Project import generated by Copybara.

GitOrigin-RevId: 01d50fa62e5b56daa6f2ebc55cf59de9c7b4fb0a
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
new file mode 100644
index 0000000..117fb79
--- /dev/null
+++ b/drivers/hwmon/max31790.c
@@ -0,0 +1,505 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * max31790.c - Part of lm_sensors, Linux kernel modules for hardware
+ *             monitoring.
+ *
+ * (C) 2015 by Il Han <corone.il.han@gmail.com>
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+/* MAX31790 registers */
+#define MAX31790_REG_GLOBAL_CONFIG	0x00
+#define MAX31790_REG_FAN_CONFIG(ch)	(0x02 + (ch))
+#define MAX31790_REG_FAN_DYNAMICS(ch)	(0x08 + (ch))
+#define MAX31790_REG_FAN_FAULT_STATUS2	0x10
+#define MAX31790_REG_FAN_FAULT_STATUS1	0x11
+#define MAX31790_REG_TACH_COUNT(ch)	(0x18 + (ch) * 2)
+#define MAX31790_REG_PWM_DUTY_CYCLE(ch)	(0x30 + (ch) * 2)
+#define MAX31790_REG_PWMOUT(ch)		(0x40 + (ch) * 2)
+#define MAX31790_REG_TARGET_COUNT(ch)	(0x50 + (ch) * 2)
+
+/* Fan Config register bits */
+#define MAX31790_FAN_CFG_RPM_MODE	0x80
+#define MAX31790_FAN_CFG_TACH_INPUT_EN	0x08
+#define MAX31790_FAN_CFG_TACH_INPUT	0x01
+
+/* Fan Dynamics register bits */
+#define MAX31790_FAN_DYN_SR_SHIFT	5
+#define MAX31790_FAN_DYN_SR_MASK	0xE0
+#define SR_FROM_REG(reg)		(((reg) & MAX31790_FAN_DYN_SR_MASK) \
+					 >> MAX31790_FAN_DYN_SR_SHIFT)
+
+#define FAN_RPM_MIN			120
+#define FAN_RPM_MAX			7864320
+
+#define RPM_FROM_REG(reg, sr)		(((reg) >> 4) ? \
+					 ((60 * (sr) * 8192) / ((reg) >> 4)) : \
+					 FAN_RPM_MAX)
+#define RPM_TO_REG(rpm, sr)		((60 * (sr) * 8192) / ((rpm) * 2))
+
+#define NR_CHANNEL			6
+
+/*
+ * Client data (each client gets its own)
+ */
+struct max31790_data {
+	struct i2c_client *client;
+	struct mutex update_lock;
+	bool valid; /* zero until following fields are valid */
+	unsigned long last_updated; /* in jiffies */
+
+	/* register values */
+	u8 fan_config[NR_CHANNEL];
+	u8 fan_dynamics[NR_CHANNEL];
+	u16 fault_status;
+	u16 tach[NR_CHANNEL * 2];
+	u16 pwm[NR_CHANNEL];
+	u16 target_count[NR_CHANNEL];
+};
+
+static struct max31790_data *max31790_update_device(struct device *dev)
+{
+	struct max31790_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	struct max31790_data *ret = data;
+	int i;
+	int rv;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+		rv = i2c_smbus_read_byte_data(client,
+				MAX31790_REG_FAN_FAULT_STATUS1);
+		if (rv < 0)
+			goto abort;
+		data->fault_status = rv & 0x3F;
+
+		rv = i2c_smbus_read_byte_data(client,
+				MAX31790_REG_FAN_FAULT_STATUS2);
+		if (rv < 0)
+			goto abort;
+		data->fault_status |= (rv & 0x3F) << 6;
+
+		for (i = 0; i < NR_CHANNEL; i++) {
+			rv = i2c_smbus_read_word_swapped(client,
+					MAX31790_REG_TACH_COUNT(i));
+			if (rv < 0)
+				goto abort;
+			data->tach[i] = rv;
+
+			if (data->fan_config[i]
+			    & MAX31790_FAN_CFG_TACH_INPUT) {
+				rv = i2c_smbus_read_word_swapped(client,
+					MAX31790_REG_TACH_COUNT(NR_CHANNEL
+								+ i));
+				if (rv < 0)
+					goto abort;
+				data->tach[NR_CHANNEL + i] = rv;
+			} else {
+				rv = i2c_smbus_read_word_swapped(client,
+						MAX31790_REG_PWMOUT(i));
+				if (rv < 0)
+					goto abort;
+				data->pwm[i] = rv;
+
+				rv = i2c_smbus_read_word_swapped(client,
+						MAX31790_REG_TARGET_COUNT(i));
+				if (rv < 0)
+					goto abort;
+				data->target_count[i] = rv;
+			}
+		}
+
+		data->last_updated = jiffies;
+		data->valid = true;
+	}
+	goto done;
+
+abort:
+	data->valid = false;
+	ret = ERR_PTR(rv);
+
+done:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };
+
+static u8 get_tach_period(u8 fan_dynamics)
+{
+	return tach_period[SR_FROM_REG(fan_dynamics)];
+}
+
+static u8 bits_for_tach_period(int rpm)
+{
+	u8 bits;
+
+	if (rpm < 500)
+		bits = 0x0;
+	else if (rpm < 1000)
+		bits = 0x1;
+	else if (rpm < 2000)
+		bits = 0x2;
+	else if (rpm < 4000)
+		bits = 0x3;
+	else if (rpm < 8000)
+		bits = 0x4;
+	else
+		bits = 0x5;
+
+	return bits;
+}
+
+static int max31790_read_fan(struct device *dev, u32 attr, int channel,
+			     long *val)
+{
+	struct max31790_data *data = max31790_update_device(dev);
+	int sr, rpm;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	switch (attr) {
+	case hwmon_fan_input:
+		sr = get_tach_period(data->fan_dynamics[channel]);
+		rpm = RPM_FROM_REG(data->tach[channel], sr);
+		*val = rpm;
+		return 0;
+	case hwmon_fan_target:
+		sr = get_tach_period(data->fan_dynamics[channel]);
+		rpm = RPM_FROM_REG(data->target_count[channel], sr);
+		*val = rpm;
+		return 0;
+	case hwmon_fan_fault:
+		*val = !!(data->fault_status & (1 << channel));
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int max31790_write_fan(struct device *dev, u32 attr, int channel,
+			      long val)
+{
+	struct max31790_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	int target_count;
+	int err = 0;
+	u8 bits;
+	int sr;
+
+	mutex_lock(&data->update_lock);
+
+	switch (attr) {
+	case hwmon_fan_target:
+		val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
+		bits = bits_for_tach_period(val);
+		data->fan_dynamics[channel] =
+			((data->fan_dynamics[channel] &
+			  ~MAX31790_FAN_DYN_SR_MASK) |
+			 (bits << MAX31790_FAN_DYN_SR_SHIFT));
+		err = i2c_smbus_write_byte_data(client,
+					MAX31790_REG_FAN_DYNAMICS(channel),
+					data->fan_dynamics[channel]);
+		if (err < 0)
+			break;
+
+		sr = get_tach_period(data->fan_dynamics[channel]);
+		target_count = RPM_TO_REG(val, sr);
+		target_count = clamp_val(target_count, 0x1, 0x7FF);
+
+		data->target_count[channel] = target_count << 5;
+
+		err = i2c_smbus_write_word_swapped(client,
+					MAX31790_REG_TARGET_COUNT(channel),
+					data->target_count[channel]);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return err;
+}
+
+static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
+{
+	const struct max31790_data *data = _data;
+	u8 fan_config = data->fan_config[channel % NR_CHANNEL];
+
+	switch (attr) {
+	case hwmon_fan_input:
+	case hwmon_fan_fault:
+		if (channel < NR_CHANNEL ||
+		    (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
+			return 0444;
+		return 0;
+	case hwmon_fan_target:
+		if (channel < NR_CHANNEL &&
+		    !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
+			return 0644;
+		return 0;
+	default:
+		return 0;
+	}
+}
+
+static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
+			     long *val)
+{
+	struct max31790_data *data = max31790_update_device(dev);
+	u8 fan_config;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	fan_config = data->fan_config[channel];
+
+	switch (attr) {
+	case hwmon_pwm_input:
+		*val = data->pwm[channel] >> 8;
+		return 0;
+	case hwmon_pwm_enable:
+		if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
+			*val = 2;
+		else if (fan_config & MAX31790_FAN_CFG_TACH_INPUT_EN)
+			*val = 1;
+		else
+			*val = 0;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
+			      long val)
+{
+	struct max31790_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	u8 fan_config;
+	int err = 0;
+
+	mutex_lock(&data->update_lock);
+
+	switch (attr) {
+	case hwmon_pwm_input:
+		if (val < 0 || val > 255) {
+			err = -EINVAL;
+			break;
+		}
+		data->pwm[channel] = val << 8;
+		err = i2c_smbus_write_word_swapped(client,
+						   MAX31790_REG_PWMOUT(channel),
+						   data->pwm[channel]);
+		break;
+	case hwmon_pwm_enable:
+		fan_config = data->fan_config[channel];
+		if (val == 0) {
+			fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN |
+					MAX31790_FAN_CFG_RPM_MODE);
+		} else if (val == 1) {
+			fan_config = (fan_config |
+				      MAX31790_FAN_CFG_TACH_INPUT_EN) &
+				     ~MAX31790_FAN_CFG_RPM_MODE;
+		} else if (val == 2) {
+			fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN |
+				      MAX31790_FAN_CFG_RPM_MODE;
+		} else {
+			err = -EINVAL;
+			break;
+		}
+		data->fan_config[channel] = fan_config;
+		err = i2c_smbus_write_byte_data(client,
+					MAX31790_REG_FAN_CONFIG(channel),
+					fan_config);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return err;
+}
+
+static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
+{
+	const struct max31790_data *data = _data;
+	u8 fan_config = data->fan_config[channel];
+
+	switch (attr) {
+	case hwmon_pwm_input:
+	case hwmon_pwm_enable:
+		if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
+			return 0644;
+		return 0;
+	default:
+		return 0;
+	}
+}
+
+static int max31790_read(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_fan:
+		return max31790_read_fan(dev, attr, channel, val);
+	case hwmon_pwm:
+		return max31790_read_pwm(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int max31790_write(struct device *dev, enum hwmon_sensor_types type,
+			  u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_fan:
+		return max31790_write_fan(dev, attr, channel, val);
+	case hwmon_pwm:
+		return max31790_write_pwm(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t max31790_is_visible(const void *data,
+				   enum hwmon_sensor_types type,
+				   u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_fan:
+		return max31790_fan_is_visible(data, attr, channel);
+	case hwmon_pwm:
+		return max31790_pwm_is_visible(data, attr, channel);
+	default:
+		return 0;
+	}
+}
+
+static const struct hwmon_channel_info *max31790_info[] = {
+	HWMON_CHANNEL_INFO(fan,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_FAULT,
+			   HWMON_F_INPUT | HWMON_F_FAULT),
+	HWMON_CHANNEL_INFO(pwm,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
+	NULL
+};
+
+static const struct hwmon_ops max31790_hwmon_ops = {
+	.is_visible = max31790_is_visible,
+	.read = max31790_read,
+	.write = max31790_write,
+};
+
+static const struct hwmon_chip_info max31790_chip_info = {
+	.ops = &max31790_hwmon_ops,
+	.info = max31790_info,
+};
+
+static int max31790_init_client(struct i2c_client *client,
+				struct max31790_data *data)
+{
+	int i, rv;
+
+	for (i = 0; i < NR_CHANNEL; i++) {
+		rv = i2c_smbus_read_byte_data(client,
+				MAX31790_REG_FAN_CONFIG(i));
+		if (rv < 0)
+			return rv;
+		data->fan_config[i] = rv;
+
+		rv = i2c_smbus_read_byte_data(client,
+				MAX31790_REG_FAN_DYNAMICS(i));
+		if (rv < 0)
+			return rv;
+		data->fan_dynamics[i] = rv;
+	}
+
+	return 0;
+}
+
+static int max31790_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct device *dev = &client->dev;
+	struct max31790_data *data;
+	struct device *hwmon_dev;
+	int err;
+
+	if (!i2c_check_functionality(adapter,
+			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+	mutex_init(&data->update_lock);
+
+	/*
+	 * Initialize the max31790 chip
+	 */
+	err = max31790_init_client(client, data);
+	if (err)
+		return err;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 data,
+							 &max31790_chip_info,
+							 NULL);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id max31790_id[] = {
+	{ "max31790", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max31790_id);
+
+static struct i2c_driver max31790_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.probe		= max31790_probe,
+	.driver = {
+		.name	= "max31790",
+	},
+	.id_table	= max31790_id,
+};
+
+module_i2c_driver(max31790_driver);
+
+MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
+MODULE_DESCRIPTION("MAX31790 sensor driver");
+MODULE_LICENSE("GPL");