pd: dingdong/hoho: inhibit USB Billboard.

USB Billboard class can be used to advertise an alternate mode capable
device that hasn't entered a mode.  Additionally it can remain after
mode entry providing its Billboard capabilities descriptor is
updated.

This CL postpones enumeration which previously occurred after boot
until tAMETimeout has passed and alternate mode has NOT been entered.
Future CL could choose to also (re)enumerate with mode capabilities
although this is not required by the USB PD specification.

BRANCH=none
BUG=chrome-os-partner:31192,chrome-os-partner:31193
TEST=manual,
With DFP_U which does not enter mode see Billboard class enumerate
else it does not.

Change-Id: I59a0815cd0ea551ba9a878907c0184df4ba9480c
Signed-off-by: Todd Broch <tbroch@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/224663
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

9 files changed, 66 insertions, 25 deletions

diff --git a/board/dingdong/board.h b/board/dingdong/board.h
index c814b6f48d..814df199bc 100644
--- a/board/dingdong/board.h
+++ b/board/dingdong/board.h
@@ -21,6 +21,7 @@
 #define CONFIG_HW_CRC
 #define CONFIG_USB
 #define CONFIG_USB_BOS
+#define CONFIG_USB_INHIBIT
 #define CONFIG_USB_POWER_DELIVERY
 #define CONFIG_USB_PD_ALT_MODE
 #define CONFIG_USB_PD_DUAL_ROLE
diff --git a/board/dingdong/usb_pd_policy.c b/board/dingdong/usb_pd_policy.c
index 2e18792733..5894427ca8 100644
--- a/board/dingdong/usb_pd_policy.c
+++ b/board/dingdong/usb_pd_policy.c
@@ -13,6 +13,7 @@
 #include "task.h"
 #include "timer.h"
 #include "util.h"
+#include "usb.h"
 #include "usb_pd.h"
 #include "version.h"
 
@@ -145,10 +146,8 @@ const uint32_t vdo_dp_mode[MODE_CNT] =  {
 
 static int svdm_response_modes(int port, uint32_t *payload)
 {
-	if (PD_VDO_VID(payload[0]) != USB_SID_DISPLAYPORT) {
-		/* TODO(tbroch) USB billboard enabled here then */
-		return 1; /* will generate a NAK */
-	}
+	if (PD_VDO_VID(payload[0]) != USB_SID_DISPLAYPORT)
+		return 0; /* nak */
 
 	memcpy(payload + 1, vdo_dp_mode, sizeof(vdo_dp_mode));
 	return MODE_CNT + 1;
@@ -187,11 +186,12 @@ static int svdm_enter_mode(int port, uint32_t *payload)
 	    (PD_VDO_OPOS(payload[0]) != OPOS))
 		return 0; /* will generate NAK */
 
+	/* TODO(tbroch) Enumerate USB BB here with updated mode choice */
 	alt_mode = OPOS;
 	return 1;
 }
 
-int pd_alt_mode(int port)
+int pd_alt_mode(void)
 {
 	return alt_mode;
 }
diff --git a/board/hoho/board.h b/board/hoho/board.h
index c341b479fe..d98ba5b135 100644
--- a/board/hoho/board.h
+++ b/board/hoho/board.h
@@ -29,6 +29,7 @@
 #define CONFIG_SPI_CS_GPIO GPIO_PD_MCDP_SPI_CS_L
 #define CONFIG_USB
 #define CONFIG_USB_BOS
+#define CONFIG_USB_INHIBIT
 #define CONFIG_USB_POWER_DELIVERY
 #define CONFIG_USB_PD_ALT_MODE
 #define CONFIG_USB_PD_DUAL_ROLE
diff --git a/board/hoho/usb_pd_policy.c b/board/hoho/usb_pd_policy.c
index 4eff69b49e..3da52023c3 100644
--- a/board/hoho/usb_pd_policy.c
+++ b/board/hoho/usb_pd_policy.c
@@ -12,6 +12,7 @@
 #include "registers.h"
 #include "task.h"
 #include "timer.h"
+#include "usb.h"
 #include "usb_pd.h"
 #include "util.h"
 #include "version.h"
@@ -145,10 +146,8 @@ const uint32_t vdo_dp_mode[MODE_CNT] =  {
 
 static int svdm_response_modes(int port, uint32_t *payload)
 {
-	if (PD_VDO_VID(payload[0]) != USB_SID_DISPLAYPORT) {
-		/* TODO(tbroch) USB billboard enabled here then */
-		return 1; /* will generate a NAK */
-	}
+	if (PD_VDO_VID(payload[0]) != USB_SID_DISPLAYPORT)
+		return 0; /* nak */
 
 	memcpy(payload + 1, vdo_dp_mode, sizeof(vdo_dp_mode));
 	return MODE_CNT + 1;
@@ -186,11 +185,12 @@ static int svdm_enter_mode(int port, uint32_t *payload)
 	    (PD_VDO_OPOS(payload[0]) != OPOS))
 		return 0; /* will generate a NAK */
 
+	/* TODO(tbroch) Enumerate USB BB here with updated mode choice */
 	alt_mode = OPOS;
 	return 1;
 }
 
-int pd_alt_mode(int port)
+int pd_alt_mode(void)
 {
 	return alt_mode;
 }
diff --git a/chip/stm32/usb.c b/chip/stm32/usb.c
index b9f69ec848..409cb4f69d 100644
--- a/chip/stm32/usb.c
+++ b/chip/stm32/usb.c
@@ -297,20 +297,37 @@ void usb_init(void)
 	/* set interrupts mask : reset/correct tranfer/errors */
 	STM32_USB_CNTR = 0xe400;
 
-	/* set pull-up on DP for FS mode */
-#ifdef CHIP_VARIANT_STM32L15X
-	STM32_SYSCFG_PMC |= 1;
-#elif defined(CHIP_FAMILY_STM32F0)
-	STM32_USB_BCDR |= 1 << 15 /* DPPU */;
-#else
-	/* hardwired or regular GPIO on other platforms */
+#ifndef CONFIG_USB_INHIBIT
+	usb_connect();
 #endif
 
 	CPRINTF("USB init done\n");
 }
-#ifndef CONFIG_USB_INHIBIT
 DECLARE_HOOK(HOOK_INIT, usb_init, HOOK_PRIO_DEFAULT);
+
+void usb_disconnect(void)
+{
+	/* disable pull-up on DP to disconnect */
+#ifdef CHIP_VARIANT_STM32L15X
+	STM32_SYSCFG_PMC &= ~1;
+#elif defined(CHIP_FAMILY_STM32F0)
+	STM32_USB_BCDR &= ~(1 << 15) /* DPPU */;
+#else
+#warn "usb disconnect not implemented for this chip family"
 #endif
+}
+
+void usb_connect(void)
+{
+	/* enable pull-up on DP to connect */
+#ifdef CHIP_VARIANT_STM32L15X
+	STM32_SYSCFG_PMC |= 1;
+#elif defined(CHIP_FAMILY_STM32F0)
+	STM32_USB_BCDR |= (1 << 15) /* DPPU */;
+#else
+#warn "usb connect not implemented for this chip family"
+#endif
+}
 
 void usb_release(void)
 {
diff --git a/common/usb_pd_policy.c b/common/usb_pd_policy.c
index f0ae2cffab..87e1062817 100644
--- a/common/usb_pd_policy.c
+++ b/common/usb_pd_policy.c
@@ -7,11 +7,13 @@
 #include "common.h"
 #include "console.h"
 #include "gpio.h"
+#include "hooks.h"
 #include "host_command.h"
 #include "registers.h"
 #include "task.h"
 #include "timer.h"
 #include "util.h"
+#include "usb.h"
 #include "usb_pd.h"
 #include "usb_pd_config.h"
 #include "version.h"
@@ -382,10 +384,6 @@ int pd_svdm(int port, int cnt, uint32_t *payload, uint32_t **rpayload)
 	return 0;
 }
 
-int pd_alt_mode(int port)
-{
-	return 0;
-}
 #endif /* CONFIG_USB_PD_ALT_MODE */
 
 #ifndef CONFIG_USB_PD_CUSTOM_VDM
@@ -395,6 +393,18 @@ int pd_vdm(int port, int cnt, uint32_t *payload, uint32_t **rpayload)
 }
 #endif /* !CONFIG_USB_PD_CUSTOM_VDM */
 
+void pd_usb_billboard_deferred(void)
+{
+#if defined(CONFIG_USB_PD_ALT_MODE) && !defined(CONFIG_USB_PD_ALT_MODE_DFP) \
+	&& !defined(CONFIG_USB_PD_SIMPLE_DFP)
+
+	if (!pd_alt_mode())
+		usb_connect();
+
+#endif
+}
+DECLARE_DEFERRED(pd_usb_billboard_deferred);
+
 #ifndef CONFIG_USB_PD_ALT_MODE_DFP
 int pd_exit_mode(int port, uint32_t *payload)
 {
diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c
index c91893c4c5..c44e070043 100644
--- a/common/usb_pd_protocol.c
+++ b/common/usb_pd_protocol.c
@@ -185,6 +185,9 @@ static const uint8_t dec4b5b[] = {
 #define PD_T_DRP_SRC           (30*MSEC) /* toggle time for source DRP */
 #define PD_T_SRC_RECOVER      (760*MSEC) /* between 660ms and 1000ms */
 
+/* from USB Type-C Specification Table 5-1 */
+#define PD_T_AME (1*SECOND) /* timeout from UFP attach to Alt Mode Entry */
+
 /* Port role at startup */
 #ifdef CONFIG_USB_PD_DUAL_ROLE
 #define PD_ROLE_DEFAULT PD_ROLE_SINK
@@ -1464,6 +1467,9 @@ void pd_task(void)
 #endif
 					set_state(port, PD_STATE_SNK_DISCOVERY);
 					timeout = 10*MSEC;
+					hook_call_deferred(
+						pd_usb_billboard_deferred,
+						PD_T_AME);
 					break;
 				}
 			}
@@ -1750,7 +1756,7 @@ static int remote_flashing(int argc, char **argv)
 void pd_send_hpd(int port, enum hpd_event hpd)
 {
 	uint32_t data[1];
-	int opos = pd_alt_mode(port);
+	int opos = pd_alt_mode();
 	if (!opos)
 		return;
 
diff --git a/include/usb.h b/include/usb.h
index df6426fc64..bce830ebb3 100644
--- a/include/usb.h
+++ b/include/usb.h
@@ -296,6 +296,8 @@ extern void (*usb_iface_request[]) (usb_uint *ep0_buf_rx, usb_uint *ep0_buf_tx);
 
 /* functions to start/stop USB */
 void usb_init(void);
+void usb_disconnect(void);
+void usb_connect(void);
 void usb_release(void);
 
 #endif /* USB_H */
diff --git a/include/usb_pd.h b/include/usb_pd.h
index c13e5e9588..072f070359 100644
--- a/include/usb_pd.h
+++ b/include/usb_pd.h
@@ -784,10 +784,9 @@ void board_flip_usb_mux(int port);
 /**
  * Determine if in alternate mode or not.
  *
- * @param port port number.
  * @return object position of mode chosen in alternate mode otherwise zero.
  */
-int pd_alt_mode(int port);
+int pd_alt_mode(void);
 
 /**
  * Send hpd over USB PD.
@@ -796,6 +795,11 @@ int pd_alt_mode(int port);
  * @param hpd hotplug detect type.
  */
 void pd_send_hpd(int port, enum hpd_event hpd);
+
+/**
+ * Enable USB Billboard Device.
+ */
+void pd_usb_billboard_deferred(void);
 /* --- Physical layer functions : chip specific --- */
 
 /* Packet preparation/retrieval */