[PATCH v2 6/8] power: cros_usbpd-charger: Add EC-based USB PD charger driver

[Tomeu Vizoso]

From: Sameer Nanda <snanda@xxxxxxxxxxxx>

This driver exposes the charger functionality in the PD EC to userspace.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
Cc: Sameer Nanda <snanda@xxxxxxxxxxxx>
Cc: Benson Leung <bleung@xxxxxxxxxxxx>
Cc: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>
---

Changes in v2:
- Split out changes to cros_ec_commands.h and the helpers added to
  mfd/cros_ec.h from the patch that adds the charger driver, as
  suggested by Lee.
- Actually call get_ec_num_ports.

 drivers/power/Kconfig              |  10 +
 drivers/power/Makefile             |   1 +
 drivers/power/cros_usbpd-charger.c | 908 +++++++++++++++++++++++++++++++++++++
 3 files changed, 919 insertions(+)
 create mode 100644 drivers/power/cros_usbpd-charger.c

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 1ddd13cc0c07..26355850d91b 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -502,6 +502,16 @@ config AXP20X_POWER
 	  This driver provides support for the power supply features of
 	  AXP20x PMIC.
 
+config CHARGER_CROS_USB_PD
+	tristate "Chrome OS EC based USB PD charger"
+	depends on MFD_CROS_EC
+	default y
+	help
+	  Say Y here to enable Chrome OS EC based USB PD charger driver. This
+	  driver gets various bits of information about what is connected to
+	  USB PD ports from the EC and converts that into power_supply
+	  properties.
+
 endif # POWER_SUPPLY
 
 source "drivers/power/reset/Kconfig"
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 0e4eab55f8d7..b83685bfae61 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -73,3 +73,4 @@ obj-$(CONFIG_CHARGER_TPS65217)	+= tps65217_charger.o
 obj-$(CONFIG_POWER_RESET)	+= reset/
 obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
 obj-$(CONFIG_AXP288_CHARGER)	+= axp288_charger.o
+obj-$(CONFIG_CHARGER_CROS_USB_PD)	+= cros_usbpd-charger.o
diff --git a/drivers/power/cros_usbpd-charger.c b/drivers/power/cros_usbpd-charger.c
new file mode 100644
index 000000000000..c1aa58b47f56
--- /dev/null
+++ b/drivers/power/cros_usbpd-charger.c
@@ -0,0 +1,908 @@
+/*
+ * Power supply driver for ChromeOS EC based USB PD Charger.
+ *
+ * Copyright (c) 2014 Google, Inc
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/fs.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+#define CROS_USB_PD_MAX_PORTS		8
+#define CROS_USB_PD_MAX_LOG_ENTRIES	30
+
+#define CROS_USB_PD_LOG_UPDATE_DELAY msecs_to_jiffies(60000)
+#define CROS_USB_PD_CACHE_UPDATE_DELAY msecs_to_jiffies(500)
+
+/* Buffer + macro for building PDLOG string */
+#define BUF_SIZE 80
+#define APPEND_STRING(buf, len, str, ...) ((len) += \
+	snprintf((buf) + (len), max(BUF_SIZE - (len), 0), (str), ##__VA_ARGS__))
+
+#define CHARGER_DIR_NAME		"CROS_USB_PD_CHARGER%d"
+#define CHARGER_DIR_NAME_LENGTH		sizeof(CHARGER_DIR_NAME)
+
+#define MANUFACTURER_MODEL_LENGTH	32
+
+struct port_data {
+	int port_number;
+	char name[CHARGER_DIR_NAME_LENGTH];
+	char manufacturer[MANUFACTURER_MODEL_LENGTH];
+	char model_name[MANUFACTURER_MODEL_LENGTH];
+	struct power_supply *psy;
+	struct power_supply_desc psy_desc;
+	int psy_type;
+	int psy_online;
+	int psy_status;
+	int psy_current_max;
+	int psy_voltage_max_design;
+	int psy_voltage_now;
+	int psy_power_max;
+	struct charger_data *charger;
+	unsigned long last_update;
+};
+
+struct charger_data {
+	struct device *dev;
+	struct cros_ec_dev *ec_dev;
+	struct cros_ec_device *ec_device;
+	int num_charger_ports;
+	int num_registered_psy;
+	struct port_data *ports[CROS_USB_PD_MAX_PORTS];
+	struct delayed_work log_work;
+	struct workqueue_struct *log_workqueue;
+	struct notifier_block notifier;
+	bool suspended;
+};
+
+#define EC_MAX_IN_SIZE EC_PROTO2_MAX_REQUEST_SIZE
+#define EC_MAX_OUT_SIZE EC_PROTO2_MAX_RESPONSE_SIZE
+uint8_t ec_inbuf[EC_MAX_IN_SIZE];
+uint8_t ec_outbuf[EC_MAX_OUT_SIZE];
+
+static enum power_supply_property cros_usb_pd_charger_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CURRENT_MAX,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+/* Current external voltage/current limit in mV/mA. Default to none. */
+static uint16_t ext_voltage_lim = EC_POWER_LIMIT_NONE;
+static uint16_t ext_current_lim = EC_POWER_LIMIT_NONE;
+
+static int ec_command(struct cros_ec_dev *ec_dev, int version, int command,
+		      uint8_t *outdata, int outsize, uint8_t *indata,
+		      int insize)
+{
+	struct cros_ec_device *ec_device = ec_dev->ec_dev;
+	struct cros_ec_command *msg;
+	int ret;
+
+	msg = kmalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	msg->version = version;
+	msg->command = ec_dev->cmd_offset + command;
+	msg->outsize = outsize;
+	msg->insize = insize;
+
+	memcpy(msg->data, outdata, outsize);
+	ret = cros_ec_cmd_xfer_status(ec_device, msg);
+	memcpy(indata, msg->data, insize);
+
+	kfree(msg);
+
+	return ret;
+}
+
+static int set_ec_usb_pd_override_ports(struct charger_data *charger,
+					int port_num)
+{
+	struct device *dev = charger->dev;
+	struct ec_params_charge_port_override req;
+	int ret;
+
+	req.override_port = port_num;
+
+	ret = ec_command(charger->ec_dev, 0, EC_CMD_PD_CHARGE_PORT_OVERRIDE,
+			 (uint8_t *)&req, sizeof(req),
+			 NULL, 0);
+	if (ret < 0) {
+		dev_info(dev, "Port Override command returned 0x%x\n", ret);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int get_ec_num_ports(struct charger_data *charger, int *num_ports)
+{
+	struct device *dev = charger->dev;
+	struct ec_response_usb_pd_ports *resp =
+	    (struct ec_response_usb_pd_ports *)ec_inbuf;
+	int ret;
+
+	*num_ports = 0;
+	ret = ec_command(charger->ec_dev, 0, EC_CMD_USB_PD_PORTS,
+			 NULL, 0, ec_inbuf, EC_MAX_IN_SIZE);
+	if (ret < 0) {
+		dev_err(dev, "Unable to query PD ports (err:0x%x)\n", ret);
+		return ret;
+	}
+	*num_ports = resp->num_ports;
+	dev_dbg(dev, "Num ports = %d\n", *num_ports);
+
+	return 0;
+}
+
+static int get_ec_usb_pd_discovery_info(struct port_data *port)
+{
+	struct charger_data *charger = port->charger;
+	struct device *dev = charger->dev;
+	struct ec_params_usb_pd_info_request req;
+	struct ec_params_usb_pd_discovery_entry resp;
+	int ret;
+
+	req.port = port->port_number;
+
+	ret = ec_command(charger->ec_dev, 0, EC_CMD_USB_PD_DISCOVERY,
+			 (uint8_t *)&req, sizeof(req),
+			 (uint8_t *)&resp, sizeof(resp));
+	if (ret < 0) {
+		dev_err(dev, "Unable to query Discovery info (err:0x%x)\n",
+			 ret);
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "Port %d: VID = 0x%x, PID=0x%x, PTYPE=0x%x\n",
+		port->port_number, resp.vid, resp.pid, resp.ptype);
+
+	snprintf(port->manufacturer, MANUFACTURER_MODEL_LENGTH, "%x", resp.vid);
+	snprintf(port->model_name, MANUFACTURER_MODEL_LENGTH, "%x", resp.pid);
+
+	return 0;
+}
+
+static int get_ec_usb_pd_power_info(struct port_data *port)
+{
+	struct charger_data *charger = port->charger;
+	struct device *dev = charger->dev;
+	struct ec_params_usb_pd_power_info req;
+	struct ec_response_usb_pd_power_info resp;
+	char role_str[80];
+	int ret, last_psy_status, last_psy_type;
+
+	req.port = port->port_number;
+	ret = ec_command(charger->ec_dev, 0, EC_CMD_USB_PD_POWER_INFO,
+			 (uint8_t *)&req, sizeof(req),
+			 (uint8_t *)&resp, sizeof(resp));
+	if (ret < 0) {
+		dev_err(dev, "Unable to query PD power info (err:0x%x)\n", ret);
+		return -EINVAL;
+	}
+
+	last_psy_status = port->psy_status;
+	last_psy_type = port->psy_type;
+
+	switch (resp.role) {
+	case USB_PD_PORT_POWER_DISCONNECTED:
+		snprintf(role_str, sizeof(role_str), "%s", "DISCONNECTED");
+		port->psy_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		port->psy_online = 0;
+		break;
+	case USB_PD_PORT_POWER_SOURCE:
+		snprintf(role_str, sizeof(role_str), "%s", "SOURCE");
+		port->psy_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		port->psy_online = 0;
+		break;
+	case USB_PD_PORT_POWER_SINK:
+		snprintf(role_str, sizeof(role_str), "%s", "SINK");
+		port->psy_status = POWER_SUPPLY_STATUS_CHARGING;
+		port->psy_online = 1;
+		break;
+	case USB_PD_PORT_POWER_SINK_NOT_CHARGING:
+		snprintf(role_str, sizeof(role_str), "%s", "NOT CHARGING");
+		port->psy_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		port->psy_online = 1;
+		break;
+	default:
+		snprintf(role_str, sizeof(role_str), "%s", "UNKNOWN");
+		dev_err(dev, "Unknown role %d\n", resp.role);
+		break;
+	}
+
+	port->psy_voltage_max_design = resp.meas.voltage_max;
+	port->psy_voltage_now = resp.meas.voltage_now;
+	port->psy_current_max = resp.meas.current_max;
+	port->psy_power_max = resp.max_power;
+
+	switch (resp.type) {
+	case USB_CHG_TYPE_BC12_SDP:
+	case USB_CHG_TYPE_VBUS:
+		port->psy_type = POWER_SUPPLY_TYPE_USB;
+		break;
+	case USB_CHG_TYPE_NONE:
+		/*
+		 * For dual-role devices when we are a source, the firmware
+		 * reports the type as NONE. Report such chargers as type
+		 * USB_PD_DRP.
+		 */
+		if (resp.role == USB_PD_PORT_POWER_SOURCE && resp.dualrole)
+			port->psy_type = POWER_SUPPLY_TYPE_USB_PD_DRP;
+		else
+			port->psy_type = POWER_SUPPLY_TYPE_USB;
+		break;
+	case USB_CHG_TYPE_PROPRIETARY:
+		port->psy_type = POWER_SUPPLY_TYPE_MAINS;
+		break;
+	case USB_CHG_TYPE_C:
+		port->psy_type = POWER_SUPPLY_TYPE_USB_TYPE_C;
+		break;
+	case USB_CHG_TYPE_BC12_DCP:
+		port->psy_type = POWER_SUPPLY_TYPE_USB_DCP;
+		break;
+	case USB_CHG_TYPE_BC12_CDP:
+		port->psy_type = POWER_SUPPLY_TYPE_USB_CDP;
+		break;
+	case USB_CHG_TYPE_PD:
+		if (resp.dualrole)
+			port->psy_type = POWER_SUPPLY_TYPE_USB_PD_DRP;
+		else
+			port->psy_type = POWER_SUPPLY_TYPE_USB_PD;
+		break;
+	case USB_CHG_TYPE_UNKNOWN:
+		/*
+		 * While the EC is trying to determine the type of charger that
+		 * has been plugged in, it will report the charger type as
+		 * unknown. Treat this case as a dedicated charger since we
+		 * don't know any better just yet. Additionally since the power
+		 * capabilities are unknown, report the max current and voltage
+		 * as zero.
+		 */
+		port->psy_type = POWER_SUPPLY_TYPE_MAINS;
+		port->psy_voltage_max_design = 0;
+		port->psy_current_max = 0;
+		break;
+	default:
+		dev_err(dev, "Port %d: default case!\n",
+			port->port_number);
+		port->psy_type = POWER_SUPPLY_TYPE_USB;
+	}
+
+	port->psy_desc.type = port->psy_type;
+
+	dev_dbg(dev,
+		"Port %d: %s type=%d=vmax=%d vnow=%d cmax=%d clim=%d pmax=%d\n",
+		port->port_number, role_str, resp.type,
+		resp.meas.voltage_max, resp.meas.voltage_now,
+		resp.meas.current_max, resp.meas.current_lim,
+		resp.max_power);
+
+	/*
+	 * If power supply type or status changed, explicitly call
+	 * power_supply_changed. This results in udev event getting generated
+	 * and allows user mode apps to react quicker instead of waiting for
+	 * their next poll of power supply status.
+	 */
+	if (last_psy_type != port->psy_type ||
+	    last_psy_status != port->psy_status) {
+		dev_dbg(dev, "Port %d: Calling power_supply_changed\n",
+			port->port_number);
+		power_supply_changed(port->psy);
+	}
+
+	return 0;
+}
+
+static int get_ec_port_status(struct port_data *port, bool ratelimit)
+{
+	int ret;
+
+	if (ratelimit &&
+	    time_is_after_jiffies(port->last_update +
+				  CROS_USB_PD_CACHE_UPDATE_DELAY))
+		return 0;
+
+	ret = get_ec_usb_pd_power_info(port);
+	if (ret < 0)
+		return ret;
+
+	ret = get_ec_usb_pd_discovery_info(port);
+	port->last_update = jiffies;
+
+	return ret;
+}
+
+static void cros_usb_pd_charger_power_changed(struct power_supply *psy)
+{
+	struct port_data *port = power_supply_get_drvdata(psy);
+	struct charger_data *charger = port->charger;
+	struct device *dev = charger->dev;
+	int i;
+
+	dev_dbg(dev, "cros_usb_pd_charger_power_changed\n");
+	for (i = 0; i < charger->num_registered_psy; i++)
+		get_ec_port_status(charger->ports[i], false);
+}
+
+static int cros_usb_pd_charger_get_prop(struct power_supply *psy,
+				    enum power_supply_property psp,
+				    union power_supply_propval *val)
+{
+	struct port_data *port = power_supply_get_drvdata(psy);
+	struct charger_data *charger = port->charger;
+	struct device *dev = charger->dev;
+	int ret;
+
+
+	/* Only refresh ec_port_status for dynamic properties */
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+		ret = get_ec_port_status(port, true);
+		if (ret < 0) {
+			dev_err(dev, "Failed to get port status (err:0x%x)\n",
+				ret);
+			return -EINVAL;
+		}
+		break;
+	default:
+		break;
+	}
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = port->psy_online;
+		break;
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = port->psy_status;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+		val->intval = port->psy_current_max * 1000;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		val->intval = port->psy_voltage_max_design * 1000;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval = port->psy_voltage_now * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+		/* TODO: send a TBD host command to the EC. */
+		val->intval = 0;
+		break;
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		val->strval = port->model_name;
+		break;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = port->manufacturer;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cros_usb_pd_charger_set_prop(struct power_supply *psy,
+				    enum power_supply_property psp,
+				    const union power_supply_propval *val)
+{
+	struct port_data *port = power_supply_get_drvdata(psy);
+	struct charger_data *charger = port->charger;
+	int port_number;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+		/*
+		 * A value of -1 implies switching to battery as the power
+		 * source. Any other value implies using this port as the
+		 * power source.
+		 */
+		port_number = val->intval;
+		if (port_number != -1)
+			port_number = port->port_number;
+		return set_ec_usb_pd_override_ports(charger, port_number);
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int cros_usb_pd_charger_is_writeable(struct power_supply *psy,
+		enum power_supply_property psp)
+{
+	int ret;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+		ret = 1;
+		break;
+	default:
+		ret = 0;
+	}
+
+	return ret;
+}
+
+static void cros_usb_pd_print_log_entry(struct ec_response_pd_log *r,
+					ktime_t tstamp)
+{
+	static const char * const fault_names[] = {
+		"---", "OCP", "fast OCP", "OVP", "Discharge"
+	};
+	static const char * const role_names[] = {
+		"Disconnected", "SRC", "SNK", "SNK (not charging)"
+	};
+	static const char * const chg_type_names[] = {
+		"None", "PD", "Type-C", "Proprietary",
+		"DCP", "CDP", "SDP", "Other", "VBUS"
+	};
+	int i;
+	int role_idx, type_idx;
+	const char *fault, *role, *chg_type;
+	struct usb_chg_measures *meas;
+	struct mcdp_info *minfo;
+	struct rtc_time rt;
+	int len = 0;
+	char buf[BUF_SIZE + 1];
+
+	/* the timestamp is the number of 1024th of seconds in the past */
+	tstamp = ktime_sub_us(tstamp,
+		 (uint64_t)r->timestamp << PD_LOG_TIMESTAMP_SHIFT);
+	rt = rtc_ktime_to_tm(tstamp);
+
+	switch (r->type) {
+	case PD_EVENT_MCU_CHARGE:
+		if (r->data & CHARGE_FLAGS_OVERRIDE)
+			APPEND_STRING(buf, len, "override ");
+		if (r->data & CHARGE_FLAGS_DELAYED_OVERRIDE)
+			APPEND_STRING(buf, len, "pending_override ");
+		role_idx = r->data & CHARGE_FLAGS_ROLE_MASK;
+		role = role_idx < ARRAY_SIZE(role_names) ?
+			role_names[role_idx] : "Unknown";
+		type_idx = (r->data & CHARGE_FLAGS_TYPE_MASK)
+			 >> CHARGE_FLAGS_TYPE_SHIFT;
+		chg_type = type_idx < ARRAY_SIZE(chg_type_names) ?
+			chg_type_names[type_idx] : "???";
+
+		if ((role_idx == USB_PD_PORT_POWER_DISCONNECTED) ||
+		    (role_idx == USB_PD_PORT_POWER_SOURCE)) {
+			APPEND_STRING(buf, len, "%s", role);
+			break;
+		}
+
+		meas = (struct usb_chg_measures *)r->payload;
+		APPEND_STRING(buf, len, "%s %s %s %dmV max %dmV / %dmA", role,
+			r->data & CHARGE_FLAGS_DUAL_ROLE ? "DRP" : "Charger",
+			chg_type,
+			meas->voltage_now,
+			meas->voltage_max,
+			meas->current_max);
+		break;
+	case PD_EVENT_ACC_RW_FAIL:
+		APPEND_STRING(buf, len, "RW signature check failed");
+		break;
+	case PD_EVENT_PS_FAULT:
+		fault = r->data < ARRAY_SIZE(fault_names) ? fault_names[r->data]
+							  : "???";
+		APPEND_STRING(buf, len, "Power supply fault: %s", fault);
+		break;
+	case PD_EVENT_VIDEO_DP_MODE:
+		APPEND_STRING(buf, len, "DP mode %sabled",
+			      (r->data == 1) ? "en" : "dis");
+		break;
+	case PD_EVENT_VIDEO_CODEC:
+		minfo = (struct mcdp_info *)r->payload;
+		APPEND_STRING(buf, len,
+			      "HDMI info: family:%04x chipid:%04x irom:%d.%d.%d fw:%d.%d.%d",
+			      MCDP_FAMILY(minfo->family),
+			      MCDP_CHIPID(minfo->chipid),
+			      minfo->irom.major, minfo->irom.minor,
+			      minfo->irom.build, minfo->fw.major,
+			      minfo->fw.minor, minfo->fw.build);
+		break;
+	default:
+		APPEND_STRING(buf, len,
+			"Event %02x (%04x) [", r->type, r->data);
+		for (i = 0; i < PD_LOG_SIZE(r->size_port); i++)
+			APPEND_STRING(buf, len, "%02x ", r->payload[i]);
+		APPEND_STRING(buf, len, "]");
+		break;
+	}
+
+	pr_info("PDLOG %d/%02d/%02d %02d:%02d:%02d.%03d P%d %s\n",
+		rt.tm_year + 1900, rt.tm_mon + 1, rt.tm_mday,
+		rt.tm_hour, rt.tm_min, rt.tm_sec,
+		(int)(ktime_to_ms(tstamp) % MSEC_PER_SEC),
+		PD_LOG_PORT(r->size_port), buf);
+}
+
+static void cros_usb_pd_log_check(struct work_struct *work)
+{
+	struct charger_data *charger = container_of(to_delayed_work(work),
+		struct charger_data, log_work);
+	struct device *dev = charger->dev;
+	union {
+		struct ec_response_pd_log r;
+		uint32_t words[8]; /* space for the payload */
+	} u;
+	int ret;
+	int entries = 0;
+	ktime_t now;
+
+	if (charger->suspended) {
+		dev_dbg(dev, "Suspended...bailing out\n");
+		return;
+	}
+
+	while (entries++ < CROS_USB_PD_MAX_LOG_ENTRIES) {
+		ret = ec_command(charger->ec_dev, 0, EC_CMD_PD_GET_LOG_ENTRY,
+				 NULL, 0, (uint8_t *)&u, sizeof(u));
+		now = ktime_get_real();
+		if (ret < 0) {
+			dev_dbg(dev, "Cannot get PD log %d\n", ret);
+			break;
+		}
+		if (u.r.type == PD_EVENT_NO_ENTRY)
+			break;
+
+		cros_usb_pd_print_log_entry(&u.r, now);
+	}
+
+	queue_delayed_work(charger->log_workqueue, &charger->log_work,
+		CROS_USB_PD_LOG_UPDATE_DELAY);
+}
+
+static int cros_usb_pd_ec_event(struct notifier_block *nb,
+	unsigned long queued_during_suspend, void *_notify)
+{
+	struct charger_data *charger;
+	struct device *dev;
+	struct cros_ec_device *ec_device;
+	u32 host_event;
+
+	charger = container_of(nb, struct charger_data, notifier);
+	dev = charger->dev;
+	ec_device = charger->ec_device;
+
+	host_event = cros_ec_get_host_event(ec_device);
+	if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU)) {
+		cros_usb_pd_charger_power_changed(charger->ports[0]->psy);
+		return NOTIFY_OK;
+	} else {
+		return NOTIFY_DONE;
+	}
+}
+
+static char *charger_supplied_to[] = {"cros-usb_pd-charger"};
+
+static int cros_usb_pd_charger_probe(struct platform_device *pd)
+{
+	struct device *dev = &pd->dev;
+	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
+	struct cros_ec_device *ec_device;
+	struct charger_data *charger;
+	struct port_data *port;
+	struct power_supply_desc *psy_desc;
+	struct power_supply_config psy_cfg = {};
+	int i;
+	int ret = -EINVAL;
+
+	dev_dbg(dev, "cros_usb_pd_charger_probe\n");
+	if (!ec_dev) {
+		WARN(1, "%s: No EC dev found\n", dev_name(dev));
+		return -EINVAL;
+	}
+
+	ec_device = ec_dev->ec_dev;
+	if (!ec_device) {
+		WARN(1, "%s: No EC device found\n", dev_name(dev));
+		return -EINVAL;
+	}
+
+	charger = devm_kzalloc(dev, sizeof(struct charger_data),
+				    GFP_KERNEL);
+	if (!charger)
+		return -ENOMEM;
+
+	charger->dev = dev;
+	charger->ec_dev = ec_dev;
+	charger->ec_device = ec_device;
+
+	platform_set_drvdata(pd, charger);
+
+	if ((get_ec_num_ports(charger, &charger->num_charger_ports) < 0) ||
+	    !charger->num_charger_ports) {
+		/*
+		 * This can happen on a system that doesn't support USB PD.
+		 * Log a message, but no need to warn.
+		 */
+		dev_info(dev, "No charging ports found\n");
+		ret = -ENODEV;
+		goto fail_nowarn;
+	}
+
+	for (i = 0; i < charger->num_charger_ports; i++) {
+		port = devm_kzalloc(dev, sizeof(struct port_data), GFP_KERNEL);
+		if (!port) {
+			dev_err(dev, "Failed to alloc port structure\n");
+			ret = -ENOMEM;
+			goto fail;
+		}
+
+		port->charger = charger;
+		port->port_number = i;
+		sprintf(port->name, CHARGER_DIR_NAME, i);
+
+		psy_desc = &port->psy_desc;
+		psy_desc->name = port->name;
+		psy_desc->type = POWER_SUPPLY_TYPE_USB;
+		psy_desc->get_property = cros_usb_pd_charger_get_prop;
+		psy_desc->set_property = cros_usb_pd_charger_set_prop;
+		psy_desc->property_is_writeable =
+			cros_usb_pd_charger_is_writeable;
+		psy_desc->external_power_changed =
+			cros_usb_pd_charger_power_changed;
+		psy_desc->properties = cros_usb_pd_charger_props;
+		psy_desc->num_properties = ARRAY_SIZE(
+			cros_usb_pd_charger_props);
+
+		psy_cfg.drv_data = port;
+		psy_cfg.supplied_to = charger_supplied_to;
+		psy_cfg.num_supplicants = ARRAY_SIZE(charger_supplied_to);
+
+		port->psy = power_supply_register_no_ws(dev, psy_desc,
+							&psy_cfg);
+		if (IS_ERR(port->psy)) {
+			dev_err(dev, "Failed to register power supply: %ld\n",
+				PTR_ERR(port->psy));
+			continue;
+		}
+
+		charger->ports[charger->num_registered_psy++] = port;
+	}
+
+	if (!charger->num_registered_psy) {
+		ret = -ENODEV;
+		dev_err(dev, "No power supplies registered\n");
+		goto fail;
+	}
+
+	if (ec_device->mkbp_event_supported) {
+		/* Get PD events from the EC */
+		charger->notifier.notifier_call = cros_usb_pd_ec_event;
+		ret = blocking_notifier_chain_register(
+			&ec_device->event_notifier, &charger->notifier);
+		if (ret < 0)
+			dev_warn(dev, "failed to register notifier\n");
+	}
+
+	/* Retrieve PD event logs periodically */
+	INIT_DELAYED_WORK(&charger->log_work, cros_usb_pd_log_check);
+	charger->log_workqueue =
+		create_singlethread_workqueue("cros_usb_pd_log");
+	queue_delayed_work(charger->log_workqueue, &charger->log_work,
+		CROS_USB_PD_LOG_UPDATE_DELAY);
+
+	return 0;
+
+fail:
+	WARN(1, "%s: Failing probe (err:0x%x)\n", dev_name(dev), ret);
+
+fail_nowarn:
+	if (charger) {
+		for (i = 0; i < charger->num_registered_psy; i++) {
+			port = charger->ports[i];
+			power_supply_unregister(port->psy);
+			devm_kfree(dev, port);
+		}
+		platform_set_drvdata(pd, NULL);
+		devm_kfree(dev, charger);
+	}
+
+	dev_info(dev, "Failing probe (err:0x%x)\n", ret);
+	return ret;
+}
+
+static int cros_usb_pd_charger_remove(struct platform_device *pd)
+{
+	struct charger_data *charger = platform_get_drvdata(pd);
+	struct device *dev = charger->dev;
+	struct port_data *port;
+	int i;
+
+	if (charger) {
+		for (i = 0; i < charger->num_registered_psy; i++) {
+			port = charger->ports[i];
+			power_supply_unregister(port->psy);
+			devm_kfree(dev, port);
+		}
+		flush_delayed_work(&charger->log_work);
+		platform_set_drvdata(pd, NULL);
+		devm_kfree(dev, charger);
+	}
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int cros_usb_pd_charger_resume(struct device *dev)
+{
+	struct charger_data *charger = dev_get_drvdata(dev);
+	int i;
+
+	if (!charger)
+		return 0;
+
+	charger->suspended = false;
+
+	dev_dbg(dev, "cros_usb_pd_charger_resume: updating power supplies\n");
+	for (i = 0; i < charger->num_registered_psy; i++) {
+		power_supply_changed(charger->ports[i]->psy);
+		charger->ports[i]->last_update =
+				jiffies - CROS_USB_PD_CACHE_UPDATE_DELAY;
+	}
+	queue_delayed_work(charger->log_workqueue, &charger->log_work,
+		CROS_USB_PD_LOG_UPDATE_DELAY);
+
+	return 0;
+}
+
+static int cros_usb_pd_charger_suspend(struct device *dev)
+{
+	struct charger_data *charger = dev_get_drvdata(dev);
+
+	charger->suspended = true;
+
+	if (charger)
+		flush_delayed_work(&charger->log_work);
+	return 0;
+}
+#endif
+
+static int set_ec_ext_power_limit(struct cros_ec_dev *ec,
+				  uint16_t current_lim, uint16_t voltage_lim)
+{
+	struct ec_params_external_power_limit_v1 req;
+	int ret;
+
+	req.current_lim = current_lim;
+	req.voltage_lim = voltage_lim;
+
+	ret = ec_command(ec, 0, EC_CMD_EXT_POWER_CURRENT_LIMIT,
+			 (uint8_t *)&req, sizeof(req), NULL, 0);
+	if (ret < 0) {
+		dev_warn(ec->dev,
+			 "External power limit command returned 0x%x\n",
+			 ret);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static ssize_t get_ec_ext_current_lim(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%d\n", ext_current_lim);
+}
+
+static ssize_t set_ec_ext_current_lim(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	int ret;
+	uint16_t tmp_val;
+	struct cros_ec_dev *ec = container_of(
+			dev, struct cros_ec_dev, class_dev);
+
+	if (kstrtou16(buf, 0, &tmp_val) < 0)
+		return -EINVAL;
+
+	ret = set_ec_ext_power_limit(ec, tmp_val, ext_voltage_lim);
+	if (ret < 0)
+		return ret;
+
+	ext_current_lim = tmp_val;
+	if (ext_current_lim == EC_POWER_LIMIT_NONE)
+		dev_info(ec->dev, "External current limit removed\n");
+	else
+		dev_info(ec->dev, "External current limit set to %dmA\n",
+			 ext_current_lim);
+
+	return count;
+}
+
+static ssize_t get_ec_ext_voltage_lim(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%d\n", ext_voltage_lim);
+}
+
+static ssize_t set_ec_ext_voltage_lim(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	int ret;
+	uint16_t tmp_val;
+
+	struct cros_ec_dev *ec = container_of(
+			dev, struct cros_ec_dev, class_dev);
+
+	if (kstrtou16(buf, 0, &tmp_val) < 0)
+		return -EINVAL;
+
+	ret = set_ec_ext_power_limit(ec, ext_current_lim, tmp_val);
+	if (ret < 0)
+		return ret;
+
+	ext_voltage_lim = tmp_val;
+	if (ext_voltage_lim == EC_POWER_LIMIT_NONE)
+		dev_info(ec->dev, "External voltage limit removed\n");
+	else
+		dev_info(ec->dev, "External voltage limit set to %dmV\n",
+			 ext_voltage_lim);
+
+	return count;
+}
+
+static DEVICE_ATTR(ext_current_lim, S_IWUSR | S_IWGRP | S_IRUGO,
+		   get_ec_ext_current_lim,
+		   set_ec_ext_current_lim);
+static DEVICE_ATTR(ext_voltage_lim, S_IWUSR | S_IWGRP | S_IRUGO,
+		   get_ec_ext_voltage_lim,
+		   set_ec_ext_voltage_lim);
+
+static struct attribute *__ext_power_cmds_attrs[] = {
+	&dev_attr_ext_current_lim.attr,
+	&dev_attr_ext_voltage_lim.attr,
+	NULL,
+};
+
+struct attribute_group cros_usb_pd_charger_attr_group = {
+	.name = "usb-pd-charger",
+	.attrs = __ext_power_cmds_attrs,
+};
+
+static SIMPLE_DEV_PM_OPS(cros_usb_pd_charger_pm_ops,
+	cros_usb_pd_charger_suspend, cros_usb_pd_charger_resume);
+
+static struct platform_driver cros_usb_pd_charger_driver = {
+	.driver = {
+		.name = "cros-usb-pd-charger",
+		.owner = THIS_MODULE,
+		.pm = &cros_usb_pd_charger_pm_ops,
+	},
+	.probe = cros_usb_pd_charger_probe,
+	.remove = cros_usb_pd_charger_remove,
+};
+
+module_platform_driver(cros_usb_pd_charger_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Chrome USB PD charger");
+MODULE_ALIAS("power_supply:cros-usb-pd-charger");
-- 
2.5.0