power: supply: PCHG: Peripheral device charger
authorDaisuke Nojiri <dnojiri@chromium.org>
Wed, 16 Jun 2021 18:51:24 +0000 (11:51 -0700)
committerSebastian Reichel <sre@kernel.org>
Fri, 16 Jul 2021 13:54:34 +0000 (15:54 +0200)
This patch adds a driver for PCHG (Peripheral CHarGer). PCHG is a
framework managing power supplies for peripheral devices.

This driver creates a sysfs node for each peripheral charge port:

/sys/class/power_supply/peripheral<n>

where <n> is the index of a charge port.

For example, when a stylus is connected to a NFC/WLC port, the node
returns:

/sys/class/power_supply/peripheral0/
capacity=50
charge_type=Standard
scope=Device
status=Charging
type=Battery

Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
drivers/power/supply/Kconfig
drivers/power/supply/Makefile
drivers/power/supply/cros_peripheral_charger.c [new file with mode: 0644]
include/linux/platform_data/cros_ec_commands.h

index 11f5368..47b7d21 100644 (file)
@@ -736,6 +736,16 @@ config CHARGER_CROS_USBPD
          what is connected to USB PD ports from the EC and converts
          that into power_supply properties.
 
+config CHARGER_CROS_PCHG
+       tristate "ChromeOS EC based peripheral charger"
+       depends on MFD_CROS_EC_DEV
+       default MFD_CROS_EC_DEV
+       help
+         Say Y here to enable ChromeOS EC based peripheral charge driver.
+         This driver gets various information about the devices connected to
+         the peripheral charge ports from the EC and converts that into
+         power_supply properties.
+
 config CHARGER_SC2731
        tristate "Spreadtrum SC2731 charger driver"
        depends on MFD_SC27XX_PMIC || COMPILE_TEST
index dde138b..2fd629d 100644 (file)
@@ -93,6 +93,7 @@ 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
+obj-$(CONFIG_CHARGER_CROS_PCHG)        += cros_peripheral_charger.o
 obj-$(CONFIG_CHARGER_SC2731)   += sc2731_charger.o
 obj-$(CONFIG_FUEL_GAUGE_SC27XX)        += sc27xx_fuel_gauge.o
 obj-$(CONFIG_CHARGER_UCS1002)  += ucs1002_power.o
diff --git a/drivers/power/supply/cros_peripheral_charger.c b/drivers/power/supply/cros_peripheral_charger.c
new file mode 100644 (file)
index 0000000..305f10d
--- /dev/null
@@ -0,0 +1,386 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Power supply driver for ChromeOS EC based Peripheral Device Charger.
+ *
+ * Copyright 2020 Google LLC.
+ */
+
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+#include <linux/stringify.h>
+#include <linux/types.h>
+
+#define DRV_NAME               "cros-ec-pchg"
+#define PCHG_DIR_PREFIX                "peripheral"
+#define PCHG_DIR_NAME          PCHG_DIR_PREFIX "%d"
+#define PCHG_DIR_NAME_LENGTH \
+               sizeof(PCHG_DIR_PREFIX __stringify(EC_PCHG_MAX_PORTS))
+#define PCHG_CACHE_UPDATE_DELAY        msecs_to_jiffies(500)
+
+struct port_data {
+       int port_number;
+       char name[PCHG_DIR_NAME_LENGTH];
+       struct power_supply *psy;
+       struct power_supply_desc psy_desc;
+       int psy_status;
+       int battery_percentage;
+       int charge_type;
+       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_registered_psy;
+       struct port_data *ports[EC_PCHG_MAX_PORTS];
+       struct notifier_block notifier;
+};
+
+static enum power_supply_property cros_pchg_props[] = {
+       POWER_SUPPLY_PROP_STATUS,
+       POWER_SUPPLY_PROP_CHARGE_TYPE,
+       POWER_SUPPLY_PROP_CAPACITY,
+       POWER_SUPPLY_PROP_SCOPE,
+};
+
+static int cros_pchg_ec_command(const struct charger_data *charger,
+                               unsigned int version,
+                               unsigned int command,
+                               const 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 const unsigned int pchg_cmd_version = 1;
+
+static bool cros_pchg_cmd_ver_check(const struct charger_data *charger)
+{
+       struct ec_params_get_cmd_versions_v1 req;
+       struct ec_response_get_cmd_versions rsp;
+       int ret;
+
+       req.cmd = EC_CMD_PCHG;
+       ret = cros_pchg_ec_command(charger, 1, EC_CMD_GET_CMD_VERSIONS,
+                                  &req, sizeof(req), &rsp, sizeof(rsp));
+       if (ret < 0) {
+               dev_warn(charger->dev,
+                        "Unable to get versions of EC_CMD_PCHG (err:%d)\n",
+                        ret);
+               return false;
+       }
+
+       return !!(rsp.version_mask & BIT(pchg_cmd_version));
+}
+
+static int cros_pchg_port_count(const struct charger_data *charger)
+{
+       struct ec_response_pchg_count rsp;
+       int ret;
+
+       ret = cros_pchg_ec_command(charger, 0, EC_CMD_PCHG_COUNT,
+                                  NULL, 0, &rsp, sizeof(rsp));
+       if (ret < 0) {
+               dev_warn(charger->dev,
+                        "Unable to get number or ports (err:%d)\n", ret);
+               return ret;
+       }
+
+       return rsp.port_count;
+}
+
+static int cros_pchg_get_status(struct port_data *port)
+{
+       struct charger_data *charger = port->charger;
+       struct ec_params_pchg req;
+       struct ec_response_pchg rsp;
+       struct device *dev = charger->dev;
+       int old_status = port->psy_status;
+       int old_percentage = port->battery_percentage;
+       int ret;
+
+       req.port = port->port_number;
+       ret = cros_pchg_ec_command(charger, pchg_cmd_version, EC_CMD_PCHG,
+                                  &req, sizeof(req), &rsp, sizeof(rsp));
+       if (ret < 0) {
+               dev_err(dev, "Unable to get port.%d status (err:%d)\n",
+                       port->port_number, ret);
+               return ret;
+       }
+
+       switch (rsp.state) {
+       case PCHG_STATE_RESET:
+       case PCHG_STATE_INITIALIZED:
+       case PCHG_STATE_ENABLED:
+       default:
+               port->psy_status = POWER_SUPPLY_STATUS_UNKNOWN;
+               port->charge_type = POWER_SUPPLY_CHARGE_TYPE_NONE;
+               break;
+       case PCHG_STATE_DETECTED:
+               port->psy_status = POWER_SUPPLY_STATUS_CHARGING;
+               port->charge_type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+               break;
+       case PCHG_STATE_CHARGING:
+               port->psy_status = POWER_SUPPLY_STATUS_CHARGING;
+               port->charge_type = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
+               break;
+       case PCHG_STATE_FULL:
+               port->psy_status = POWER_SUPPLY_STATUS_FULL;
+               port->charge_type = POWER_SUPPLY_CHARGE_TYPE_NONE;
+               break;
+       }
+
+       port->battery_percentage = rsp.battery_percentage;
+
+       if (port->psy_status != old_status ||
+                       port->battery_percentage != old_percentage)
+               power_supply_changed(port->psy);
+
+       dev_dbg(dev,
+               "Port %d: state=%d battery=%d%%\n",
+               port->port_number, rsp.state, rsp.battery_percentage);
+
+       return 0;
+}
+
+static int cros_pchg_get_port_status(struct port_data *port, bool ratelimit)
+{
+       int ret;
+
+       if (ratelimit &&
+           time_is_after_jiffies(port->last_update + PCHG_CACHE_UPDATE_DELAY))
+               return 0;
+
+       ret = cros_pchg_get_status(port);
+       if (ret < 0)
+               return ret;
+
+       port->last_update = jiffies;
+
+       return ret;
+}
+
+static int cros_pchg_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);
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_STATUS:
+       case POWER_SUPPLY_PROP_CAPACITY:
+       case POWER_SUPPLY_PROP_CHARGE_TYPE:
+               cros_pchg_get_port_status(port, true);
+               break;
+       default:
+               break;
+       }
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_STATUS:
+               val->intval = port->psy_status;
+               break;
+       case POWER_SUPPLY_PROP_CAPACITY:
+               val->intval = port->battery_percentage;
+               break;
+       case POWER_SUPPLY_PROP_CHARGE_TYPE:
+               val->intval = port->charge_type;
+               break;
+       case POWER_SUPPLY_PROP_SCOPE:
+               val->intval = POWER_SUPPLY_SCOPE_DEVICE;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int cros_pchg_event(const struct charger_data *charger,
+                          unsigned long host_event)
+{
+       int i;
+
+       for (i = 0; i < charger->num_registered_psy; i++)
+               cros_pchg_get_port_status(charger->ports[i], false);
+
+       return NOTIFY_OK;
+}
+
+static u32 cros_get_device_event(const struct charger_data *charger)
+{
+       struct ec_params_device_event req;
+       struct ec_response_device_event rsp;
+       struct device *dev = charger->dev;
+       int ret;
+
+       req.param = EC_DEVICE_EVENT_PARAM_GET_CURRENT_EVENTS;
+       ret = cros_pchg_ec_command(charger, 0, EC_CMD_DEVICE_EVENT,
+                                  &req, sizeof(req), &rsp, sizeof(rsp));
+       if (ret < 0) {
+               dev_warn(dev, "Unable to get device events (err:%d)\n", ret);
+               return 0;
+       }
+
+       return rsp.event_mask;
+}
+
+static int cros_ec_notify(struct notifier_block *nb,
+                         unsigned long queued_during_suspend,
+                         void *data)
+{
+       struct cros_ec_device *ec_dev = (struct cros_ec_device *)data;
+       u32 host_event = cros_ec_get_host_event(ec_dev);
+       struct charger_data *charger =
+                       container_of(nb, struct charger_data, notifier);
+       u32 device_event_mask;
+
+       if (!host_event)
+               return NOTIFY_DONE;
+
+       if (!(host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_DEVICE)))
+               return NOTIFY_DONE;
+
+       /*
+        * todo: Retrieve device event mask in common place
+        * (e.g. cros_ec_proto.c).
+        */
+       device_event_mask = cros_get_device_event(charger);
+       if (!(device_event_mask & EC_DEVICE_EVENT_MASK(EC_DEVICE_EVENT_WLC)))
+               return NOTIFY_DONE;
+
+       return cros_pchg_event(charger, host_event);
+}
+
+static int cros_pchg_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
+       struct cros_ec_device *ec_device = ec_dev->ec_dev;
+       struct power_supply_desc *psy_desc;
+       struct charger_data *charger;
+       struct power_supply *psy;
+       struct port_data *port;
+       struct notifier_block *nb;
+       int num_ports;
+       int ret;
+       int i;
+
+       charger = devm_kzalloc(dev, sizeof(*charger), GFP_KERNEL);
+       if (!charger)
+               return -ENOMEM;
+
+       charger->dev = dev;
+       charger->ec_dev = ec_dev;
+       charger->ec_device = ec_device;
+
+       ret = cros_pchg_port_count(charger);
+       if (ret <= 0) {
+               /*
+                * This feature is enabled by the EC and the kernel driver is
+                * included by default for CrOS devices. Don't need to be loud
+                * since this error can be normal.
+                */
+               dev_info(dev, "No peripheral charge ports (err:%d)\n", ret);
+               return -ENODEV;
+       }
+
+       if (!cros_pchg_cmd_ver_check(charger)) {
+               dev_err(dev, "EC_CMD_PCHG version %d isn't available.\n",
+                       pchg_cmd_version);
+               return -EOPNOTSUPP;
+       }
+
+       num_ports = ret;
+       if (num_ports > EC_PCHG_MAX_PORTS) {
+               dev_err(dev, "Too many peripheral charge ports (%d)\n",
+                       num_ports);
+               return -ENOBUFS;
+       }
+
+       dev_info(dev, "%d peripheral charge ports found\n", num_ports);
+
+       for (i = 0; i < num_ports; i++) {
+               struct power_supply_config psy_cfg = {};
+
+               port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+               if (!port)
+                       return -ENOMEM;
+
+               port->charger = charger;
+               port->port_number = i;
+               snprintf(port->name, sizeof(port->name), PCHG_DIR_NAME, i);
+
+               psy_desc = &port->psy_desc;
+               psy_desc->name = port->name;
+               psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
+               psy_desc->get_property = cros_pchg_get_prop;
+               psy_desc->external_power_changed = NULL;
+               psy_desc->properties = cros_pchg_props;
+               psy_desc->num_properties = ARRAY_SIZE(cros_pchg_props);
+               psy_cfg.drv_data = port;
+
+               psy = devm_power_supply_register(dev, psy_desc, &psy_cfg);
+               if (IS_ERR(psy))
+                       return dev_err_probe(dev, PTR_ERR(psy),
+                                       "Failed to register power supply\n");
+               port->psy = psy;
+
+               charger->ports[charger->num_registered_psy++] = port;
+       }
+
+       if (!charger->num_registered_psy)
+               return -ENODEV;
+
+       nb = &charger->notifier;
+       nb->notifier_call = cros_ec_notify;
+       ret = blocking_notifier_chain_register(&ec_dev->ec_dev->event_notifier,
+                                              nb);
+       if (ret < 0)
+               dev_err(dev, "Failed to register notifier (err:%d)\n", ret);
+
+       return 0;
+}
+
+static struct platform_driver cros_pchg_driver = {
+       .driver = {
+               .name = DRV_NAME,
+       },
+       .probe = cros_pchg_probe
+};
+
+module_platform_driver(cros_pchg_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS EC peripheral device charger");
+MODULE_ALIAS("platform:" DRV_NAME);
index 45f53af..271bd87 100644 (file)
@@ -4228,6 +4228,7 @@ enum ec_device_event {
        EC_DEVICE_EVENT_TRACKPAD,
        EC_DEVICE_EVENT_DSP,
        EC_DEVICE_EVENT_WIFI,
+       EC_DEVICE_EVENT_WLC,
 };
 
 enum ec_device_event_param {
@@ -5460,6 +5461,72 @@ struct ec_response_rollback_info {
 /* Issue AP reset */
 #define EC_CMD_AP_RESET 0x0125
 
+/**
+ * Get the number of peripheral charge ports
+ */
+#define EC_CMD_PCHG_COUNT 0x0134
+
+#define EC_PCHG_MAX_PORTS 8
+
+struct ec_response_pchg_count {
+       uint8_t port_count;
+} __ec_align1;
+
+/**
+ * Get the status of a peripheral charge port
+ */
+#define EC_CMD_PCHG 0x0135
+
+struct ec_params_pchg {
+       uint8_t port;
+} __ec_align1;
+
+struct ec_response_pchg {
+       uint32_t error;                 /* enum pchg_error */
+       uint8_t state;                  /* enum pchg_state state */
+       uint8_t battery_percentage;
+       uint8_t unused0;
+       uint8_t unused1;
+       /* Fields added in version 1 */
+       uint32_t fw_version;
+       uint32_t dropped_event_count;
+} __ec_align2;
+
+enum pchg_state {
+       /* Charger is reset and not initialized. */
+       PCHG_STATE_RESET = 0,
+       /* Charger is initialized or disabled. */
+       PCHG_STATE_INITIALIZED,
+       /* Charger is enabled and ready to detect a device. */
+       PCHG_STATE_ENABLED,
+       /* Device is in proximity. */
+       PCHG_STATE_DETECTED,
+       /* Device is being charged. */
+       PCHG_STATE_CHARGING,
+       /* Device is fully charged. It implies DETECTED (& not charging). */
+       PCHG_STATE_FULL,
+       /* In download (a.k.a. firmware update) mode */
+       PCHG_STATE_DOWNLOAD,
+       /* In download mode. Ready for receiving data. */
+       PCHG_STATE_DOWNLOADING,
+       /* Device is ready for data communication. */
+       PCHG_STATE_CONNECTED,
+       /* Put no more entry below */
+       PCHG_STATE_COUNT,
+};
+
+#define EC_PCHG_STATE_TEXT { \
+       [PCHG_STATE_RESET] = "RESET", \
+       [PCHG_STATE_INITIALIZED] = "INITIALIZED", \
+       [PCHG_STATE_ENABLED] = "ENABLED", \
+       [PCHG_STATE_DETECTED] = "DETECTED", \
+       [PCHG_STATE_CHARGING] = "CHARGING", \
+       [PCHG_STATE_FULL] = "FULL", \
+       [PCHG_STATE_DOWNLOAD] = "DOWNLOAD", \
+       [PCHG_STATE_DOWNLOADING] = "DOWNLOADING", \
+       [PCHG_STATE_CONNECTED] = "CONNECTED", \
+       }
+
 /*****************************************************************************/
 /* Voltage regulator controls */