pd: manage total source current available

Add a policy to handle the case where the device can source the
`CONFIG_USB_PD_MAX_SINGLE_SOURCE_CURRENT` over one of its type-C port if
there is no sink connected on the other ones.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=chrome-os-partner:56110
TEST=manual: on Kevin, plug and unplug various devices on the 2 ports,
while measuring the type-C pull-up with Twinkie.

Change-Id: Id5961f04d0a1b1073f5ab340068efd9079918209
Reviewed-on: https://chromium-review.googlesource.com/373818
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Shawn N <shawnn@chromium.org>

3 files changed, 32 insertions, 9 deletions

diff --git a/include/charge_manager.h b/include/charge_manager.h
index 28546e22a1..7427d12aca 100644
--- a/include/charge_manager.h
+++ b/include/charge_manager.h
@@ -91,6 +91,17 @@ int charge_manager_get_charger_current(void);
 void charge_manager_save_log(int port);
 #endif
 
+/* Update whether a given port is sourcing current. */
+void charge_manager_source_port(int port, int enable);
+
+/*
+ * Get PD source power data objects.
+ *
+ * @param src_pdo pointer to the data to return.
+ * @return number of PDOs returned.
+ */
+int charge_manager_get_source_pdo(const uint32_t **src_pdo);
+
 /* Board-level callback functions */
 
 /*
diff --git a/include/config.h b/include/config.h
index 0228dd439b..56c0088990 100644
--- a/include/config.h
+++ b/include/config.h
@@ -2165,6 +2165,14 @@
 
 /* Default pull-up value on the USB-C ports when they are used as source. */
 #define CONFIG_USB_PD_PULLUP TYPEC_RP_1A5
+/*
+ * Override the pull-up value when only zero or one port is actively sourcing
+ * current and we can advertise more current than what is defined by
+ * `CONFIG_USB_PD_PULLUP`.
+ * Should be defined with one of the tcpc_rp_value.
+ */
+#undef CONFIG_USB_PD_MAX_SINGLE_SOURCE_CURRENT
+
 
 /******************************************************************************/
 /* USB port switch */
diff --git a/include/usb_pd.h b/include/usb_pd.h
index 00b149475b..28a94efdb3 100644
--- a/include/usb_pd.h
+++ b/include/usb_pd.h
@@ -701,6 +701,7 @@ enum pd_states {
 #define PD_FLAGS_VCONN_ON          (1 << 12)/* vconn is being sourced */
 #define PD_FLAGS_TRY_SRC           (1 << 13)/* Try.SRC states are active */
 #define PD_FLAGS_PARTNER_USB_COMM  (1 << 14)/* port partner is USB comms */
+#define PD_FLAGS_UPDATE_SRC_CAPS   (1 << 15)/* send new source capabilities */
 /* Flags to clear on a disconnect */
 #define PD_FLAGS_RESET_ON_DISCONNECT_MASK (PD_FLAGS_PARTNER_DR_POWER | \
 					   PD_FLAGS_PARTNER_DR_DATA | \
@@ -713,7 +714,8 @@ enum pd_states {
 					   PD_FLAGS_PARTNER_EXTPOWER | \
 					   PD_FLAGS_VCONN_ON | \
 					   PD_FLAGS_TRY_SRC | \
-					   PD_FLAGS_PARTNER_USB_COMM)
+					   PD_FLAGS_PARTNER_USB_COMM | \
+					   PD_FLAGS_UPDATE_SRC_CAPS)
 
 
 enum pd_cc_states {
@@ -970,6 +972,14 @@ void pd_set_external_voltage_limit(int port, int mv);
 void pd_set_input_current_limit(int port, uint32_t max_ma,
 				uint32_t supply_voltage);
 
+
+/**
+ * Update the power contract if it exists.
+ *
+ * @param port USB-C port number.
+ */
+void pd_update_contract(int port);
+
 /**
  * Set the type-C input current limit.
  *
@@ -1201,18 +1211,12 @@ void pd_send_vdm(int port, uint32_t vid, int cmd, const uint32_t *data,
 /* Power Data Objects for the source and the sink */
 extern const uint32_t pd_src_pdo[];
 extern const int pd_src_pdo_cnt;
+extern const uint32_t pd_src_pdo_max[];
+extern const int pd_src_pdo_max_cnt;
 extern const uint32_t pd_snk_pdo[];
 extern const int pd_snk_pdo_cnt;
 
 /**
- * Get PD source power data objects.
- *
- * @param src_pdo pointer to the data to return.
- * @return number of PDOs returned.
- */
-int pd_get_source_pdo(const uint32_t **src_pdo);
-
-/**
  * Request that a host event be sent to notify the AP of a PD power event.
  *
  * @param mask host event mask.