recipes-kernel/linux/files/0001-hwmon-mp2981-driver.patch

From f5bee334b0a56b8c69f5d82b1ebf513d94e6ede0 Mon Sep 17 00:00:00 2001
From: Avery Yang <avery.zl.yang@fii-na.corp-partner.google.com>
Date: Tue, 5 Nov 2024 19:26:02 +0800
Subject: [PATCH] hwmon mp2981 driver

Signed-off-by: Avery Yang <avery.zl.yang@fii-na.corp-partner.google.com>
---
 drivers/hwmon/Kconfig  |  10 ++
 drivers/hwmon/Makefile |   1 +
 drivers/hwmon/mp2981.c | 212 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 223 insertions(+)
 create mode 100644 drivers/hwmon/mp2981.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index d48268e9cb63..136b37e1d50b 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1386,6 +1386,16 @@ config SENSORS_LM95245
 	  This driver can also be built as a module. If so, the module
 	  will be called lm95245.
 
+config SENSORS_MP2981
+        tristate "Monolithic Power System MP2981"
+        depends on I2C
+        select REGMAP_I2C
+        help
+          If you say yes here you get support for MP2981 temperature sensor.
+
+          This driver can also be built as a module. If so, the module
+          will be called mp2981.
+
 config SENSORS_PC87360
 	tristate "National Semiconductor PC87360 family"
 	depends on !PPC
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index bfe3f3c919a4..b8e8df35cb98 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -144,6 +144,7 @@ obj-$(CONFIG_SENSORS_MAX31760)  += max31760.o
 obj-$(CONFIG_SENSORS_MAX31790)	+= max31790.o
 obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
 obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
+obj-$(CONFIG_SENSORS_MP2981)   += mp2981.o
 obj-$(CONFIG_SENSORS_TC654)	+= tc654.o
 obj-$(CONFIG_SENSORS_TPS23861)	+= tps23861.o
 obj-$(CONFIG_SENSORS_MLXREG_FAN) += mlxreg-fan.o
diff --git a/drivers/hwmon/mp2981.c b/drivers/hwmon/mp2981.c
new file mode 100644
index 000000000000..6dd9c97c3fea
--- /dev/null
+++ b/drivers/hwmon/mp2981.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for MPS Digital LLC Controllers(MP2981)
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+/* MP2981 telemetry register */
+#define MP2981_VIN_REG	0x88
+#define MP2981_VOUT_REG	0x8B
+#define MP2981_IOUT_REG	0x8C
+#define MP2981_TEMP_REG	0x8D
+#define MP2981_POUT_REG	0x96
+
+#define MP2981_VIN_UINT	125
+#define MP2981_VOUT_UINT	625
+#define MP2981_VOUT_DIV	10
+#define MP2981_IOUT_UINT	500
+#define MP2981_TEMP_UINT	1000
+#define MP2981_POUT_UINT	1000000
+
+/* Each client has this additional data */
+struct mp2981_data {
+	struct i2c_client *client;
+	/* lock for preventing concurrency issue */
+	struct mutex lock;
+};
+
+static umode_t mp2981_is_visible(const void *data, enum hwmon_sensor_types type,
+				 u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_temp:
+	case hwmon_in:
+	case hwmon_curr:
+	case hwmon_power:
+		return 0444;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int mp2981_read(struct device *dev, enum hwmon_sensor_types type,
+		       u32 attr, int channel, long *val)
+{
+	int ret;
+	struct mp2981_data *data;
+
+	data = dev_get_drvdata(dev);
+	if (!data) {
+		dev_err(dev, "failed to get driver data\n");
+		return -ENOMEM;
+	}
+
+	mutex_lock(&data->lock);
+
+	switch (type) {
+	case hwmon_in:
+		ret = i2c_smbus_write_byte_data(data->client, 0, 0);
+		if (ret < 0) {
+			dev_err(dev, "failed to change page, errno = %d\n", ret);
+			break;
+		}
+
+		ret = i2c_smbus_read_word_data(data->client, channel == 0 ?
+								MP2981_VIN_REG : MP2981_VOUT_REG);
+		if (ret < 0) {
+			dev_err(dev, "failed to read %s, errno = %d\n", channel == 0 ?
+									"vin" : "vout", ret);
+			break;
+		}
+
+		*val = channel == 0 ? (ret & GENMASK(9, 0)) * MP2981_VIN_UINT :
+					DIV_ROUND_CLOSEST((ret & GENMASK(8, 0)) * MP2981_VOUT_UINT,
+							  MP2981_VOUT_DIV);
+		break;
+	case hwmon_temp:
+		ret = i2c_smbus_write_byte_data(data->client, 0, 0);
+		if (ret < 0) {
+			dev_err(dev, "failed to change page, errno = %d\n", ret);
+			break;
+		}
+
+		ret = i2c_smbus_read_byte_data(data->client, MP2981_TEMP_REG);
+		if (ret < 0) {
+			dev_err(dev, "failed to read temp, errno = %d\n", ret);
+			break;
+		}
+
+		*val = ret * MP2981_TEMP_UINT;
+		break;
+	case hwmon_curr:
+		ret = i2c_smbus_write_byte_data(data->client, 0, 0);
+		if (ret < 0) {
+			dev_err(dev, "failed to change page, errno = %d\n", ret);
+			break;
+		}
+
+		ret = i2c_smbus_read_word_data(data->client, MP2981_IOUT_REG);
+		if (ret < 0) {
+			dev_err(dev, "failed to read iout, errno = %d\n", ret);
+			break;
+		}
+
+		*val = (ret & GENMASK(9, 0)) * MP2981_IOUT_UINT;
+		break;
+	case hwmon_power:
+		ret = i2c_smbus_write_byte_data(data->client, 0, 0);
+		if (ret < 0) {
+			dev_err(dev, "failed to change page, errno = %d\n", ret);
+			break;
+		}
+
+		ret = i2c_smbus_read_word_data(data->client, MP2981_POUT_REG);
+		if (ret < 0) {
+			dev_err(dev, "failed to read pout, errno = %d\n", ret);
+			break;
+		}
+
+		*val = (ret & GENMASK(10, 0)) * MP2981_POUT_UINT;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	mutex_unlock(&data->lock);
+	return ret;
+}
+
+static const struct hwmon_channel_info *mp2981_info[] = {
+	HWMON_CHANNEL_INFO(in, HWMON_I_INPUT, HWMON_I_INPUT),
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+	HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT),
+	HWMON_CHANNEL_INFO(power, HWMON_P_INPUT),
+	NULL
+};
+
+static const struct hwmon_ops mp2981_hwmon_ops = {
+	.is_visible = mp2981_is_visible,
+	.read = mp2981_read,
+};
+
+static const struct hwmon_chip_info mp2981_chip_info = {
+	.ops = &mp2981_hwmon_ops,
+	.info = mp2981_info,
+};
+
+static int mp2981_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device *hwmon_dev;
+	struct mp2981_data *data;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+				     I2C_FUNC_SMBUS_WORD_DATA)) {
+		dev_err(dev, "check failed, smbus byte and/or word data not supported!\n");
+		return -ENODEV;
+	}
+
+	data = devm_kzalloc(dev, sizeof(struct mp2981_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	mutex_init(&data->lock);
+	data->client = client;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 data, &mp2981_chip_info,
+							 NULL);
+	if (IS_ERR(hwmon_dev)) {
+		dev_err(dev, "unable to register mp2981 hwmon device\n");
+		return PTR_ERR(hwmon_dev);
+	}
+
+	dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
+
+	return 0;
+}
+
+static const struct i2c_device_id mp2981_ids[] = {
+	{"mp2981", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, mp2981_ids);
+
+static const struct of_device_id __maybe_unused mp2981_of_match[] = {
+	{.compatible = "mps,mp2981"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, mp2981_of_match);
+
+static struct i2c_driver mp2981_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "mp2981",
+		.of_match_table = mp2981_of_match,
+	},
+	.probe_new	= mp2981_probe,
+	.id_table	= mp2981_ids,
+};
+module_i2c_driver(mp2981_driver);
+
+MODULE_AUTHOR("Noah Wang <Noah.Wang@monolithicpower.com>");
+MODULE_DESCRIPTION("MP2981 driver");
+MODULE_LICENSE("GPL");
-- 
2.34.1