[PATCH v2 2/3] power: supply: add cros-ec USBPD charger driver.

[Enric Balletbo i Serra <enric.balletbo@collabora.com>]

From: Sameer Nanda <snanda@chromium.org>

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.

Signed-off-by: Sameer Nanda <snanda@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
---

Changes in v2:
- [2/3] Add SPDX header, use devm_ variant and drop .owner
- [2/3] Removed the PD log functionality (will be send on a follow up patch)
- [2/3] Removed the extra custom sysfs attributes (will be send on a follow up patch)

 drivers/power/supply/Kconfig              |  10 +
 drivers/power/supply/Makefile             |   1 +
 drivers/power/supply/cros_usbpd-charger.c | 511 ++++++++++++++++++++++
 include/linux/mfd/cros_ec.h               |   2 +
 4 files changed, 524 insertions(+)
 create mode 100644 drivers/power/supply/cros_usbpd-charger.c

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 428b426842f4..046eb23ba6f0 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -624,4 +624,14 @@ config CHARGER_RT9455
 	help
 	  Say Y to enable support for Richtek RT9455 battery charger.
 
+config CHARGER_CROS_USBPD
+	tristate "ChromeOS EC based USBPD charger"
+	depends on MFD_CROS_EC
+	default n
+	help
+	  Say Y here to enable ChromeOS EC based USBPD 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
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index e83aa843bcc6..907e26f824b2 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -83,3 +83,4 @@ obj-$(CONFIG_CHARGER_TPS65090)	+= tps65090-charger.o
 obj-$(CONFIG_CHARGER_TPS65217)	+= tps65217_charger.o
 obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
 obj-$(CONFIG_AXP288_CHARGER)	+= axp288_charger.o
+obj-$(CONFIG_CHARGER_CROS_USBPD)	+= cros_usbpd-charger.o
diff --git a/drivers/power/supply/cros_usbpd-charger.c b/drivers/power/supply/cros_usbpd-charger.c
new file mode 100644
index 000000000000..c57d1c41828c
--- /dev/null
+++ b/drivers/power/supply/cros_usbpd-charger.c
@@ -0,0 +1,511 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Power supply driver for ChromeOS EC based USB PD Charger.
+ *
+ * Copyright (c) 2014 - 2018 Google, Inc
+ */
+
+#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/slab.h>
+
+#define CHARGER_DIR_NAME			"CROS_USBPD_CHARGER%d"
+#define CHARGER_DIR_NAME_LENGTH			sizeof(CHARGER_DIR_NAME)
+#define CHARGER_CACHE_UPDATE_DELAY		msecs_to_jiffies(500)
+#define CHARGER_MANUFACTURER_MODEL_LENGTH	32
+
+#define DRV_NAME "cros-usbpd-charger"
+
+struct port_data {
+	int port_number;
+	char name[CHARGER_DIR_NAME_LENGTH];
+	char manufacturer[CHARGER_MANUFACTURER_MODEL_LENGTH];
+	char model_name[CHARGER_MANUFACTURER_MODEL_LENGTH];
+	struct power_supply *psy;
+	struct power_supply_desc psy_desc;
+	int psy_usb_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[EC_USB_PD_MAX_PORTS];
+	struct notifier_block notifier;
+};
+
+static enum power_supply_property cros_usbpd_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_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+static int cros_usbpd_charger_ec_command(struct charger_data *charger,
+					 unsigned int version,
+					 unsigned int command,
+					 void *outdata,
+					 unsigned int outsize,
+					 void *indata,
+					 unsigned int insize)
+{
+	struct cros_ec_dev *ec_dev = charger->ec_dev;
+	struct cros_ec_command *msg;
+	int ret;
+
+	msg = kzalloc(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;
+
+	if (outsize)
+		memcpy(msg->data, outdata, outsize);
+
+	ret = cros_ec_cmd_xfer_status(charger->ec_device, msg);
+	if (ret >= 0 && insize)
+		memcpy(indata, msg->data, insize);
+
+	kfree(msg);
+	return ret;
+}
+
+static int cros_usbpd_charger_get_num_ports(struct charger_data *charger)
+{
+	struct ec_response_usb_pd_ports resp;
+	int ret;
+
+	ret = cros_usbpd_charger_ec_command(charger, 0, EC_CMD_USB_PD_PORTS,
+					    NULL, 0, &resp, sizeof(resp));
+	if (ret < 0) {
+		dev_err(charger->dev,
+			"Unable to get the number or ports (err:0x%x)\n", ret);
+		return ret;
+	}
+
+	return resp.num_ports;
+}
+
+static int cros_usbpd_charger_get_discovery_info(struct port_data *port)
+{
+	struct charger_data *charger = port->charger;
+	struct ec_params_usb_pd_discovery_entry resp;
+	struct ec_params_usb_pd_info_request req;
+	int ret;
+
+	req.port = port->port_number;
+
+	ret = cros_usbpd_charger_ec_command(charger, 0,
+					    EC_CMD_USB_PD_DISCOVERY,
+					    &req, sizeof(req),
+					    &resp, sizeof(resp));
+	if (ret < 0) {
+		dev_err(charger->dev,
+			"Unable to query discovery info (err:0x%x)\n", ret);
+		return ret;
+	}
+
+	dev_dbg(charger->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, sizeof(port->manufacturer), "%x",
+		 resp.vid);
+	snprintf(port->model_name, sizeof(port->model_name), "%x", resp.pid);
+
+	return 0;
+}
+
+static int cros_usbpd_charger_get_power_info(struct port_data *port)
+{
+	struct charger_data *charger = port->charger;
+	struct ec_response_usb_pd_power_info resp;
+	struct ec_params_usb_pd_power_info req;
+	int last_psy_status, last_psy_usb_type;
+	struct device *dev = charger->dev;
+	int ret;
+
+	req.port = port->port_number;
+	ret = cros_usbpd_charger_ec_command(charger, 0,
+					    EC_CMD_USB_PD_POWER_INFO,
+					    &req, sizeof(req),
+					    &resp, sizeof(resp));
+	if (ret < 0) {
+		dev_err(dev, "Unable to query PD power info (err:0x%x)\n", ret);
+		return ret;
+	}
+
+	last_psy_status = port->psy_status;
+	last_psy_usb_type = port->psy_usb_type;
+
+	switch (resp.role) {
+	case USB_PD_PORT_POWER_DISCONNECTED:
+		port->psy_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		port->psy_online = 0;
+		break;
+	case USB_PD_PORT_POWER_SOURCE:
+		port->psy_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		port->psy_online = 0;
+		break;
+	case USB_PD_PORT_POWER_SINK:
+		port->psy_status = POWER_SUPPLY_STATUS_CHARGING;
+		port->psy_online = 1;
+		break;
+	case USB_PD_PORT_POWER_SINK_NOT_CHARGING:
+		port->psy_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		port->psy_online = 1;
+		break;
+	default:
+		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_usb_type = POWER_SUPPLY_USB_TYPE_SDP;
+		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_usb_type = POWER_SUPPLY_USB_TYPE_PD_DRP;
+		else
+			port->psy_usb_type = POWER_SUPPLY_USB_TYPE_SDP;
+		break;
+	case USB_CHG_TYPE_OTHER:
+	case USB_CHG_TYPE_PROPRIETARY:
+		port->psy_usb_type = POWER_SUPPLY_USB_TYPE_APPLE_BRICK_ID;
+		break;
+	case USB_CHG_TYPE_C:
+		port->psy_usb_type = POWER_SUPPLY_USB_TYPE_C;
+		break;
+	case USB_CHG_TYPE_BC12_DCP:
+		port->psy_usb_type = POWER_SUPPLY_USB_TYPE_DCP;
+		break;
+	case USB_CHG_TYPE_BC12_CDP:
+		port->psy_usb_type = POWER_SUPPLY_USB_TYPE_CDP;
+		break;
+	case USB_CHG_TYPE_PD:
+		if (resp.dualrole)
+			port->psy_usb_type = POWER_SUPPLY_USB_TYPE_PD_DRP;
+		else
+			port->psy_usb_type = POWER_SUPPLY_USB_TYPE_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. Additionally since the power capabilities are
+		 * unknown, report the max current and voltage as zero.
+		 */
+		port->psy_usb_type = POWER_SUPPLY_USB_TYPE_UNKNOWN;
+		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_usb_type = POWER_SUPPLY_USB_TYPE_SDP;
+	}
+
+	port->psy_desc.type = POWER_SUPPLY_TYPE_USB;
+
+	dev_dbg(dev,
+		"Port %d: type=%d vmax=%d vnow=%d cmax=%d clim=%d pmax=%d\n",
+		port->port_number, 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_usb_type != port->psy_usb_type ||
+	    last_psy_status != port->psy_status)
+		power_supply_changed(port->psy);
+
+	return 0;
+}
+
+static int cros_usbpd_charger_get_port_status(struct port_data *port,
+					      bool ratelimit)
+{
+	int ret;
+
+	if (ratelimit &&
+	    time_is_after_jiffies(port->last_update +
+				  CHARGER_CACHE_UPDATE_DELAY))
+		return 0;
+
+	ret = cros_usbpd_charger_get_power_info(port);
+	if (ret < 0)
+		return ret;
+
+	ret = cros_usbpd_charger_get_discovery_info(port);
+	port->last_update = jiffies;
+
+	return ret;
+}
+
+static void cros_usbpd_charger_power_changed(struct power_supply *psy)
+{
+	struct port_data *port = power_supply_get_drvdata(psy);
+	struct charger_data *charger = port->charger;
+	int i;
+
+	for (i = 0; i < charger->num_registered_psy; i++)
+		cros_usbpd_charger_get_port_status(charger->ports[i], false);
+}
+
+static int cros_usbpd_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 cros_ec_device *ec_device = charger->ec_device;
+	struct device *dev = charger->dev;
+	int ret;
+
+	/* Only refresh ec_port_status for dynamic properties */
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		/*
+		 * If mkbp_event_supported, then we can be assured that
+		 * the driver's state for the online property is consistent
+		 * with the hardware. However, if we aren't event driven,
+		 * the optimization before to skip an ec_port_status get
+		 * and only returned cached values of the online property will
+		 * cause a delay in detecting a cable attach until one of the
+		 * other properties are read.
+		 *
+		 * Allow an ec_port_status refresh for online property check
+		 * if we're not already online to check for plug events if
+		 * not mkbp_event_supported.
+		 */
+		if (ec_device->mkbp_event_supported || port->psy_online)
+			break;
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = cros_usbpd_charger_get_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_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_usbpd_charger_ec_event(struct notifier_block *nb,
+				       unsigned long queued_during_suspend,
+				       void *_notify)
+{
+	struct cros_ec_device *ec_device;
+	struct charger_data *charger;
+	struct device *dev;
+	u32 host_event;
+
+	charger = container_of(nb, struct charger_data, notifier);
+	ec_device = charger->ec_device;
+	dev = charger->dev;
+
+	host_event = cros_ec_get_host_event(ec_device);
+	if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU)) {
+		cros_usbpd_charger_power_changed(charger->ports[0]->psy);
+		return NOTIFY_OK;
+	} else {
+		return NOTIFY_DONE;
+	}
+}
+
+static int cros_usbpd_charger_probe(struct platform_device *pd)
+{
+	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
+	struct cros_ec_device *ec_device = ec_dev->ec_dev;
+	struct power_supply_desc *psy_desc;
+	struct device *dev = &pd->dev;
+	struct charger_data *charger;
+	struct power_supply *psy;
+	struct port_data *port;
+	int ret = -EINVAL;
+	int i;
+
+	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);
+
+	charger->num_charger_ports = cros_usbpd_charger_get_num_ports(charger);
+	if (charger->num_charger_ports <= 0) {
+		/*
+		 * 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++) {
+		struct power_supply_config psy_cfg = {};
+
+		port = devm_kzalloc(dev, sizeof(struct port_data), GFP_KERNEL);
+		if (!port) {
+			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_usbpd_charger_get_prop;
+		psy_desc->external_power_changed =
+					cros_usbpd_charger_power_changed;
+		psy_desc->properties = cros_usbpd_charger_props;
+		psy_desc->num_properties =
+					ARRAY_SIZE(cros_usbpd_charger_props);
+		psy_cfg.drv_data = port;
+
+		psy = devm_power_supply_register_no_ws(dev, psy_desc,
+						       &psy_cfg);
+		if (IS_ERR(psy)) {
+			dev_err(dev, "Failed to register power supply\n");
+			continue;
+		}
+		port->psy = psy;
+
+		charger->ports[charger->num_registered_psy++] = port;
+		ec_device->charger = psy;
+	}
+
+	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_usbpd_charger_ec_event;
+		ret = blocking_notifier_chain_register(
+						&ec_device->event_notifier,
+						&charger->notifier);
+		if (ret < 0)
+			dev_warn(dev, "failed to register notifier\n");
+	}
+
+	return 0;
+
+fail:
+	WARN(1, "%s: Failing probe (err:0x%x)\n", dev_name(dev), ret);
+
+fail_nowarn:
+	dev_info(dev, "Failing probe (err:0x%x)\n", ret);
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int cros_usbpd_charger_resume(struct device *dev)
+{
+	struct charger_data *charger = dev_get_drvdata(dev);
+	int i;
+
+	if (!charger)
+		return 0;
+
+	for (i = 0; i < charger->num_registered_psy; i++) {
+		power_supply_changed(charger->ports[i]->psy);
+		charger->ports[i]->last_update =
+				jiffies - CHARGER_CACHE_UPDATE_DELAY;
+	}
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(cros_usbpd_charger_pm_ops, NULL,
+			 cros_usbpd_charger_resume);
+
+static struct platform_driver cros_usbpd_charger_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.pm = &cros_usbpd_charger_pm_ops,
+	},
+	.probe = cros_usbpd_charger_probe
+};
+
+module_platform_driver(cros_usbpd_charger_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS EC USBPD charger");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index f36125ee9245..a1eb39344231 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -19,6 +19,7 @@
 #include <linux/cdev.h>
 #include <linux/device.h>
 #include <linux/notifier.h>
+#include <linux/power_supply.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/mutex.h>
 
@@ -143,6 +144,7 @@ struct cros_ec_device {
 			struct cros_ec_command *msg);
 	int (*pkt_xfer)(struct cros_ec_device *ec,
 			struct cros_ec_command *msg);
+	struct power_supply *charger;
 	struct mutex lock;
 	bool mkbp_event_supported;
 	struct blocking_notifier_head event_notifier;
-- 
2.17.0