1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * g762 - Driver for the Global Mixed-mode Technology Inc. fan speed
4  *        PWM controller chips from G762 family, i.e. G762 and G763
15  *  http://natisbad.org/NAS/refs/GMT_EDS-762_763-080710-0.2.pdf
27  *       http://www.gmt.com.tw/product/datasheet/EDS-762_3.pdf
36 #include <linux/hwmon-sysfs.h>
67 #define G762_REG_FAN_CMD1_FAN_MODE      0x10 /* fan mode: closed/open-loop */
71 #define G762_REG_FAN_CMD1_PULSE_PER_REV 0x01 /* pulse per fan revolution */
73 #define G762_REG_FAN_CMD2_GEAR_MODE_1   0x08 /* fan gear mode */
75 #define G762_REG_FAN_CMD2_FAN_STARTV_1  0x02 /* fan startup voltage */
78 #define G762_REG_FAN_STA_FAIL           0x02 /* fan fail */
79 #define G762_REG_FAN_STA_OOC            0x01 /* fan out of control */
95  * Extract pulse count per fan revolution value (2 or 4) from given
102  * Extract fan clock divisor (1, 2, 4 or 8) from given FAN_CMD1
110  * Extract fan gear mode multiplier value (0, 2 or 4) from given
131 	u8 set_cnt;  /* controls fan rotation speed in closed-loop mode */
132 	u8 act_cnt;  /* provides access to current fan RPM value */
133 	u8 fan_sta;  /* bit 0: set when actual fan speed is more than
134 		      *        25% outside requested fan speed
135 		      * bit 1: set when no transition occurs on fan
138 	u8 set_out;  /* controls fan rotation speed in open-loop mode */
145 		      *         00: Divide fan clock by 1
146 		      *         01: Divide fan clock by 2
147 		      *         10: Divide fan clock by 4
148 		      *         11: Divide fan clock by 8
149 		      *   4: FAN_MODE 1:closed-loop, 0:open-loop
151 		      *   6: DET_FAN_OOC enable "fan ooc" status
152 		      *   7: DET_FAN_FAIL enable "fan fail" status
154 	u8 fan_cmd2; /* 0,1: FAN_STARTV 0,1,2,3 -> 0,32,64,96 dac_code
164  * Convert count value from fan controller register (FAN_SET_CNT) into fan
166  * influence of additional parameters (fan clock divisor, fan gear mode)
172 	if (cnt == 0xff)  /* setting cnt to 255 stops the fan */  in rpm_from_cnt()
179  * Convert fan RPM value from sysfs into count value for fan controller
188 	if (!rpm)	/* to stop the fan, set cnt to 255 */  in cnt_from_rpm()
199 	struct i2c_client *client = data->client;  in g762_update_client()
202 	mutex_lock(&data->update_lock);  in g762_update_client()
203 	if (time_before(jiffies, data->last_updated + G762_UPDATE_INTERVAL) &&  in g762_update_client()
204 	    likely(data->valid))  in g762_update_client()
210 	data->set_cnt = ret;  in g762_update_client()
215 	data->act_cnt = ret;  in g762_update_client()
220 	data->fan_sta = ret;  in g762_update_client()
225 	data->set_out = ret;  in g762_update_client()
230 	data->fan_cmd1 = ret;  in g762_update_client()
235 	data->fan_cmd2 = ret;  in g762_update_client()
237 	data->last_updated = jiffies;  in g762_update_client()
238 	data->valid = true;  in g762_update_client()
240 	mutex_unlock(&data->update_lock);  in g762_update_client()
261 		return -EINVAL;  in do_set_clk_freq()
265 	data->clk_freq = val;  in do_set_clk_freq()
279 	mutex_lock(&data->update_lock);  in do_set_pwm_mode()
282 		data->fan_cmd1 |=  G762_REG_FAN_CMD1_OUT_MODE;  in do_set_pwm_mode()
285 		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_OUT_MODE;  in do_set_pwm_mode()
288 		ret = -EINVAL;  in do_set_pwm_mode()
291 	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,  in do_set_pwm_mode()
292 					data->fan_cmd1);  in do_set_pwm_mode()
293 	data->valid = false;  in do_set_pwm_mode()
295 	mutex_unlock(&data->update_lock);  in do_set_pwm_mode()
300 /* Set fan clock divisor. Accepts either 1, 2, 4 or 8. */
309 	mutex_lock(&data->update_lock);  in do_set_fan_div()
312 		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;  in do_set_fan_div()
313 		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;  in do_set_fan_div()
316 		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;  in do_set_fan_div()
317 		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;  in do_set_fan_div()
320 		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;  in do_set_fan_div()
321 		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;  in do_set_fan_div()
324 		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;  in do_set_fan_div()
325 		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;  in do_set_fan_div()
328 		ret = -EINVAL;  in do_set_fan_div()
331 	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,  in do_set_fan_div()
332 					data->fan_cmd1);  in do_set_fan_div()
333 	data->valid = false;  in do_set_fan_div()
335 	mutex_unlock(&data->update_lock);  in do_set_fan_div()
340 /* Set fan gear mode. Accepts either 0, 1 or 2. */
349 	mutex_lock(&data->update_lock);  in do_set_fan_gear_mode()
352 		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;  in do_set_fan_gear_mode()
353 		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;  in do_set_fan_gear_mode()
356 		data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_0;  in do_set_fan_gear_mode()
357 		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;  in do_set_fan_gear_mode()
360 		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;  in do_set_fan_gear_mode()
361 		data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_1;  in do_set_fan_gear_mode()
364 		ret = -EINVAL;  in do_set_fan_gear_mode()
367 	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,  in do_set_fan_gear_mode()
368 					data->fan_cmd2);  in do_set_fan_gear_mode()
369 	data->valid = false;  in do_set_fan_gear_mode()
371 	mutex_unlock(&data->update_lock);  in do_set_fan_gear_mode()
376 /* Set number of fan pulses per revolution. Accepts either 2 or 4. */
385 	mutex_lock(&data->update_lock);  in do_set_fan_pulses()
388 		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PULSE_PER_REV;  in do_set_fan_pulses()
391 		data->fan_cmd1 |=  G762_REG_FAN_CMD1_PULSE_PER_REV;  in do_set_fan_pulses()
394 		ret = -EINVAL;  in do_set_fan_pulses()
397 	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,  in do_set_fan_pulses()
398 					data->fan_cmd1);  in do_set_fan_pulses()
399 	data->valid = false;  in do_set_fan_pulses()
401 	mutex_unlock(&data->update_lock);  in do_set_fan_pulses()
406 /* Set fan mode. Accepts either 1 (open-loop) or 2 (closed-loop). */
415 	mutex_lock(&data->update_lock);  in do_set_pwm_enable()
418 		data->fan_cmd1 |=  G762_REG_FAN_CMD1_FAN_MODE;  in do_set_pwm_enable()
421 		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_FAN_MODE;  in do_set_pwm_enable()
424 		 * unknown reason, fan will not rotate as expected, no matter  in do_set_pwm_enable()
427 		 * value of 254 if it is 255 when switching to open-loop.  in do_set_pwm_enable()
429 		if (data->set_cnt == 0xff)  in do_set_pwm_enable()
430 			i2c_smbus_write_byte_data(data->client,  in do_set_pwm_enable()
434 		ret = -EINVAL;  in do_set_pwm_enable()
438 	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,  in do_set_pwm_enable()
439 					data->fan_cmd1);  in do_set_pwm_enable()
440 	data->valid = false;  in do_set_pwm_enable()
442 	mutex_unlock(&data->update_lock);  in do_set_pwm_enable()
456 	mutex_lock(&data->update_lock);  in do_set_pwm_polarity()
459 		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PWM_POLARITY;  in do_set_pwm_polarity()
462 		data->fan_cmd1 |=  G762_REG_FAN_CMD1_PWM_POLARITY;  in do_set_pwm_polarity()
465 		ret = -EINVAL;  in do_set_pwm_polarity()
468 	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,  in do_set_pwm_polarity()
469 					data->fan_cmd1);  in do_set_pwm_polarity()
470 	data->valid = false;  in do_set_pwm_polarity()
472 	mutex_unlock(&data->update_lock);  in do_set_pwm_polarity()
478  * Set pwm value. Accepts values between 0 (stops the fan) and
479  * 255 (full speed). This only makes sense in open-loop mode.
484 	struct i2c_client *client = data->client;  in do_set_pwm()
488 		return -EINVAL;  in do_set_pwm()
490 	mutex_lock(&data->update_lock);  in do_set_pwm()
492 	data->valid = false;  in do_set_pwm()
493 	mutex_unlock(&data->update_lock);  in do_set_pwm()
499  * Set fan RPM value. Can be called both in closed and open-loop mode
500  * but effect will only be seen after closed-loop mode is configured.
510 	mutex_lock(&data->update_lock);  in do_set_fan_target()
511 	data->set_cnt = cnt_from_rpm(val, data->clk_freq,  in do_set_fan_target()
512 				     G762_PULSE_FROM_REG(data->fan_cmd1),  in do_set_fan_target()
513 				     G762_CLKDIV_FROM_REG(data->fan_cmd1),  in do_set_fan_target()
514 				     G762_GEARMULT_FROM_REG(data->fan_cmd2));  in do_set_fan_target()
515 	ret = i2c_smbus_write_byte_data(data->client, G762_REG_SET_CNT,  in do_set_fan_target()
516 					data->set_cnt);  in do_set_fan_target()
517 	data->valid = false;  in do_set_fan_target()
518 	mutex_unlock(&data->update_lock);  in do_set_fan_target()
523 /* Set fan startup voltage. Accepted values are either 0, 1, 2 or 3. */
532 	mutex_lock(&data->update_lock);  in do_set_fan_startv()
535 		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;  in do_set_fan_startv()
536 		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;  in do_set_fan_startv()
539 		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;  in do_set_fan_startv()
540 		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;  in do_set_fan_startv()
543 		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;  in do_set_fan_startv()
544 		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;  in do_set_fan_startv()
547 		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;  in do_set_fan_startv()
548 		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;  in do_set_fan_startv()
551 		ret = -EINVAL;  in do_set_fan_startv()
554 	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,  in do_set_fan_startv()
555 					data->fan_cmd2);  in do_set_fan_startv()
556 	data->valid = false;  in do_set_fan_startv()
558 	mutex_unlock(&data->update_lock);  in do_set_fan_startv()
587 	clk_disable_unprepare(g762->clk);  in g762_of_clock_disable()
588 	clk_put(g762->clk);  in g762_of_clock_disable()
598 	if (!client->dev.of_node)  in g762_of_clock_enable()
601 	clk = of_clk_get(client->dev.of_node, 0);  in g762_of_clock_enable()
603 		dev_err(&client->dev, "failed to get clock\n");  in g762_of_clock_enable()
609 		dev_err(&client->dev, "failed to enable clock\n");  in g762_of_clock_enable()
614 	ret = do_set_clk_freq(&client->dev, clk_freq);  in g762_of_clock_enable()
616 		dev_err(&client->dev, "invalid clock freq %lu\n", clk_freq);  in g762_of_clock_enable()
621 	data->clk = clk;  in g762_of_clock_enable()
623 	devm_add_action(&client->dev, g762_of_clock_disable, data);  in g762_of_clock_enable()
643 	if (of_property_read_u32(client->dev.of_node, pname, &pval))  in g762_of_prop_import_one()
646 	dev_dbg(&client->dev, "found %s (%d)\n", pname, pval);  in g762_of_prop_import_one()
647 	ret = (*psetter)(&client->dev, pval);  in g762_of_prop_import_one()
649 		dev_err(&client->dev, "unable to set %s (%d)\n", pname, pval);  in g762_of_prop_import_one()
658 	if (!client->dev.of_node)  in g762_of_prop_import()
694 	struct g762_platform_data *pdata = dev_get_platdata(&client->dev);  in g762_pdata_prop_import()
700 	ret = do_set_fan_gear_mode(&client->dev, pdata->fan_gear_mode);  in g762_pdata_prop_import()
704 	ret = do_set_pwm_polarity(&client->dev, pdata->pwm_polarity);  in g762_pdata_prop_import()
708 	ret = do_set_fan_startv(&client->dev, pdata->fan_startv);  in g762_pdata_prop_import()
712 	return do_set_clk_freq(&client->dev, pdata->clk_freq);  in g762_pdata_prop_import()
720  * Read function for fan1_input sysfs file. Return current fan RPM value, or
721  * 0 if fan is out of control.
732 	mutex_lock(&data->update_lock);  in fan1_input_show()
733 	/* reverse logic: fan out of control reporting is enabled low */  in fan1_input_show()
734 	if (data->fan_sta & G762_REG_FAN_STA_OOC) {  in fan1_input_show()
735 		rpm = rpm_from_cnt(data->act_cnt, data->clk_freq,  in fan1_input_show()
736 				   G762_PULSE_FROM_REG(data->fan_cmd1),  in fan1_input_show()
737 				   G762_CLKDIV_FROM_REG(data->fan_cmd1),  in fan1_input_show()
738 				   G762_GEARMULT_FROM_REG(data->fan_cmd2));  in fan1_input_show()
740 	mutex_unlock(&data->update_lock);  in fan1_input_show()
746  * Read and write functions for pwm1_mode sysfs file. Get and set fan speed
758 		       !!(data->fan_cmd1 & G762_REG_FAN_CMD1_OUT_MODE));  in pwm1_mode_show()
769 		return -EINVAL;  in pwm1_mode_store()
779  * Read and write functions for fan1_div sysfs file. Get and set fan
780  * controller prescaler value
790 	return sprintf(buf, "%d\n", G762_CLKDIV_FROM_REG(data->fan_cmd1));  in fan1_div_show()
800 		return -EINVAL;  in fan1_div_store()
811  * of tachometer pulses per fan revolution.
821 	return sprintf(buf, "%d\n", G762_PULSE_FROM_REG(data->fan_cmd1));  in fan1_pulses_show()
832 		return -EINVAL;  in fan1_pulses_store()
842  * Read and write functions for pwm1_enable. Get and set fan speed control mode
843  * (i.e. closed or open-loop).
848  *  0 : no fan speed control (i.e. fan at full speed)
849  *  1 : manual fan speed control enabled (use pwm[1-*]) (open-loop)
850  *  2+: automatic fan speed control enabled (use fan[1-*]_target) (closed-loop)
853  * and it is not emulated by g762 driver. -EINVAL is returned in this case.
864 		       (!!(data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE)) + 1);  in pwm1_enable_show()
875 		return -EINVAL;  in pwm1_enable_store()
886  * (which affects fan speed) in open-loop mode. 0 stops the fan and 255
897 	return sprintf(buf, "%d\n", data->set_out);  in pwm1_show()
907 		return -EINVAL;  in pwm1_store()
917  * Read and write function for fan1_target sysfs file. Get/set the fan speed in
918  * closed-loop mode. Speed is given as a RPM value; then the chip will regulate
919  * the fan speed using pulses from fan tachometer.
936 	mutex_lock(&data->update_lock);  in fan1_target_show()
937 	rpm = rpm_from_cnt(data->set_cnt, data->clk_freq,  in fan1_target_show()
938 			   G762_PULSE_FROM_REG(data->fan_cmd1),  in fan1_target_show()
939 			   G762_CLKDIV_FROM_REG(data->fan_cmd1),  in fan1_target_show()
940 			   G762_GEARMULT_FROM_REG(data->fan_cmd2));  in fan1_target_show()
941 	mutex_unlock(&data->update_lock);  in fan1_target_show()
954 		return -EINVAL;  in fan1_target_store()
972 	return sprintf(buf, "%u\n", !!(data->fan_sta & G762_REG_FAN_STA_FAIL));  in fan1_fault_show()
987 	return sprintf(buf, "%u\n", !(data->fan_sta & G762_REG_FAN_STA_OOC));  in fan1_alarm_show()
1017  * Enable both fan failure detection and fan out of control protection. The
1028 	data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_FAIL;  in g762_fan_init()
1029 	data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_OOC;  in g762_fan_init()
1030 	data->valid = false;  in g762_fan_init()
1032 	return i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,  in g762_fan_init()
1033 					 data->fan_cmd1);  in g762_fan_init()
1038 	struct device *dev = &client->dev;  in g762_probe()
1043 	if (!i2c_check_functionality(client->adapter,  in g762_probe()
1045 		return -ENODEV;  in g762_probe()
1049 		return -ENOMEM;  in g762_probe()
1052 	data->client = client;  in g762_probe()
1053 	mutex_init(&data->update_lock);  in g762_probe()
1055 	/* Enable fan failure detection and fan out of control protection */  in g762_probe()
1072 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,  in g762_probe()