[PATCH 0/3] power: supply: Acer Aspire 1 embedded controller

[PATCH 0/3] power: supply: Acer Aspire 1 embedded controller

[Nikita Travkin]

The laptop contains an embedded controller that provides a set of
features:

- Battery and charger monitoring
- USB Type-C DP alt mode HPD monitoring
- Lid status detection
- Small amount of keyboard configuration*

[*] The keyboard is handled by the same EC but it has a dedicated i2c
bus and is already enabled. This port only provides fn key behavior
configuration.

Unfortunately, while all this functionality is implemented in ACPI, it's
currently not possible to use ACPI to boot Linux on such Qualcomm
devices. Thus this series implements and enables a new driver that
provides support for the EC features.

The EC would be one of the last pieces to get almost full support for the
Acer Aspire 1 laptop in the upstream Linux kernel.

This series is similar to the EC driver for Lenovo Yoga C630, proposed
in [1] but seemingly never followed up...

[1] https://lore.kernel.org/all/20230205152809.2233436-1-dmitry.baryshkov@linaro.org/

Signed-off-by: Nikita Travkin <nikita@trvn.ru>
---
Nikita Travkin (3):
      dt-bindings: power: supply: Add Acer Aspire 1 EC
      power: supply: Add Acer Aspire 1 embedded controller driver
      arm64: dts: qcom: acer-aspire1: Add embedded controller

 .../bindings/power/supply/acer,aspire1-ec.yaml     |  73 ++++
 arch/arm64/boot/dts/qcom/sc7180-acer-aspire1.dts   |  40 +-
 drivers/power/supply/Kconfig                       |  14 +
 drivers/power/supply/Makefile                      |   1 +
 drivers/power/supply/acer-aspire1-ec.c             | 432 +++++++++++++++++++++
 5 files changed, 559 insertions(+), 1 deletion(-)
---
base-commit: 8e00ce02066e8f6f1ad5eab49a2ede7bf7a5ef64
change-id: 20231206-aspire1-ec-6b3d2cac1a72

Best regards,
-- 
Nikita Travkin <nikita@trvn.ru>

[PATCH 1/3] dt-bindings: power: supply: Add Acer Aspire 1 EC

[Nikita Travkin]

Add binding for the EC found in the Acer Aspire 1 laptop.

Signed-off-by: Nikita Travkin <nikita@trvn.ru>
---
 .../bindings/power/supply/acer,aspire1-ec.yaml     | 73 ++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/supply/acer,aspire1-ec.yaml b/Documentation/devicetree/bindings/power/supply/acer,aspire1-ec.yaml
new file mode 100644
index 000000000000..3fc6dea7fa5c
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/supply/acer,aspire1-ec.yaml
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/supply/acer,aspire1-ec.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Acer Aspire 1 Embedded Controller
+
+maintainers:
+  - Nikita Travkin <nikita@trvn.ru>
+
+description:
+  The Acer Aspire 1 laptop uses an embedded controller to control battery
+  and charging as well as to provide a set of misc features such as the
+  laptop lid status and HPD events for the USB Type-C DP alt mode.
+
+properties:
+  compatible:
+    const: acer,aspire1-ec
+
+  reg:
+    const: 0x76
+
+  interrupts:
+    maxItems: 1
+
+  acer,media-keys-on-top:
+    description: Configure the keyboard layout to use media features of
+      the fn row when the fn key is not pressed. The firmware may choose
+      to add this property when user selects the fn mode in the firmware
+      setup utility.
+    type: boolean
+
+  connector:
+    $ref: /schemas/connector/usb-connector.yaml#
+
+    properties:
+      reg:
+        maxItems: 1
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |+
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        embedded-controller@76 {
+            compatible = "acer,aspire1-ec";
+            reg = <0x76>;
+
+            interrupts-extended = <&tlmm 30 IRQ_TYPE_LEVEL_LOW>;
+
+            connector {
+                compatible = "usb-c-connector";
+
+                port {
+                    ec_dp_in: endpoint {
+                        remote-endpoint = <&mdss_dp_out>;
+                    };
+                };
+            };
+        };
+    };

-- 
2.43.0

[PATCH 2/3] power: supply: Add Acer Aspire 1 embedded controller driver

[Nikita Travkin]

Acer Aspire 1 is a Snapdragon 7c based laptop. It uses an embedded
controller to control the charging and battery management, as well as to
perform a set of misc functions.

Unfortunately, while all this functionality is implemented in ACPI, it's
currently not possible to use ACPI to boot Linux on such Qualcomm
devices. To allow Linux to still support the features provided by EC,
this driver reimplments the relevant ACPI parts. This allows us to boot
the laptop with Device Tree and retain all the features.

Signed-off-by: Nikita Travkin <nikita@trvn.ru>
---
 drivers/power/supply/Kconfig           |  14 ++
 drivers/power/supply/Makefile          |   1 +
 drivers/power/supply/acer-aspire1-ec.c | 432 +++++++++++++++++++++++++++++++++
 3 files changed, 447 insertions(+)

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index f21cb05815ec..47d2ad14447b 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -984,4 +984,18 @@ config FUEL_GAUGE_MM8013
 	  the state of charge, temperature, cycle count, actual and design
 	  capacity, etc.
 
+config EC_ACER_ASPIRE1
+	tristate "Acer Aspire 1 Emedded Controller driver"
+	depends on I2C
+	depends on DRM
+	help
+	  Say Y here to enable the EC driver for the (Snapdragon-based)
+	  Acer Aspire 1 laptop. The EC handles battery and charging
+	  monitoring as well as some misc functions like the lid sensor
+	  and USB Type-C DP HPD events.
+
+	  This driver provides battery and AC status support for the mentioned
+	  laptop where this information is not properly exposed via the
+	  standard ACPI devices.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 58b567278034..6049c87820c0 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -114,3 +114,4 @@ obj-$(CONFIG_CHARGER_SURFACE)	+= surface_charger.o
 obj-$(CONFIG_BATTERY_UG3105)	+= ug3105_battery.o
 obj-$(CONFIG_CHARGER_QCOM_SMB2)	+= qcom_pmi8998_charger.o
 obj-$(CONFIG_FUEL_GAUGE_MM8013)	+= mm8013.o
+obj-$(CONFIG_EC_ACER_ASPIRE1)	+= acer-aspire1-ec.o
diff --git a/drivers/power/supply/acer-aspire1-ec.c b/drivers/power/supply/acer-aspire1-ec.c
new file mode 100644
index 000000000000..845a11abf951
--- /dev/null
+++ b/drivers/power/supply/acer-aspire1-ec.c
@@ -0,0 +1,432 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2023, Nikita Travkin <nikita@trvn.ru> */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/delay.h>
+
+#include <linux/usb/typec_mux.h>
+#include <drm/drm_bridge.h>
+
+#define ASPIRE_EC_EVENT			0x05
+
+#define ASPIRE_EC_EVENT_WATCHDOG	0x20
+#define ASPIRE_EC_EVENT_LID_CLOSE	0x9b
+#define ASPIRE_EC_EVENT_LID_OPEN	0x9c
+#define ASPIRE_EC_EVENT_FG_INF_CHG	0x85
+#define ASPIRE_EC_EVENT_FG_STA_CHG	0xc6
+#define ASPIRE_EC_EVENT_HPD_DIS		0xa3
+#define ASPIRE_EC_EVENT_HPD_CON		0xa4
+
+#define ASPIRE_EC_FG_DYNAMIC		0x07
+#define ASPIRE_EC_FG_STATIC		0x08
+
+#define ASPIRE_EC_FG_FLAG_PRESENT	BIT(0)
+#define ASPIRE_EC_FG_FLAG_FULL		BIT(1)
+#define ASPIRE_EC_FG_FLAG_DISCHARGING	BIT(2)
+#define ASPIRE_EC_FG_FLAG_CHARGING	BIT(3)
+
+#define ASPIRE_EC_RAM_READ		0x20
+#define ASPIRE_EC_RAM_WRITE		0x21
+
+#define ASPIRE_EC_RAM_WATCHDOG		0x19
+#define ASPIRE_EC_RAM_KBD_MODE		0x43
+
+#define ASPIRE_EC_RAM_KBD_FN_EN		BIT(0)
+#define ASPIRE_EC_RAM_KBD_MEDIA_ON_TOP	BIT(5)
+#define ASPIRE_EC_RAM_KBD_ALWAYS_SET	BIT(6)
+#define ASPIRE_EC_RAM_KBD_NUM_LAYER_EN	BIT(7)
+
+#define ASPIRE_EC_RAM_KBD_MODE_2	0x60
+
+#define ASPIRE_EC_RAM_KBD_MEDIA_NOTIFY	BIT(3)
+
+#define ASPIRE_EC_RAM_HPD_STATUS	0xf4
+#define ASPIRE_EC_HPD_CONNECTED		0x03
+
+#define ASPIRE_EC_RAM_LID_STATUS	0x4c
+#define ASPIRE_EC_LID_OPEN		BIT(6)
+
+struct aspire_ec {
+	struct i2c_client *client;
+	struct power_supply *psy;
+	struct input_dev *idev;
+
+	bool bridge_configured;
+	struct drm_bridge bridge;
+	struct work_struct work;
+};
+
+struct aspire_ec_psy_static_data {
+	u8 unk1;
+	u8 flags;
+	__le16 unk2;
+	__le16 voltage_design;
+	__le16 capacity_full;
+	__le16 unk3;
+	__le16 serial;
+	u8 model_id;
+	u8 vendor_id;
+} __packed;
+
+static const char * const aspire_ec_psy_battery_model[] = {
+	"AP18C4K",
+	"AP18C8K",
+	"AP19B8K",
+	"AP16M4J",
+	"AP16M5J",
+};
+
+static const char * const aspire_ec_psy_battery_vendor[] = {
+	"SANYO",
+	"SONY",
+	"PANASONIC",
+	"SAMSUNG",
+	"SIMPLO",
+	"MOTOROLA",
+	"CELXPERT",
+	"LGC",
+	"GETAC",
+	"MURATA",
+};
+
+struct aspire_ec_psy_dynamic_data {
+	u8 unk1;
+	u8 flags;
+	u8 unk2;
+	__le16 capacity_now;
+	__le16 voltage_now;
+	__le16 current_now;
+	__le16 unk3;
+	__le16 unk4;
+} __packed;
+
+static int aspire_ec_psy_get_property(struct power_supply *psy,
+				      enum power_supply_property psp,
+				      union power_supply_propval *val)
+{
+	struct aspire_ec *ec = power_supply_get_drvdata(psy);
+	struct aspire_ec_psy_static_data sdat;
+	struct aspire_ec_psy_dynamic_data ddat;
+
+	i2c_smbus_read_i2c_block_data(ec->client, ASPIRE_EC_FG_STATIC, sizeof(sdat), (u8 *)&sdat);
+	i2c_smbus_read_i2c_block_data(ec->client, ASPIRE_EC_FG_DYNAMIC, sizeof(ddat), (u8 *)&ddat);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+		if (ddat.flags & ASPIRE_EC_FG_FLAG_CHARGING)
+			val->intval = POWER_SUPPLY_STATUS_CHARGING;
+		else if (ddat.flags & ASPIRE_EC_FG_FLAG_DISCHARGING)
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		else if (ddat.flags & ASPIRE_EC_FG_FLAG_FULL)
+			val->intval = POWER_SUPPLY_STATUS_FULL;
+		break;
+
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval = le16_to_cpu(ddat.voltage_now) * 1000;
+		break;
+
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		val->intval = le16_to_cpu(sdat.voltage_design) * 1000;
+		break;
+
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		val->intval = le16_to_cpu(ddat.capacity_now) * 1000;
+		break;
+
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+		val->intval = le16_to_cpu(sdat.capacity_full) * 1000;
+		break;
+
+	case POWER_SUPPLY_PROP_CAPACITY:
+		val->intval = le16_to_cpu(ddat.capacity_now) * 100
+			      / le16_to_cpu(sdat.capacity_full);
+		break;
+
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		val->intval = (s16)le16_to_cpu(ddat.current_now) * 1000;
+		break;
+
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = 1;
+		break;
+
+	case POWER_SUPPLY_PROP_SCOPE:
+		val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
+		break;
+
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		if (sdat.model_id - 1 < ARRAY_SIZE(aspire_ec_psy_battery_model))
+			val->strval = aspire_ec_psy_battery_model[sdat.model_id - 1];
+		else
+			val->strval = "Unknown";
+		break;
+
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		if (sdat.vendor_id - 3 < ARRAY_SIZE(aspire_ec_psy_battery_vendor))
+			val->strval = aspire_ec_psy_battery_vendor[sdat.vendor_id - 3];
+		else
+			val->strval = "Unknown";
+		break;
+
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static enum power_supply_property aspire_ec_psy_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_SCOPE,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+static const struct power_supply_desc aspire_ec_psy_desc = {
+	.name		= "aspire-ec",
+	.type		= POWER_SUPPLY_TYPE_BATTERY,
+	.get_property	= aspire_ec_psy_get_property,
+	.properties	= aspire_ec_psy_props,
+	.num_properties	= ARRAY_SIZE(aspire_ec_psy_props),
+};
+
+static int aspire_ec_ram_read(struct i2c_client *client, u8 off, u8 *data, u8 data_len)
+{
+	i2c_smbus_write_byte_data(client, ASPIRE_EC_RAM_READ, off);
+	i2c_smbus_read_i2c_block_data(client, ASPIRE_EC_RAM_READ, data_len, data);
+	return 0;
+}
+
+static int aspire_ec_ram_write(struct i2c_client *client, u8 off, u8 data)
+{
+	u8 tmp[2] = {off, data};
+
+	i2c_smbus_write_i2c_block_data(client, ASPIRE_EC_RAM_WRITE, sizeof(tmp), tmp);
+	return 0;
+}
+
+static irqreturn_t aspire_ec_irq_handler(int irq, void *data)
+{
+	struct aspire_ec *ec = data;
+	int id;
+	u8 tmp;
+
+	/*
+	 * The original ACPI firmware actually has a small sleep in the handler.
+	 *
+	 * It seems like in most cases it's not needed but when the device
+	 * just exits suspend, our i2c driver has a brief time where data
+	 * transfer is not possible yet. So this delay allows us to suppress
+	 * quite a bunch of spurious error messages in dmesg. Thus it's kept.
+	 */
+	usleep_range(15000, 30000);
+
+	id = i2c_smbus_read_byte_data(ec->client, ASPIRE_EC_EVENT);
+	if (id < 0) {
+		dev_err(&ec->client->dev, "Failed to read event id: %pe\n", ERR_PTR(id));
+		return IRQ_HANDLED;
+	}
+
+	switch (id) {
+	case 0x0: /* No event */
+		break;
+
+	case ASPIRE_EC_EVENT_WATCHDOG:
+		/*
+		 * Here acpi responds to the event and clears some bit.
+		 * Notify (\_SB.I2C3.BAT1, 0x81) // Information Change
+		 * Notify (\_SB.I2C3.ADP1, 0x80) // Status Change
+		 */
+		aspire_ec_ram_read(ec->client, ASPIRE_EC_RAM_WATCHDOG, &tmp, sizeof(tmp));
+		aspire_ec_ram_write(ec->client, ASPIRE_EC_RAM_WATCHDOG, tmp & 0xbf);
+		break;
+
+	case ASPIRE_EC_EVENT_LID_CLOSE:
+		/* Notify (\_SB.LID0, 0x80) // Status Change */
+		input_report_switch(ec->idev, SW_LID, 1);
+		input_sync(ec->idev);
+		break;
+
+	case ASPIRE_EC_EVENT_LID_OPEN:
+		/* Notify (\_SB.LID0, 0x80) // Status Change */
+		input_report_switch(ec->idev, SW_LID, 0);
+		input_sync(ec->idev);
+		break;
+
+	case ASPIRE_EC_EVENT_FG_INF_CHG:
+		/* Notify (\_SB.I2C3.BAT1, 0x81) // Information Change */
+	case ASPIRE_EC_EVENT_FG_STA_CHG:
+		/* Notify (\_SB.I2C3.BAT1, 0x80) // Status Change */
+		power_supply_changed(ec->psy);
+		break;
+
+	case ASPIRE_EC_EVENT_HPD_DIS:
+		if (ec->bridge_configured)
+			drm_bridge_hpd_notify(&ec->bridge, connector_status_disconnected);
+		break;
+
+	case ASPIRE_EC_EVENT_HPD_CON:
+		if (ec->bridge_configured)
+			drm_bridge_hpd_notify(&ec->bridge, connector_status_connected);
+		break;
+
+	default:
+		dev_warn(&ec->client->dev, "Unknown event id=0x%x\n", id);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int aspire_ec_bridge_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
+{
+	return flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR ? 0 : -EINVAL;
+}
+
+static void aspire_ec_bridge_update_hpd_work(struct work_struct *work)
+{
+	struct aspire_ec *ec = container_of(work, struct aspire_ec, work);
+	u8 tmp;
+
+	aspire_ec_ram_read(ec->client, ASPIRE_EC_RAM_HPD_STATUS, &tmp, sizeof(tmp));
+	if (tmp == ASPIRE_EC_HPD_CONNECTED)
+		drm_bridge_hpd_notify(&ec->bridge, connector_status_connected);
+	else
+		drm_bridge_hpd_notify(&ec->bridge, connector_status_disconnected);
+}
+
+static void aspire_ec_bridge_hpd_enable(struct drm_bridge *bridge)
+{
+	struct aspire_ec *ec = container_of(bridge, struct aspire_ec, bridge);
+
+	schedule_work(&ec->work);
+}
+
+static const struct drm_bridge_funcs aspire_ec_bridge_funcs = {
+	.hpd_enable = aspire_ec_bridge_hpd_enable,
+	.attach = aspire_ec_bridge_attach,
+};
+
+static int aspire_ec_probe(struct i2c_client *client)
+{
+	struct power_supply_config psy_cfg = {0};
+	struct device *dev = &client->dev;
+	struct fwnode_handle *fwnode;
+	struct aspire_ec *ec;
+	int ret;
+	u8 tmp;
+
+	ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL);
+	if (!ec)
+		return -ENOMEM;
+
+	ec->client = client;
+	i2c_set_clientdata(client, ec);
+
+	/* Battery status reports */
+	psy_cfg.drv_data = ec;
+	ec->psy = devm_power_supply_register(dev, &aspire_ec_psy_desc, &psy_cfg);
+	if (IS_ERR(ec->psy))
+		return dev_err_probe(dev, PTR_ERR(ec->psy),
+				     "Failed to register power supply\n");
+
+	/* Lid switch */
+	ec->idev = devm_input_allocate_device(dev);
+	if (!ec->idev)
+		return -ENOMEM;
+
+	ec->idev->name = "aspire-ec";
+	ec->idev->phys = "aspire-ec/input0";
+	input_set_capability(ec->idev, EV_SW, SW_LID);
+
+	ret = input_register_device(ec->idev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Input device register failed\n");
+
+	/* Enable the keyboard fn keys */
+	tmp = ASPIRE_EC_RAM_KBD_FN_EN | ASPIRE_EC_RAM_KBD_ALWAYS_SET;
+	if (device_property_read_bool(dev, "acer,media-keys-on-top"))
+		tmp |= ASPIRE_EC_RAM_KBD_MEDIA_ON_TOP;
+	aspire_ec_ram_write(client, ASPIRE_EC_RAM_KBD_MODE, tmp);
+
+	aspire_ec_ram_read(client, ASPIRE_EC_RAM_KBD_MODE_2, &tmp, sizeof(tmp));
+	tmp |= ASPIRE_EC_RAM_KBD_MEDIA_NOTIFY;
+	aspire_ec_ram_write(client, ASPIRE_EC_RAM_KBD_MODE_2, tmp);
+
+	/* External Type-C display attach reports */
+	fwnode = device_get_named_child_node(dev, "connector");
+	if (fwnode) {
+		INIT_WORK(&ec->work, aspire_ec_bridge_update_hpd_work);
+		ec->bridge.funcs = &aspire_ec_bridge_funcs;
+		ec->bridge.of_node = to_of_node(fwnode);
+		ec->bridge.ops = DRM_BRIDGE_OP_HPD;
+		ec->bridge.type = DRM_MODE_CONNECTOR_USB;
+
+		ret = devm_drm_bridge_add(dev, &ec->bridge);
+		if (ret) {
+			fwnode_handle_put(fwnode);
+			return dev_err_probe(dev, ret, "Failed to register drm bridge\n");
+		}
+
+		ec->bridge_configured = true;
+	}
+
+	ret = devm_request_threaded_irq(dev, client->irq, NULL,
+					aspire_ec_irq_handler, IRQF_ONESHOT,
+					dev_name(dev), ec);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to request irq\n");
+
+	return 0;
+}
+
+static int aspire_ec_resume(struct device *dev)
+{
+	struct aspire_ec *ec = i2c_get_clientdata(to_i2c_client(dev));
+	u8 tmp;
+
+	aspire_ec_ram_read(ec->client, ASPIRE_EC_RAM_LID_STATUS, &tmp, sizeof(tmp));
+	input_report_switch(ec->idev, SW_LID, !!(tmp & ASPIRE_EC_LID_OPEN));
+	input_sync(ec->idev);
+
+	return 0;
+}
+
+static const struct i2c_device_id aspire_ec_id[] = {
+	{ "aspire1-ec", },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, aspire_ec_id);
+
+static const struct of_device_id aspire_ec_of_match[] = {
+	{ .compatible = "acer,aspire1-ec", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, aspire_ec_of_match);
+
+static DEFINE_SIMPLE_DEV_PM_OPS(aspire_ec_pm_ops, NULL, aspire_ec_resume);
+
+static struct i2c_driver aspire_ec_driver = {
+	.driver = {
+		.name = "aspire-ec",
+		.of_match_table = aspire_ec_of_match,
+		.pm = pm_sleep_ptr(&aspire_ec_pm_ops),
+	},
+	.probe = aspire_ec_probe,
+	.id_table = aspire_ec_id,
+};
+module_i2c_driver(aspire_ec_driver);
+
+MODULE_DESCRIPTION("Acer Aspire 1 embedded controller");
+MODULE_AUTHOR("Nikita Travkin <nikita@trvn.ru>");
+MODULE_LICENSE("GPL");

-- 
2.43.0

[PATCH 3/3] arm64: dts: qcom: acer-aspire1: Add embedded controller

[Nikita Travkin]

The laptop contains an embedded controller that provides a set of
features:

- Battery and charger monitoring
- USB Type-C DP alt mode HPD monitoring
- Lid status detection
- Small amount of keyboard configuration*

[*] The keyboard is handled by the same EC but it has a dedicated i2c
bus and is already enabled. This port only provides fn key behavior
configuration.

Add the EC to the device tree and describe the relationship between the
EC-managed type-c port and the SoC DisplayPort.

Signed-off-by: Nikita Travkin <nikita@trvn.ru>
---
 arch/arm64/boot/dts/qcom/sc7180-acer-aspire1.dts | 40 +++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7180-acer-aspire1.dts b/arch/arm64/boot/dts/qcom/sc7180-acer-aspire1.dts
index dbb48934d499..a29f542fa612 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-acer-aspire1.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-acer-aspire1.dts
@@ -147,7 +147,25 @@ &i2c2 {
 	clock-frequency = <400000>;
 	status = "okay";
 
-	/* embedded-controller@76 */
+	embedded-controller@76 {
+		compatible = "acer,aspire1-ec";
+		reg = <0x76>;
+
+		interrupts-extended = <&tlmm 30 IRQ_TYPE_LEVEL_LOW>;
+
+		pinctrl-0 = <&ec_int_default>;
+		pinctrl-names = "default";
+
+		connector {
+			compatible = "usb-c-connector";
+
+			port {
+				ec_dp_in: endpoint {
+					remote-endpoint = <&mdss_dp_out>;
+				};
+			};
+		};
+	};
 };
 
 &i2c4 {
@@ -298,6 +316,19 @@ &mdss {
 	status = "okay";
 };
 
+&mdss_dp {
+	data-lanes = <0 1>;
+
+	vdda-1p2-supply = <&vreg_l3c_1p2>;
+	vdda-0p9-supply = <&vreg_l4a_0p8>;
+
+	status = "okay";
+};
+
+&mdss_dp_out {
+	remote-endpoint = <&ec_dp_in>;
+};
+
 &mdss_dsi0 {
 	vdda-supply = <&vreg_l3c_1p2>;
 	status = "okay";
@@ -687,6 +718,13 @@ codec_irq_default: codec-irq-deault-state {
 		bias-disable;
 	};
 
+	ec_int_default: ec-int-default-state {
+		pins = "gpio30";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+	};
+
 	edp_bridge_irq_default: edp-bridge-irq-default-state {
 		pins = "gpio11";
 		function = "gpio";

-- 
2.43.0

Re: [PATCH 1/3] dt-bindings: power: supply: Add Acer Aspire 1 EC

[Krzysztof Kozlowski]

On 07/12/2023 12:20, Nikita Travkin wrote:
> Add binding for the EC found in the Acer Aspire 1 laptop.
> 
> Signed-off-by: Nikita Travkin <nikita@trvn.ru>
> ---
>  .../bindings/power/supply/acer,aspire1-ec.yaml     | 73 ++++++++++++++++++++++
>  1 file changed, 73 insertions(+)
> 


> +
> +  acer,media-keys-on-top:
> +    description: Configure the keyboard layout to use media features of
> +      the fn row when the fn key is not pressed. The firmware may choose
> +      to add this property when user selects the fn mode in the firmware
> +      setup utility.
> +    type: boolean
> +
> +  connector:
> +    $ref: /schemas/connector/usb-connector.yaml#
> +
> +    properties:
> +      reg:
> +        maxItems: 1

You cannot have it... Add it to the example and see the results.

> +
> +    unevaluatedProperties: false

It should be fine to drop this as well, so you don't need anything else
than $ref.



Best regards,
Krzysztof

Re: [PATCH 1/3] dt-bindings: power: supply: Add Acer Aspire 1 EC

[Nikita Travkin]

Krzysztof Kozlowski писал(а) 07.12.2023 21:56:
> On 07/12/2023 12:20, Nikita Travkin wrote:
>> Add binding for the EC found in the Acer Aspire 1 laptop.
>>
>> Signed-off-by: Nikita Travkin <nikita@trvn.ru>
>> ---
>>  .../bindings/power/supply/acer,aspire1-ec.yaml     | 73 ++++++++++++++++++++++
>>  1 file changed, 73 insertions(+)
>>
> 
> 
>> +
>> +  acer,media-keys-on-top:
>> +    description: Configure the keyboard layout to use media features of
>> +      the fn row when the fn key is not pressed. The firmware may choose
>> +      to add this property when user selects the fn mode in the firmware
>> +      setup utility.
>> +    type: boolean
>> +
>> +  connector:
>> +    $ref: /schemas/connector/usb-connector.yaml#
>> +
>> +    properties:
>> +      reg:
>> +        maxItems: 1
> 
> You cannot have it... Add it to the example and see the results.
> 

Gah, I had connector@0 at first with all the num-cells etc,
later simplified it, but missed this part...

>> +
>> +    unevaluatedProperties: false
> 
> It should be fine to drop this as well, so you don't need anything else
> than $ref.
> 

Will drop this too then.

Thanks!
Nikita

> 
> 
> Best regards,
> Krzysztof

Re: [PATCH 2/3] power: supply: Add Acer Aspire 1 embedded controller driver

[Konrad Dybcio]

On 12/7/23 12:20, Nikita Travkin wrote:
> Acer Aspire 1 is a Snapdragon 7c based laptop. It uses an embedded
> controller to control the charging and battery management, as well as to
> perform a set of misc functions.
> 
> Unfortunately, while all this functionality is implemented in ACPI, it's
> currently not possible to use ACPI to boot Linux on such Qualcomm
> devices. To allow Linux to still support the features provided by EC,
> this driver reimplments the relevant ACPI parts. This allows us to boot
> the laptop with Device Tree and retain all the features.
> 
> Signed-off-by: Nikita Travkin <nikita@trvn.ru>
> ---
[...]

> +	case POWER_SUPPLY_PROP_CAPACITY:
> +		val->intval = le16_to_cpu(ddat.capacity_now) * 100
> +			      / le16_to_cpu(sdat.capacity_full);
It may be just my OCD and im not the maintainer here, but I'd do
/= here

[...]

> +	case POWER_SUPPLY_PROP_MODEL_NAME:
> +		if (sdat.model_id - 1 < ARRAY_SIZE(aspire_ec_psy_battery_model))
> +			val->strval = aspire_ec_psy_battery_model[sdat.model_id - 1];
> +		else
> +			val->strval = "Unknown";
Would it make sense to print the model_id that's absent from the LUT
here and similarly below?

> +		break;
> +
> +	case POWER_SUPPLY_PROP_MANUFACTURER:
> +		if (sdat.vendor_id - 3 < ARRAY_SIZE(aspire_ec_psy_battery_vendor))
> +			val->strval = aspire_ec_psy_battery_vendor[sdat.vendor_id - 3];
> +		else
> +			val->strval = "Unknown";
> +		break;
> +
> +	default:
> +		return -EINVAL;
> +	}
Another ocd trip, i'd add a newline before return

> +	return 0;
> +}
[...]

> +	/*
> +	 * The original ACPI firmware actually has a small sleep in the handler.
> +	 *
> +	 * It seems like in most cases it's not needed but when the device
> +	 * just exits suspend, our i2c driver has a brief time where data
> +	 * transfer is not possible yet. So this delay allows us to suppress
> +	 * quite a bunch of spurious error messages in dmesg. Thus it's kept.
Ouch.. do you think i2c-geni needs fixing on this part?

[...]

> +	switch (id) {
> +	case 0x0: /* No event */
> +		break;
Is this a NOP/watchdog sort of thing?

[...]

> +
> +static struct i2c_driver aspire_ec_driver = {
> +	.driver = {
> +		.name = "aspire-ec",
> +		.of_match_table = aspire_ec_of_match,
> +		.pm = pm_sleep_ptr(&aspire_ec_pm_ops),
> +	},
> +	.probe = aspire_ec_probe,
> +	.id_table = aspire_ec_id,
Since it's tristate, I'd expect an entry for .remove_new here

Konrad

Re: [PATCH 3/3] arm64: dts: qcom: acer-aspire1: Add embedded controller

[Konrad Dybcio]

On 12/7/23 12:20, Nikita Travkin wrote:
> The laptop contains an embedded controller that provides a set of
> features:
> 
> - Battery and charger monitoring
> - USB Type-C DP alt mode HPD monitoring
> - Lid status detection
> - Small amount of keyboard configuration*
> 
> [*] The keyboard is handled by the same EC but it has a dedicated i2c
> bus and is already enabled. This port only provides fn key behavior
> configuration.
> 
> Add the EC to the device tree and describe the relationship between the
> EC-managed type-c port and the SoC DisplayPort.
> 
> Signed-off-by: Nikita Travkin <nikita@trvn.ru>
> ---
lgtm but I'll wait for bindings to settle so that the computer can
say it's happy as well

Konrad

Re: [PATCH 2/3] power: supply: Add Acer Aspire 1 embedded controller driver

[Nikita Travkin]

Konrad Dybcio писал(а) 08.12.2023 00:24:
> On 12/7/23 12:20, Nikita Travkin wrote:
>> Acer Aspire 1 is a Snapdragon 7c based laptop. It uses an embedded
>> controller to control the charging and battery management, as well as to
>> perform a set of misc functions.
>>
>> Unfortunately, while all this functionality is implemented in ACPI, it's
>> currently not possible to use ACPI to boot Linux on such Qualcomm
>> devices. To allow Linux to still support the features provided by EC,
>> this driver reimplments the relevant ACPI parts. This allows us to boot
>> the laptop with Device Tree and retain all the features.
>>
>> Signed-off-by: Nikita Travkin <nikita@trvn.ru>
>> ---
> [...]
> 
>> +	case POWER_SUPPLY_PROP_CAPACITY:
>> +		val->intval = le16_to_cpu(ddat.capacity_now) * 100
>> +			      / le16_to_cpu(sdat.capacity_full);
> It may be just my OCD and im not the maintainer here, but I'd do
> /= here

Hm you're right, this did look a bit ugly to me when I split the line
(it was 101/100), Will probably use /= to make it nicer in v2.

> 
> [...]
> 
>> +	case POWER_SUPPLY_PROP_MODEL_NAME:
>> +		if (sdat.model_id - 1 < ARRAY_SIZE(aspire_ec_psy_battery_model))
>> +			val->strval = aspire_ec_psy_battery_model[sdat.model_id - 1];
>> +		else
>> +			val->strval = "Unknown";
> Would it make sense to print the model_id that's absent from the LUT
> here and similarly below?
> 

The original ACPI code returns "Unknown" like this when the value
is not in the table. I suppose I could warn here but not sure how
useful it would be... And since this is a rather "hot" path, would
need to warn only once, so extra complexity for a very unlikely
situation IMO.

>> +		break;
>> +
>> +	case POWER_SUPPLY_PROP_MANUFACTURER:
>> +		if (sdat.vendor_id - 3 < ARRAY_SIZE(aspire_ec_psy_battery_vendor))
>> +			val->strval = aspire_ec_psy_battery_vendor[sdat.vendor_id - 3];
>> +		else
>> +			val->strval = "Unknown";
>> +		break;
>> +
>> +	default:
>> +		return -EINVAL;
>> +	}
> Another ocd trip, i'd add a newline before return
>

Yeah I agree here, missed this. Will add in v2.

>> +	return 0;
>> +}
> [...]
> 
>> +	/*
>> +	 * The original ACPI firmware actually has a small sleep in the handler.
>> +	 *
>> +	 * It seems like in most cases it's not needed but when the device
>> +	 * just exits suspend, our i2c driver has a brief time where data
>> +	 * transfer is not possible yet. So this delay allows us to suppress
>> +	 * quite a bunch of spurious error messages in dmesg. Thus it's kept.
> Ouch.. do you think i2c-geni needs fixing on this part?

Not sure, it seems like when we exit suspend, this handler
gets triggered before geni (or it's dependencies?) is considered
"awake" (my guess is when the clocks are still off):

[  119.246867] PM: suspend entry (s2idle)
(...)
[  119.438052] printk: Suspending console(s) (use no_console_suspend to debug)
[  119.942498] geni_i2c 888000.i2c: error turning SE resources:-13
[  119.942550] aspire-ec 2-0076: Failed to read event id: -EACCES
(...)
[  119.942657] geni_i2c 888000.i2c: error turning SE resources:-13
[  119.942666] aspire-ec 2-0076: Failed to read event id: -EACCES
(...)
[  120.881452] PM: suspend exit

FWIW it doesn't seem to be a big problem since this is
a level interrupt, so it will be retried until the event
can be cleared, but since ACPI also has the sleep, I'm
happy to inherit in and suppress a couple of red lines :)

> 
> [...]
> 
>> +	switch (id) {
>> +	case 0x0: /* No event */
>> +		break;
> Is this a NOP/watchdog sort of thing?
> 

This is a NOP, yes. I think I was hitting spurious interrupts
once or twice so I suppressed this.

> [...]
> 
>> +
>> +static struct i2c_driver aspire_ec_driver = {
>> +	.driver = {
>> +		.name = "aspire-ec",
>> +		.of_match_table = aspire_ec_of_match,
>> +		.pm = pm_sleep_ptr(&aspire_ec_pm_ops),
>> +	},
>> +	.probe = aspire_ec_probe,
>> +	.id_table = aspire_ec_id,
> Since it's tristate, I'd expect an entry for .remove_new here
> 

All the resources I allocate are devm_ so I believe I shouldn't need
to clean anything up on remove...

Thanks for the review!
Nikita

> Konrad