cr50: Detect debug cable and switch the PHY

This adds support for RD Detection on cr50. It can be used to detect a
debug device and signal the controller to switch from the AP PHY to the
to CCD PHY. When RDCC1 and 2 no longer detect the debug device, then
the controller switches back to using the USB to AP PHY.

BUG=chrome-os-partner:50700
BRANCH=none
TEST=change the value on RDCC1 and RDCC1 and check that the usb
controller connects to the right PHY.

Change-Id: Ice01a45a31fe1932945f89df2e3b851f4d287a17
Signed-off-by: Mary Ruthven <mruthven@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/338454
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

1 files changed, 75 insertions, 0 deletions

diff --git a/chip/g/rdd.c b/chip/g/rdd.c
new file mode 100644
index 0000000000..63df750484
--- /dev/null
+++ b/chip/g/rdd.c
@@ -0,0 +1,75 @@
+/* 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 "clock.h"
+#include "console.h"
+#include "gpio.h"
+#include "hooks.h"
+#include "registers.h"
+#include "task.h"
+#include "usb_api.h"
+
+#define CCD_PHY USB_SEL_PHY1
+#define AP_PHY USB_SEL_PHY0
+
+uint16_t ccd_detect;
+
+static int debug_cable_is_detected(void)
+{
+	uint8_t cc1 = GREAD_FIELD(RDD, INPUT_PIN_VALUES, CC1);
+	uint8_t cc2 = GREAD_FIELD(RDD, INPUT_PIN_VALUES, CC2);
+
+	return (cc1 == cc2 && (cc1 == 3 || cc1 == 1));
+}
+
+void rdd_interrupt(void)
+{
+	if (debug_cable_is_detected()) {
+		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);
+	} 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);
+	}
+
+	/* Connect to selected phy */
+	usb_init();
+
+	/* Clear interrupt */
+	GWRITE_FIELD(RDD, INT_STATE, INTR_DEBUG_STATE_DETECTED, 1);
+}
+DECLARE_IRQ(GC_IRQNUM_RDD0_INTR_DEBUG_STATE_DETECTED_INT, rdd_interrupt, 1);
+
+void rdd_init(void)
+{
+	/* Enable RDD */
+	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);
+
+	/* Enable RDD interrupts */
+	task_enable_irq(GC_IRQNUM_RDD0_INTR_DEBUG_STATE_DETECTED_INT);
+	GWRITE_FIELD(RDD, INT_ENABLE, INTR_DEBUG_STATE_DETECTED, 1);
+}
+DECLARE_HOOK(HOOK_INIT, rdd_init, HOOK_PRIO_DEFAULT);
+
+static int command_test_rdd(int argc, char **argv)
+{
+	GWRITE_FIELD(RDD, INT_TEST, INTR_DEBUG_STATE_DETECTED, 1);
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(test_rdd, command_test_rdd, "", "", NULL);