usbpd: support dynamic PDO selection

Support dynamic PDO selection CONFIG_USB_PD_DPS.
This config controls the charging voltage and power according to the
input power and battery configuration.

DPS would continuously evaluate the system load and current charging
voltage, and decide a new one by below:
1. If the PDO can fulfill system desired power.
2. If the PDO is efficient for the battery configuration.

To detect if the system load cannot be fulfilled by the current PDO,
it checks:
1. if the input current closes to the PDO current limit.
2. if the input power closes to the PDO maximum power.

To detect if the system load can be fulfilled by a more efficient PDO,
it checks:
- if the voltage of a new PDO is closer to the battery voltage than the
   current PDO, and the power is able fulfill the system load.

BUG=b:169532537
TEST=1. tested on asurada, the charging voltage is able to switch to
     different PDOs under different system loads
     2. tested that the DPS is able to switch charge port
     (e.g. C1 12V -> C0 9V) based on the provided PDOs.
BRANCH=asurada

Change-Id: I7c7706b331dc0d4f8ac68569dc7ed852fc9308e3
Signed-off-by: Eric Yilun Lin <yllin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2897064
Tested-by: Eric Yilun Lin <yllin@google.com>
Reviewed-by: Diana Z <dzigterman@chromium.org>
Commit-Queue: Eric Yilun Lin <yllin@google.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/util/config_allowed.txt b/util/config_allowed.txt
index ffdadb450b..2542d2389c 100644
--- a/util/config_allowed.txt
+++ b/util/config_allowed.txt
@@ -1016,6 +1016,7 @@ CONFIG_USB_PD_COMM_DISABLED
 CONFIG_USB_PD_COMM_LOCKED
 CONFIG_USB_PD_CUSTOM_PDO
 CONFIG_USB_PD_DEBUG_DR
+CONFIG_USB_PD_DPS
 CONFIG_USB_PD_DYNAMIC_SRC_CAP
 CONFIG_USB_PD_EXTENDED_MESSAGES
 CONFIG_USB_PD_FLASH