cr50: enable AP and EC UART in CCD MODE

When the debug cable is plugged in enable the EC and AP UART output.
Disable the output when the cable is disconnected so servo can use the
UARTs.

BUG=chrome-os-partner:52322
BRANCH=none
TEST=Verify commands can be sent to the EC UART through usb when suzy q
is connected. Verify servo can interact with the EC UART when suzy q is
not connected.

Change-Id: I2ce0e9da464b24e295e732aa638bfc32323cc72d
Signed-off-by: Mary Ruthven <mruthven@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/338858
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

5 files changed, 102 insertions, 29 deletions

diff --git a/board/cr50/build.mk b/board/cr50/build.mk
index 09dd749239..7232785edf 100644
--- a/board/cr50/build.mk
+++ b/board/cr50/build.mk
@@ -30,6 +30,7 @@ dirs-y += $(BDIR)/tpm2
 
 # Objects that we need to build
 board-y =  board.o
+board-${CONFIG_RDD} += rdd.o
 board-y += tpm2/NVMem.o
 board-y += tpm2/aes.o
 board-y += tpm2/ecc.o
diff --git a/board/cr50/gpio.inc b/board/cr50/gpio.inc
index 1c6d04f4b9..ef4b5eb21b 100644
--- a/board/cr50/gpio.inc
+++ b/board/cr50/gpio.inc
@@ -54,14 +54,14 @@ PINMUX(GPIO(BATT_PRES),       M2, 0)
 /* UARTs */
 PINMUX(FUNC(UART0_TX),        A0, DIO_OUTPUT)	/* Cr50 console */
 PINMUX(FUNC(UART0_RX),        A1, DIO_INPUT | DIO_WAKE_LOW)
-/* AP console */
-/* TODO(crosbug.com/p/52281, crosbug.com/p/50700). Don't fight servo */
-/* PINMUX(FUNC(UART1_TX),        A7, DIO_OUTPUT) */
-PINMUX(FUNC(UART1_RX),        A3, DIO_INPUT)
-/* EC console */
-/* TODO(crosbug.com/p/52281, crosbug.com/p/50700). Don't fight servo */
-/* PINMUX(FUNC(UART2_TX),        B5, DIO_OUTPUT) */
-PINMUX(FUNC(UART2_RX),        B6, DIO_INPUT)
+/* UART1_TX and UART2_TX are configured in usart.c. They are not set as outputs
+ * here in order to avoid interfering with servo. They can be controlled using
+ * the 'uart' console command.
+ *   UART1_TX = DIOA7	AP console
+ *   UART2_TX = DIOB5	EC console
+ */
+PINMUX(FUNC(UART1_RX),        A3, DIO_INPUT)	/* AP console */
+PINMUX(FUNC(UART2_RX),        B6, DIO_INPUT)	/* EC console */
 
 /* I2C pins are bi-directional */
 PINMUX(FUNC(I2C0_SCL),        B0, DIO_INPUT)
diff --git a/board/cr50/rdd.c b/board/cr50/rdd.c
new file mode 100644
index 0000000000..66f6c8c313
--- /dev/null
+++ b/board/cr50/rdd.c
@@ -0,0 +1,64 @@
+/* Copyright 2016 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 "console.h"
+#include "rdd.h"
+#include "registers.h"
+#include "usb_api.h"
+
+static void usart_tx_connect(void)
+{
+	GWRITE(PINMUX, DIOA7_SEL, GC_PINMUX_UART1_TX_SEL);
+	GWRITE(PINMUX, DIOB5_SEL, GC_PINMUX_UART2_TX_SEL);
+}
+
+static void usart_tx_disconnect(void)
+{
+	GWRITE(PINMUX, DIOA7_SEL, GC_PINMUX_DIOA3_SEL_DEFAULT);
+	GWRITE(PINMUX, DIOB5_SEL, GC_PINMUX_DIOB5_SEL_DEFAULT);
+}
+
+void rdd_attached(void)
+{
+	/* Select the CCD PHY */
+	usb_select_phy(USB_SEL_PHY1);
+
+	/* Connect to selected phy */
+	usb_init();
+}
+
+void rdd_detached(void)
+{
+	/* Disconnect from AP and EC UART TX */
+	usart_tx_disconnect();
+
+	/* Select the AP PHY */
+	usb_select_phy(USB_SEL_PHY0);
+
+	/* Connect to selected phy */
+	usb_init();
+}
+
+static int command_uart(int argc, char **argv)
+{
+	static int enabled;
+
+	if (argc > 1) {
+		if (!strcasecmp("enable", argv[1])) {
+			enabled = 1;
+			usart_tx_connect();
+		} else if (!strcasecmp("disable", argv[1])) {
+			enabled = 0;
+			usart_tx_disconnect();
+		}
+	}
+
+	ccprintf("UART %s\n", enabled ? "enabled" : "disabled");
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(uart, command_uart,
+	"[enable|disable]",
+	"Get/set the UART TX connection state",
+	NULL);
diff --git a/chip/g/rdd.c b/chip/g/rdd.c
index 63df750484..59a27ee475 100644
--- a/chip/g/rdd.c
+++ b/chip/g/rdd.c
@@ -7,16 +7,14 @@
 #include "console.h"
 #include "gpio.h"
 #include "hooks.h"
+#include "rdd.h"
 #include "registers.h"
 #include "task.h"
 #include "usb_api.h"
 
-#define CCD_PHY USB_SEL_PHY1
-#define AP_PHY USB_SEL_PHY0
+static uint16_t debug_detect;
 
-uint16_t ccd_detect;
-
-static int debug_cable_is_detected(void)
+int debug_cable_is_attached(void)
 {
 	uint8_t cc1 = GREAD_FIELD(RDD, INPUT_PIN_VALUES, CC1);
 	uint8_t cc2 = GREAD_FIELD(RDD, INPUT_PIN_VALUES, CC2);
@@ -26,25 +24,18 @@ static int debug_cable_is_detected(void)
 
 void rdd_interrupt(void)
 {
-	if (debug_cable_is_detected()) {
+	if (debug_cable_is_attached()) {
 		ccprintf("Debug Accessory connected\n");
 		/* Detect when debug cable is disconnected */
-		GWRITE(RDD, PROG_DEBUG_STATE_MAP, ~ccd_detect);
-
-		/* Select the CCD PHY */
-		usb_select_phy(CCD_PHY);
+		GWRITE(RDD, PROG_DEBUG_STATE_MAP, ~debug_detect);
+		rdd_attached();
 	} else {
 		ccprintf("Debug Accessory disconnected\n");
 		/* Detect when debug cable is connected */
-		GWRITE(RDD, PROG_DEBUG_STATE_MAP, ccd_detect);
-
-		/* Select the AP PHY */
-		usb_select_phy(AP_PHY);
+		GWRITE(RDD, PROG_DEBUG_STATE_MAP, debug_detect);
+		rdd_detached();
 	}
 
-	/* Connect to selected phy */
-	usb_init();
-
 	/* Clear interrupt */
 	GWRITE_FIELD(RDD, INT_STATE, INTR_DEBUG_STATE_DETECTED, 1);
 }
@@ -56,10 +47,13 @@ void rdd_init(void)
 	clock_enable_module(MODULE_RDD, 1);
 	GWRITE(RDD, POWER_DOWN_B, 1);
 
-	ccd_detect = GREAD(RDD, PROG_DEBUG_STATE_MAP);
-	/* Detect cable disconnect if CCD is enabled */
-	if (usb_get_phy() == CCD_PHY)
-		GWRITE(RDD, PROG_DEBUG_STATE_MAP, ~ccd_detect);
+	debug_detect = GREAD(RDD, PROG_DEBUG_STATE_MAP);
+
+	/* If cable is attached, detect when it is disconnected */
+	if (debug_cable_is_attached()) {
+		GWRITE(RDD, PROG_DEBUG_STATE_MAP, ~debug_detect);
+		rdd_attached();
+	}
 
 	/* Enable RDD interrupts */
 	task_enable_irq(GC_IRQNUM_RDD0_INTR_DEBUG_STATE_DETECTED_INT);
diff --git a/chip/g/rdd.h b/chip/g/rdd.h
new file mode 100644
index 0000000000..53dd687a16
--- /dev/null
+++ b/chip/g/rdd.h
@@ -0,0 +1,14 @@
+/* Copyright 2016 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_RDD_H
+#define __CROS_RDD_H
+
+/* Detach from debug cable */
+void rdd_detached(void);
+
+/* Attach to debug cable */
+void rdd_attached(void);
+#endif  /* __CROS_RDD_H */