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>

board/cr50/board.h

@@ -28,6 +28,7 @@
 #define CONFIG_USB
 #define CONFIG_USB_HID
 #define CONFIG_USB_CONSOLE
+#define CONFIG_USB_SELECT_PHY
 
 #define CONFIG_STREAM_USART
 #define CONFIG_STREAM_USB

chip/g/build.mk

@@ -50,6 +50,7 @@ chip-$(CONFIG_USB)+=usb.o usb_endpoints.o
 chip-$(CONFIG_USB_CONSOLE)+=usb_console.o
 chip-$(CONFIG_USB_HID)+=usb_hid.o
 chip-$(CONFIG_USB_BLOB)+=blob.o
+chip-$(CONFIG_RDD)+=rdd.o
 chip-$(CONFIG_STREAM_USB)+=usb-stream.o
 chip-$(CONFIG_STREAM_USART)+=usart.o
 

chip/g/clock.c

@@ -30,6 +30,9 @@ void clock_enable_module(enum module_id module, int enable)
 		clock_func(PERIPH_I2C0);
 		clock_func(PERIPH_I2C1);
 		break;
+	case MODULE_RDD:
+		clock_func(PERIPH_RDD0);
+		break;
 	case MODULE_SPI_FLASH:
 	case MODULE_SPI_MASTER:
 		clock_func(PERIPH_SPI);

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);

chip/g/usb.c

@@ -314,13 +314,19 @@ static uint8_t configuration_value;
 
 /* Default PHY to use */
 static uint32_t which_phy = USB_SEL_PHY1;
-static inline void select_phy(uint32_t phy)
+
+void usb_select_phy(uint32_t phy)
 {
 	which_phy = phy;
 	GR_USB_GGPIO = GGPIO_WRITE(USB_CUSTOM_CFG_REG,
 				   (USB_PHY_ACTIVE | which_phy));
 }
 
+uint32_t usb_get_phy(void)
+{
+	return which_phy;
+}
+
 /* Reset all this to a good starting state. */
 static void initialize_dma_buffers(void)
 {
@@ -1237,7 +1243,7 @@ void usb_init(void)
 	GR_USB_DOEPMSK = 0;
 
 	/* Select the correct PHY */
-	select_phy(which_phy);
+	usb_select_phy(which_phy);
 	gpio_set_level(GPIO_CCD_MODE_L, !(which_phy == USB_SEL_PHY1));
 
 	/* Full-Speed Serial PHY */
@@ -1363,9 +1369,9 @@ static int command_usb(int argc, char **argv)
 		else if (!strcasecmp("off", argv[1]))
 			usb_release();
 		else if (!strcasecmp("a", argv[1]))
-			select_phy(USB_SEL_PHY0);
+			usb_select_phy(USB_SEL_PHY0);
 		else if (!strcasecmp("b", argv[1]))
-			select_phy(USB_SEL_PHY1);
+			usb_select_phy(USB_SEL_PHY1);
 	}
 
 	showregs();

include/config.h

@@ -1480,6 +1480,9 @@
 /* Size of RAM available on the chip, in bytes */
 #undef CONFIG_RAM_SIZE
 
+/* Enable RDD peripheral */
+#undef CONFIG_RDD
+
 /* Support IR357x Link voltage regulator debugging / reprogramming */
 #undef CONFIG_REGULATOR_IR357X
 
@@ -1945,6 +1948,9 @@
 /* Disable automatic initialization of USB peripheral */
 #undef CONFIG_USB_INHIBIT_INIT
 
+/* Support control of multiple PHY */
+#undef CONFIG_USB_SELECT_PHY
+
 /* Support simple control of power to the device's USB ports */
 #undef CONFIG_USB_PORT_POWER_DUMB
 

include/module_id.h

@@ -32,21 +32,22 @@ enum module_id {
 	MODULE_PORT80,
 	MODULE_POWER_LED,
 	MODULE_PWM,	/* 20 */
+	MODULE_RDD,
 	MODULE_SPI,
 	MODULE_SPI_FLASH,
 	MODULE_SPI_MASTER,
-	MODULE_SWITCH,
-	MODULE_SYSTEM,	/* 25 */
+	MODULE_SWITCH,	/* 25 */
+	MODULE_SYSTEM,
 	MODULE_TASK,
 	MODULE_THERMAL,
 	MODULE_UART,
-	MODULE_USART,
-	MODULE_USB,	/* 30 */
+	MODULE_USART,	/* 30 */
+	MODULE_USB,
 	MODULE_USB_DEBUG,
 	MODULE_USB_PD,
 	MODULE_USB_PORT_POWER,
-	MODULE_USB_SWITCH,
-	MODULE_VBOOT,	/* 35 */
+	MODULE_USB_SWITCH,	/* 35 */
+	MODULE_VBOOT,
 
 	/* Module count; not an actual module */
 	MODULE_COUNT

include/usb_api.h

@@ -42,4 +42,11 @@ void usb_disconnect(void);
  */
 void usb_release(void);
 
+#ifdef CONFIG_USB_SELECT_PHY
+/* Select which PHY to use. */
+void usb_select_phy(uint32_t phy);
+
+/* Get the current PHY */
+uint32_t usb_get_phy(void);
+#endif
 #endif /* __CROS_EC_USB_API_H */