1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * max6650.c - Part of lm_sensors, Linux kernel modules for hardware
12  * This module has only been tested with the MAX6650 chip. It should
13  * also work with the MAX6651. It does not distinguish max6650 and max6651
18  *        http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
27 #include <linux/hwmon-sysfs.h>
40 /* clock: The clock frequency of the chip (max6651 can be clocked externally) */
91 /* Minimum and maximum values of the FAN-RPM */
129 		.compatible = "maxim,max6650",
133 		.compatible = "maxim,max6651",
143 	 * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.  in dac_to_pwm()
146 	return clamp_val(255 - (255 * dac) / DAC_LIMIT(v12), 0, 255);  in dac_to_pwm()
153 	return limit - (limit * pwm) / 255;  in pwm_to_dac()
159 	struct i2c_client *client = data->client;  in max6650_update_device()
163 	mutex_lock(&data->update_lock);  in max6650_update_device()
165 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {  in max6650_update_device()
166 		for (i = 0; i < data->nr_fans; i++) {  in max6650_update_device()
172 			data->tach[i] = reg;  in max6650_update_device()
185 		data->alarm |= reg;  in max6650_update_device()
186 		data->last_updated = jiffies;  in max6650_update_device()
187 		data->valid = true;  in max6650_update_device()
191 	mutex_unlock(&data->update_lock);  in max6650_update_device()
204 	u8 config = data->config;  in max6650_set_operating_mode()
211 	result = i2c_smbus_write_byte_data(data->client, MAX6650_REG_CONFIG,  in max6650_set_operating_mode()
216 	data->config = config;  in max6650_set_operating_mode()
225  * The MAX6650/1 will automatically control fan speed when in closed loop
230  * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use
275 	 *     KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1  in max6650_set_target()
278 	kscale = DIV_FROM_REG(data->config);  in max6650_set_target()
279 	ktach = ((clock * kscale) / (256 * rpm / 60)) - 1;  in max6650_set_target()
284 	data->speed = ktach;  in max6650_set_target()
286 	return i2c_smbus_write_byte_data(data->client, MAX6650_REG_SPEED,  in max6650_set_target()
287 					 data->speed);  in max6650_set_target()
307 	alarm = data->alarm & attr->index;  in alarm_show()
309 		mutex_lock(&data->update_lock);  in alarm_show()
310 		data->alarm &= ~attr->index;  in alarm_show()
311 		data->valid = false;  in alarm_show()
312 		mutex_unlock(&data->update_lock);  in alarm_show()
335 		if (!(data->alarm_en & to_sensor_dev_attr(devattr)->index))  in max6650_attrs_visible()
339 	return a->mode;  in max6650_attrs_visible()
361 	struct device *dev = &client->dev;  in max6650_init_client()
368 	if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt",  in max6650_init_client()
373 	if (of_property_read_u32(dev->of_node, "maxim,fan-prescale",  in max6650_init_client()
431 	data->config = reg;  in max6650_init_client()
438 	data->speed = reg;  in max6650_init_client()
445 	data->dac = reg;  in max6650_init_client()
452 	data->count = reg;  in max6650_init_client()
459 	data->alarm_en = reg;  in max6650_init_client()
461 	if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm",  in max6650_init_client()
481 	struct max6650_data *data = cdev->devdata;  in max6650_get_cur_state()
483 	*state = data->cooling_dev_state;  in max6650_get_cur_state()
491 	struct max6650_data *data = cdev->devdata;  in max6650_set_cur_state()
492 	struct i2c_client *client = data->client;  in max6650_set_cur_state()
497 	mutex_lock(&data->update_lock);  in max6650_set_cur_state()
499 	data->dac = pwm_to_dac(state, data->config & MAX6650_CFG_V12);  in max6650_set_cur_state()
500 	err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);  in max6650_set_cur_state()
505 		data->cooling_dev_state = state;  in max6650_set_cur_state()
508 	mutex_unlock(&data->update_lock);  in max6650_set_cur_state()
532 			*val = dac_to_pwm(data->dac,  in max6650_read()
533 					  data->config & MAX6650_CFG_V12);  in max6650_read()
545 			mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4;  in max6650_read()
546 			*val = (4 - mode) & 3; /* {0 1 2 3} -> {0 3 2 1} */  in max6650_read()
549 			return -EOPNOTSUPP;  in max6650_read()
563 			*val = DIV_ROUND_CLOSEST(data->tach[channel] * 120,  in max6650_read()
564 						 DIV_FROM_REG(data->count));  in max6650_read()
567 			*val = DIV_FROM_REG(data->count);  in max6650_read()
575 			*val = 60 * DIV_FROM_REG(data->config) * clock /  in max6650_read()
576 				(256 * (data->speed + 1));  in max6650_read()
579 			*val = !!(data->alarm & MAX6650_ALRM_MIN);  in max6650_read()
580 			data->alarm &= ~MAX6650_ALRM_MIN;  in max6650_read()
581 			data->valid = false;  in max6650_read()
584 			*val = !!(data->alarm & MAX6650_ALRM_MAX);  in max6650_read()
585 			data->alarm &= ~MAX6650_ALRM_MAX;  in max6650_read()
586 			data->valid = false;  in max6650_read()
589 			*val = !!(data->alarm & MAX6650_ALRM_TACH);  in max6650_read()
590 			data->alarm &= ~MAX6650_ALRM_TACH;  in max6650_read()
591 			data->valid = false;  in max6650_read()
594 			return -EOPNOTSUPP;  in max6650_read()
598 		return -EOPNOTSUPP;  in max6650_read()
617 	mutex_lock(&data->update_lock);  in max6650_write()
624 					 data->config & MAX6650_CFG_V12);  in max6650_write()
625 			ret = i2c_smbus_write_byte_data(data->client,  in max6650_write()
629 			data->dac = reg;  in max6650_write()
633 				ret = -EINVAL;  in max6650_write()
640 			ret = -EOPNOTSUPP;  in max6650_write()
661 				ret = -EINVAL;  in max6650_write()
664 			ret = i2c_smbus_write_byte_data(data->client,  in max6650_write()
668 			data->count = reg;  in max6650_write()
672 				ret = -EINVAL;  in max6650_write()
678 			ret = -EOPNOTSUPP;  in max6650_write()
683 		ret = -EOPNOTSUPP;  in max6650_write()
688 	mutex_unlock(&data->update_lock);  in max6650_write()
698 	if (channel && (channel >= data->nr_fans || type != hwmon_fan))  in max6650_is_visible()
710 			if (data->alarm_en & MAX6650_ALRM_MIN)  in max6650_is_visible()
714 			if (data->alarm_en & MAX6650_ALRM_MAX)  in max6650_is_visible()
718 			if (data->alarm_en & MAX6650_ALRM_TACH)  in max6650_is_visible()
765 	struct device *dev = &client->dev;  in max6650_probe()
772 		return -ENOMEM;  in max6650_probe()
774 	data->client = client;  in max6650_probe()
776 	mutex_init(&data->update_lock);  in max6650_probe()
778 	data->nr_fans = (uintptr_t)i2c_get_match_data(client);  in max6650_probe()
781 	 * Initialize the max6650 chip  in max6650_probe()
788 							 client->name, data,  in max6650_probe()
797 						dev->of_node, client->name,  in max6650_probe()
809 	{ "max6650", 1 },
810 	{ "max6651", 4 },
817 		.name	= "max6650",
827 MODULE_DESCRIPTION("MAX6650 sensor driver");