[linux-2.6-block.git] / drivers / hwmon / emc2305.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Hardware monitoring driver for EMC2305 fan controller
 *
 * Copyright (C) 2022 Nvidia Technologies Ltd.
 */

#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/platform_data/emc2305.h>
#include <linux/thermal.h>

static const unsigned short
emc2305_normal_i2c[] = { 0x27, 0x2c, 0x2d, 0x2e, 0x2f, 0x4c, 0x4d, I2C_CLIENT_END };

#define EMC2305_REG_DRIVE_FAIL_STATUS	0x27
#define EMC2305_REG_VENDOR		0xfe
#define EMC2305_FAN_MAX			0xff
#define EMC2305_FAN_MIN			0x00
#define EMC2305_FAN_MAX_STATE		10
#define EMC2305_DEVICE			0x34
#define EMC2305_VENDOR			0x5d
#define EMC2305_REG_PRODUCT_ID		0xfd
#define EMC2305_TACH_REGS_UNUSE_BITS	3
#define EMC2305_TACH_CNT_MULTIPLIER	0x02
#define EMC2305_TACH_RANGE_MIN		480

#define EMC2305_PWM_DUTY2STATE(duty, max_state, pwm_max) \
	DIV_ROUND_CLOSEST((duty) * (max_state), (pwm_max))
#define EMC2305_PWM_STATE2DUTY(state, max_state, pwm_max) \
	DIV_ROUND_CLOSEST((state) * (pwm_max), (max_state))

/*
 * Factor by equations [2] and [3] from data sheet; valid for fans where the number of edges
 * equal (poles * 2 + 1).
 */
#define EMC2305_RPM_FACTOR		3932160

#define EMC2305_REG_FAN_DRIVE(n)	(0x30 + 0x10 * (n))
#define EMC2305_REG_FAN_MIN_DRIVE(n)	(0x38 + 0x10 * (n))
#define EMC2305_REG_FAN_TACH(n)		(0x3e + 0x10 * (n))

enum emc230x_product_id {
	EMC2305 = 0x34,
	EMC2303 = 0x35,
	EMC2302 = 0x36,
	EMC2301 = 0x37,
};

static const struct i2c_device_id emc2305_ids[] = {
	{ "emc2305", 0 },
	{ "emc2303", 0 },
	{ "emc2302", 0 },
	{ "emc2301", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, emc2305_ids);

/**
 * struct emc2305_cdev_data - device-specific cooling device state
 * @cdev: cooling device
 * @cur_state: cooling current state
 * @last_hwmon_state: last cooling state updated by hwmon subsystem
 * @last_thermal_state: last cooling state updated by thermal subsystem
 *
 * The 'last_hwmon_state' and 'last_thermal_state' fields are provided to support fan low limit
 * speed feature. The purpose of this feature is to provides ability to limit fan speed
 * according to some system wise considerations, like absence of some replaceable units (PSU or
 * line cards), high system ambient temperature, unreliable transceivers temperature sensing or
 * some other factors which indirectly impacts system's airflow
 * Fan low limit feature is supported through 'hwmon' interface: 'hwmon' 'pwm' attribute is
 * used for setting low limit for fan speed in case 'thermal' subsystem is configured in
 * kernel. In this case setting fan speed through 'hwmon' will never let the 'thermal'
 * subsystem to select a lower duty cycle than the duty cycle selected with the 'pwm'
 * attribute.
 * From other side, fan speed is to be updated in hardware through 'pwm' only in case the
 * requested fan speed is above last speed set by 'thermal' subsystem, otherwise requested fan
 * speed will be just stored with no PWM update.
 */
struct emc2305_cdev_data {
	struct thermal_cooling_device *cdev;
	unsigned int cur_state;
	unsigned long last_hwmon_state;
	unsigned long last_thermal_state;
};

/**
 * struct emc2305_data - device-specific data
 * @client: i2c client
 * @hwmon_dev: hwmon device
 * @max_state: maximum cooling state of the cooling device
 * @pwm_num: number of PWM channels
 * @pwm_separate: separate PWM settings for every channel
 * @pwm_min: array of minimum PWM per channel
 * @cdev_data: array of cooling devices data
 */
struct emc2305_data {
	struct i2c_client *client;
	struct device *hwmon_dev;
	u8 max_state;
	u8 pwm_num;
	bool pwm_separate;
	u8 pwm_min[EMC2305_PWM_MAX];
	struct emc2305_cdev_data cdev_data[EMC2305_PWM_MAX];
};

static char *emc2305_fan_name[] = {
	"emc2305_fan",
	"emc2305_fan1",
	"emc2305_fan2",
	"emc2305_fan3",
	"emc2305_fan4",
	"emc2305_fan5",
};

static void emc2305_unset_tz(struct device *dev);

static int emc2305_get_max_channel(const struct emc2305_data *data)
{
	return data->pwm_num;
}

static int emc2305_get_cdev_idx(struct thermal_cooling_device *cdev)
{
	struct emc2305_data *data = cdev->devdata;
	size_t len = strlen(cdev->type);
	int ret;

	if (len <= 0)
		return -EINVAL;

	/*
	 * Returns index of cooling device 0..4 in case of separate PWM setting.
	 * Zero index is used in case of one common PWM setting.
	 * If the mode is not set as pwm_separate, all PWMs are to be bound
	 * to the common thermal zone and should work at the same speed
	 * to perform cooling for the same thermal junction.
	 * Otherwise, return specific channel that will be used in bound
	 * related PWM to the thermal zone.
	 */
	if (!data->pwm_separate)
		return 0;

	ret = cdev->type[len - 1];
	switch (ret) {
	case '1' ... '5':
		return ret - '1';
	default:
		break;
	}
	return -EINVAL;
}

static int emc2305_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)
{
	int cdev_idx;
	struct emc2305_data *data = cdev->devdata;

	cdev_idx = emc2305_get_cdev_idx(cdev);
	if (cdev_idx < 0)
		return cdev_idx;

	*state = data->cdev_data[cdev_idx].cur_state;
	return 0;
}

static int emc2305_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)
{
	struct emc2305_data *data = cdev->devdata;
	*state = data->max_state;
	return 0;
}

static int __emc2305_set_cur_state(struct emc2305_data *data, int cdev_idx, unsigned long state)
{
	int ret;
	struct i2c_client *client = data->client;
	u8 val, i;

	state = max_t(unsigned long, state, data->cdev_data[cdev_idx].last_hwmon_state);

	val = EMC2305_PWM_STATE2DUTY(state, data->max_state, EMC2305_FAN_MAX);

	data->cdev_data[cdev_idx].cur_state = state;
	if (data->pwm_separate) {
		ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(cdev_idx), val);
		if (ret < 0)
			return ret;
	} else {
		/*
		 * Set the same PWM value in all channels
		 * if common PWM channel is used.
		 */
		for (i = 0; i < data->pwm_num; i++) {
			ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i), val);
			if (ret < 0)
				return ret;
		}
	}

	return 0;
}

static int emc2305_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
{
	int cdev_idx, ret;
	struct emc2305_data *data = cdev->devdata;

	if (state > data->max_state)
		return -EINVAL;

	cdev_idx =  emc2305_get_cdev_idx(cdev);
	if (cdev_idx < 0)
		return cdev_idx;

	/* Save thermal state. */
	data->cdev_data[cdev_idx].last_thermal_state = state;
	ret = __emc2305_set_cur_state(data, cdev_idx, state);
	if (ret < 0)
		return ret;

	return 0;
}

static const struct thermal_cooling_device_ops emc2305_cooling_ops = {
	.get_max_state = emc2305_get_max_state,
	.get_cur_state = emc2305_get_cur_state,
	.set_cur_state = emc2305_set_cur_state,
};

static int emc2305_show_fault(struct device *dev, int channel)
{
	struct emc2305_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int status_reg;

	status_reg = i2c_smbus_read_byte_data(client, EMC2305_REG_DRIVE_FAIL_STATUS);
	if (status_reg < 0)
		return status_reg;

	return status_reg & (1 << channel) ? 1 : 0;
}

static int emc2305_show_fan(struct device *dev, int channel)
{
	struct emc2305_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;

	ret = i2c_smbus_read_word_swapped(client, EMC2305_REG_FAN_TACH(channel));
	if (ret <= 0)
		return ret;

	ret = ret >> EMC2305_TACH_REGS_UNUSE_BITS;
	ret = EMC2305_RPM_FACTOR / ret;
	if (ret <= EMC2305_TACH_RANGE_MIN)
		return 0;

	return ret * EMC2305_TACH_CNT_MULTIPLIER;
}

static int emc2305_show_pwm(struct device *dev, int channel)
{
	struct emc2305_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;

	return i2c_smbus_read_byte_data(client, EMC2305_REG_FAN_DRIVE(channel));
}

static int emc2305_set_pwm(struct device *dev, long val, int channel)
{
	struct emc2305_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;

	if (val < data->pwm_min[channel] || val > EMC2305_FAN_MAX)
		return -EINVAL;

	ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val);
	if (ret < 0)
		return ret;
	data->cdev_data[channel].cur_state = EMC2305_PWM_DUTY2STATE(val, data->max_state,
								    EMC2305_FAN_MAX);
	return 0;
}

static int emc2305_set_single_tz(struct device *dev, int idx)
{
	struct emc2305_data *data = dev_get_drvdata(dev);
	long pwm;
	int i, cdev_idx, ret;

	cdev_idx = (idx) ? idx - 1 : 0;
	pwm = data->pwm_min[cdev_idx];

	data->cdev_data[cdev_idx].cdev =
		thermal_cooling_device_register(emc2305_fan_name[idx], data,
						&emc2305_cooling_ops);

	if (IS_ERR(data->cdev_data[cdev_idx].cdev)) {
		dev_err(dev, "Failed to register cooling device %s\n", emc2305_fan_name[idx]);
		return PTR_ERR(data->cdev_data[cdev_idx].cdev);
	}
	/* Set minimal PWM speed. */
	if (data->pwm_separate) {
		ret = emc2305_set_pwm(dev, pwm, cdev_idx);
		if (ret < 0)
			return ret;
	} else {
		for (i = 0; i < data->pwm_num; i++) {
			ret = emc2305_set_pwm(dev, pwm, i);
			if (ret < 0)
				return ret;
		}
	}
	data->cdev_data[cdev_idx].cur_state =
		EMC2305_PWM_DUTY2STATE(data->pwm_min[cdev_idx], data->max_state,
				       EMC2305_FAN_MAX);
	data->cdev_data[cdev_idx].last_hwmon_state =
		EMC2305_PWM_DUTY2STATE(data->pwm_min[cdev_idx], data->max_state,
				       EMC2305_FAN_MAX);
	return 0;
}

static int emc2305_set_tz(struct device *dev)
{
	struct emc2305_data *data = dev_get_drvdata(dev);
	int i, ret;

	if (!data->pwm_separate)
		return emc2305_set_single_tz(dev, 0);

	for (i = 0; i < data->pwm_num; i++) {
		ret = emc2305_set_single_tz(dev, i + 1);
		if (ret)
			goto thermal_cooling_device_register_fail;
	}
	return 0;

thermal_cooling_device_register_fail:
	emc2305_unset_tz(dev);
	return ret;
}

static void emc2305_unset_tz(struct device *dev)
{
	struct emc2305_data *data = dev_get_drvdata(dev);
	int i;

	/* Unregister cooling device. */
	for (i = 0; i < EMC2305_PWM_MAX; i++)
		if (data->cdev_data[i].cdev)
			thermal_cooling_device_unregister(data->cdev_data[i].cdev);
}

static umode_t
emc2305_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel)
{
	int max_channel = emc2305_get_max_channel(data);

	/* Don't show channels which are not physically connected. */
	if (channel >= max_channel)
		return 0;
	switch (type) {
	case hwmon_fan:
		switch (attr) {
		case hwmon_fan_input:
			return 0444;
		case hwmon_fan_fault:
			return 0444;
		default:
			break;
		}
		break;
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_input:
			return 0644;
		default:
			break;
		}
		break;
	default:
		break;
	}

	return 0;
};

static int
emc2305_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val)
{
	struct emc2305_data *data = dev_get_drvdata(dev);
	int cdev_idx;

	switch (type) {
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_input:
			/* If thermal is configured - handle PWM limit setting. */
			if (IS_REACHABLE(CONFIG_THERMAL)) {
				if (data->pwm_separate)
					cdev_idx = channel;
				else
					cdev_idx = 0;
				data->cdev_data[cdev_idx].last_hwmon_state =
					EMC2305_PWM_DUTY2STATE(val, data->max_state,
							       EMC2305_FAN_MAX);
				/*
				 * Update PWM only in case requested state is not less than the
				 * last thermal state.
				 */
				if (data->cdev_data[cdev_idx].last_hwmon_state >=
				    data->cdev_data[cdev_idx].last_thermal_state)
					return __emc2305_set_cur_state(data, cdev_idx,
							data->cdev_data[cdev_idx].last_hwmon_state);
				return 0;
			}
			return emc2305_set_pwm(dev, val, channel);
		default:
			break;
		}
		break;
	default:
		break;
	}

	return -EOPNOTSUPP;
};

static int
emc2305_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val)
{
	int ret;

	switch (type) {
	case hwmon_fan:
		switch (attr) {
		case hwmon_fan_input:
			ret = emc2305_show_fan(dev, channel);
			if (ret < 0)
				return ret;
			*val = ret;
			return 0;
		case hwmon_fan_fault:
			ret = emc2305_show_fault(dev, channel);
			if (ret < 0)
				return ret;
			*val = ret;
			return 0;
		default:
			break;
		}
		break;
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_input:
			ret = emc2305_show_pwm(dev, channel);
			if (ret < 0)
				return ret;
			*val = ret;
			return 0;
		default:
			break;
		}
		break;
	default:
		break;
	}

	return -EOPNOTSUPP;
};

static const struct hwmon_ops emc2305_ops = {
	.is_visible = emc2305_is_visible,
	.read = emc2305_read,
	.write = emc2305_write,
};

static const struct hwmon_channel_info * const emc2305_info[] = {
	HWMON_CHANNEL_INFO(fan,
			   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_INPUT,
			   HWMON_PWM_INPUT,
			   HWMON_PWM_INPUT,
			   HWMON_PWM_INPUT),
	NULL
};

static const struct hwmon_chip_info emc2305_chip_info = {
	.ops = &emc2305_ops,
	.info = emc2305_info,
};

static int emc2305_identify(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct emc2305_data *data = i2c_get_clientdata(client);
	int ret;

	ret = i2c_smbus_read_byte_data(client, EMC2305_REG_PRODUCT_ID);
	if (ret < 0)
		return ret;

	switch (ret) {
	case EMC2305:
		data->pwm_num = 5;
		break;
	case EMC2303:
		data->pwm_num = 3;
		break;
	case EMC2302:
		data->pwm_num = 2;
		break;
	case EMC2301:
		data->pwm_num = 1;
		break;
	default:
		return -ENODEV;
	}

	return 0;
}

static int emc2305_probe(struct i2c_client *client)
{
	struct i2c_adapter *adapter = client->adapter;
	struct device *dev = &client->dev;
	struct emc2305_data *data;
	struct emc2305_platform_data *pdata;
	int vendor;
	int ret;
	int i;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
		return -ENODEV;

	vendor = i2c_smbus_read_byte_data(client, EMC2305_REG_VENDOR);
	if (vendor != EMC2305_VENDOR)
		return -ENODEV;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	i2c_set_clientdata(client, data);
	data->client = client;

	ret = emc2305_identify(dev);
	if (ret)
		return ret;

	pdata = dev_get_platdata(&client->dev);
	if (pdata) {
		if (!pdata->max_state || pdata->max_state > EMC2305_FAN_MAX_STATE)
			return -EINVAL;
		data->max_state = pdata->max_state;
		/*
		 * Validate a number of active PWM channels. Note that
		 * configured number can be less than the actual maximum
		 * supported by the device.
		 */
		if (!pdata->pwm_num || pdata->pwm_num > EMC2305_PWM_MAX)
			return -EINVAL;
		data->pwm_num = pdata->pwm_num;
		data->pwm_separate = pdata->pwm_separate;
		for (i = 0; i < EMC2305_PWM_MAX; i++)
			data->pwm_min[i] = pdata->pwm_min[i];
	} else {
		data->max_state = EMC2305_FAN_MAX_STATE;
		data->pwm_separate = false;
		for (i = 0; i < EMC2305_PWM_MAX; i++)
			data->pwm_min[i] = EMC2305_FAN_MIN;
	}

	data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "emc2305", data,
							       &emc2305_chip_info, NULL);
	if (IS_ERR(data->hwmon_dev))
		return PTR_ERR(data->hwmon_dev);

	if (IS_REACHABLE(CONFIG_THERMAL)) {
		ret = emc2305_set_tz(dev);
		if (ret != 0)
			return ret;
	}

	for (i = 0; i < data->pwm_num; i++) {
		ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_MIN_DRIVE(i),
						data->pwm_min[i]);
		if (ret < 0)
			return ret;
	}

	return 0;
}

static void emc2305_remove(struct i2c_client *client)
{
	struct device *dev = &client->dev;

	if (IS_REACHABLE(CONFIG_THERMAL))
		emc2305_unset_tz(dev);
}

static struct i2c_driver emc2305_driver = {
	.class  = I2C_CLASS_HWMON,
	.driver = {
		.name = "emc2305",
	},
	.probe = emc2305_probe,
	.remove	  = emc2305_remove,
	.id_table = emc2305_ids,
	.address_list = emc2305_normal_i2c,
};

module_i2c_driver(emc2305_driver);

MODULE_AUTHOR("Nvidia");
MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
0d8400c5 MS	1	// SPDX-License-Identifier: GPL-2.0+
	2	/*
	3	* Hardware monitoring driver for EMC2305 fan controller
	4	*
	5	* Copyright (C) 2022 Nvidia Technologies Ltd.
	6	*/
	7
	8	#include <linux/err.h>
	9	#include <linux/hwmon.h>
	10	#include <linux/i2c.h>
	11	#include <linux/module.h>
	12	#include <linux/platform_data/emc2305.h>
	13	#include <linux/thermal.h>
0d8400c5 MS	14
	15	static const unsigned short
	16	emc2305_normal_i2c[] = { 0x27, 0x2c, 0x2d, 0x2e, 0x2f, 0x4c, 0x4d, I2C_CLIENT_END };
	17
	18	#define EMC2305_REG_DRIVE_FAIL_STATUS 0x27
0d8400c5 MS	19	#define EMC2305_REG_VENDOR 0xfe
	20	#define EMC2305_FAN_MAX 0xff
	21	#define EMC2305_FAN_MIN 0x00
	22	#define EMC2305_FAN_MAX_STATE 10
	23	#define EMC2305_DEVICE 0x34
	24	#define EMC2305_VENDOR 0x5d
	25	#define EMC2305_REG_PRODUCT_ID 0xfd
	26	#define EMC2305_TACH_REGS_UNUSE_BITS 3
	27	#define EMC2305_TACH_CNT_MULTIPLIER 0x02
	28	#define EMC2305_TACH_RANGE_MIN 480
	29
	30	#define EMC2305_PWM_DUTY2STATE(duty, max_state, pwm_max) \
	31	DIV_ROUND_CLOSEST((duty) * (max_state), (pwm_max))
	32	#define EMC2305_PWM_STATE2DUTY(state, max_state, pwm_max) \
	33	DIV_ROUND_CLOSEST((state) * (pwm_max), (max_state))
	34
	35	/*
	36	* Factor by equations [2] and [3] from data sheet; valid for fans where the number of edges
	37	* equal (poles * 2 + 1).
	38	*/
	39	#define EMC2305_RPM_FACTOR 3932160
	40
	41	#define EMC2305_REG_FAN_DRIVE(n) (0x30 + 0x10 * (n))
	42	#define EMC2305_REG_FAN_MIN_DRIVE(n) (0x38 + 0x10 * (n))
	43	#define EMC2305_REG_FAN_TACH(n) (0x3e + 0x10 * (n))
	44
	45	enum emc230x_product_id {
	46	EMC2305 = 0x34,
	47	EMC2303 = 0x35,
	48	EMC2302 = 0x36,
	49	EMC2301 = 0x37,
	50	};
	51
	52	static const struct i2c_device_id emc2305_ids[] = {
	53	{ "emc2305", 0 },
	54	{ "emc2303", 0 },
	55	{ "emc2302", 0 },
	56	{ "emc2301", 0 },
	57	{ }
	58	};
	59	MODULE_DEVICE_TABLE(i2c, emc2305_ids);
	60
	61	/**
e11037a5 RD	62	* struct emc2305_cdev_data - device-specific cooling device state
	63	* @cdev: cooling device
	64	* @cur_state: cooling current state
	65	* @last_hwmon_state: last cooling state updated by hwmon subsystem
	66	* @last_thermal_state: last cooling state updated by thermal subsystem
0d8400c5 MS	67	*
	68	* The 'last_hwmon_state' and 'last_thermal_state' fields are provided to support fan low limit
	69	* speed feature. The purpose of this feature is to provides ability to limit fan speed
	70	* according to some system wise considerations, like absence of some replaceable units (PSU or
	71	* line cards), high system ambient temperature, unreliable transceivers temperature sensing or
	72	* some other factors which indirectly impacts system's airflow
	73	* Fan low limit feature is supported through 'hwmon' interface: 'hwmon' 'pwm' attribute is
	74	* used for setting low limit for fan speed in case 'thermal' subsystem is configured in
	75	* kernel. In this case setting fan speed through 'hwmon' will never let the 'thermal'
	76	* subsystem to select a lower duty cycle than the duty cycle selected with the 'pwm'
	77	* attribute.
	78	* From other side, fan speed is to be updated in hardware through 'pwm' only in case the
	79	* requested fan speed is above last speed set by 'thermal' subsystem, otherwise requested fan
	80	* speed will be just stored with no PWM update.
	81	*/
	82	struct emc2305_cdev_data {
	83	struct thermal_cooling_device *cdev;
	84	unsigned int cur_state;
	85	unsigned long last_hwmon_state;
	86	unsigned long last_thermal_state;
	87	};
	88
	89	/**
e11037a5 RD	90	* struct emc2305_data - device-specific data
	91	* @client: i2c client
	92	* @hwmon_dev: hwmon device
	93	* @max_state: maximum cooling state of the cooling device
	94	* @pwm_num: number of PWM channels
	95	* @pwm_separate: separate PWM settings for every channel
	96	* @pwm_min: array of minimum PWM per channel
	97	* @cdev_data: array of cooling devices data
0d8400c5 MS	98	*/
	99	struct emc2305_data {
	100	struct i2c_client *client;
	101	struct device *hwmon_dev;
	102	u8 max_state;
	103	u8 pwm_num;
	104	bool pwm_separate;
	105	u8 pwm_min[EMC2305_PWM_MAX];
	106	struct emc2305_cdev_data cdev_data[EMC2305_PWM_MAX];
	107	};
	108
	109	static char *emc2305_fan_name[] = {
	110	"emc2305_fan",
	111	"emc2305_fan1",
	112	"emc2305_fan2",
	113	"emc2305_fan3",
	114	"emc2305_fan4",
	115	"emc2305_fan5",
	116	};
	117
	118	static void emc2305_unset_tz(struct device *dev);
	119
	120	static int emc2305_get_max_channel(const struct emc2305_data *data)
	121	{
	122	return data->pwm_num;
	123	}
	124
	125	static int emc2305_get_cdev_idx(struct thermal_cooling_device *cdev)
	126	{
	127	struct emc2305_data *data = cdev->devdata;
	128	size_t len = strlen(cdev->type);
	129	int ret;
	130
	131	if (len <= 0)
	132	return -EINVAL;
	133
	134	/*
	135	* Returns index of cooling device 0..4 in case of separate PWM setting.
	136	* Zero index is used in case of one common PWM setting.
	137	* If the mode is not set as pwm_separate, all PWMs are to be bound
	138	* to the common thermal zone and should work at the same speed
	139	* to perform cooling for the same thermal junction.
	140	* Otherwise, return specific channel that will be used in bound
	141	* related PWM to the thermal zone.
	142	*/
	143	if (!data->pwm_separate)
	144	return 0;
	145
	146	ret = cdev->type[len - 1];
	147	switch (ret) {
	148	case '1' ... '5':
	149	return ret - '1';
	150	default:
	151	break;
	152	}
	153	return -EINVAL;
	154	}
	155
	156	static int emc2305_get_cur_state(struct thermal_cooling_device cdev, unsigned long state)
	157	{
	158	int cdev_idx;
	159	struct emc2305_data *data = cdev->devdata;
	160
	161	cdev_idx = emc2305_get_cdev_idx(cdev);
162	if (cdev_idx < 0)
163	return cdev_idx;
164
165	*state = data->cdev_data[cdev_idx].cur_state;
166	return 0;
167	}
168
169	static int emc2305_get_max_state(struct thermal_cooling_device cdev, unsigned long state)
170	{
171	struct emc2305_data *data = cdev->devdata;
172	*state = data->max_state;
173	return 0;
174	}
175
364ffd25	176	static int __emc2305_set_cur_state(struct emc2305_data *data, int cdev_idx, unsigned long state)
0d8400c5	177	{
364ffd25	178	int ret;
0d8400c5 MS	179	struct i2c_client *client = data->client;
	180	u8 val, i;
	181
0d8400c5 MS	182	state = max_t(unsigned long, state, data->cdev_data[cdev_idx].last_hwmon_state);
	183
	184	val = EMC2305_PWM_STATE2DUTY(state, data->max_state, EMC2305_FAN_MAX);
0d8400c5 MS	185
	186	data->cdev_data[cdev_idx].cur_state = state;
	187	if (data->pwm_separate) {
	188	ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(cdev_idx), val);
	189	if (ret < 0)
	190	return ret;
	191	} else {
	192	/*
	193	* Set the same PWM value in all channels
	194	* if common PWM channel is used.
	195	*/
	196	for (i = 0; i < data->pwm_num; i++) {
	197	ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i), val);
	198	if (ret < 0)
	199	return ret;
	200	}
	201	}
	202
	203	return 0;
	204	}
	205
364ffd25 XQ	206	static int emc2305_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
	207	{
	208	int cdev_idx, ret;
	209	struct emc2305_data *data = cdev->devdata;
	210
	211	if (state > data->max_state)
	212	return -EINVAL;
	213
	214	cdev_idx = emc2305_get_cdev_idx(cdev);
	215	if (cdev_idx < 0)
	216	return cdev_idx;
	217
	218	/* Save thermal state. */
	219	data->cdev_data[cdev_idx].last_thermal_state = state;
	220	ret = __emc2305_set_cur_state(data, cdev_idx, state);
	221	if (ret < 0)
	222	return ret;
	223
	224	return 0;
	225	}
	226
0d8400c5 MS	227	static const struct thermal_cooling_device_ops emc2305_cooling_ops = {
	228	.get_max_state = emc2305_get_max_state,
	229	.get_cur_state = emc2305_get_cur_state,
	230	.set_cur_state = emc2305_set_cur_state,
	231	};
	232
	233	static int emc2305_show_fault(struct device *dev, int channel)
	234	{
	235	struct emc2305_data *data = dev_get_drvdata(dev);
	236	struct i2c_client *client = data->client;
	237	int status_reg;
	238
	239	status_reg = i2c_smbus_read_byte_data(client, EMC2305_REG_DRIVE_FAIL_STATUS);
	240	if (status_reg < 0)
	241	return status_reg;
	242
	243	return status_reg & (1 << channel) ? 1 : 0;
	244	}
	245
	246	static int emc2305_show_fan(struct device *dev, int channel)
	247	{
	248	struct emc2305_data *data = dev_get_drvdata(dev);
	249	struct i2c_client *client = data->client;
	250	int ret;
	251
	252	ret = i2c_smbus_read_word_swapped(client, EMC2305_REG_FAN_TACH(channel));
	253	if (ret <= 0)
	254	return ret;
	255
	256	ret = ret >> EMC2305_TACH_REGS_UNUSE_BITS;
	257	ret = EMC2305_RPM_FACTOR / ret;
	258	if (ret <= EMC2305_TACH_RANGE_MIN)
	259	return 0;
	260
	261	return ret * EMC2305_TACH_CNT_MULTIPLIER;
	262	}
	263
	264	static int emc2305_show_pwm(struct device *dev, int channel)
	265	{
	266	struct emc2305_data *data = dev_get_drvdata(dev);
	267	struct i2c_client *client = data->client;
	268
	269	return i2c_smbus_read_byte_data(client, EMC2305_REG_FAN_DRIVE(channel));
	270	}
	271
	272	static int emc2305_set_pwm(struct device *dev, long val, int channel)
	273	{
	274	struct emc2305_data *data = dev_get_drvdata(dev);
	275	struct i2c_client *client = data->client;
	276	int ret;
	277
	278	if (val < data->pwm_min[channel] \|\| val > EMC2305_FAN_MAX)
	279	return -EINVAL;
	280
	281	ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val);
	282	if (ret < 0)
	283	return ret;
	284	data->cdev_data[channel].cur_state = EMC2305_PWM_DUTY2STATE(val, data->max_state,
	285	EMC2305_FAN_MAX);
	286	return 0;
	287	}
	288
	289	static int emc2305_set_single_tz(struct device *dev, int idx)
	290	{
291	struct emc2305_data *data = dev_get_drvdata(dev);
292	long pwm;
293	int i, cdev_idx, ret;
294
295	cdev_idx = (idx) ? idx - 1 : 0;
296	pwm = data->pwm_min[cdev_idx];
297
298	data->cdev_data[cdev_idx].cdev =
299	thermal_cooling_device_register(emc2305_fan_name[idx], data,
300	&emc2305_cooling_ops);
301
302	if (IS_ERR(data->cdev_data[cdev_idx].cdev)) {
303	dev_err(dev, "Failed to register cooling device %s\n", emc2305_fan_name[idx]);
304	return PTR_ERR(data->cdev_data[cdev_idx].cdev);
305	}
306	/* Set minimal PWM speed. */
307	if (data->pwm_separate) {
308	ret = emc2305_set_pwm(dev, pwm, cdev_idx);
309	if (ret < 0)
310	return ret;
311	} else {
312	for (i = 0; i < data->pwm_num; i++) {
313	ret = emc2305_set_pwm(dev, pwm, i);
314	if (ret < 0)
315	return ret;
316	}
317	}
318	data->cdev_data[cdev_idx].cur_state =
319	EMC2305_PWM_DUTY2STATE(data->pwm_min[cdev_idx], data->max_state,
320	EMC2305_FAN_MAX);
321	data->cdev_data[cdev_idx].last_hwmon_state =
322	EMC2305_PWM_DUTY2STATE(data->pwm_min[cdev_idx], data->max_state,
323	EMC2305_FAN_MAX);
324	return 0;
325	}
326
327	static int emc2305_set_tz(struct device *dev)
328	{
329	struct emc2305_data *data = dev_get_drvdata(dev);
330	int i, ret;
331
332	if (!data->pwm_separate)
333	return emc2305_set_single_tz(dev, 0);
334
335	for (i = 0; i < data->pwm_num; i++) {
336	ret = emc2305_set_single_tz(dev, i + 1);
337	if (ret)
338	goto thermal_cooling_device_register_fail;
339	}
340	return 0;
341
342	thermal_cooling_device_register_fail:
343	emc2305_unset_tz(dev);
344	return ret;
345	}
346
347	static void emc2305_unset_tz(struct device *dev)
348	{
349	struct emc2305_data *data = dev_get_drvdata(dev);
350	int i;
351
352	/* Unregister cooling device. */
353	for (i = 0; i < EMC2305_PWM_MAX; i++)
354	if (data->cdev_data[i].cdev)
355	thermal_cooling_device_unregister(data->cdev_data[i].cdev);
356	}
357
358	static umode_t
359	emc2305_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel)
360	{
361	int max_channel = emc2305_get_max_channel(data);
362
363	/* Don't show channels which are not physically connected. */
364	if (channel >= max_channel)
365	return 0;
366	switch (type) {
367	case hwmon_fan:
368	switch (attr) {
369	case hwmon_fan_input:
370	return 0444;
371	case hwmon_fan_fault:
372	return 0444;
373	default:
374	break;
375	}
376	break;
377	case hwmon_pwm:
378	switch (attr) {
379	case hwmon_pwm_input:
380	return 0644;
381	default:
382	break;
383	}
384	break;
385	default:
386	break;
387	}
388
389	return 0;
390	};
391
392	static int
393	emc2305_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val)
394	{
395	struct emc2305_data *data = dev_get_drvdata(dev);
396	int cdev_idx;
397
398	switch (type) {
399	case hwmon_pwm:
400	switch (attr) {
401	case hwmon_pwm_input:
402	/* If thermal is configured - handle PWM limit setting. */
403	if (IS_REACHABLE(CONFIG_THERMAL)) {
404	if (data->pwm_separate)
405	cdev_idx = channel;
406	else
407	cdev_idx = 0;
408	data->cdev_data[cdev_idx].last_hwmon_state =
409	EMC2305_PWM_DUTY2STATE(val, data->max_state,
410	EMC2305_FAN_MAX);
411	/*
412	* Update PWM only in case requested state is not less than the
413	* last thermal state.
414	*/
415	if (data->cdev_data[cdev_idx].last_hwmon_state >=
416	data->cdev_data[cdev_idx].last_thermal_state)
364ffd25	417	return __emc2305_set_cur_state(data, cdev_idx,
0d8400c5 MS	418	data->cdev_data[cdev_idx].last_hwmon_state);
	419	return 0;
	420	}
	421	return emc2305_set_pwm(dev, val, channel);
	422	default:
	423	break;
	424	}
	425	break;
	426	default:
	427	break;
	428	}
	429
	430	return -EOPNOTSUPP;
	431	};
	432
	433	static int
	434	emc2305_read(struct device dev, enum hwmon_sensor_types type, u32 attr, int channel, long val)
	435	{
	436	int ret;
	437
	438	switch (type) {
	439	case hwmon_fan:
	440	switch (attr) {
	441	case hwmon_fan_input:
	442	ret = emc2305_show_fan(dev, channel);
	443	if (ret < 0)
	444	return ret;
	445	*val = ret;
	446	return 0;
	447	case hwmon_fan_fault:
	448	ret = emc2305_show_fault(dev, channel);
	449	if (ret < 0)
	450	return ret;
	451	*val = ret;
	452	return 0;
	453	default:
	454	break;
	455	}
	456	break;
	457	case hwmon_pwm:
	458	switch (attr) {
	459	case hwmon_pwm_input:
	460	ret = emc2305_show_pwm(dev, channel);
	461	if (ret < 0)
	462	return ret;
	463	*val = ret;
	464	return 0;
	465	default:
	466	break;
	467	}
	468	break;
	469	default:
	470	break;
	471	}
	472
	473	return -EOPNOTSUPP;
	474	};
	475
	476	static const struct hwmon_ops emc2305_ops = {
	477	.is_visible = emc2305_is_visible,
	478	.read = emc2305_read,
	479	.write = emc2305_write,
	480	};
	481
c1686de1	482	static const struct hwmon_channel_info * const emc2305_info[] = {
0d8400c5 MS	483	HWMON_CHANNEL_INFO(fan,
	484	HWMON_F_INPUT \| HWMON_F_FAULT,
	485	HWMON_F_INPUT \| HWMON_F_FAULT,
	486	HWMON_F_INPUT \| HWMON_F_FAULT,
	487	HWMON_F_INPUT \| HWMON_F_FAULT,
	488	HWMON_F_INPUT \| HWMON_F_FAULT),
	489	HWMON_CHANNEL_INFO(pwm,
	490	HWMON_PWM_INPUT,
	491	HWMON_PWM_INPUT,
	492	HWMON_PWM_INPUT,
	493	HWMON_PWM_INPUT,
	494	HWMON_PWM_INPUT),
	495	NULL
	496	};
	497
	498	static const struct hwmon_chip_info emc2305_chip_info = {
	499	.ops = &emc2305_ops,
	500	.info = emc2305_info,
	501	};
	502
	503	static int emc2305_identify(struct device *dev)
	504	{
	505	struct i2c_client *client = to_i2c_client(dev);
	506	struct emc2305_data *data = i2c_get_clientdata(client);
	507	int ret;
	508
	509	ret = i2c_smbus_read_byte_data(client, EMC2305_REG_PRODUCT_ID);
	510	if (ret < 0)
	511	return ret;
	512
	513	switch (ret) {
	514	case EMC2305:
	515	data->pwm_num = 5;
	516	break;
	517	case EMC2303:
	518	data->pwm_num = 3;
	519	break;
	520	case EMC2302:
	521	data->pwm_num = 2;
	522	break;
	523	case EMC2301:
	524	data->pwm_num = 1;
	525	break;
	526	default:
	527	return -ENODEV;
	528	}
	529
	530	return 0;
	531	}
	532
deeab9ea	533	static int emc2305_probe(struct i2c_client *client)
0d8400c5 MS	534	{
	535	struct i2c_adapter *adapter = client->adapter;
	536	struct device *dev = &client->dev;
	537	struct emc2305_data *data;
	538	struct emc2305_platform_data *pdata;
4d50591e	539	int vendor;
0d8400c5 MS	540	int ret;
	541	int i;
	542
	543	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA \| I2C_FUNC_SMBUS_WORD_DATA))
	544	return -ENODEV;
	545
	546	vendor = i2c_smbus_read_byte_data(client, EMC2305_REG_VENDOR);
	547	if (vendor != EMC2305_VENDOR)
	548	return -ENODEV;
	549
0d8400c5 MS	550	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	551	if (!data)
	552	return -ENOMEM;
	553
	554	i2c_set_clientdata(client, data);
	555	data->client = client;
	556
	557	ret = emc2305_identify(dev);
	558	if (ret)
	559	return ret;
	560
	561	pdata = dev_get_platdata(&client->dev);
	562	if (pdata) {
	563	if (!pdata->max_state \|\| pdata->max_state > EMC2305_FAN_MAX_STATE)
	564	return -EINVAL;
	565	data->max_state = pdata->max_state;
	566	/*
	567	* Validate a number of active PWM channels. Note that
	568	* configured number can be less than the actual maximum
	569	* supported by the device.
	570	*/
	571	if (!pdata->pwm_num \|\| pdata->pwm_num > EMC2305_PWM_MAX)
	572	return -EINVAL;
	573	data->pwm_num = pdata->pwm_num;
	574	data->pwm_separate = pdata->pwm_separate;
	575	for (i = 0; i < EMC2305_PWM_MAX; i++)
	576	data->pwm_min[i] = pdata->pwm_min[i];
	577	} else {
	578	data->max_state = EMC2305_FAN_MAX_STATE;
	579	data->pwm_separate = false;
	580	for (i = 0; i < EMC2305_PWM_MAX; i++)
	581	data->pwm_min[i] = EMC2305_FAN_MIN;
	582	}
	583
	584	data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "emc2305", data,
	585	&emc2305_chip_info, NULL);
	586	if (IS_ERR(data->hwmon_dev))
	587	return PTR_ERR(data->hwmon_dev);
	588
	589	if (IS_REACHABLE(CONFIG_THERMAL)) {
	590	ret = emc2305_set_tz(dev);
	591	if (ret != 0)
	592	return ret;
	593	}
	594
	595	for (i = 0; i < data->pwm_num; i++) {
	596	ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_MIN_DRIVE(i),
	597	data->pwm_min[i]);
	598	if (ret < 0)
	599	return ret;
	600	}
	601
	602	return 0;
	603	}
	604
0baf6dcc	605	static void emc2305_remove(struct i2c_client *client)
0d8400c5 MS	606	{
	607	struct device *dev = &client->dev;
	608
	609	if (IS_REACHABLE(CONFIG_THERMAL))
	610	emc2305_unset_tz(dev);
0d8400c5 MS	611	}
	612
	613	static struct i2c_driver emc2305_driver = {
	614	.class = I2C_CLASS_HWMON,
	615	.driver = {
	616	.name = "emc2305",
	617	},
1975d167	618	.probe = emc2305_probe,
0d8400c5 MS	619	.remove = emc2305_remove,
	620	.id_table = emc2305_ids,
	621	.address_list = emc2305_normal_i2c,
	622	};
	623
	624	module_i2c_driver(emc2305_driver);
	625
	626	MODULE_AUTHOR("Nvidia");
	627	MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver");
	628	MODULE_LICENSE("GPL");