1 // SPDX-License-Identifier: GPL-2.0-only
8  * Links to reference manuals for the supported PWM chips can be found in
12  * - Periods start with the inactive level.
13  * - Hardware has to be stopped in general to update settings.
16  * - When atmel_pwm_apply() is called with state->enabled=false a change in
17  *   state->polarity isn't honored.
18  * - Instead of sleeping to wait for a completed period, the interrupt
29 #include <linux/pwm.h>
32 /* The following is global registers for PWM controller */
40 /* The following register is PWM channel related registers */
50 /* The following registers for PWM v1 */
55 /* The following registers for PWM v2 */
87 	 * pending we delay disabling the PWM until the new configuration is
107 	return readl_relaxed(chip->base + offset);  in atmel_pwm_readl()
113 	writel_relaxed(val, chip->base + offset);  in atmel_pwm_writel()
143 	chip->update_pending &= ~isr;  in atmel_pwm_update_pending()
148 	spin_lock(&chip->lock);  in atmel_pwm_set_pending()
156 	chip->update_pending |= (1 << ch);  in atmel_pwm_set_pending()
158 	spin_unlock(&chip->lock);  in atmel_pwm_set_pending()
165 	spin_lock(&chip->lock);  in atmel_pwm_test_pending()
167 	if (chip->update_pending & (1 << ch)) {  in atmel_pwm_test_pending()
170 		if (chip->update_pending & (1 << ch))  in atmel_pwm_test_pending()
174 	spin_unlock(&chip->lock);  in atmel_pwm_test_pending()
188 	return ret ? -ETIMEDOUT : 0;  in atmel_pwm_wait_nonpending()
197 	unsigned long long cycles = state->period;  in atmel_pwm_calculate_cprd_and_pres()
209 	shift = fls(cycles) - atmel_pwm->data->cfg.period_bits;  in atmel_pwm_calculate_cprd_and_pres()
213 		return -EINVAL;  in atmel_pwm_calculate_cprd_and_pres()
230 	unsigned long long cycles = state->duty_cycle;  in atmel_pwm_calculate_cdty()
235 	*cdty = cprd - cycles;  in atmel_pwm_calculate_cdty()
238 static void atmel_pwm_update_cdty(struct pwm_chip *chip, struct pwm_device *pwm,  in atmel_pwm_update_cdty()  argument
244 	if (atmel_pwm->data->regs.duty_upd ==  in atmel_pwm_update_cdty()
245 	    atmel_pwm->data->regs.period_upd) {  in atmel_pwm_update_cdty()
246 		val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);  in atmel_pwm_update_cdty()
248 		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);  in atmel_pwm_update_cdty()
251 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,  in atmel_pwm_update_cdty()
252 			    atmel_pwm->data->regs.duty_upd, cdty);  in atmel_pwm_update_cdty()
253 	atmel_pwm_set_pending(atmel_pwm, pwm->hwpwm);  in atmel_pwm_update_cdty()
257 				    struct pwm_device *pwm,  in atmel_pwm_set_cprd_cdty()  argument
262 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,  in atmel_pwm_set_cprd_cdty()
263 			    atmel_pwm->data->regs.duty, cdty);  in atmel_pwm_set_cprd_cdty()
264 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,  in atmel_pwm_set_cprd_cdty()
265 			    atmel_pwm->data->regs.period, cprd);  in atmel_pwm_set_cprd_cdty()
268 static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm,  in atmel_pwm_disable()  argument
274 	atmel_pwm_wait_nonpending(atmel_pwm, pwm->hwpwm);  in atmel_pwm_disable()
276 	atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm);  in atmel_pwm_disable()
279 	 * Wait for the PWM channel disable operation to be effective before  in atmel_pwm_disable()
284 	while ((atmel_pwm_readl(atmel_pwm, PWM_SR) & (1 << pwm->hwpwm)) &&  in atmel_pwm_disable()
289 		clk_disable(atmel_pwm->clk);  in atmel_pwm_disable()
292 static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in atmel_pwm_apply()  argument
300 	if (state->enabled) {  in atmel_pwm_apply()
301 		unsigned long clkrate = clk_get_rate(atmel_pwm->clk);  in atmel_pwm_apply()
303 		if (pwm->state.enabled &&  in atmel_pwm_apply()
304 		    pwm->state.polarity == state->polarity &&  in atmel_pwm_apply()
305 		    pwm->state.period == state->period) {  in atmel_pwm_apply()
306 			u32 cmr = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);  in atmel_pwm_apply()
308 			cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,  in atmel_pwm_apply()
309 						  atmel_pwm->data->regs.period);  in atmel_pwm_apply()
313 			atmel_pwm_update_cdty(chip, pwm, cdty);  in atmel_pwm_apply()
327 		if (pwm->state.enabled) {  in atmel_pwm_apply()
328 			atmel_pwm_disable(chip, pwm, false);  in atmel_pwm_apply()
330 			ret = clk_enable(atmel_pwm->clk);  in atmel_pwm_apply()
338 		val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);  in atmel_pwm_apply()
340 		if (state->polarity == PWM_POLARITY_NORMAL)  in atmel_pwm_apply()
344 		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);  in atmel_pwm_apply()
345 		atmel_pwm_set_cprd_cdty(chip, pwm, cprd, cdty);  in atmel_pwm_apply()
346 		atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm);  in atmel_pwm_apply()
347 	} else if (pwm->state.enabled) {  in atmel_pwm_apply()
348 		atmel_pwm_disable(chip, pwm, true);  in atmel_pwm_apply()
354 static int atmel_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,  in atmel_pwm_get_state()  argument
361 	cmr = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);  in atmel_pwm_get_state()
363 	if (sr & (1 << pwm->hwpwm)) {  in atmel_pwm_get_state()
364 		unsigned long rate = clk_get_rate(atmel_pwm->clk);  in atmel_pwm_get_state()
370 		cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,  in atmel_pwm_get_state()
371 					  atmel_pwm->data->regs.period);  in atmel_pwm_get_state()
374 		state->period = DIV64_U64_ROUND_UP(tmp, rate);  in atmel_pwm_get_state()
377 		atmel_pwm_wait_nonpending(atmel_pwm, pwm->hwpwm);  in atmel_pwm_get_state()
379 		cdty = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,  in atmel_pwm_get_state()
380 					  atmel_pwm->data->regs.duty);  in atmel_pwm_get_state()
381 		tmp = (u64)(cprd - cdty) * NSEC_PER_SEC;  in atmel_pwm_get_state()
383 		state->duty_cycle = DIV64_U64_ROUND_UP(tmp, rate);  in atmel_pwm_get_state()
385 		state->enabled = true;  in atmel_pwm_get_state()
387 		state->enabled = false;  in atmel_pwm_get_state()
391 		state->polarity = PWM_POLARITY_INVERSED;  in atmel_pwm_get_state()
393 		state->polarity = PWM_POLARITY_NORMAL;  in atmel_pwm_get_state()
444 		.compatible = "atmel,at91sam9rl-pwm",
447 		.compatible = "atmel,sama5d3-pwm",
450 		.compatible = "atmel,sama5d2-pwm",
453 		.compatible = "microchip,sam9x60-pwm",
472 	cnt = bitmap_weight(&sr, chip->npwm);  in atmel_pwm_enable_clk_if_on()
478 		ret = clk_enable(atmel_pwm->clk);  in atmel_pwm_enable_clk_if_on()
481 				"failed to enable clock for pwm %pe\n",  in atmel_pwm_enable_clk_if_on()
492 	while (cnt--)  in atmel_pwm_enable_clk_if_on()
493 		clk_disable(atmel_pwm->clk);  in atmel_pwm_enable_clk_if_on()
504 	chip = devm_pwmchip_alloc(&pdev->dev, 4, sizeof(*atmel_pwm));  in atmel_pwm_probe()
509 	atmel_pwm->data = of_device_get_match_data(&pdev->dev);  in atmel_pwm_probe()
511 	atmel_pwm->update_pending = 0;  in atmel_pwm_probe()
512 	spin_lock_init(&atmel_pwm->lock);  in atmel_pwm_probe()
514 	atmel_pwm->base = devm_platform_ioremap_resource(pdev, 0);  in atmel_pwm_probe()
515 	if (IS_ERR(atmel_pwm->base))  in atmel_pwm_probe()
516 		return PTR_ERR(atmel_pwm->base);  in atmel_pwm_probe()
518 	atmel_pwm->clk = devm_clk_get_prepared(&pdev->dev, NULL);  in atmel_pwm_probe()
519 	if (IS_ERR(atmel_pwm->clk))  in atmel_pwm_probe()
520 		return dev_err_probe(&pdev->dev, PTR_ERR(atmel_pwm->clk),  in atmel_pwm_probe()
521 				     "failed to get prepared PWM clock\n");  in atmel_pwm_probe()
523 	chip->ops = &atmel_pwm_ops;  in atmel_pwm_probe()
529 	ret = devm_pwmchip_add(&pdev->dev, chip);  in atmel_pwm_probe()
531 		dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");  in atmel_pwm_probe()
545 		.name = "atmel-pwm",
552 MODULE_ALIAS("platform:atmel-pwm");
554 MODULE_DESCRIPTION("Atmel PWM driver");