driver/bc12/max14637.c - chromiumos/platform/ec - Git at Google

 /* Copyright 2017 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.
  */

 /*
  * MAX14637 USB BC 1.2 Charger Detector driver.
  *
  * NOTE: The driver assumes that CHG_AL_N and SW_OPEN are not connected,
  * therefore the value of CHG_DET indicates whether the source is NOT a
  * low-power standard downstream port (SDP).  In order to use higher currents,
  * the system will have to charge ramp.
  */

 #include "max14637.h"
 #include "cannonlake.h"
 #include "charge_manager.h"
 #include "chipset.h"
 #include "common.h"
 #include "console.h"
 #include "gpio.h"
 #include "hooks.h"
 #include "power.h"
 #include "task.h"
 #include "tcpm.h"
 #include "timer.h"
 #include "usb_charge.h"
 #include "usb_pd.h"
 #include "util.h"

 #define CPRINTS(format, args...) cprints(CC_USBPD, format, ## args)

 #if defined(CONFIG_CHARGE_RAMP_SW) || defined(CONFIG_CHARGE_RAMP_HW)
 /**
  * Returns true if the charger detect pin is activated.
  *
  * @parm cfg driver for chip to read the charger detect pin for.
  * @return 1 if charger detect is activated (high when active high or
  *	low with active low), otherwise 0.
  */
 static int is_chg_det_activated(const struct max14637_config_t * const cfg)
 {
 	return !!gpio_get_level(cfg->chg_det_pin) ^
 		!!(cfg->flags & MAX14637_FLAGS_CHG_DET_ACTIVE_LOW);
 }
 #endif

 /**
  * Activates the Chip Enable GPIO based on the enabled value.
  *
  * @param cfg driver for chip that will set chip enable gpio.
  * @param enable 1 to activate gpio (high for active high and low for active
  *	low).
  */
 static void activate_chip_enable(
 	const struct max14637_config_t * const cfg, const int enable)
 {
 	gpio_set_level(
 		cfg->chip_enable_pin,
 		!!enable ^ !!(cfg->flags & MAX14637_FLAGS_ENABLE_ACTIVE_LOW));
 }

 /**
  * Perform BC1.2 detection and update charge manager.
  *
  * @param port: The Type-C port where VBUS is present.
  */
 static void bc12_detect(const int port)
 {
 	const struct max14637_config_t * const cfg = &max14637_config[port];
 	struct charge_port_info new_chg;

 	/*
 	 * Enable the IC to begin detection and connect switches if
 	 * necessary. This is only necessary if the port power role is a
 	 * sink. If the power role is a source then just keep the max14637
 	 * powered on so that data switches are close. Note that the gpio enable
 	 * for this chip is active by default. In order to trigger bc1.2
 	 * detection, the chip enable must be driven low, then high again so the
 	 * chip will start bc1.2 client side detection. Add a 100 msec delay to
 	 * avoid collision with a device that might be doing bc1.2 client side
 	 * detection.
 	 */
 	msleep(100);
 	activate_chip_enable(cfg, 0);
 	msleep(1);
 	activate_chip_enable(cfg, 1);

 	new_chg.voltage = USB_CHARGER_VOLTAGE_MV;
 #if defined(CONFIG_CHARGE_RAMP_SW) || defined(CONFIG_CHARGE_RAMP_HW)
 	/*
 	 * Apple or TomTom charger detection can take as long as 600ms.  Wait a
 	 * little bit longer for margin.
 	 */
 	msleep(630);

 	/*
 	 * The driver assumes that CHG_AL_N and SW_OPEN are not connected,
 	 * therefore an activated CHG_DET indicates whether the source is NOT a
 	 * low-power standard downstream port (SDP). The system will have to
 	 * ramp the current to determine the limit.  The Type-C spec prohibits
 	 * proprietary methods now, therefore 1500mA is the max.
 	 */
 	new_chg.current = is_chg_det_activated(cfg) ? USB_CHARGER_MAX_CURR_MA :
 						      500;
 #else
 	/*
 	 * If the board doesn't support charge ramping, then assume the lowest
 	 * denominator; that is assume the charger detected is a weak dedicated
 	 * charging port (DCP) which can only supply 500mA.
 	 */
 	new_chg.current = 500;
 #endif /* !defined(CONFIG_CHARGE_RAMP_SW && CONFIG_CHARGE_RAMP_HW) */

 	charge_manager_update_charge(CHARGE_SUPPLIER_OTHER, port, &new_chg);
 }

 /**
  * If VBUS is present and port power role is sink, then trigger bc1.2 client
  * detection. If VBUS is not present then update charge manager. Note that both
  * chip_enable and VBUS must be active for the IC to be powered up. Chip enable
  * is kept enabled by default so that bc1.2 client detection is not triggered
  * when the port power role is source.
  *
  * @param port: Which USB Type-C port to examine.
  */
 static void detect_or_power_down_ic(const int port)
 {
 	int vbus_present;

 #ifdef CONFIG_USB_PD_VBUS_DETECT_TCPC
 	vbus_present = tcpm_check_vbus_level(port, VBUS_PRESENT);
 #else
 	vbus_present = pd_snk_is_vbus_provided(port);
 #endif /* !defined(CONFIG_USB_PD_VBUS_DETECT_TCPC) */

 	if (vbus_present) {
 #if defined(CONFIG_POWER_PP5000_CONTROL) && defined(HAS_TASK_CHIPSET)
 		/* Turn on the 5V rail to allow the chip to be powered. */
 		power_5v_enable(task_get_current(), 1);
 #endif
 		if (pd_get_power_role(port) == PD_ROLE_SINK)
 			bc12_detect(port);
 	} else {
 		/* Let charge manager know there's no more charge available. */
 		charge_manager_update_charge(CHARGE_SUPPLIER_OTHER, port, NULL);
 #if defined(CONFIG_POWER_PP5000_CONTROL) && defined(HAS_TASK_CHIPSET)
 		/* Issue a request to turn off the rail. */
 		power_5v_enable(task_get_current(), 0);
 #endif
 	}
 }

 static void max14637_usb_charger_task(const int port)
 {
 	uint32_t evt;
 	const struct max14637_config_t * const cfg = &max14637_config[port];

 	ASSERT(port >= 0 && port < CONFIG_USB_PD_PORT_MAX_COUNT);
 	/*
 	 * Have chip enable active as default state so data switches are closed
 	 * and bc1.2 client side detection is not activated when the port power
 	 * role is a source.
 	 */
 	activate_chip_enable(cfg, 1);
 	/* Check whether bc1.2 client mode detection needs to be triggered */
 	detect_or_power_down_ic(port);

 	while (1) {
 		evt = task_wait_event(-1);

 		if (evt & USB_CHG_EVENT_VBUS)
 			detect_or_power_down_ic(port);
 	}
 }

 #if defined(CONFIG_CHARGE_RAMP_SW) || defined(CONFIG_CHARGE_RAMP_HW)
 static int max14637_ramp_allowed(int supplier)
 {
 	/*
 	 * Due to the limitations in the application of the MAX14637, we
 	 * don't quite know exactly what we're plugged into.  Therefore,
 	 * the supplier type will be CHARGE_SUPPLIER_OTHER.
 	 */
 	return supplier == CHARGE_SUPPLIER_OTHER;
 }

 static int max14637_ramp_max(int supplier, int sup_curr)
 {
 	/* Use the current limit that was decided by the MAX14637. */
 	if (supplier == CHARGE_SUPPLIER_OTHER)
 		return sup_curr;
 	else
 		return 500;
 }
 #endif /* CONFIG_CHARGE_RAMP_SW || CONFIG_CHARGE_RAMP_HW */

 /* Called on AP S5 -> S3  and S3/S0iX -> S0 transition */
 static void bc12_chipset_startup(void)
 {
 	int port;

 	/*
 	 * For each port, trigger a new USB_CHG_EVENT_VBUS event to handle cases
 	 * where there was no change in VBUS following an AP resume/startup
 	 * event. If a legacy charger is connected to the port, then VBUS will
 	 * not drop even during the USB PD hard reset.
 	 */
 	for (port = 0; port < CONFIG_USB_PD_PORT_MAX_COUNT; port++)
 		task_set_event(USB_CHG_PORT_TO_TASK_ID(port),
 			       USB_CHG_EVENT_VBUS, 0);
 }
 DECLARE_HOOK(HOOK_CHIPSET_STARTUP, bc12_chipset_startup, HOOK_PRIO_DEFAULT);
 DECLARE_HOOK(HOOK_CHIPSET_RESUME, bc12_chipset_startup, HOOK_PRIO_DEFAULT);

 const struct bc12_drv max14637_drv = {
 	.usb_charger_task = max14637_usb_charger_task,
 #if defined(CONFIG_CHARGE_RAMP_SW) || defined(CONFIG_CHARGE_RAMP_HW)
 	.ramp_allowed = max14637_ramp_allowed,
 	.ramp_max = max14637_ramp_max,
 #endif /* CONFIG_CHARGE_RAMP_SW || CONFIG_CHARGE_RAMP_HW */
 };

 #ifdef CONFIG_BC12_SINGLE_DRIVER
 /* provide a default bc12_ports[] for backward compatibility */
 struct bc12_config bc12_ports[CHARGE_PORT_COUNT] = {
 	[0 ... (CHARGE_PORT_COUNT - 1)] = {
 		.drv = &max14637_drv,
 	},
 };
 #endif /* CONFIG_BC12_SINGLE_DRIVER */
	/* Copyright 2017 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.
	*/

	/*
	* MAX14637 USB BC 1.2 Charger Detector driver.
	*
	* NOTE: The driver assumes that CHG_AL_N and SW_OPEN are not connected,
	* therefore the value of CHG_DET indicates whether the source is NOT a
	* low-power standard downstream port (SDP). In order to use higher currents,
	* the system will have to charge ramp.
	*/

	#include "max14637.h"
	#include "cannonlake.h"
	#include "charge_manager.h"
	#include "chipset.h"
	#include "common.h"
	#include "console.h"
	#include "gpio.h"
	#include "hooks.h"
	#include "power.h"
	#include "task.h"
	#include "tcpm.h"
	#include "timer.h"
	#include "usb_charge.h"
	#include "usb_pd.h"
	#include "util.h"

	#define CPRINTS(format, args...) cprints(CC_USBPD, format, ## args)

	#if defined(CONFIG_CHARGE_RAMP_SW) \|\| defined(CONFIG_CHARGE_RAMP_HW)
	/**
	* Returns true if the charger detect pin is activated.
	*
	* @parm cfg driver for chip to read the charger detect pin for.
	* @return 1 if charger detect is activated (high when active high or
	* low with active low), otherwise 0.
	*/
	static int is_chg_det_activated(const struct max14637_config_t * const cfg)
	{
	return !!gpio_get_level(cfg->chg_det_pin) ^
	!!(cfg->flags & MAX14637_FLAGS_CHG_DET_ACTIVE_LOW);
	}
	#endif

	/**
	* Activates the Chip Enable GPIO based on the enabled value.
	*
	* @param cfg driver for chip that will set chip enable gpio.
	* @param enable 1 to activate gpio (high for active high and low for active
	* low).
	*/
	static void activate_chip_enable(
	const struct max14637_config_t * const cfg, const int enable)
	{
	gpio_set_level(
	cfg->chip_enable_pin,
	!!enable ^ !!(cfg->flags & MAX14637_FLAGS_ENABLE_ACTIVE_LOW));
	}

	/**
	* Perform BC1.2 detection and update charge manager.
	*
	* @param port: The Type-C port where VBUS is present.
	*/
	static void bc12_detect(const int port)
	{
	const struct max14637_config_t * const cfg = &max14637_config[port];
	struct charge_port_info new_chg;

	/*
	* Enable the IC to begin detection and connect switches if
	* necessary. This is only necessary if the port power role is a
	* sink. If the power role is a source then just keep the max14637
	* powered on so that data switches are close. Note that the gpio enable
	* for this chip is active by default. In order to trigger bc1.2
	* detection, the chip enable must be driven low, then high again so the
	* chip will start bc1.2 client side detection. Add a 100 msec delay to
	* avoid collision with a device that might be doing bc1.2 client side
	* detection.
	*/
	msleep(100);
	activate_chip_enable(cfg, 0);
	msleep(1);
	activate_chip_enable(cfg, 1);

	new_chg.voltage = USB_CHARGER_VOLTAGE_MV;
	#if defined(CONFIG_CHARGE_RAMP_SW) \|\| defined(CONFIG_CHARGE_RAMP_HW)
	/*
	* Apple or TomTom charger detection can take as long as 600ms. Wait a
	* little bit longer for margin.
	*/
	msleep(630);

	/*
	* The driver assumes that CHG_AL_N and SW_OPEN are not connected,
	* therefore an activated CHG_DET indicates whether the source is NOT a
	* low-power standard downstream port (SDP). The system will have to
	* ramp the current to determine the limit. The Type-C spec prohibits
	* proprietary methods now, therefore 1500mA is the max.
	*/
	new_chg.current = is_chg_det_activated(cfg) ? USB_CHARGER_MAX_CURR_MA :
	500;
	#else
	/*
	* If the board doesn't support charge ramping, then assume the lowest
	* denominator; that is assume the charger detected is a weak dedicated
	* charging port (DCP) which can only supply 500mA.
	*/
	new_chg.current = 500;
	#endif /* !defined(CONFIG_CHARGE_RAMP_SW && CONFIG_CHARGE_RAMP_HW) */

	charge_manager_update_charge(CHARGE_SUPPLIER_OTHER, port, &new_chg);
	}

	/**
	* If VBUS is present and port power role is sink, then trigger bc1.2 client
	* detection. If VBUS is not present then update charge manager. Note that both
	* chip_enable and VBUS must be active for the IC to be powered up. Chip enable
	* is kept enabled by default so that bc1.2 client detection is not triggered
	* when the port power role is source.
	*
	* @param port: Which USB Type-C port to examine.
	*/
	static void detect_or_power_down_ic(const int port)
	{
	int vbus_present;

	#ifdef CONFIG_USB_PD_VBUS_DETECT_TCPC
	vbus_present = tcpm_check_vbus_level(port, VBUS_PRESENT);
	#else
	vbus_present = pd_snk_is_vbus_provided(port);
	#endif /* !defined(CONFIG_USB_PD_VBUS_DETECT_TCPC) */

	if (vbus_present) {
	#if defined(CONFIG_POWER_PP5000_CONTROL) && defined(HAS_TASK_CHIPSET)
	/* Turn on the 5V rail to allow the chip to be powered. */
	power_5v_enable(task_get_current(), 1);
	#endif
	if (pd_get_power_role(port) == PD_ROLE_SINK)
	bc12_detect(port);
	} else {
	/* Let charge manager know there's no more charge available. */
	charge_manager_update_charge(CHARGE_SUPPLIER_OTHER, port, NULL);
	#if defined(CONFIG_POWER_PP5000_CONTROL) && defined(HAS_TASK_CHIPSET)
	/* Issue a request to turn off the rail. */
	power_5v_enable(task_get_current(), 0);
	#endif
	}
	}

	static void max14637_usb_charger_task(const int port)
	{
	uint32_t evt;
	const struct max14637_config_t * const cfg = &max14637_config[port];

	ASSERT(port >= 0 && port < CONFIG_USB_PD_PORT_MAX_COUNT);
	/*
	* Have chip enable active as default state so data switches are closed
	* and bc1.2 client side detection is not activated when the port power
	* role is a source.
	*/
	activate_chip_enable(cfg, 1);
	/* Check whether bc1.2 client mode detection needs to be triggered */
	detect_or_power_down_ic(port);

	while (1) {
	evt = task_wait_event(-1);

	if (evt & USB_CHG_EVENT_VBUS)
	detect_or_power_down_ic(port);
	}
	}

	#if defined(CONFIG_CHARGE_RAMP_SW) \|\| defined(CONFIG_CHARGE_RAMP_HW)
	static int max14637_ramp_allowed(int supplier)
	{
	/*
	* Due to the limitations in the application of the MAX14637, we
	* don't quite know exactly what we're plugged into. Therefore,
	* the supplier type will be CHARGE_SUPPLIER_OTHER.
	*/
	return supplier == CHARGE_SUPPLIER_OTHER;
	}

	static int max14637_ramp_max(int supplier, int sup_curr)
	{
	/* Use the current limit that was decided by the MAX14637. */
	if (supplier == CHARGE_SUPPLIER_OTHER)
	return sup_curr;
	else
	return 500;
	}
	#endif /* CONFIG_CHARGE_RAMP_SW \|\| CONFIG_CHARGE_RAMP_HW */

	/* Called on AP S5 -> S3 and S3/S0iX -> S0 transition */
	static void bc12_chipset_startup(void)
	{
	int port;

	/*
	* For each port, trigger a new USB_CHG_EVENT_VBUS event to handle cases
	* where there was no change in VBUS following an AP resume/startup
	* event. If a legacy charger is connected to the port, then VBUS will
	* not drop even during the USB PD hard reset.
	*/
	for (port = 0; port < CONFIG_USB_PD_PORT_MAX_COUNT; port++)
	task_set_event(USB_CHG_PORT_TO_TASK_ID(port),
	USB_CHG_EVENT_VBUS, 0);
	}
	DECLARE_HOOK(HOOK_CHIPSET_STARTUP, bc12_chipset_startup, HOOK_PRIO_DEFAULT);
	DECLARE_HOOK(HOOK_CHIPSET_RESUME, bc12_chipset_startup, HOOK_PRIO_DEFAULT);

	const struct bc12_drv max14637_drv = {
	.usb_charger_task = max14637_usb_charger_task,
	#if defined(CONFIG_CHARGE_RAMP_SW) \|\| defined(CONFIG_CHARGE_RAMP_HW)
	.ramp_allowed = max14637_ramp_allowed,
	.ramp_max = max14637_ramp_max,
	#endif /* CONFIG_CHARGE_RAMP_SW \|\| CONFIG_CHARGE_RAMP_HW */
	};

	#ifdef CONFIG_BC12_SINGLE_DRIVER
	/* provide a default bc12_ports[] for backward compatibility */
	struct bc12_config bc12_ports[CHARGE_PORT_COUNT] = {
	[0 ... (CHARGE_PORT_COUNT - 1)] = {
	.drv = &max14637_drv,
	},
	};
	#endif /* CONFIG_BC12_SINGLE_DRIVER */