honeybuns: manage USB and DP hardware

Get the USB hub out of reset only when there is a USB host,
same thing for the DisplayPort hardware.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=chrome-os-partner:37078
TEST=Plug and un-plug Honeybuns to Samus. See both the USB devices
connected and the external display.

Change-Id: Iabbeb0650d18c4c0c3324f47d99f9aaa35601c16
Reviewed-on: https://chromium-review.googlesource.com/281927
Trybot-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Alec Berg <alecaberg@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>

5 files changed, 66 insertions, 24 deletions

diff --git a/board/honeybuns/board.c b/board/honeybuns/board.c
index b58ca7e075..d7d504a581 100644
--- a/board/honeybuns/board.c
+++ b/board/honeybuns/board.c
@@ -85,9 +85,6 @@ const void * const usb_strings[] = {
 };
 BUILD_ASSERT(ARRAY_SIZE(usb_strings) == USB_STR_COUNT);
 
-
-
-
 void board_set_usb_mux(int port, enum typec_mux mux,
 		       enum usb_switch usb, int polarity)
 {
@@ -95,9 +92,17 @@ void board_set_usb_mux(int port, enum typec_mux mux,
 	if (mux == TYPEC_MUX_NONE) {
 		/* put the mux in the high impedance state */
 		gpio_set_level(GPIO_SS_MUX_OE_L, 1);
+		/* Disable display hardware */
+		gpio_set_level(GPIO_BRIDGE_RESET_L, 0);
+		gpio_set_level(GPIO_SPLITTER_RESET_L, 0);
+		/* Put the USB hub under reset */
+		hx3_enable(0);
 		return;
 	}
 
+	/* Trigger USB Hub configuration */
+	hx3_enable(1);
+
 	if ((mux == TYPEC_MUX_DOCK) || (mux == TYPEC_MUX_USB)) {
 		/* Low selects USB Dock */
 		gpio_set_level(GPIO_SS_MUX_SEL, 0);
@@ -108,6 +113,12 @@ void board_set_usb_mux(int port, enum typec_mux mux,
 
 	/* clear OE line to make mux active */
 	gpio_set_level(GPIO_SS_MUX_OE_L, 0);
+
+	if (mux != TYPEC_MUX_USB) {
+		/* Enable display hardware */
+		gpio_set_level(GPIO_BRIDGE_RESET_L, 1);
+		gpio_set_level(GPIO_SPLITTER_RESET_L, 1);
+	}
 }
 
 int board_get_usb_mux(int port, const char **dp_str, const char **usb_str)
diff --git a/board/honeybuns/board.h b/board/honeybuns/board.h
index 085c057d91..e527e9f367 100644
--- a/board/honeybuns/board.h
+++ b/board/honeybuns/board.h
@@ -100,6 +100,9 @@ enum usb_strings {
 #define PD_MAX_CURRENT_MA     3000
 #define PD_MAX_VOLTAGE_MV     20000
 
+/* Enable/disable USB Hub */
+void hx3_enable(int enable);
+
 #endif /* !__ASSEMBLER__ */
 
 /* USB interface indexes (use define rather than enum to expand them) */
diff --git a/board/honeybuns/ec.tasklist b/board/honeybuns/ec.tasklist
index 72649e8217..ad72bfe7bb 100644
--- a/board/honeybuns/ec.tasklist
+++ b/board/honeybuns/ec.tasklist
@@ -18,5 +18,6 @@
  */
 #define CONFIG_TASK_LIST \
 	TASK_ALWAYS(HOOKS, hook_task, NULL, TASK_STACK_SIZE) \
+	TASK_ALWAYS(USBCFG, hx3_task, NULL, TASK_STACK_SIZE) \
 	TASK_ALWAYS(CONSOLE, console_task, NULL, LARGER_TASK_STACK_SIZE) \
 	TASK_ALWAYS(PD, pd_task, NULL, TASK_STACK_SIZE)
diff --git a/board/honeybuns/gpio.inc b/board/honeybuns/gpio.inc
index e18f30ff11..c6a8ffdf08 100644
--- a/board/honeybuns/gpio.inc
+++ b/board/honeybuns/gpio.inc
@@ -26,9 +26,9 @@ GPIO(SS_MUX_SEL,        PIN(B, 14), GPIO_OUT_LOW)
 GPIO(PD_SBU_ENABLE,     PIN(A, 7),  GPIO_OUT_LOW)
 
 /* Chip Resets */
-GPIO(BRIDGE_RESET_L,    PIN(B, 0),  GPIO_OUT_HIGH)
-GPIO(SPLITTER_RESET_L,  PIN(B, 1),  GPIO_OUT_HIGH)
-GPIO(HUB_RESET_L,       PIN(B, 15), GPIO_OUT_HIGH)
+GPIO(BRIDGE_RESET_L,    PIN(B, 0),  GPIO_OUT_LOW)
+GPIO(SPLITTER_RESET_L,  PIN(B, 1),  GPIO_OUT_LOW)
+GPIO(HUB_RESET_L,       PIN(B, 15), GPIO_OUT_LOW)
 
 
 /*
diff --git a/board/honeybuns/hx3.c b/board/honeybuns/hx3.c
index df9bcfe121..7944035bce 100644
--- a/board/honeybuns/hx3.c
+++ b/board/honeybuns/hx3.c
@@ -10,6 +10,7 @@
 #include "gpio.h"
 #include "hooks.h"
 #include "i2c.h"
+#include "task.h"
 #include "timer.h"
 #include "usb.h"
 #include "util.h"
@@ -69,44 +70,70 @@ const uint8_t hx3_settings[5 + HX3_SETTINGS_SIZE] = {
 	 /* Free space for more strings */
 };
 
-static void configure_hx3(void)
+static int hx3_configured;
+
+static int configure_hx3(void)
 {
 	int ret;
 	int remaining, len;
 	uint8_t *data = (uint8_t *)hx3_settings;
 	uint16_t addr = 0x0000;
-
-	/* Reset the bridge to put it back in bootloader mode */
-	gpio_set_level(GPIO_HUB_RESET_L, 0);
-	/* Keep the reset low at least 10ms (same as the RC) */
-	msleep(50);
-	gpio_set_level(GPIO_HUB_RESET_L, 1);
-	msleep(50);
+	int success = 1;
 
 	remaining = sizeof(hx3_settings);
-	while (remaining) {
+	while (remaining && gpio_get_level(GPIO_HUB_RESET_L)) {
 		/* do 64-byte Page Write */
 		len = MIN(remaining, 64);
-		i2c_lock(0, 1);
+		i2c_lock(I2C_PORT_MASTER, 1);
 		/* send Page Write address */
-		ret = i2c_xfer(0, HX3_I2C_ADDR, (uint8_t *)&addr, 2,
-			       NULL, 0, I2C_XFER_START);
+		ret = i2c_xfer(I2C_PORT_MASTER, HX3_I2C_ADDR,
+			       (uint8_t *)&addr, 2, NULL, 0, I2C_XFER_START);
 		/* send page data */
-		ret |= i2c_xfer(0, HX3_I2C_ADDR, data, len,
-				NULL, 0, I2C_XFER_STOP);
-		i2c_lock(0, 0);
-		if (ret != EC_SUCCESS)
+		ret |= i2c_xfer(I2C_PORT_MASTER, HX3_I2C_ADDR,
+				data, len, NULL, 0, I2C_XFER_STOP);
+		i2c_lock(I2C_PORT_MASTER, 0);
+		if (ret != EC_SUCCESS) {
+			success = 0;
 			ccprintf("HX3 transfer failed %d\n", ret);
+			break;
+		}
 		remaining -= len;
 		data += len;
 	}
+	return gpio_get_level(GPIO_HUB_RESET_L) ? success : 0;
 }
-DECLARE_HOOK(HOOK_INIT, configure_hx3, HOOK_PRIO_DEFAULT);
 
+void hx3_task(void)
+{
+	while (1) {
+		task_wait_event(-1);
+		if (!hx3_configured && gpio_get_level(GPIO_HUB_RESET_L)) {
+			/* wait for the HX3 to come out of reset */
+			msleep(5);
+			hx3_configured = configure_hx3();
+		}
+	}
+}
+
+void hx3_enable(int enable)
+{
+	/* Release reset when the Hub is enabled */
+	gpio_set_level(GPIO_HUB_RESET_L, !!enable);
+	/* Trigger I2C configuration if needed */
+	if (enable)
+		task_wake(TASK_ID_USBCFG);
+	else
+		hx3_configured = 0;
+}
 
 static int command_hx3(int argc, char **argv)
 {
-	configure_hx3();
+	/* Reset the bridge to put it back in bootloader mode */
+	hx3_enable(0);
+	/* Keep the reset low at least 10ms (same as the RC) */
+	msleep(50);
+	/* Release reset and wait for the hub to come up */
+	hx3_enable(1);
 
 	return EC_SUCCESS;
 }