diff mbox series

[v7,1/2] power: supply: PCHG: Peripheral device charger

Message ID 20210616185131.1792509-1-dnojiri@chromium.org (mailing list archive)
State Not Applicable, archived
Headers show
Series [v7,1/2] power: supply: PCHG: Peripheral device charger | expand

Commit Message

Daisuke Nojiri June 16, 2021, 6:51 p.m. UTC
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>
---
v2
* Separate mfd/cros_ec_dev.c
* Make CONFIG_CHARGER_CROS_PCHG default to CONFIG_MFD_CROS_EC_DEV
v3
* Return POWER_SUPPLY_SCOPE_DEVICE for POWER_SUPPLY_PROP_SCOPE
* POWER_SUPPLY_TYPE_WIRELESS -> POWER_SUPPLY_TYPE_BATTERY
v4
* Return NOTIFY_DONE when a non-host event is notified.
v5
* Change sysfs node prefix from PCHG to peripheral.
* Update EC_CMD_PCHG to v1 and make probe fail if EC doesn't support it.
* Call power_supply_changed if status or battery percentage changed.
* Add PCHG_STATE_FULL. It's sent from EC explicitly for fully charged battery.
* Register each port as a wakeup source.
v6
* Add POWER_SUPPLY_PROP_CHARGE_TYPE support.
v7
* Make cros_pchg_probe return EOPNOTSUPP (instead of ENOTSUPP).
---
 drivers/power/supply/Kconfig                  |  10 +
 drivers/power/supply/Makefile                 |   1 +
 .../power/supply/cros_peripheral_charger.c    | 396 ++++++++++++++++++
 .../linux/platform_data/cros_ec_commands.h    |  67 +++
 4 files changed, 474 insertions(+)
 create mode 100644 drivers/power/supply/cros_peripheral_charger.c

Comments

Sebastian Reichel July 16, 2021, 1:57 p.m. UTC | #1
Hi,

On Wed, Jun 16, 2021 at 11:51:24AM -0700, Daisuke Nojiri wrote:
> 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>
> ---
> [...]
> +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,
> +	/*
> +	 * todo: Add the following.
> +	 *
> +	 * POWER_SUPPLY_PROP_TECHNOLOGY,
> +	 * POWER_SUPPLY_PROP_ERROR,
> +	 * POWER_SUPPLY_PROP_SERIAL_NUMBER,
> +	 *
> +	 * POWER_SUPPLY_PROP_ONLINE can't be used because it indicates the
> +	 * system is powered by AC.
> +	 */
> +};
> [...]

Thanks, I queued the driver with the above TODO removed. Please
track this downstream, the note is not useful in mainline kernel,
since we do not have (AFAIK) the necessary documentation to add
more features.

-- Sebastian
diff mbox series

Patch

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index e696364126f1d4..766841f190b39a 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -735,6 +735,16 @@  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
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index a7309a3d1a4707..0f0d80c2a468d1 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -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
index 00000000000000..4543adf3eaf193
--- /dev/null
+++ b/drivers/power/supply/cros_peripheral_charger.c
@@ -0,0 +1,396 @@ 
+// 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,
+	/*
+	 * todo: Add the following.
+	 *
+	 * POWER_SUPPLY_PROP_TECHNOLOGY,
+	 * POWER_SUPPLY_PROP_ERROR,
+	 * POWER_SUPPLY_PROP_SERIAL_NUMBER,
+	 *
+	 * POWER_SUPPLY_PROP_ONLINE can't be used because it indicates the
+	 * system is powered by AC.
+	 */
+};
+
+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);
diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index 45f53afc46e224..271bd87bff0a25 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -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 */