text: /* Copyright (c) 2014 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.
   */
  
  #include "adc.h"
  #include "board.h"
  #include "common.h"
  #include "console.h"
  #include "gpio.h"
  #include "hooks.h"
  #include "registers.h"
  #include "task.h"
  #include "timer.h"
  #include "util.h"
  #include "usb_pd.h"
  
  #define CPRINTF(format, args...) cprintf(CC_USBPD, format, ## args)
  #define CPRINTS(format, args...) cprints(CC_USBPD, format, ## args)
  
  /* Acceptable margin between requested VBUS and measured value */
  #define MARGIN_MV 400 /* mV */
  
  #define PDO_FIXED_FLAGS (PDO_FIXED_EXTERNAL)
  
  /* we are not acting as a source */
  const uint32_t pd_src_pdo[] = {
  		PDO_FIXED(5000,   500, PDO_FIXED_FLAGS),
  };
  const int pd_src_pdo_cnt = ARRAY_SIZE(pd_src_pdo);
  
  /* Fake PDOs : we just want our pre-defined voltages */
  const uint32_t pd_snk_pdo[] = {
  		PDO_FIXED(5000,   500, PDO_FIXED_FLAGS),
  		PDO_FIXED(12000,  500, PDO_FIXED_FLAGS),
  		PDO_FIXED(20000,  500, PDO_FIXED_FLAGS),
  };
  const int pd_snk_pdo_cnt = ARRAY_SIZE(pd_snk_pdo);
  
  void pd_set_input_current_limit(int port, uint32_t max_ma,
  				uint32_t supply_voltage)
  {
  	/* No battery, nothing to do */
  	return;
  }
  
  int pd_is_valid_input_voltage(int mv)
  {
  	/* Any voltage less than the max is allowed */
  	return 1;
  }
  
  int pd_check_requested_voltage(uint32_t rdo)
  {
  	/* Never acting as a source */
  	return EC_ERROR_INVAL;
  }
  
  void pd_transition_voltage(int idx)
  {
  	/* No operation: sink only */
  }
  
  int pd_set_power_supply_ready(int port)
  {
  	/* Never acting as a source */
  	return EC_ERROR_INVAL;
  }
  
  void pd_power_supply_reset(int port)
  {
  }
  
  int pd_board_checks(void)
  {
  	static int blinking;
  	int vbus;
  	int led5 = 0, led12 = 0, led20 = 0;
  	unsigned select_mv = pd_get_max_voltage();
  
  	/* LED blinking state for the default indicator */
  	blinking = (blinking + 1) & 3;
  
  	vbus = adc_read_channel(ADC_CH_VBUS_SENSE);
  
  	if (select_mv > 0) {
  		/* is current VBUS voltage matching the request ? */
  		int diff = vbus - select_mv;
  		int correct = (diff < MARGIN_MV) && (diff > -MARGIN_MV);
  		/*
  		 * turn on the LED if the voltage is correct
  		 * or we are in on-period of the duty cycle.
  		 */
  		int led_value = correct || !blinking;
  		/* decide which LED is used */
  		switch (select_mv) {
  		case 5000:
  			led5 = led_value;
  			break;
  		case 12000:
  			led12 = led_value;
  			break;
  		case 20000:
  			led20 = led_value;
  			break;
  		}
  	}
  	/* switch  LEDs */
  	gpio_set_level(GPIO_LED_PP5000, led5);
  	gpio_set_level(GPIO_LED_PP12000, led12);
  	gpio_set_level(GPIO_LED_PP20000, led20);
  
  	return EC_SUCCESS;
  }
  
  int pd_check_power_swap(int port)
  {
  	/* Always refuse power swap */
  	return 0;
  }
  
  int pd_check_data_swap(int port, int data_role)
  {
  	/* Always refuse data swap */
  	return 0;
  }
  
  void pd_execute_data_swap(int port, int data_role)
  {
  	/* Do nothing */
  }
  
  void pd_check_pr_role(int port, int pr_role, int partner_pr_swap)
  {
  }
  
  void pd_check_dr_role(int port, int dr_role, int partner_dr_swap)
  {
  }
  
  int pd_custom_vdm(int port, int cnt, uint32_t *payload,
  		  uint32_t **rpayload)
  {
  	return 0;
  }
  