1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * pwm-fan.c - Hwmon driver for fans connected to PWM lines.
11 #include <linux/hwmon-sysfs.h>
49 	atomic_inc(&ctx->pulses);  in pulse_handler()
57 	unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);  in sample_timer()
61 		pulses = atomic_read(&ctx->pulses);  in sample_timer()
62 		atomic_sub(pulses, &ctx->pulses);  in sample_timer()
63 		ctx->rpm = (unsigned int)(pulses * 1000 * 60) /  in sample_timer()
64 			(ctx->pulses_per_revolution * delta);  in sample_timer()
66 		ctx->sample_start = ktime_get();  in sample_timer()
69 	mod_timer(&ctx->rpm_timer, jiffies + HZ);  in sample_timer()
78 	mutex_lock(&ctx->lock);  in __set_pwm()
79 	if (ctx->pwm_value == pwm)  in __set_pwm()
82 	pwm_init_state(ctx->pwm, &state);  in __set_pwm()
83 	period = ctx->pwm->args.period;  in __set_pwm()
84 	state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);  in __set_pwm()
87 	ret = pwm_apply_state(ctx->pwm, &state);  in __set_pwm()
89 		ctx->pwm_value = pwm;  in __set_pwm()
91 	mutex_unlock(&ctx->lock);  in __set_pwm()
99 	for (i = 0; i < ctx->pwm_fan_max_state; ++i)  in pwm_fan_update_state()
100 		if (pwm < ctx->pwm_fan_cooling_levels[i + 1])  in pwm_fan_update_state()
103 	ctx->pwm_fan_state = i;  in pwm_fan_update_state()
114 		return -EINVAL;  in pwm_store()
129 	return sprintf(buf, "%u\n", ctx->pwm_value);  in pwm_show()
137 	return sprintf(buf, "%u\n", ctx->rpm);  in rpm_show()
156 	if (n == 1 && ctx->irq <= 0)  in pwm_fan_attrs_visible()
159 	return a->mode;  in pwm_fan_attrs_visible()
172 /* thermal cooling device callbacks */
176 	struct pwm_fan_ctx *ctx = cdev->devdata;  in pwm_fan_get_max_state()
179 		return -EINVAL;  in pwm_fan_get_max_state()
181 	*state = ctx->pwm_fan_max_state;  in pwm_fan_get_max_state()
189 	struct pwm_fan_ctx *ctx = cdev->devdata;  in pwm_fan_get_cur_state()
192 		return -EINVAL;  in pwm_fan_get_cur_state()
194 	*state = ctx->pwm_fan_state;  in pwm_fan_get_cur_state()
202 	struct pwm_fan_ctx *ctx = cdev->devdata;  in pwm_fan_set_cur_state()
205 	if (!ctx || (state > ctx->pwm_fan_max_state))  in pwm_fan_set_cur_state()
206 		return -EINVAL;  in pwm_fan_set_cur_state()
208 	if (state == ctx->pwm_fan_state)  in pwm_fan_set_cur_state()
211 	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);  in pwm_fan_set_cur_state()
213 		dev_err(&cdev->device, "Cannot set pwm!\n");  in pwm_fan_set_cur_state()
217 	ctx->pwm_fan_state = state;  in pwm_fan_set_cur_state()
231 	struct device_node *np = dev->of_node;  in pwm_fan_of_get_cooling_data()
234 	if (!of_find_property(np, "cooling-levels", NULL))  in pwm_fan_of_get_cooling_data()
237 	ret = of_property_count_u32_elems(np, "cooling-levels");  in pwm_fan_of_get_cooling_data()
240 		return ret ? : -EINVAL;  in pwm_fan_of_get_cooling_data()
244 	ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),  in pwm_fan_of_get_cooling_data()
246 	if (!ctx->pwm_fan_cooling_levels)  in pwm_fan_of_get_cooling_data()
247 		return -ENOMEM;  in pwm_fan_of_get_cooling_data()
249 	ret = of_property_read_u32_array(np, "cooling-levels",  in pwm_fan_of_get_cooling_data()
250 					 ctx->pwm_fan_cooling_levels, num);  in pwm_fan_of_get_cooling_data()
252 		dev_err(dev, "Property 'cooling-levels' cannot be read!\n");  in pwm_fan_of_get_cooling_data()
257 		if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {  in pwm_fan_of_get_cooling_data()
259 				ctx->pwm_fan_cooling_levels[i], MAX_PWM);  in pwm_fan_of_get_cooling_data()
260 			return -EINVAL;  in pwm_fan_of_get_cooling_data()
264 	ctx->pwm_fan_max_state = num - 1;  in pwm_fan_of_get_cooling_data()
277 	pwm_disable(ctx->pwm);  in pwm_fan_pwm_disable()
278 	del_timer_sync(&ctx->rpm_timer);  in pwm_fan_pwm_disable()
284 	struct device *dev = &pdev->dev;  in pwm_fan_probe()
293 		return -ENOMEM;  in pwm_fan_probe()
295 	mutex_init(&ctx->lock);  in pwm_fan_probe()
297 	ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL);  in pwm_fan_probe()
298 	if (IS_ERR(ctx->pwm))  in pwm_fan_probe()
299 		return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");  in pwm_fan_probe()
303 	ctx->irq = platform_get_irq_optional(pdev, 0);  in pwm_fan_probe()
304 	if (ctx->irq == -EPROBE_DEFER)  in pwm_fan_probe()
305 		return ctx->irq;  in pwm_fan_probe()
307 	ctx->reg_en = devm_regulator_get_optional(dev, "fan");  in pwm_fan_probe()
308 	if (IS_ERR(ctx->reg_en)) {  in pwm_fan_probe()
309 		if (PTR_ERR(ctx->reg_en) != -ENODEV)  in pwm_fan_probe()
310 			return PTR_ERR(ctx->reg_en);  in pwm_fan_probe()
312 		ctx->reg_en = NULL;  in pwm_fan_probe()
314 		ret = regulator_enable(ctx->reg_en);  in pwm_fan_probe()
320 					       ctx->reg_en);  in pwm_fan_probe()
325 	ctx->pwm_value = MAX_PWM;  in pwm_fan_probe()
327 	pwm_init_state(ctx->pwm, &state);  in pwm_fan_probe()
329 	 * __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned  in pwm_fan_probe()
335 		return -EINVAL;  in pwm_fan_probe()
339 	state.duty_cycle = ctx->pwm->args.period - 1;  in pwm_fan_probe()
342 	ret = pwm_apply_state(ctx->pwm, &state);  in pwm_fan_probe()
347 	timer_setup(&ctx->rpm_timer, sample_timer, 0);  in pwm_fan_probe()
352 	of_property_read_u32(dev->of_node, "pulses-per-revolution", &ppr);  in pwm_fan_probe()
353 	ctx->pulses_per_revolution = ppr;  in pwm_fan_probe()
354 	if (!ctx->pulses_per_revolution) {  in pwm_fan_probe()
355 		dev_err(dev, "pulses-per-revolution can't be zero.\n");  in pwm_fan_probe()
356 		return -EINVAL;  in pwm_fan_probe()
359 	if (ctx->irq > 0) {  in pwm_fan_probe()
360 		ret = devm_request_irq(dev, ctx->irq, pulse_handler, 0,  in pwm_fan_probe()
361 				       pdev->name, ctx);  in pwm_fan_probe()
366 		ctx->sample_start = ktime_get();  in pwm_fan_probe()
367 		mod_timer(&ctx->rpm_timer, jiffies + HZ);  in pwm_fan_probe()
381 	ctx->pwm_fan_state = ctx->pwm_fan_max_state;  in pwm_fan_probe()
384 			dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);  in pwm_fan_probe()
388 				"Failed to register pwm-fan as cooling device: %d\n",  in pwm_fan_probe()
392 		ctx->cdev = cdev;  in pwm_fan_probe()
405 	pwm_get_args(ctx->pwm, &args);  in pwm_fan_disable()
407 	if (ctx->pwm_value) {  in pwm_fan_disable()
408 		ret = pwm_config(ctx->pwm, 0, args.period);  in pwm_fan_disable()
412 		pwm_disable(ctx->pwm);  in pwm_fan_disable()
415 	if (ctx->reg_en) {  in pwm_fan_disable()
416 		ret = regulator_disable(ctx->reg_en);  in pwm_fan_disable()
428 	pwm_fan_disable(&pdev->dev);  in pwm_fan_shutdown()
444 	if (ctx->reg_en) {  in pwm_fan_resume()
445 		ret = regulator_enable(ctx->reg_en);  in pwm_fan_resume()
452 	if (ctx->pwm_value == 0)  in pwm_fan_resume()
455 	pwm_get_args(ctx->pwm, &pargs);  in pwm_fan_resume()
456 	duty = DIV_ROUND_UP_ULL(ctx->pwm_value * (pargs.period - 1), MAX_PWM);  in pwm_fan_resume()
457 	ret = pwm_config(ctx->pwm, duty, pargs.period);  in pwm_fan_resume()
460 	return pwm_enable(ctx->pwm);  in pwm_fan_resume()
467 	{ .compatible = "pwm-fan", },
476 		.name		= "pwm-fan",
485 MODULE_ALIAS("platform:pwm-fan");