1 // SPDX-License-Identifier: GPL-2.0-only
3  * NXP LPC18xx State Configurable Timer - Pulse Width Modulator driver
9  * NXP LPC18xx provides a State Configurable Timer (SCT) which can be configured
12  * SCT supports 16 outputs, 16 events and 16 registers. Each event will be
13  * triggered when its related register matches the SCT counter value, and it
18  * global to all the channels, thus PWM driver will refuse setting different
28 #include <linux/pwm.h>
30 /* LPC18xx SCT registers */
73 /* LPC18xx SCT unified counter */
76 /* LPC18xx SCT events */
82 /* SCT conflict resolution */
115 	writel(val, lpc18xx_pwm->base + reg);  in lpc18xx_pwm_writel()
121 	return readl(lpc18xx_pwm->base + reg);  in lpc18xx_pwm_readl()
125 					 struct pwm_device *pwm,  in lpc18xx_pwm_set_conflict_res()  argument
132 	 * when duty_ns == period_ns. LPC18xx SCT allows to set a conflict  in lpc18xx_pwm_set_conflict_res()
136 	val &= ~LPC18XX_PWM_RES_MASK(pwm->hwpwm);  in lpc18xx_pwm_set_conflict_res()
137 	val |= LPC18XX_PWM_RES(pwm->hwpwm, action);  in lpc18xx_pwm_set_conflict_res()
149 	 * As period_ns >= min_period_ns = DIV_ROUND_UP(NSEC_PER_SEC, lpc18xx_pwm->clk_rate);  in lpc18xx_pwm_config_period()
152 	val = mul_u64_u64_div_u64(period_ns, lpc18xx_pwm->clk_rate, NSEC_PER_SEC);  in lpc18xx_pwm_config_period()
155 			   LPC18XX_PWM_MATCH(lpc18xx_pwm->period_event),  in lpc18xx_pwm_config_period()
156 			   val - 1);  in lpc18xx_pwm_config_period()
159 			   LPC18XX_PWM_MATCHREL(lpc18xx_pwm->period_event),  in lpc18xx_pwm_config_period()
160 			   val - 1);  in lpc18xx_pwm_config_period()
164 				    struct pwm_device *pwm, u64 duty_ns)  in lpc18xx_pwm_config_duty()  argument
167 	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];  in lpc18xx_pwm_config_duty()
174 	val = mul_u64_u64_div_u64(duty_ns, lpc18xx_pwm->clk_rate, NSEC_PER_SEC);  in lpc18xx_pwm_config_duty()
177 			   LPC18XX_PWM_MATCH(lpc18xx_data->duty_event),  in lpc18xx_pwm_config_duty()
181 			   LPC18XX_PWM_MATCHREL(lpc18xx_data->duty_event),  in lpc18xx_pwm_config_duty()
185 static int lpc18xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,  in lpc18xx_pwm_config()  argument
191 	if (period_ns < lpc18xx_pwm->min_period_ns ||  in lpc18xx_pwm_config()
192 	    period_ns > lpc18xx_pwm->max_period_ns) {  in lpc18xx_pwm_config()
194 		return -ERANGE;  in lpc18xx_pwm_config()
197 	requested_events = bitmap_weight(&lpc18xx_pwm->event_map,  in lpc18xx_pwm_config()
201 	 * The PWM supports only a single period for all PWM channels.  in lpc18xx_pwm_config()
205 	if (requested_events > 2 && lpc18xx_pwm->period_ns != period_ns &&  in lpc18xx_pwm_config()
206 	    lpc18xx_pwm->period_ns) {  in lpc18xx_pwm_config()
207 		dev_err(pwmchip_parent(chip), "conflicting period requested for PWM %u\n",  in lpc18xx_pwm_config()
208 			pwm->hwpwm);  in lpc18xx_pwm_config()
209 		return -EBUSY;  in lpc18xx_pwm_config()
212 	if ((requested_events <= 2 && lpc18xx_pwm->period_ns != period_ns) ||  in lpc18xx_pwm_config()
213 	    !lpc18xx_pwm->period_ns) {  in lpc18xx_pwm_config()
214 		lpc18xx_pwm->period_ns = period_ns;  in lpc18xx_pwm_config()
218 	lpc18xx_pwm_config_duty(chip, pwm, duty_ns);  in lpc18xx_pwm_config()
223 static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm, enum pwm_polarity pola…  in lpc18xx_pwm_enable()  argument
226 	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];  in lpc18xx_pwm_enable()
231 			   LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event),  in lpc18xx_pwm_enable()
232 			   LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_data->duty_event) |  in lpc18xx_pwm_enable()
236 			   LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),  in lpc18xx_pwm_enable()
240 		set_event = lpc18xx_pwm->period_event;  in lpc18xx_pwm_enable()
241 		clear_event = lpc18xx_data->duty_event;  in lpc18xx_pwm_enable()
244 		set_event = lpc18xx_data->duty_event;  in lpc18xx_pwm_enable()
245 		clear_event = lpc18xx_pwm->period_event;  in lpc18xx_pwm_enable()
249 	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm),  in lpc18xx_pwm_enable()
251 	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm),  in lpc18xx_pwm_enable()
253 	lpc18xx_pwm_set_conflict_res(lpc18xx_pwm, pwm, res_action);  in lpc18xx_pwm_enable()
258 static void lpc18xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in lpc18xx_pwm_disable()  argument
261 	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];  in lpc18xx_pwm_disable()
264 			   LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event), 0);  in lpc18xx_pwm_disable()
265 	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm), 0);  in lpc18xx_pwm_disable()
266 	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm), 0);  in lpc18xx_pwm_disable()
269 static int lpc18xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)  in lpc18xx_pwm_request()  argument
272 	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];  in lpc18xx_pwm_request()
275 	event = find_first_zero_bit(&lpc18xx_pwm->event_map,  in lpc18xx_pwm_request()
281 		return -EBUSY;  in lpc18xx_pwm_request()
284 	set_bit(event, &lpc18xx_pwm->event_map);  in lpc18xx_pwm_request()
285 	lpc18xx_data->duty_event = event;  in lpc18xx_pwm_request()
290 static void lpc18xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)  in lpc18xx_pwm_free()  argument
293 	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];  in lpc18xx_pwm_free()
295 	clear_bit(lpc18xx_data->duty_event, &lpc18xx_pwm->event_map);  in lpc18xx_pwm_free()
298 static int lpc18xx_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in lpc18xx_pwm_apply()  argument
302 	bool enabled = pwm->state.enabled;  in lpc18xx_pwm_apply()
304 	if (state->polarity != pwm->state.polarity && pwm->state.enabled) {  in lpc18xx_pwm_apply()
305 		lpc18xx_pwm_disable(chip, pwm);  in lpc18xx_pwm_apply()
309 	if (!state->enabled) {  in lpc18xx_pwm_apply()
311 			lpc18xx_pwm_disable(chip, pwm);  in lpc18xx_pwm_apply()
316 	err = lpc18xx_pwm_config(chip, pwm, state->duty_cycle, state->period);  in lpc18xx_pwm_apply()
321 		err = lpc18xx_pwm_enable(chip, pwm, state->polarity);  in lpc18xx_pwm_apply()
332 	{ .compatible = "nxp,lpc1850-sct-pwm" },
344 	chip = devm_pwmchip_alloc(&pdev->dev, LPC18XX_NUM_PWMS, sizeof(*lpc18xx_pwm));  in lpc18xx_pwm_probe()
349 	lpc18xx_pwm->base = devm_platform_ioremap_resource(pdev, 0);  in lpc18xx_pwm_probe()
350 	if (IS_ERR(lpc18xx_pwm->base))  in lpc18xx_pwm_probe()
351 		return PTR_ERR(lpc18xx_pwm->base);  in lpc18xx_pwm_probe()
353 	lpc18xx_pwm->pwm_clk = devm_clk_get_enabled(&pdev->dev, "pwm");  in lpc18xx_pwm_probe()
354 	if (IS_ERR(lpc18xx_pwm->pwm_clk))  in lpc18xx_pwm_probe()
355 		return dev_err_probe(&pdev->dev, PTR_ERR(lpc18xx_pwm->pwm_clk),  in lpc18xx_pwm_probe()
356 				     "failed to get pwm clock\n");  in lpc18xx_pwm_probe()
358 	lpc18xx_pwm->clk_rate = clk_get_rate(lpc18xx_pwm->pwm_clk);  in lpc18xx_pwm_probe()
359 	if (!lpc18xx_pwm->clk_rate)  in lpc18xx_pwm_probe()
360 		return dev_err_probe(&pdev->dev,  in lpc18xx_pwm_probe()
361 				     -EINVAL, "pwm clock has no frequency\n");  in lpc18xx_pwm_probe()
366 	if (lpc18xx_pwm->clk_rate > NSEC_PER_SEC)  in lpc18xx_pwm_probe()
367 		return dev_err_probe(&pdev->dev, -EINVAL, "pwm clock to fast\n");  in lpc18xx_pwm_probe()
369 	lpc18xx_pwm->max_period_ns =  in lpc18xx_pwm_probe()
370 		mul_u64_u64_div_u64(NSEC_PER_SEC, LPC18XX_PWM_TIMER_MAX, lpc18xx_pwm->clk_rate);  in lpc18xx_pwm_probe()
372 	lpc18xx_pwm->min_period_ns = DIV_ROUND_UP(NSEC_PER_SEC,  in lpc18xx_pwm_probe()
373 						  lpc18xx_pwm->clk_rate);  in lpc18xx_pwm_probe()
375 	chip->ops = &lpc18xx_pwm_ops;  in lpc18xx_pwm_probe()
377 	/* SCT counter must be in unify (32 bit) mode */  in lpc18xx_pwm_probe()
385 	set_bit(LPC18XX_PWM_EVENT_PERIOD, &lpc18xx_pwm->event_map);  in lpc18xx_pwm_probe()
386 	lpc18xx_pwm->period_event = LPC18XX_PWM_EVENT_PERIOD;  in lpc18xx_pwm_probe()
389 			   LPC18XX_PWM_EVSTATEMSK(lpc18xx_pwm->period_event),  in lpc18xx_pwm_probe()
392 	val = LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_pwm->period_event) |  in lpc18xx_pwm_probe()
395 			   LPC18XX_PWM_EVCTRL(lpc18xx_pwm->period_event), val);  in lpc18xx_pwm_probe()
398 			   BIT(lpc18xx_pwm->period_event));  in lpc18xx_pwm_probe()
409 		return dev_err_probe(&pdev->dev, ret, "pwmchip_add failed\n");  in lpc18xx_pwm_probe()
431 		.name = "lpc18xx-sct-pwm",
440 MODULE_DESCRIPTION("NXP LPC18xx PWM driver");