power: supply: add cros-ec USBPD charger driver.
authorSameer Nanda <snanda@chromium.org>
Wed, 2 May 2018 15:44:17 +0000 (17:44 +0200)
committerSebastian Reichel <sre@kernel.org>
Thu, 5 Jul 2018 15:12:52 +0000 (17:12 +0200)
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>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
drivers/power/supply/Kconfig
drivers/power/supply/Makefile
drivers/power/supply/cros_usbpd-charger.c [new file with mode: 0644]

index 428b426..046eb23 100644 (file)
@@ -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
index e83aa84..907e26f 100644 (file)
@@ -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 (file)
index 0000000..3a0c96f
--- /dev/null
@@ -0,0 +1,544 @@
+// 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,
+       POWER_SUPPLY_PROP_USB_TYPE
+};
+
+static enum power_supply_usb_type cros_usbpd_charger_usb_types[] = {
+       POWER_SUPPLY_USB_TYPE_UNKNOWN,
+       POWER_SUPPLY_USB_TYPE_SDP,
+       POWER_SUPPLY_USB_TYPE_DCP,
+       POWER_SUPPLY_USB_TYPE_CDP,
+       POWER_SUPPLY_USB_TYPE_C,
+       POWER_SUPPLY_USB_TYPE_PD,
+       POWER_SUPPLY_USB_TYPE_PD_DRP,
+       POWER_SUPPLY_USB_TYPE_APPLE_BRICK_ID
+};
+
+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_USB_TYPE:
+               val->intval = port->psy_usb_type;
+               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 void cros_usbpd_charger_unregister_notifier(void *data)
+{
+       struct charger_data *charger = data;
+       struct cros_ec_device *ec_device = charger->ec_device;
+
+       blocking_notifier_chain_unregister(&ec_device->event_notifier,
+                                          &charger->notifier);
+}
+
+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_desc->usb_types = cros_usbpd_charger_usb_types;
+               psy_desc->num_usb_types =
+                               ARRAY_SIZE(cros_usbpd_charger_usb_types);
+               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;
+       }
+
+       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");
+               } else {
+                       ret = devm_add_action_or_reset(dev,
+                                       cros_usbpd_charger_unregister_notifier,
+                                       charger);
+                       if (ret < 0)
+                               goto fail;
+               }
+       }
+
+       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);