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- /*
- * PD Buddy - USB Power Delivery for everyone
- * Copyright (C) 2017 Clayton G. Hobbs <clay@lakeserv.net>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #include "device_policy_manager.h"
-
- #include <stdint.h>
-
- #include <hal.h>
-
- #include "led.h"
- #include "pd.h"
-
-
- /* The voltage and current we want */
- /* XXX In the future, these won't be *quite* so convenient to access */
- static uint16_t dpm_desired_v = 400; /* 0.05 V increments */
- static uint16_t dpm_desired_i = 225; /* 0.01 A increments */
-
- /* Whether or not the power supply is unconstrained */
- static uint8_t dpm_unconstrained_power;
-
- bool pdb_dpm_evaluate_capability(const union pd_msg *capabilities, union pd_msg *request)
- {
- /* Get the number of PDOs */
- uint8_t numobj = PD_NUMOBJ_GET(capabilities);
-
- /* Make the LED blink to indicate ongoing power negotiations */
- chEvtSignal(pdb_led_thread, PDB_EVT_LED_FAST_BLINK);
-
- /* Get whether or not the power supply is constrained */
- if (capabilities->obj[0] & PD_PDO_SRC_FIXED_UNCONSTRAINED) {
- dpm_unconstrained_power = 1;
- } else {
- dpm_unconstrained_power = 0;
- }
-
- /* Look at the PDOs to see if one matches our desires */
- for (uint8_t i = 0; i < numobj; i++) {
- /* Fixed Supply PDOs come first, so when we see a PDO that isn't a
- * Fixed Supply, stop reading. */
- if ((capabilities->obj[i] & PD_PDO_TYPE) != PD_PDO_TYPE_FIXED) {
- break;
- }
- /* If the V from the PDO equals our desired V and the I is at least our
- * desired I */
- if (PD_PDO_SRC_FIXED_VOLTAGE_GET(capabilities, i) == dpm_desired_v
- && PD_PDO_SRC_FIXED_CURRENT_GET(capabilities, i) >= dpm_desired_i) {
- /* We got what we wanted, so build a request for that */
- request->hdr = PD_MSGTYPE_REQUEST | PD_DATAROLE_UFP |
- PD_SPECREV_2_0 | PD_POWERROLE_SINK | PD_NUMOBJ(1);
- request->obj[0] = PD_RDO_FV_MAX_CURRENT_SET(dpm_desired_i)
- | PD_RDO_FV_CURRENT_SET(dpm_desired_i)
- | PD_RDO_NO_USB_SUSPEND | PD_RDO_OBJPOS_SET(i + 1);
- return true;
- }
- }
- /* Nothing matched, so get 5 V */
- request->hdr = PD_MSGTYPE_REQUEST | PD_DATAROLE_UFP |
- PD_SPECREV_2_0 | PD_POWERROLE_SINK | PD_NUMOBJ(1);
- request->obj[0] = PD_RDO_FV_MAX_CURRENT_SET(10)
- | PD_RDO_FV_CURRENT_SET(10)
- | PD_RDO_NO_USB_SUSPEND | PD_RDO_CAP_MISMATCH
- | PD_RDO_OBJPOS_SET(1);
- return false;
- }
-
- void pdb_dpm_get_sink_capability(union pd_msg *cap)
- {
- /* If we want 5 V, we need to send only one PDO */
- if (dpm_desired_v == 100) {
- /* Sink_Capabilities message */
- cap->hdr = PD_MSGTYPE_SINK_CAPABILITIES | PD_DATAROLE_UFP
- | PD_SPECREV_2_0 | PD_POWERROLE_SINK | PD_NUMOBJ(1);
- /* vSafe5V at the desired current. */
- cap->obj[0] = PD_PDO_TYPE_FIXED
- | PD_PDO_SNK_FIXED_VOLTAGE_SET(dpm_desired_v)
- | PD_PDO_SNK_FIXED_CURRENT_SET(dpm_desired_i);
- /* Otherwise, send two PDOs, one for 5 V and one for the desired power. */
- } else {
- /* Sink_Capabilities message */
- cap->hdr = PD_MSGTYPE_SINK_CAPABILITIES | PD_DATAROLE_UFP
- | PD_SPECREV_2_0 | PD_POWERROLE_SINK | PD_NUMOBJ(2);
- /* First, vSafe5V. 100 mA, 5 V, and higher capability. */
- cap->obj[0] = PD_PDO_TYPE_FIXED
- | PD_PDO_SNK_FIXED_VOLTAGE_SET(100)
- | PD_PDO_SNK_FIXED_CURRENT_SET(10);
- /* Next, desired_v and desired_i */
- cap->obj[1] = PD_PDO_TYPE_FIXED
- | PD_PDO_SNK_FIXED_VOLTAGE_SET(dpm_desired_v)
- | PD_PDO_SNK_FIXED_CURRENT_SET(dpm_desired_i);
- }
-
- /* Set the unconstrained power flag. */
- if (dpm_unconstrained_power) {
- cap->obj[0] |= PD_PDO_SNK_FIXED_UNCONSTRAINED;
- }
- }
-
- void pdb_dpm_output_on(void)
- {
- chEvtSignal(pdb_led_thread, PDB_EVT_LED_MEDIUM_BLINK_OFF);
- palSetLine(LINE_OUT_CTRL);
- }
-
- void pdb_dpm_output_off(void)
- {
- chEvtSignal(pdb_led_thread, PDB_EVT_LED_ON);
- palClearLine(LINE_OUT_CTRL);
- }
|