cr50: Use own CCD EXT state machine

The state machine in common/case_closed_debug.c only handles a subset
of what we need to do for Cr50 external case closed debugging, and
also supports a 'partial' CCD state that doesn't exist for Cr50.  Move
the few lines of code from that we actually need into our file.

BUG=none
BRANCH=cr50
TEST=manual
	Assert CCD_MODE_L
	See 'CCD EXT enable'
	Confirm Cr50 console appears as a RW /dev/ttyUSBn endpoint
	Confirm firmware update over USB works

	Deassert CCD_MODE_L
	See 'CCD EXT disable'
	Confirm Cr50 console appears as a RW /dev/ttyUSBn endpoint
	Confirm firmware update over USB does not work (can't find device)

Change-Id: Id96f2770632839a9690740ece54bc2eb71d39a38
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/647909
Reviewed-by: Mary Ruthven <mruthven@chromium.org>

2 files changed, 45 insertions, 22 deletions

diff --git a/board/cr50/board.h b/board/cr50/board.h
index ad0dae24bb..a82c63720c 100644
--- a/board/cr50/board.h
+++ b/board/cr50/board.h
@@ -97,7 +97,6 @@
 #define CONFIG_STREAM_USART2
 
 /* Enable Case Closed Debugging */
-#define CONFIG_CASE_CLOSED_DEBUG
 #define CONFIG_CASE_CLOSED_DEBUG_V1
 #define CONFIG_PHYSICAL_PRESENCE
 
diff --git a/board/cr50/rdd.c b/board/cr50/rdd.c
index 85b27ad0eb..e55737387d 100644
--- a/board/cr50/rdd.c
+++ b/board/cr50/rdd.c
@@ -14,10 +14,22 @@
 #include "system.h"
 #include "uartn.h"
 #include "usb_api.h"
+#include "usb_console.h"
 #include "usb_i2c.h"
+#include "usb_spi.h"
+
+/* Include the dazzlingly complex macro to instantiate the USB SPI config */
+USB_SPI_CONFIG(ccd_usb_spi, USB_IFACE_SPI, USB_EP_SPI);
 
 #define CPRINTS(format, args...) cprints(CC_USB, format, ## args)
 
+static enum device_state state = DEVICE_STATE_INIT;
+
+int ccd_ext_is_enabled(void)
+{
+	return state == DEVICE_STATE_CONNECTED;
+}
+
 /* If the UART TX is connected the pinmux select will have a non-zero value */
 int uart_tx_is_connected(int uart)
 {
@@ -80,14 +92,34 @@ void uartn_tx_disconnect(int uart)
 	uart_select_tx(uart, 0);
 }
 
-static void configure_ccd(int enable)
+static void rdd_check_pin(void)
 {
-	if (enable) {
-		if (ccd_ext_is_enabled())
-			return;
+	/* The CCD mode pin is active low. */
+	int enable = !gpio_get_level(GPIO_CCD_MODE_L);
 
-		/* Enable CCD */
-		ccd_set_mode(CCD_MODE_ENABLED);
+	if (enable == ccd_ext_is_enabled())
+		return;
+
+	if (enable) {
+		/*
+		 * If we're not disconnected, release USB to ensure it's in a
+		 * good state before we usb_init().  This matches what
+		 * common/case_closed_debug.c does.
+		 *
+		 * Not sure exactly why this is necessary.  It could be because
+		 * that also has CCD_MODE_PARTIAL, and the only way to go
+		 * cleanly between ENABLED and PARTIAL is to disable things and
+		 * then re-enable only what's needed?
+		 */
+		if (state != DEVICE_STATE_DISCONNECTED)
+			usb_release();
+
+		CPRINTS("CCD EXT enable");
+		state = DEVICE_STATE_CONNECTED;
+
+		usb_console_enable(1, 0);
+		usb_spi_enable(&ccd_usb_spi, 1);
+		usb_init();
 
 		/* Attempt to connect UART TX */
 		uartn_tx_connect(UART_AP);
@@ -96,28 +128,20 @@ static void configure_ccd(int enable)
 		/* Turn on 3.3V rail used for INAs and initialize I2CM module */
 		usb_i2c_board_enable();
 	} else {
+		CPRINTS("CCD EXT disable");
+		state = DEVICE_STATE_DISCONNECTED;
+
+		usb_release();
+		usb_console_enable(0, 0);
+		usb_spi_enable(&ccd_usb_spi, 0);
+
 		/* Disconnect from AP and EC UART TX peripheral from gpios */
 		uartn_tx_disconnect(UART_EC);
 		uartn_tx_disconnect(UART_AP);
 
-		/* Disable CCD */
-		ccd_set_mode(CCD_MODE_DISABLED);
-
 		/* Turn off 3.3V rail to INAs and disconnect I2CM module */
 		usb_i2c_board_disable();
 	}
-	CPRINTS("CCD is now %sabled.", enable ? "en" : "dis");
-}
-
-static void rdd_check_pin(void)
-{
-	/* The CCD mode pin is active low. */
-	int enable = !gpio_get_level(GPIO_CCD_MODE_L);
-
-	if (enable == ccd_ext_is_enabled())
-		return;
-
-	configure_ccd(enable);
 }
 DECLARE_HOOK(HOOK_SECOND, rdd_check_pin, HOOK_PRIO_DEFAULT);