charger: Move USB charger / BC1.2 task to common code

Move the task responsible for detection of USB chargers to common code
to reduce code duplication.

BUG=chrome-os-partner:40920
TEST=Manual on samus_pd. Plug USB charger, verify detection is correct
on both charge ports.
BRANCH=None

Change-Id: I362f8b5b51741509e459c66928131f1f6d2a3b1d
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/276210
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Alec Berg <alecaberg@chromium.org>

5 files changed, 158 insertions, 4 deletions

diff --git a/common/build.mk b/common/build.mk
index be87443078..3941a40c5f 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -76,6 +76,7 @@ common-$(CONFIG_STREAM)+=in_stream.o out_stream.o stream_adaptor.o
 common-$(CONFIG_SWITCH)+=switch.o
 common-$(CONFIG_SW_CRC)+=crc.o
 common-$(CONFIG_TEMP_SENSOR)+=temp_sensor.o thermal.o throttle_ap.o
+common-$(CONFIG_USB_CHARGER)+=usb_charger.o
 common-$(CONFIG_USB_PORT_POWER_DUMB)+=usb_port_power_dumb.o
 common-$(CONFIG_USB_PORT_POWER_SMART)+=usb_port_power_smart.o
 common-$(CONFIG_USB_POWER_DELIVERY)+=usb_pd_protocol.o usb_pd_policy.o
diff --git a/common/charge_manager.c b/common/charge_manager.c
index b52f297c45..24fbae2d38 100644
--- a/common/charge_manager.c
+++ b/common/charge_manager.c
@@ -23,6 +23,19 @@
 #define POWER_SWAP_TIMEOUT (PD_T_SRC_RECOVER_MAX + PD_T_SRC_TURN_ON + \
 			    PD_T_SAFE_0V + 500 * MSEC)
 
+/* Charge supplier priority: lower number indicates higher priority. */
+test_mockable const int supplier_priority[] = {
+	[CHARGE_SUPPLIER_PD] = 0,
+	[CHARGE_SUPPLIER_TYPEC] = 1,
+	[CHARGE_SUPPLIER_PROPRIETARY] = 1,
+	[CHARGE_SUPPLIER_BC12_DCP] = 1,
+	[CHARGE_SUPPLIER_BC12_CDP] = 2,
+	[CHARGE_SUPPLIER_BC12_SDP] = 3,
+	[CHARGE_SUPPLIER_OTHER] = 3,
+	[CHARGE_SUPPLIER_VBUS] = 4
+};
+BUILD_ASSERT(ARRAY_SIZE(supplier_priority) == CHARGE_SUPPLIER_COUNT);
+
 /* Keep track of available charge for each charge port. */
 static struct charge_port_info available_charge[CHARGE_SUPPLIER_COUNT]
 					       [CONFIG_USB_PD_PORT_COUNT];
diff --git a/common/charge_ramp.c b/common/charge_ramp.c
index cc71f987b6..e5f6d99e26 100644
--- a/common/charge_ramp.c
+++ b/common/charge_ramp.c
@@ -197,10 +197,8 @@ void chg_ramp_task(void)
 
 			/* Detect delay is over, fall through to next state */
 			ramp_st_new = CHG_RAMP_OVERCURRENT_DETECT;
-#ifdef CONFIG_USB_PD_HOST_EVENT_ON_POWER_CHANGE
 			/* notify host of power info change */
 			pd_send_host_event(PD_EVENT_POWER_CHANGE);
-#endif
 		case CHG_RAMP_OVERCURRENT_DETECT:
 			/* Check if we should ramp or go straight to stable */
 			task_wait_time = SECOND;
@@ -297,10 +295,8 @@ void chg_ramp_task(void)
 #ifdef CONFIG_USB_PD_LOGGING
 				charge_manager_save_log(active_port);
 #endif
-#ifdef CONFIG_USB_PD_HOST_EVENT_ON_POWER_CHANGE
 				/* notify host of power info change */
 				pd_send_host_event(PD_EVENT_POWER_CHANGE);
-#endif
 			}
 
 			/* Keep an eye on VBUS and restart ramping if it dips */
diff --git a/common/usb_charger.c b/common/usb_charger.c
new file mode 100644
index 0000000000..bb85fc3c7f
--- /dev/null
+++ b/common/usb_charger.c
@@ -0,0 +1,138 @@
+/* Copyright 2015 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.
+ */
+
+/*
+ * USB charger / BC1.2 task. This code assumes that CONFIG_CHARGE_MANAGER
+ * is defined and implemented. PI3USB9281 is the only charger detector
+ * currently supported.
+ */
+
+#include "charge_manager.h"
+#include "common.h"
+#include "ec_commands.h"
+#include "gpio.h"
+#include "pi3usb9281.h"
+#include "task.h"
+#include "timer.h"
+#include "usb_pd.h"
+
+/* Wait after a charger is detected to debounce pin contact order */
+#define USB_CHG_DEBOUNCE_DELAY_MS 1000
+/*
+ * Wait after reset, before re-enabling attach interrupt, so that the
+ * spurious attach interrupt from certain ports is ignored.
+ */
+#define USB_CHG_RESET_DELAY_MS 100
+
+void usb_charger_task(void)
+{
+	int port = (task_get_current() == TASK_ID_USB_CHG_P0 ? 0 : 1);
+#if (CONFIG_USB_PD_PORT_COUNT == 1)
+	int vbus_source = GPIO_USB_C0_5V_EN;
+#else
+	int vbus_source = (port == 0 ? GPIO_USB_C0_5V_EN : GPIO_USB_C1_5V_EN);
+#endif
+	int device_type, charger_status;
+	struct charge_port_info charge;
+	int type;
+	charge.voltage = USB_BC12_CHARGE_VOLTAGE;
+
+	while (1) {
+		/* Read interrupt register to clear on chip */
+		pi3usb9281_get_interrupts(port);
+
+		if (gpio_get_level(vbus_source)) {
+			/* If we're sourcing VBUS then we're not charging */
+			device_type = charger_status = 0;
+		} else {
+			/* Set device type */
+			device_type = pi3usb9281_get_device_type(port);
+			charger_status = pi3usb9281_get_charger_status(port);
+		}
+
+		/* Debounce pin plug order if we detect a charger */
+		if (device_type || PI3USB9281_CHG_STATUS_ANY(charger_status)) {
+			msleep(USB_CHG_DEBOUNCE_DELAY_MS);
+
+			/*
+			 * Trigger chip reset to refresh detection registers.
+			 * WARNING: This reset is acceptable for samus_pd,
+			 * but may not be acceptable for devices that have
+			 * an OTG / device mode, as we may be interrupting
+			 * the connection.
+			 */
+			pi3usb9281_reset(port);
+			/*
+			 * Restore data switch settings - switches return to
+			 * closed on reset until restored.
+			 */
+			board_set_usb_switches(port, USB_SWITCH_RESTORE);
+			/* Clear possible disconnect interrupt */
+			pi3usb9281_get_interrupts(port);
+			/* Mask attach interrupt */
+			pi3usb9281_set_interrupt_mask(port,
+						      0xff &
+						      ~PI3USB9281_INT_ATTACH);
+			/* Re-enable interrupts */
+			pi3usb9281_enable_interrupts(port);
+			msleep(USB_CHG_RESET_DELAY_MS);
+
+			/* Clear possible attach interrupt */
+			pi3usb9281_get_interrupts(port);
+			/* Re-enable attach interrupt */
+			pi3usb9281_set_interrupt_mask(port, 0xff);
+
+			/* Re-read ID registers */
+			device_type = pi3usb9281_get_device_type(port);
+			charger_status = pi3usb9281_get_charger_status(port);
+		}
+
+		/* Attachment: decode + update available charge */
+		if (device_type || PI3USB9281_CHG_STATUS_ANY(charger_status)) {
+			if (PI3USB9281_CHG_STATUS_ANY(charger_status))
+				type = CHARGE_SUPPLIER_PROPRIETARY;
+			else if (device_type & PI3USB9281_TYPE_CDP)
+				type = CHARGE_SUPPLIER_BC12_CDP;
+			else if (device_type & PI3USB9281_TYPE_DCP)
+				type = CHARGE_SUPPLIER_BC12_DCP;
+			else if (device_type & PI3USB9281_TYPE_SDP)
+				type = CHARGE_SUPPLIER_BC12_SDP;
+			else
+				type = CHARGE_SUPPLIER_OTHER;
+
+			charge.current = pi3usb9281_get_ilim(device_type,
+							     charger_status);
+			charge_manager_update_charge(type, port, &charge);
+		} else { /* Detachment: update available charge to 0 */
+			charge.current = 0;
+			charge_manager_update_charge(
+						CHARGE_SUPPLIER_PROPRIETARY,
+						port,
+						&charge);
+			charge_manager_update_charge(
+						CHARGE_SUPPLIER_BC12_CDP,
+						port,
+						&charge);
+			charge_manager_update_charge(
+						CHARGE_SUPPLIER_BC12_DCP,
+						port,
+						&charge);
+			charge_manager_update_charge(
+						CHARGE_SUPPLIER_BC12_SDP,
+						port,
+						&charge);
+			charge_manager_update_charge(
+						CHARGE_SUPPLIER_OTHER,
+						port,
+						&charge);
+		}
+
+		/* notify host of power info change */
+		pd_send_host_event(PD_EVENT_POWER_CHANGE);
+
+		/* Wait for interrupt */
+		task_wait_event(-1);
+	}
+}
diff --git a/common/usb_pd_policy.c b/common/usb_pd_policy.c
index 19c69a7369..3972e2289c 100644
--- a/common/usb_pd_policy.c
+++ b/common/usb_pd_policy.c
@@ -914,3 +914,9 @@ int pd_custom_flash_vdm(int port, int cnt, uint32_t *payload)
 	}
 	return rsize;
 }
+
+static void stub_pd_send_host_event(int mask)
+{
+}
+void pd_send_host_event(int mask)
+	__attribute__((weak, alias("stub_pd_send_host_event")));