[PATCH v8 2/6] platform: arm64: Add driver for EC found on Qualcomm reference devices

[Anvesh Jain P <anvesh.p@oss.qualcomm.com>]

From: Sibi Sankar <sibi.sankar@oss.qualcomm.com>

Add Embedded controller driver support for Hamoa/Purwa/Glymur qualcomm
reference boards. It handles fan control, temperature sensors, access
to EC state changes and supports reporting suspend entry/exit to the
EC.

Co-developed-by: Maya Matuszczyk <maccraft123mc@gmail.com>
Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com>
Signed-off-by: Sibi Sankar <sibi.sankar@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Acked-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Tested-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Co-developed-by: Anvesh Jain P <anvesh.p@oss.qualcomm.com>
Signed-off-by: Anvesh Jain P <anvesh.p@oss.qualcomm.com>
---
 MAINTAINERS                            |   8 +
 drivers/platform/arm64/Kconfig         |  13 +
 drivers/platform/arm64/Makefile        |   1 +
 drivers/platform/arm64/qcom-hamoa-ec.c | 452 +++++++++++++++++++++++++++++++++
 4 files changed, 474 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 62b89d0013d2..0bf0d6d55550 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21980,6 +21980,14 @@ F:	Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
 F:	drivers/misc/fastrpc.c
 F:	include/uapi/misc/fastrpc.h
 
+QUALCOMM HAMOA EMBEDDED CONTROLLER DRIVER
+M:	Anvesh Jain P <anvesh.p@oss.qualcomm.com>
+M:	Sibi Sankar <sibi.sankar@oss.qualcomm.com>
+L:	linux-arm-msm@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/embedded-controller/qcom,hamoa-crd-ec.yaml
+F:	drivers/platform/arm64/qcom-hamoa-ec.c
+
 QUALCOMM HEXAGON ARCHITECTURE
 M:	Brian Cain <brian.cain@oss.qualcomm.com>
 L:	linux-hexagon@vger.kernel.org
diff --git a/drivers/platform/arm64/Kconfig b/drivers/platform/arm64/Kconfig
index 10f905d7d6bf..e32e01b2a9bd 100644
--- a/drivers/platform/arm64/Kconfig
+++ b/drivers/platform/arm64/Kconfig
@@ -90,4 +90,17 @@ config EC_LENOVO_THINKPAD_T14S
 
 	  Say M or Y here to include this support.
 
+config EC_QCOM_HAMOA
+	tristate "Embedded Controller driver for Qualcomm Hamoa/Glymur reference devices"
+	depends on ARCH_QCOM || COMPILE_TEST
+	depends on I2C
+	depends on THERMAL || THERMAL=n
+	help
+	  Say M or Y here to enable the Embedded Controller driver for Qualcomm
+	  Snapdragon-based Hamoa/Glymur reference devices. The driver handles fan
+	  control, temperature sensors, access to EC state changes and supports
+	  reporting suspend entry/exit to the EC.
+
+	  This driver currently supports Hamoa/Purwa/Glymur reference devices.
+
 endif # ARM64_PLATFORM_DEVICES
diff --git a/drivers/platform/arm64/Makefile b/drivers/platform/arm64/Makefile
index 60c131cff6a1..7681be4a46e9 100644
--- a/drivers/platform/arm64/Makefile
+++ b/drivers/platform/arm64/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_EC_ACER_ASPIRE1)	+= acer-aspire1-ec.o
 obj-$(CONFIG_EC_HUAWEI_GAOKUN)	+= huawei-gaokun-ec.o
 obj-$(CONFIG_EC_LENOVO_YOGA_C630) += lenovo-yoga-c630.o
 obj-$(CONFIG_EC_LENOVO_THINKPAD_T14S) += lenovo-thinkpad-t14s.o
+obj-$(CONFIG_EC_QCOM_HAMOA) += qcom-hamoa-ec.o
diff --git a/drivers/platform/arm64/qcom-hamoa-ec.c b/drivers/platform/arm64/qcom-hamoa-ec.c
new file mode 100644
index 000000000000..253f927c9aca
--- /dev/null
+++ b/drivers/platform/arm64/qcom-hamoa-ec.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Maya Matuszczyk <maccraft123mc@gmail.com>
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/thermal.h>
+
+#define EC_SCI_EVT_READ_CMD	0x05
+#define EC_FW_VERSION_CMD	0x0e
+#define EC_MODERN_STANDBY_CMD	0x23
+#define EC_FAN_DBG_CONTROL_CMD	0x30
+#define EC_SCI_EVT_CONTROL_CMD	0x35
+#define EC_THERMAL_CAP_CMD	0x42
+
+#define EC_FW_VERSION_RESP_LEN	4
+#define EC_THERMAL_CAP_RESP_LEN	3
+#define EC_FAN_DEBUG_CMD_LEN	6
+#define EC_FAN_SPEED_DATA_SIZE	4
+
+#define EC_MODERN_STANDBY_ENTER	0x01
+#define EC_MODERN_STANDBY_EXIT	0x00
+
+#define EC_FAN_DEBUG_MODE_OFF   0
+#define EC_FAN_DEBUG_MODE_ON    BIT(0)
+#define EC_FAN_ON               BIT(1)
+#define EC_FAN_DEBUG_TYPE_PWM   BIT(2)
+#define EC_MAX_FAN_CNT		2
+#define EC_FAN_NAME_SIZE	20
+#define EC_FAN_MAX_PWM		255
+
+enum qcom_ec_sci_events {
+	EC_FAN1_STATUS_CHANGE_EVT = 0x30,
+	EC_FAN2_STATUS_CHANGE_EVT,
+	EC_FAN1_SPEED_CHANGE_EVT,
+	EC_FAN2_SPEED_CHANGE_EVT,
+	EC_NEW_LUT_SET_EVT,
+	EC_FAN_PROFILE_SWITCH_EVT,
+	EC_THERMISTOR_1_THRESHOLD_CROSS_EVT,
+	EC_THERMISTOR_2_THRESHOLD_CROSS_EVT,
+	EC_THERMISTOR_3_THRESHOLD_CROSS_EVT,
+	/* Reserved: 0x39 - 0x3c/0x3f */
+	EC_RECOVERED_FROM_RESET_EVT = 0x3d,
+};
+
+struct qcom_ec_version {
+	u8 main_version;
+	u8 sub_version;
+	u8 test_version;
+};
+
+struct qcom_ec_thermal_cap {
+#define EC_THERMAL_FAN_CNT(x)		(FIELD_GET(GENMASK(1, 0), (x)))
+#define EC_THERMAL_FAN_TYPE(x)		(FIELD_GET(GENMASK(4, 2), (x)))
+#define EC_THERMAL_THERMISTOR_MASK(x)	(FIELD_GET(GENMASK(7, 0), (x)))
+	u8 fan_cnt;
+	u8 fan_type;
+	u8 thermistor_mask;
+};
+
+struct qcom_ec_cooling_dev {
+	struct thermal_cooling_device *cdev;
+	struct device *parent_dev;
+	u8 fan_id;
+	u8 state;
+};
+
+struct qcom_ec {
+	struct qcom_ec_cooling_dev *ec_cdev;
+	struct qcom_ec_thermal_cap thermal_cap;
+	struct qcom_ec_version version;
+	struct i2c_client *client;
+};
+
+static int qcom_ec_read(struct qcom_ec *ec, u8 cmd, u8 resp_len, u8 *resp)
+{
+	int ret;
+
+	ret = i2c_smbus_read_i2c_block_data(ec->client, cmd, resp_len, resp);
+
+	if (ret < 0)
+		return ret;
+	else if (ret == 0 || ret == 0xff)
+		return -EOPNOTSUPP;
+
+	if (resp[0] >= resp_len)
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * EC Device Firmware Version:
+ *
+ * Read Response:
+ * ----------------------------------------------------------------------
+ * | Offset	| Name		| Description				|
+ * ----------------------------------------------------------------------
+ * | 0x00	| Byte count	| Number of bytes in response		|
+ * |		|		| (excluding byte count)		|
+ * ----------------------------------------------------------------------
+ * | 0x01	| Test-version	| Test-version of EC firmware		|
+ * ----------------------------------------------------------------------
+ * | 0x02	| Sub-version	| Sub-version of EC firmware		|
+ * ----------------------------------------------------------------------
+ * | 0x03	| Main-version	| Main-version of EC firmware		|
+ * ----------------------------------------------------------------------
+ *
+ */
+static int qcom_ec_read_fw_version(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct qcom_ec *ec = i2c_get_clientdata(client);
+	struct qcom_ec_version *version = &ec->version;
+	u8 resp[EC_FW_VERSION_RESP_LEN];
+	int ret;
+
+	ret = qcom_ec_read(ec, EC_FW_VERSION_CMD, EC_FW_VERSION_RESP_LEN, resp);
+	if (ret < 0)
+		return ret;
+
+	version->main_version = resp[3];
+	version->sub_version = resp[2];
+	version->test_version = resp[1];
+
+	dev_dbg(dev, "EC Version %d.%d.%d\n",
+		version->main_version, version->sub_version, version->test_version);
+
+	return 0;
+}
+
+/*
+ * EC Device Thermal Capabilities:
+ *
+ * Read Response:
+ * ------------------------------------------------------------------------------
+ * | Offset		| Name		| Description				|
+ * ------------------------------------------------------------------------------
+ * | 0x00		| Byte count	| Number of bytes in response		|
+ * |			|		| (excluding byte count)		|
+ * ------------------------------------------------------------------------------
+ * | 0x02 (LSB)	| EC Thermal	| Bit 0-1: Number of fans		|
+ * | 0x03		| Capabilities	| Bit 2-4: Type of fan			|
+ * |			|		| Bit 5-6: Reserved			|
+ * |			|		| Bit 7: Data Valid/Invalid		|
+ * |			|		|	 (Valid - 1, Invalid - 0)	|
+ * |			|		| Bit 8-15: Thermistor 0 - 7 presence	|
+ * |			|		|	    (1 present, 0 absent)	|
+ * ------------------------------------------------------------------------------
+ *
+ */
+static int qcom_ec_thermal_capabilities(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct qcom_ec *ec = i2c_get_clientdata(client);
+	struct qcom_ec_thermal_cap *cap = &ec->thermal_cap;
+	u8 resp[EC_THERMAL_CAP_RESP_LEN];
+	int ret;
+
+	ret = qcom_ec_read(ec, EC_THERMAL_CAP_CMD, EC_THERMAL_CAP_RESP_LEN, resp);
+	if (ret < 0)
+		return ret;
+
+	cap->fan_cnt = min(EC_MAX_FAN_CNT, EC_THERMAL_FAN_CNT(resp[1]));
+	cap->fan_type = EC_THERMAL_FAN_TYPE(resp[1]);
+	cap->thermistor_mask = EC_THERMAL_THERMISTOR_MASK(resp[2]);
+
+	dev_dbg(dev, "Fan count: %d Fan Type: %d Thermistor Mask: %x\n",
+		cap->fan_cnt, cap->fan_type, cap->thermistor_mask);
+
+	return 0;
+}
+
+static irqreturn_t qcom_ec_irq(int irq, void *data)
+{
+	struct qcom_ec *ec = data;
+	struct device *dev = &ec->client->dev;
+	int val;
+
+	val = i2c_smbus_read_byte_data(ec->client, EC_SCI_EVT_READ_CMD);
+	if (val < 0) {
+		dev_err_ratelimited(dev, "Failed to read EC SCI Event: %d\n", val);
+		return IRQ_HANDLED;
+	}
+
+	switch (val) {
+	case EC_FAN1_STATUS_CHANGE_EVT:
+		dev_dbg_ratelimited(dev, "Fan1 status changed\n");
+		break;
+	case EC_FAN2_STATUS_CHANGE_EVT:
+		dev_dbg_ratelimited(dev, "Fan2 status changed\n");
+		break;
+	case EC_FAN1_SPEED_CHANGE_EVT:
+		dev_dbg_ratelimited(dev, "Fan1 speed crossed low/high trip point\n");
+		break;
+	case EC_FAN2_SPEED_CHANGE_EVT:
+		dev_dbg_ratelimited(dev, "Fan2 speed crossed low/high trip point\n");
+		break;
+	case EC_NEW_LUT_SET_EVT:
+		dev_dbg_ratelimited(dev, "New LUT set\n");
+		break;
+	case EC_FAN_PROFILE_SWITCH_EVT:
+		dev_dbg_ratelimited(dev, "FAN Profile switched\n");
+		break;
+	case EC_THERMISTOR_1_THRESHOLD_CROSS_EVT:
+		dev_dbg_ratelimited(dev, "Thermistor 1 threshold crossed\n");
+		break;
+	case EC_THERMISTOR_2_THRESHOLD_CROSS_EVT:
+		dev_dbg_ratelimited(dev, "Thermistor 2 threshold crossed\n");
+		break;
+	case EC_THERMISTOR_3_THRESHOLD_CROSS_EVT:
+		dev_dbg_ratelimited(dev, "Thermistor 3 threshold crossed\n");
+		break;
+	case EC_RECOVERED_FROM_RESET_EVT:
+		dev_dbg_ratelimited(dev, "EC recovered from reset\n");
+		break;
+	default:
+		dev_notice_ratelimited(dev, "Unknown EC event: %d\n", val);
+		break;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int qcom_ec_sci_evt_control(struct device *dev, bool enable)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	return i2c_smbus_write_byte_data(client, EC_SCI_EVT_CONTROL_CMD, !!enable);
+}
+
+static int qcom_ec_fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)
+{
+	*state = EC_FAN_MAX_PWM;
+
+	return 0;
+}
+
+static int qcom_ec_fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)
+{
+	struct qcom_ec_cooling_dev *ec_cdev = cdev->devdata;
+
+	*state = ec_cdev->state;
+
+	return 0;
+}
+
+/*
+ * Fan Debug control command:
+ *
+ * Command Payload:
+ * --------------------------------------------------------------------------------------
+ * | Offset		| Name		| Description					|
+ * --------------------------------------------------------------------------------------
+ * | 0x00		| Command	| Fan control command				|
+ * --------------------------------------------------------------------------------------
+ * | 0x01		| Fan ID	| 0x1 : Fan 1					|
+ * |			|		| 0x2 : Fan 2					|
+ * --------------------------------------------------------------------------------------
+ * | 0x02		| Byte count = 4| Size of data to set fan speed			|
+ * --------------------------------------------------------------------------------------
+ * | 0x03		| Mode		| Bit 0: Debug Mode On/Off (0 - OFF, 1 - ON )	|
+ * |			|		| Bit 1: Fan On/Off (0 - Off, 1 - ON)		|
+ * |			|		| Bit 2: Debug Type (0 - RPM, 1 - PWM)		|
+ * --------------------------------------------------------------------------------------
+ * | 0x04 (LSB)	| Speed in RPM	| RPM value, if mode selected is RPM		|
+ * | 0x05		|		|						|
+ * --------------------------------------------------------------------------------------
+ * | 0x06		| Speed in PWM	| PWM value, if mode selected is PWM (0 - 255)	|
+ * ______________________________________________________________________________________
+ *
+ */
+static int qcom_ec_fan_debug_mode_off(struct qcom_ec_cooling_dev *ec_cdev)
+{
+	struct device *dev = ec_cdev->parent_dev;
+	struct i2c_client *client = to_i2c_client(dev);
+	u8 request[6] = { ec_cdev->fan_id, EC_FAN_SPEED_DATA_SIZE,
+			  EC_FAN_DEBUG_MODE_OFF, 0, 0, 0 };
+	int ret;
+
+	ret = i2c_smbus_write_i2c_block_data(client, EC_FAN_DBG_CONTROL_CMD,
+					     sizeof(request), request);
+	if (ret) {
+		dev_err(dev, "Failed to turn off fan%d debug mode: %d\n",
+			ec_cdev->fan_id, ret);
+	}
+
+	return ret;
+}
+
+static int qcom_ec_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+{
+	struct qcom_ec_cooling_dev *ec_cdev = cdev->devdata;
+	struct device *dev = ec_cdev->parent_dev;
+	struct i2c_client *client = to_i2c_client(dev);
+	u8 request[6] = { ec_cdev->fan_id, EC_FAN_SPEED_DATA_SIZE,
+			  EC_FAN_DEBUG_MODE_ON | EC_FAN_ON | EC_FAN_DEBUG_TYPE_PWM,
+			  0, 0, state };
+	int ret;
+
+	ret = i2c_smbus_write_i2c_block_data(client, EC_FAN_DBG_CONTROL_CMD,
+					     sizeof(request), request);
+	if (ret) {
+		dev_err(dev, "Failed to set fan pwm: %d\n", ret);
+		return ret;
+	}
+
+	ec_cdev->state = state;
+
+	return 0;
+}
+
+static const struct thermal_cooling_device_ops qcom_ec_thermal_ops = {
+	.get_max_state = qcom_ec_fan_get_max_state,
+	.get_cur_state = qcom_ec_fan_get_cur_state,
+	.set_cur_state = qcom_ec_fan_set_cur_state,
+};
+
+static int qcom_ec_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	return i2c_smbus_write_byte_data(client, EC_MODERN_STANDBY_CMD,
+					 EC_MODERN_STANDBY_EXIT);
+}
+
+static int qcom_ec_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	return i2c_smbus_write_byte_data(client, EC_MODERN_STANDBY_CMD,
+					 EC_MODERN_STANDBY_ENTER);
+}
+
+static int qcom_ec_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct qcom_ec *ec;
+	unsigned int i;
+	int ret;
+
+	ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL);
+	if (!ec)
+		return -ENOMEM;
+
+	ec->client = client;
+
+	ret = devm_request_threaded_irq(dev, client->irq, NULL, qcom_ec_irq,
+					IRQF_ONESHOT, "qcom_ec", ec);
+	if (ret < 0)
+		return ret;
+
+	i2c_set_clientdata(client, ec);
+
+	ret = qcom_ec_read_fw_version(dev);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to read EC firmware version\n");
+
+	ret = qcom_ec_sci_evt_control(dev, true);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to enable SCI events\n");
+
+	ret = qcom_ec_thermal_capabilities(dev);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to read thermal capabilities\n");
+
+	if (ec->thermal_cap.fan_cnt == 0) {
+		dev_warn(dev, FW_BUG "Failed to get fan count, firmware update required\n");
+		return 0;
+	}
+
+	ec->ec_cdev = devm_kcalloc(dev, ec->thermal_cap.fan_cnt, sizeof(*ec->ec_cdev), GFP_KERNEL);
+	if (!ec->ec_cdev)
+		return -ENOMEM;
+
+	for (i = 0; i < ec->thermal_cap.fan_cnt; i++) {
+		struct qcom_ec_cooling_dev *ec_cdev = &ec->ec_cdev[i];
+		char name[EC_FAN_NAME_SIZE];
+
+		scnprintf(name, sizeof(name), "qcom_ec_fan_%u", i);
+		ec_cdev->fan_id = i + 1;
+		ec_cdev->parent_dev = dev;
+
+		ec_cdev->cdev = devm_thermal_of_cooling_device_register(dev, NULL, name, ec_cdev,
+									&qcom_ec_thermal_ops);
+		if (IS_ERR(ec_cdev->cdev)) {
+			return dev_err_probe(dev, PTR_ERR(ec_cdev->cdev),
+					     "Failed to register fan%d cooling device\n", i);
+		}
+	}
+
+	return 0;
+}
+
+static void qcom_ec_remove(struct i2c_client *client)
+{
+	struct qcom_ec *ec = i2c_get_clientdata(client);
+	struct device *dev = &client->dev;
+	int ret;
+
+	ret = qcom_ec_sci_evt_control(dev, false);
+	if (ret < 0)
+		dev_err(dev, "Failed to disable SCI events: %d\n", ret);
+
+	for (int i = 0; i < ec->thermal_cap.fan_cnt; i++) {
+		struct qcom_ec_cooling_dev *ec_cdev = &ec->ec_cdev[i];
+
+		qcom_ec_fan_debug_mode_off(ec_cdev);
+	}
+}
+
+static const struct of_device_id qcom_ec_of_match[] = {
+	{ .compatible = "qcom,hamoa-crd-ec" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_ec_of_match);
+
+static const struct i2c_device_id qcom_ec_i2c_id_table[] = {
+	{ "qcom-hamoa-ec", },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, qcom_ec_i2c_id_table);
+
+static DEFINE_SIMPLE_DEV_PM_OPS(qcom_ec_pm_ops,
+		qcom_ec_suspend,
+		qcom_ec_resume);
+
+static struct i2c_driver qcom_ec_i2c_driver = {
+	.driver = {
+		.name = "qcom-hamoa-ec",
+		.of_match_table = qcom_ec_of_match,
+		.pm = &qcom_ec_pm_ops
+	},
+	.probe = qcom_ec_probe,
+	.remove = qcom_ec_remove,
+	.id_table = qcom_ec_i2c_id_table,
+};
+module_i2c_driver(qcom_ec_i2c_driver);
+
+MODULE_DESCRIPTION("QCOM Hamoa Embedded Controller");
+MODULE_LICENSE("GPL");

-- 
2.34.1