set.
- *
- * @return EC_SUCCESS, or EC_ERROR_* on error.
- */
-int tca6416a_write_bit(int port,
-			enum tca6416a_bank bank, uint8_t bit, int val);
-
-/*
- * Get a bit in the supplied bank
- *
- * @param port  The I2C port of TCA6416A.
- * @param bank  The bank the bit belongs to.
- * @param bit   The index of the bit to get.
- *
- * @return bit value, or -1 on error.
- */
-int tca6416a_read_bit(int port, enum tca6416a_bank bank, uint8_t bit);
-
-/*
- * Write a byt to the supplied bank
- *
- * @param port The I2C port of TCA6416A.
- * @param bank  The bank to write the byte to.
- *
- * @return EC_SUCCESS, or EC_ERROR_* on error.
- */
-int tca6416a_write_byte(int port, enum tca6416a_bank bank, uint8_t val);
-
-/*
- * Read a byte in the supplied bank
- *
- * @param port  The I2C port of TCA6416A.
- * @param bank  The bank to read byte from.
- *
- * @return byte value, or -1 on error.
- */
-int tca6416a_read_byte(int port, enum tca6416a_bank bank);
-
-#endif /* __CROS_EC_IOEXPANDER_TCA6416A_H */
diff --git a/board/servo_v4p1/tca6424a.c b/board/servo_v4p1/tca6424a.c
deleted file mode 100644
index 28c768b046..0000000000
--- a/board/servo_v4p1/tca6424a.c
+++ /dev/null
@@ -1,63 +0,0 @@
-/* Copyright 2020 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "i2c.h"
-#include "tca6424a.h"
-
-int tca6424a_write_bit(int port, enum tca6424a_bank bank, uint8_t bit, int val)
-{
-	int tmp;
-	int ret;
-
-	/* Read output port register */
-	ret = i2c_read8(port, TCA6424A_ADDR_FLAGS, bank, &tmp);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	if (val)
-		tmp |= BIT(bit);
-	else
-		tmp &= ~BIT(bit);
-
-	/* Write back modified output port register */
-	ret = i2c_write8(port, TCA6424A_ADDR_FLAGS, bank, tmp);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	return EC_SUCCESS;
-}
-
-int tca6424a_write_byte(int port, enum tca6424a_bank bank, uint8_t val)
-{
-	int ret;
-
-	ret = i2c_write8(port, TCA6424A_ADDR_FLAGS, bank, val);
-	if (ret != EC_SUCCESS)
-		return ret;
-
-	return EC_SUCCESS;
-}
-
-int tca6424a_read_byte(int port, enum tca6424a_bank bank)
-{
-	int tmp;
-
-	if (i2c_read8(port, TCA6424A_ADDR_FLAGS, bank, &tmp) != EC_SUCCESS)
-		return -1;
-
-	return tmp;
-}
-
-int tca6424a_read_bit(int port, enum tca6424a_bank bank, uint8_t bit)
-{
-	int tmp;
-	int mask = 1 << bit;
-
-	/* Read input port register */
-	if (i2c_read8(port, TCA6424A_ADDR_FLAGS, bank, &tmp) != EC_SUCCESS)
-		return -1;
-
-	return (tmp & mask) >> bit;
-}
diff --git a/board/servo_v4p1/tca6424a.h b/board/servo_v4p1/tca6424a.h
deleted file mode 100644
index 80db7ebdba..0000000000
--- a/board/servo_v4p1/tca6424a.h
+++ /dev/null
@@ -1,69 +0,0 @@
-/* Copyright 2020 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef __CROS_EC_IOEXPANDER_TCA6424A_H
-#define __CROS_EC_IOEXPANDER_TCA6424A_H
-
-#include <stdint.h>
-
-#define TCA6424A_ADDR_FLAGS 0x23
-
-enum tca6424a_bank {
-	TCA6424A_IN_PORT_0  = 0x0,
-	TCA6424A_IN_PORT_1  = 0x1,
-	TCA6424A_IN_PORT_2  = 0x2,
-	TCA6424A_OUT_PORT_0 = 0x4,
-	TCA6424A_OUT_PORT_1 = 0x5,
-	TCA6424A_OUT_PORT_2 = 0x6,
-	TCA6424A_DIR_PORT_0 = 0xc,
-	TCA6424A_DIR_PORT_1 = 0xd,
-	TCA6424A_DIR_PORT_2 = 0xe,
-};
-
-/*
- * Set a bit in the supplied bank
- *
- * @param port  The I2C port of TCA6424A.
- * @param bank  The bank the bit belongs to.
- * @param bit   The index of the bit to set.
- * @param val   The value to set.
- *
- * @return EC_SUCCESS, or EC_ERROR_* on error.
- */
-int tca6424a_write_bit(int port,
-			enum tca6424a_bank bank, uint8_t bit, int val);
-
-/*
- * Get a bit in the supplied bank
- *
- * @param port  The I2C port of TCA6424A.
- * @param bank  The bank the bit belongs to.
- * @param bit   The index of the bit to get.
- *
- * @return bit value, or -1 on error.
- */
-int tca6424a_read_bit(int port, enum tca6424a_bank bank, uint8_t bit);
-
-/*
- * Write a byt to the supplied bank
- *
- * @param port The I2C port of TCA6424A.
- * @param bank  The bank to write the byte to.
- *
- * @return EC_SUCCESS, or EC_ERROR_* on error.
- */
-int tca6424a_write_byte(int port, enum tca6424a_bank bank, uint8_t val);
-
-/*
- * Read a byte in the supplied bank
- *
- * @param port  The I2C port of TCA6424A.
- * @param bank  The bank to read byte from.
- *
- * @return byte value, or -1 on error.
- */
-int tca6424a_read_byte(int port, enum tca6424a_bank bank);
-
-#endif /* __CROS_EC_IOEXPANDER_TCA6424A_H */