charge_manager: Move supplier list and priority hierarchy to board

Allow the list of charge suppliers and port selection priority to be
specified at the board level.

BUG=chrome-os-partner:32650
TEST=Manual on samus_pd. Plug + unplug PD and BC1.2 chargers, verify
that PD is always preferred and higher power port / supplier is always
selected.
BRANCH=Samus

Change-Id: Ic867a40120c809111bf76bf290ed6f204eab1168
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/225292
Reviewed-by: Alec Berg <alecaberg@chromium.org>

5 files changed, 41 insertions, 25 deletions

diff --git a/board/samus_pd/board.c b/board/samus_pd/board.c
index 9c46b97952..74b0bf9b19 100644
--- a/board/samus_pd/board.c
+++ b/board/samus_pd/board.c
@@ -40,6 +40,14 @@ const struct pwm_t pwm_channels[] = {
 };
 BUILD_ASSERT(ARRAY_SIZE(pwm_channels) == PWM_CH_COUNT);
 
+/* Charge supplier priority: lower number indicates higher priority. */
+const int supplier_priority[] = {
+	[CHARGE_SUPPLIER_PD] = 0,
+	[CHARGE_SUPPLIER_TYPEC] = 1,
+	[CHARGE_SUPPLIER_BC12] = 1,
+};
+BUILD_ASSERT(ARRAY_SIZE(supplier_priority) == CHARGE_SUPPLIER_COUNT);
+
 void vbus0_evt(enum gpio_signal signal)
 {
 	ccprintf("VBUS %d, %d!\n", signal, gpio_get_level(signal));
diff --git a/board/samus_pd/board.h b/board/samus_pd/board.h
index 8729cdc2a2..06fae2e79e 100644
--- a/board/samus_pd/board.h
+++ b/board/samus_pd/board.h
@@ -67,7 +67,6 @@
 #define TIM_CLOCK32 2
 #define TIM_ADC     3
 
-#include "charge_manager.h"
 #include "gpio_signal.h"
 
 /* ADC signal */
@@ -87,6 +86,17 @@ enum pwm_channel {
 	PWM_CH_COUNT
 };
 
+/* Charge suppliers */
+enum charge_supplier {
+	CHARGE_SUPPLIER_PD,
+	CHARGE_SUPPLIER_TYPEC,
+	CHARGE_SUPPLIER_BC12,
+	CHARGE_SUPPLIER_COUNT
+};
+
+/* supplier_priority table defined in board.c */
+extern const int supplier_priority[];
+
 /* Charge current limit min / max, based on PWM duty cycle */
 #define PWM_0_MA	500
 #define PWM_100_MA	4000
diff --git a/board/samus_pd/usb_pd_policy.c b/board/samus_pd/usb_pd_policy.c
index ea297b8c13..99eebf3f0d 100644
--- a/board/samus_pd/usb_pd_policy.c
+++ b/board/samus_pd/usb_pd_policy.c
@@ -4,6 +4,7 @@
  */
 
 #include "atomic.h"
+#include "charge_manager.h"
 #include "common.h"
 #include "console.h"
 #include "gpio.h"
diff --git a/common/charge_manager.c b/common/charge_manager.c
index a7a787247d..af648f2cfd 100644
--- a/common/charge_manager.c
+++ b/common/charge_manager.c
@@ -68,33 +68,33 @@ static int charge_manager_is_seeded(void)
  */
 static void charge_manager_refresh(void)
 {
-	enum charge_supplier new_supplier = CHARGE_SUPPLIER_NONE;
+	int new_supplier = CHARGE_SUPPLIER_NONE;
 	int new_port = CHARGE_PORT_NONE;
 	int new_charge_current, new_charge_voltage, i, j;
 
 	/*
 	 * Charge supplier selection logic:
-	 * 1. Prefer higher priority (lower CHARGE_SUPPLIER index) supply.
-	 * 2. Prefer higher power over lower.
+	 * 1. Prefer higher priority supply.
+	 * 2. Prefer higher power over lower in case priority is tied.
 	 * available_charge can be changed at any time by other tasks,
 	 * so make no assumptions about its consistency.
 	 */
 	for (i = 0; i < CHARGE_SUPPLIER_COUNT; ++i)
 		for (j = 0; j < PD_PORT_COUNT; ++j)
 			if (available_charge[i][j].current > 0 &&
-			    available_charge[i][j].voltage > 0) {
+			    available_charge[i][j].voltage > 0 &&
+			    (new_supplier == CHARGE_SUPPLIER_NONE ||
+			     supplier_priority[i] <
+			     supplier_priority[new_supplier] ||
+			    (supplier_priority[i] ==
+			     supplier_priority[new_supplier] &&
+			     POWER(available_charge[i][j]) >
+			     POWER(available_charge[new_supplier]
+						   [new_port])))) {
 				new_supplier = i;
 				new_port = j;
-				goto got_supplier;
 			}
 
-got_supplier:
-	if (new_supplier != CHARGE_SUPPLIER_NONE)
-		for (i = new_port + 1; i < PD_PORT_COUNT; ++i)
-			if (POWER(available_charge[new_supplier][i]) >
-			    POWER(available_charge[new_supplier][new_port]))
-				new_port = i;
-
 	if (new_supplier == CHARGE_SUPPLIER_NONE)
 		new_charge_current = new_charge_voltage = 0;
 	else {
@@ -125,10 +125,15 @@ DECLARE_DEFERRED(charge_manager_refresh);
  * @param charge_port		Charge port to update.
  * @param charge		Charge port current / voltage.
  */
-void charge_manager_update(enum charge_supplier supplier,
+void charge_manager_update(int supplier,
 			   int charge_port,
 			   struct charge_port_info *charge)
 {
+	if (supplier < 0 || supplier >= CHARGE_SUPPLIER_COUNT) {
+		CPRINTS("Invalid charge supplier: %d", supplier);
+		return;
+	}
+
 	/* Update charge table if needed. */
 	if (available_charge[supplier][charge_port].current !=
 		charge->current ||
diff --git a/include/charge_manager.h b/include/charge_manager.h
index a5b4b6d275..44ed605a23 100644
--- a/include/charge_manager.h
+++ b/include/charge_manager.h
@@ -7,23 +7,15 @@
 #define __CHARGE_MANAGER_H
 
 /* Charge port that indicates no active port */
+#define CHARGE_SUPPLIER_NONE -1
 #define CHARGE_PORT_NONE -1
+
 /* Initial charge state */
 #define CHARGE_CURRENT_UNINITIALIZED -1
 #define CHARGE_VOLTAGE_UNINITIALIZED -1
 
 #define POWER(charge_port) ((charge_port.current) * (charge_port.voltage))
 
-/* Charge suppliers, sorted by priority */
-enum charge_supplier {
-	CHARGE_SUPPLIER_NONE = -1,
-	/* Highest priority supplier first */
-	CHARGE_SUPPLIER_PD = 0,
-	CHARGE_SUPPLIER_TYPEC = 1,
-	CHARGE_SUPPLIER_BC12 = 2,
-	CHARGE_SUPPLIER_COUNT
-};
-
 /* Charge tasks report available current and voltage */
 struct charge_port_info {
 	int current;
@@ -31,7 +23,7 @@ struct charge_port_info {
 };
 
 /* Called by charging tasks to update their available charge */
-void charge_manager_update(enum charge_supplier supplier,
+void charge_manager_update(int supplier,
 			   int charge_port,
 			   struct charge_port_info *charge);