[PATCH] hwmon: Driver for Sensylink CTF2304

[Il Han <corone.il.han@gmail.com>]

The driver supports the Sensylink CTF2304.

Signed-off-by: Il Han <corone.il.han@gmail.com>
---
 Documentation/hwmon/ctf2304.rst |  41 +++
 Documentation/hwmon/index.rst   |   1 +
 drivers/hwmon/Kconfig           |  10 +
 drivers/hwmon/Makefile          |   1 +
 drivers/hwmon/ctf2304.c         | 522 ++++++++++++++++++++++++++++++++
 5 files changed, 575 insertions(+)
 create mode 100644 Documentation/hwmon/ctf2304.rst
 create mode 100644 drivers/hwmon/ctf2304.c

diff --git a/Documentation/hwmon/ctf2304.rst b/Documentation/hwmon/ctf2304.rst
new file mode 100644
index 000000000000..e1584524d612
--- /dev/null
+++ b/Documentation/hwmon/ctf2304.rst
@@ -0,0 +1,41 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver ctf2304
+=====================
+
+Supported chips:
+
+  * Sensylink CTF2304
+
+    Prefix: 'ctf2304'
+
+    Addresses scanned: -
+
+    Datasheet:
+
+Author: Il Han <corone.il.han@gmail.com>
+
+
+Description
+-----------
+
+This driver implements support for the Sensylink CTF2304 chip.
+
+The CTF2304 controls the speeds of up to four fans using four independent
+PWM outputs with local and remote temperature and remote voltage sensing.
+
+
+Sysfs entries
+-------------
+
+================== === =======================================================
+fan[1-4]_input     RO  fan tachometer speed in RPM
+fan[1-4]_target    RW  desired fan speed in RPM
+fan[1-4]_div       RW  sets the RPM range of the fan
+pwm[1-4]_enable    RW  regulator mode,
+                       0=auto temperature mode, 1=manual mode, 2=rpm mode
+pwm[1-4]           RW  read: current pwm duty cycle,
+                       write: target pwm duty cycle (0-255)
+in[0-7]_input      RO  measured output voltage
+temp[1-9]_input    RO  measured temperature
+================== === =======================================================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index f1fe75f596a5..a74cd43a3916 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -54,6 +54,7 @@ Hardware Monitoring Kernel Drivers
    coretemp
    corsair-cpro
    corsair-psu
+   ctf2304
    da9052
    da9055
    dell-smm-hwmon
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 5b3b76477b0e..da9fbb0f8af3 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -474,6 +474,16 @@ config SENSORS_CORSAIR_PSU
 	  This driver can also be built as a module. If so, the module
 	  will be called corsair-psu.
 
+config SENSORS_CTF2304
+	tristate "Sensylink CTF2304 sensor chip"
+	depends on I2C
+	help
+	  If you say yes here you get support for PWM and Fan Controller
+	  with temperature and voltage sensing.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called ctf2304.
+
 config SENSORS_DRIVETEMP
 	tristate "Hard disk drives with temperature sensors"
 	depends on SCSI && ATA
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 88712b5031c8..3742b52f032d 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -60,6 +60,7 @@ obj-$(CONFIG_SENSORS_BT1_PVT)	+= bt1-pvt.o
 obj-$(CONFIG_SENSORS_CORETEMP)	+= coretemp.o
 obj-$(CONFIG_SENSORS_CORSAIR_CPRO) += corsair-cpro.o
 obj-$(CONFIG_SENSORS_CORSAIR_PSU) += corsair-psu.o
+obj-$(CONFIG_SENSORS_CTF2304)	+= ctf2304.o
 obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o
 obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o
 obj-$(CONFIG_SENSORS_DELL_SMM)	+= dell-smm-hwmon.o
diff --git a/drivers/hwmon/ctf2304.c b/drivers/hwmon/ctf2304.c
new file mode 100644
index 000000000000..102c41957219
--- /dev/null
+++ b/drivers/hwmon/ctf2304.c
@@ -0,0 +1,522 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ctf2304.c - Part of lm_sensors, Linux kernel modules for hardware
+ *             monitoring.
+ *
+ * (C) 2023 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>
+
+/* CTF2304 registers */
+#define CTF2304_REG_LOCAL_TEMP		0x00
+#define CTF2304_REG_REMOTE_CHANNEL(ch)	(0x01 + (ch))
+#define CTF2304_REG_TACH_COUNT(ch)	(0x09 + (ch))
+#define CTF2304_REG_FAN_CONFIG1		0x10
+#define CTF2304_REG_FAN_CONFIG2		0x11
+#define CTF2304_REG_FAN_RPM_CTRL	0x18
+#define CTF2304_REG_PWMOUT(ch)		(0x40 + (ch))
+#define CTF2304_REG_TARGET_COUNT(ch)	(0x44 + (ch))
+
+/* Fan Configure1 register bits */
+#define CTF2304_FAN_CFG1_TRANGE		0x0400
+#define CTF2304_FAN_CFG1_MODE_MASK	(0x7)
+#define CTF2304_FAN_CFG1_MODE_SHIFT	7
+
+/* Fan Configure2 register bits */
+#define CTF2304_FAN_CFG2_MODE_MASK(ch)	(0x6 << (ch) * 4)
+#define CTF2304_FAN_CFG2_MODE_SHIFT(ch)	(1 + (ch) * 4)
+#define CTF2304_FAN_CFG2_DCY_MODE	0
+#define CTF2304_FAN_CFG2_RPM_MODE	1
+#define CTF2304_FAN_CFG2_TEMP_MODE	2
+#define CTF2304_FAN_CFG2_MAX_MODE	3
+
+/* Fan RPM CTRL register bits */
+#define CTF2304_FAN_DIV_MASK(ch)	(0x6 << (ch) * 4)
+#define CTF2304_FAN_DIV_SHIFT(ch)	(1 + (ch) * 4)
+
+#define CTF2304_VCC			3300
+
+#define FAN_RPM_MIN			480
+#define FAN_RPM_MAX			1966080
+
+#define FAN_COUNT_REG_MAX		0xFFF0
+
+#define TEMP_FROM_REG(reg, tr)		((tr) ? \
+					 (((((reg) & 0x7FF0) * 1000) >> 8) \
+					  + ((reg) >> 15) ? -64000 : 0) : \
+					 (((reg) * 1000) >> 8))
+#define VOLT_FROM_REG(reg, fs)		((((reg) >> 4) * (fs)) >> 12)
+#define DIV_FROM_REG(reg)		(1 << (reg))
+#define DIV_TO_REG(div)			((div == 8) ? 0x3 : \
+					 (div == 4) ? 0x2 : \
+					 (div == 1) ? 0x0 : 0x1)
+#define RPM_FROM_REG(reg)		(((reg) >> 4) ? \
+					 ((32768 * 60) / ((reg) >> 4)) : \
+					 FAN_RPM_MAX)
+#define RPM_TO_REG(rpm)			((rpm) ? \
+					 ((32768 * 60) / (rpm)) : \
+					 FAN_COUNT_REG_MAX)
+
+#define NR_CHANNEL			8
+#define NR_FAN_CHANNEL			4
+
+/*
+ * Client data (each client gets its own)
+ */
+struct ctf2304_data {
+	struct i2c_client *client;
+	struct mutex update_lock;
+	char valid; /* zero until following fields are valid */
+	unsigned long last_updated; /* in jiffies */
+
+	/* register values */
+	u16 local_temp;
+	u16 remote_channel[NR_CHANNEL];
+	u16 tach[NR_FAN_CHANNEL];
+	u16 fan_config1;
+	u16 fan_config2;
+	u16 fan_rpm_ctrl;
+	u16 pwm[NR_FAN_CHANNEL];
+	u16 target_count[NR_FAN_CHANNEL];
+};
+
+static struct ctf2304_data *ctf2304_update_device(struct device *dev)
+{
+	struct ctf2304_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	struct ctf2304_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_word_swapped(client,
+				CTF2304_REG_LOCAL_TEMP);
+		if (rv < 0)
+			goto abort;
+		data->local_temp = rv;
+
+		for (i = 0; i < NR_CHANNEL; i++) {
+			rv = i2c_smbus_read_word_swapped(client,
+					CTF2304_REG_REMOTE_CHANNEL(i));
+			if (rv < 0)
+				goto abort;
+			data->remote_channel[i] = rv;
+		}
+
+		rv = i2c_smbus_read_word_swapped(client,
+				CTF2304_REG_FAN_CONFIG1);
+		if (rv < 0)
+			goto abort;
+		data->fan_config1 = rv;
+		rv = i2c_smbus_read_word_swapped(client,
+				CTF2304_REG_FAN_CONFIG2);
+		if (rv < 0)
+			goto abort;
+		data->fan_config2 = rv;
+		rv = i2c_smbus_read_word_swapped(client,
+				CTF2304_REG_FAN_RPM_CTRL);
+		if (rv < 0)
+			goto abort;
+		data->fan_rpm_ctrl = rv;
+
+		for (i = 0; i < NR_FAN_CHANNEL; i++) {
+			rv = i2c_smbus_read_word_swapped(client,
+					CTF2304_REG_TACH_COUNT(i));
+			if (rv < 0)
+				goto abort;
+			data->tach[i] = rv;
+			rv = i2c_smbus_read_word_swapped(client,
+					CTF2304_REG_PWMOUT(i));
+			if (rv < 0)
+				goto abort;
+			data->pwm[i] = rv;
+			rv = i2c_smbus_read_word_swapped(client,
+					CTF2304_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 data;
+}
+
+static int ctf2304_read_temp(struct device *dev, u32 attr, int channel,
+			     long *val)
+{
+	struct ctf2304_data *data = ctf2304_update_device(dev);
+	u16 reg;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		if (channel == 0)
+			reg = data->local_temp;
+		else
+			reg = data->remote_channel[channel-1];
+		*val = TEMP_FROM_REG(reg, (data->fan_config1
+					   & CTF2304_FAN_CFG1_TRANGE));
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int get_full_scale(u16 config)
+{
+	int full_scale;
+	u8 bits;
+
+	bits = (config >> CTF2304_FAN_CFG1_MODE_SHIFT)
+	       & CTF2304_FAN_CFG1_MODE_MASK;
+
+	if (bits == 0x0)
+		full_scale = 2560;
+	else if (bits == 0x1)
+		full_scale = CTF2304_VCC;
+	else if (bits == 0x2)
+		full_scale = 4096;
+	else if (bits == 0x3)
+		full_scale = 2048;
+	else if (bits == 0x4)
+		full_scale = 1024;
+	else if (bits == 0x5)
+		full_scale = 512;
+	else
+		full_scale = 256;
+
+	return full_scale;
+}
+
+static int ctf2304_read_in(struct device *dev, u32 attr, int channel,
+			   long *val)
+{
+	struct ctf2304_data *data = ctf2304_update_device(dev);
+
+	switch (attr) {
+	case hwmon_temp_input:
+		*val = VOLT_FROM_REG(data->remote_channel[channel],
+				     get_full_scale(data->fan_config1));
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ctf2304_read_fan(struct device *dev, u32 attr, int channel,
+			    long *val)
+{
+	struct ctf2304_data *data = ctf2304_update_device(dev);
+	u8 bits;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	switch (attr) {
+	case hwmon_fan_input:
+		if (data->tach[channel] == FAN_COUNT_REG_MAX)
+			*val = 0;
+		else
+			*val = RPM_FROM_REG(data->tach[channel]);
+		return 0;
+	case hwmon_fan_target:
+		*val = RPM_FROM_REG(data->target_count[channel]);
+		return 0;
+	case hwmon_fan_div:
+		bits = (data->fan_rpm_ctrl & CTF2304_FAN_DIV_MASK(channel))
+		       >> CTF2304_FAN_DIV_SHIFT(channel);
+		*val = DIV_FROM_REG(bits);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ctf2304_write_fan(struct device *dev, u32 attr, int channel,
+			     long val)
+{
+	struct ctf2304_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	int target_count;
+	int err = 0;
+
+	mutex_lock(&data->update_lock);
+
+	switch (attr) {
+	case hwmon_fan_target:
+		val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
+		target_count = RPM_TO_REG(val);
+		target_count = clamp_val(target_count, 0x1, 0xFFF);
+		data->target_count[channel] = target_count << 4;
+		err = i2c_smbus_write_word_swapped(client,
+				CTF2304_REG_TARGET_COUNT(channel),
+				data->target_count[channel]);
+		break;
+	case hwmon_fan_div:
+		data->fan_rpm_ctrl = (data->fan_rpm_ctrl
+				      & ~CTF2304_FAN_DIV_MASK(channel))
+				     | (DIV_TO_REG(val)
+					<< CTF2304_FAN_DIV_SHIFT(channel));
+		err = i2c_smbus_write_word_swapped(client,
+				CTF2304_REG_FAN_RPM_CTRL,
+				data->fan_rpm_ctrl);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return err;
+}
+
+static int ctf2304_read_pwm(struct device *dev, u32 attr, int channel,
+			    long *val)
+{
+	struct ctf2304_data *data = ctf2304_update_device(dev);
+	u8 bits;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	switch (attr) {
+	case hwmon_pwm_input:
+		*val = data->pwm[channel] >> 8;
+		return 0;
+	case hwmon_pwm_enable:
+		bits = (data->fan_config2
+			& CTF2304_FAN_CFG2_MODE_MASK(channel))
+		       >> CTF2304_FAN_CFG2_MODE_SHIFT(channel);
+		if (bits == CTF2304_FAN_CFG2_RPM_MODE)
+			*val = 2;
+		else if (bits == CTF2304_FAN_CFG2_DCY_MODE)
+			*val = 1;
+		else
+			*val = 0;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ctf2304_write_pwm(struct device *dev, u32 attr, int channel,
+			     long val)
+{
+	struct ctf2304_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	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] = (data->pwm[channel] & 0xFF) | (val << 8);
+		err = i2c_smbus_write_word_swapped(client,
+						   CTF2304_REG_PWMOUT(channel),
+						   data->pwm[channel]);
+		break;
+	case hwmon_pwm_enable:
+		if (val == 0) {
+			data->fan_config2 = (data->fan_config2
+					     & ~CTF2304_FAN_CFG2_MODE_MASK(channel))
+					    | (CTF2304_FAN_CFG2_TEMP_MODE
+					       << CTF2304_FAN_CFG2_MODE_SHIFT(channel));
+		} else if (val == 1) {
+			data->fan_config2 = (data->fan_config2
+					     & ~CTF2304_FAN_CFG2_MODE_MASK(channel))
+					    | (CTF2304_FAN_CFG2_DCY_MODE
+					       << CTF2304_FAN_CFG2_MODE_SHIFT(channel));
+		} else if (val == 2) {
+			data->fan_config2 = (data->fan_config2
+					     & ~CTF2304_FAN_CFG2_MODE_MASK(channel))
+					    | (CTF2304_FAN_CFG2_RPM_MODE
+					       << CTF2304_FAN_CFG2_MODE_SHIFT(channel));
+		} else {
+			err = -EINVAL;
+			break;
+		}
+		err = i2c_smbus_write_word_swapped(client,
+						   CTF2304_REG_FAN_CONFIG2,
+						   data->fan_config2);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return err;
+}
+
+static int ctf2304_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_temp:
+		return ctf2304_read_temp(dev, attr, channel, val);
+	case hwmon_in:
+		return ctf2304_read_in(dev, attr, channel, val);
+	case hwmon_fan:
+		return ctf2304_read_fan(dev, attr, channel, val);
+	case hwmon_pwm:
+		return ctf2304_read_pwm(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ctf2304_write(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_fan:
+		return ctf2304_write_fan(dev, attr, channel, val);
+	case hwmon_pwm:
+		return ctf2304_write_pwm(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t ctf2304_is_visible(const void *data,
+				  enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_temp:
+	case hwmon_in:
+		return 0444;
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+			return 0444;
+		case hwmon_fan_target:
+		case hwmon_fan_div:
+			return 0644;
+		default:
+			break;
+		}
+		break;
+	case hwmon_pwm:
+		return 0644;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static const struct hwmon_channel_info *ctf2304_info[] = {
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT),
+	HWMON_CHANNEL_INFO(in,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT),
+	HWMON_CHANNEL_INFO(fan,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_DIV),
+	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),
+	NULL
+};
+
+static const struct hwmon_ops ctf2304_hwmon_ops = {
+	.is_visible = ctf2304_is_visible,
+	.read = ctf2304_read,
+	.write = ctf2304_write,
+};
+
+static const struct hwmon_chip_info ctf2304_chip_info = {
+	.ops = &ctf2304_hwmon_ops,
+	.info = ctf2304_info,
+};
+
+static int ctf2304_probe(struct i2c_client *client)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct device *dev = &client->dev;
+	struct ctf2304_data *data;
+	struct device *hwmon_dev;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	data = devm_kzalloc(dev, sizeof(struct ctf2304_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+	mutex_init(&data->update_lock);
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 data,
+							 &ctf2304_chip_info,
+							 NULL);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id ctf2304_id[] = {
+	{ "ctf2304", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ctf2304_id);
+
+static struct i2c_driver ctf2304_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "ctf2304",
+	},
+	.probe_new	= ctf2304_probe,
+	.id_table	= ctf2304_id,
+};
+
+module_i2c_driver(ctf2304_driver);
+
+MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
+MODULE_DESCRIPTION("CTF2304 sensor driver");
+MODULE_LICENSE("GPL");
-- 
2.26.3