1 // SPDX-License-Identifier: GPL-2.0-only
5  *     Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
9  * PWM driver for Samsung SoCs
21 #include <linux/pwm.h>
59  * struct samsung_pwm_channel - private data of PWM channel
71  * struct samsung_pwm_chip - private data of PWM chip
72  * @chip:		generic PWM chip
74  * @inverter_mask:	inverter status for all channels - one bit per channel
75  * @disabled_mask:	disabled status for all channels - one bit per channel
76  * @base:		base address of mapped PWM registers
95  * PWM block is shared between pwm-samsung and samsung_pwm_timer drivers
101  * because all the supported SoCs contain only one instance of the PWM
120 static void pwm_samsung_set_divisor(struct samsung_pwm_chip *pwm,  in pwm_samsung_set_divisor()  argument
128 	bits = (fls(divisor) - 1) - pwm->variant.div_base;  in pwm_samsung_set_divisor()
132 	reg = readl(pwm->base + REG_TCFG1);  in pwm_samsung_set_divisor()
135 	writel(reg, pwm->base + REG_TCFG1);  in pwm_samsung_set_divisor()
142 	struct samsung_pwm_variant *variant = &chip->variant;  in pwm_samsung_is_tdiv()
145 	reg = readl(chip->base + REG_TCFG1);  in pwm_samsung_is_tdiv()
149 	return (BIT(reg) & variant->tclk_mask) == 0;  in pwm_samsung_is_tdiv()
158 	rate = clk_get_rate(chip->base_clk);  in pwm_samsung_get_tin_rate()
160 	reg = readl(chip->base + REG_TCFG0);  in pwm_samsung_get_tin_rate()
171 	struct samsung_pwm_variant *variant = &chip->variant;  in pwm_samsung_calc_tin()
177 		clk = (chan < 2) ? chip->tclk0 : chip->tclk1;  in pwm_samsung_calc_tin()
184 		dev_warn(chip->chip.dev,  in pwm_samsung_calc_tin()
185 			"tclk of PWM %d is inoperational, using tdiv\n", chan);  in pwm_samsung_calc_tin()
189 	dev_dbg(chip->chip.dev, "tin parent at %lu\n", rate);  in pwm_samsung_calc_tin()
192 	 * Compare minimum PWM frequency that can be achieved with possible  in pwm_samsung_calc_tin()
196 	if (variant->bits < 32) {  in pwm_samsung_calc_tin()
198 		for (div = variant->div_base; div < 4; ++div)  in pwm_samsung_calc_tin()
199 			if ((rate >> (variant->bits + div)) < freq)  in pwm_samsung_calc_tin()
206 		div = variant->div_base;  in pwm_samsung_calc_tin()
214 static int pwm_samsung_request(struct pwm_chip *chip, struct pwm_device *pwm)  in pwm_samsung_request()  argument
219 	if (!(our_chip->variant.output_mask & BIT(pwm->hwpwm))) {  in pwm_samsung_request()
220 		dev_warn(chip->dev,  in pwm_samsung_request()
221 			"tried to request PWM channel %d without output\n",  in pwm_samsung_request()
222 			pwm->hwpwm);  in pwm_samsung_request()
223 		return -EINVAL;  in pwm_samsung_request()
228 		return -ENOMEM;  in pwm_samsung_request()
230 	pwm_set_chip_data(pwm, our_chan);  in pwm_samsung_request()
235 static void pwm_samsung_free(struct pwm_chip *chip, struct pwm_device *pwm)  in pwm_samsung_free()  argument
237 	kfree(pwm_get_chip_data(pwm));  in pwm_samsung_free()
240 static int pwm_samsung_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in pwm_samsung_enable()  argument
243 	unsigned int tcon_chan = to_tcon_channel(pwm->hwpwm);  in pwm_samsung_enable()
249 	tcon = readl(our_chip->base + REG_TCON);  in pwm_samsung_enable()
253 	writel(tcon, our_chip->base + REG_TCON);  in pwm_samsung_enable()
257 	writel(tcon, our_chip->base + REG_TCON);  in pwm_samsung_enable()
259 	our_chip->disabled_mask &= ~BIT(pwm->hwpwm);  in pwm_samsung_enable()
266 static void pwm_samsung_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in pwm_samsung_disable()  argument
269 	unsigned int tcon_chan = to_tcon_channel(pwm->hwpwm);  in pwm_samsung_disable()
275 	tcon = readl(our_chip->base + REG_TCON);  in pwm_samsung_disable()
277 	writel(tcon, our_chip->base + REG_TCON);  in pwm_samsung_disable()
279 	our_chip->disabled_mask |= BIT(pwm->hwpwm);  in pwm_samsung_disable()
285 				      struct pwm_device *pwm)  in pwm_samsung_manual_update()  argument
287 	unsigned int tcon_chan = to_tcon_channel(pwm->hwpwm);  in pwm_samsung_manual_update()
293 	tcon = readl(chip->base + REG_TCON);  in pwm_samsung_manual_update()
295 	writel(tcon, chip->base + REG_TCON);  in pwm_samsung_manual_update()
298 	writel(tcon, chip->base + REG_TCON);  in pwm_samsung_manual_update()
303 static int __pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm,  in __pwm_samsung_config()  argument
307 	struct samsung_pwm_channel *chan = pwm_get_chip_data(pwm);  in __pwm_samsung_config()
308 	u32 tin_ns = chan->tin_ns, tcnt, tcmp, oldtcmp;  in __pwm_samsung_config()
316 		return -ERANGE;  in __pwm_samsung_config()
318 	tcnt = readl(our_chip->base + REG_TCNTB(pwm->hwpwm));  in __pwm_samsung_config()
319 	oldtcmp = readl(our_chip->base + REG_TCMPB(pwm->hwpwm));  in __pwm_samsung_config()
324 	/* Check to see if we are changing the clock rate of the PWM. */  in __pwm_samsung_config()
325 	if (chan->period_ns != period_ns || force_period) {  in __pwm_samsung_config()
331 		dev_dbg(our_chip->chip.dev, "duty_ns=%d, period_ns=%d (%u)\n",  in __pwm_samsung_config()
334 		tin_rate = pwm_samsung_calc_tin(our_chip, pwm->hwpwm, period);  in __pwm_samsung_config()
336 		dev_dbg(our_chip->chip.dev, "tin_rate=%lu\n", tin_rate);  in __pwm_samsung_config()
344 		return -ERANGE;  in __pwm_samsung_config()
353 	tcmp = tcnt - tcmp;  in __pwm_samsung_config()
356 	--tcnt;  in __pwm_samsung_config()
357 	/* -1UL will give 100% duty. */  in __pwm_samsung_config()
358 	--tcmp;  in __pwm_samsung_config()
360 	dev_dbg(our_chip->chip.dev,  in __pwm_samsung_config()
363 	/* Update PWM registers. */  in __pwm_samsung_config()
364 	writel(tcnt, our_chip->base + REG_TCNTB(pwm->hwpwm));  in __pwm_samsung_config()
365 	writel(tcmp, our_chip->base + REG_TCMPB(pwm->hwpwm));  in __pwm_samsung_config()
368 	 * In case the PWM is currently at 100% duty cycle, force a manual  in __pwm_samsung_config()
369 	 * update to prevent the signal staying high if the PWM is disabled  in __pwm_samsung_config()
372 	if (oldtcmp == (u32) -1) {  in __pwm_samsung_config()
373 		dev_dbg(our_chip->chip.dev, "Forcing manual update");  in __pwm_samsung_config()
374 		pwm_samsung_manual_update(our_chip, pwm);  in __pwm_samsung_config()
377 	chan->period_ns = period_ns;  in __pwm_samsung_config()
378 	chan->tin_ns = tin_ns;  in __pwm_samsung_config()
379 	chan->duty_ns = duty_ns;  in __pwm_samsung_config()
384 static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm,  in pwm_samsung_config()  argument
387 	return __pwm_samsung_config(chip, pwm, duty_ns, period_ns, false);  in pwm_samsung_config()
399 	tcon = readl(chip->base + REG_TCON);  in pwm_samsung_set_invert()
402 		chip->inverter_mask |= BIT(channel);  in pwm_samsung_set_invert()
405 		chip->inverter_mask &= ~BIT(channel);  in pwm_samsung_set_invert()
409 	writel(tcon, chip->base + REG_TCON);  in pwm_samsung_set_invert()
415 				    struct pwm_device *pwm,  in pwm_samsung_set_polarity()  argument
422 	pwm_samsung_set_invert(our_chip, pwm->hwpwm, invert);  in pwm_samsung_set_polarity()
467 	{ .compatible = "samsung,s3c2410-pwm", .data = &s3c24xx_variant },
468 	{ .compatible = "samsung,s3c6400-pwm", .data = &s3c64xx_variant },
469 	{ .compatible = "samsung,s5p6440-pwm", .data = &s5p64x0_variant },
470 	{ .compatible = "samsung,s5pc100-pwm", .data = &s5pc100_variant },
471 	{ .compatible = "samsung,exynos4210-pwm", .data = &s5p64x0_variant },
478 	struct device_node *np = chip->chip.dev->of_node;  in pwm_samsung_parse_dt()
486 		return -ENODEV;  in pwm_samsung_parse_dt()
488 	memcpy(&chip->variant, match->data, sizeof(chip->variant));  in pwm_samsung_parse_dt()
490 	of_property_for_each_u32(np, "samsung,pwm-outputs", prop, cur, val) {  in pwm_samsung_parse_dt()
492 			dev_err(chip->chip.dev,  in pwm_samsung_parse_dt()
493 				"%s: invalid channel index in samsung,pwm-outputs property\n",  in pwm_samsung_parse_dt()
497 		chip->variant.output_mask |= BIT(val);  in pwm_samsung_parse_dt()
505 	return -ENODEV;  in pwm_samsung_parse_dt()
511 	struct device *dev = &pdev->dev;  in pwm_samsung_probe()
517 	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);  in pwm_samsung_probe()
519 		return -ENOMEM;  in pwm_samsung_probe()
521 	chip->chip.dev = &pdev->dev;  in pwm_samsung_probe()
522 	chip->chip.ops = &pwm_samsung_ops;  in pwm_samsung_probe()
523 	chip->chip.base = -1;  in pwm_samsung_probe()
524 	chip->chip.npwm = SAMSUNG_PWM_NUM;  in pwm_samsung_probe()
525 	chip->inverter_mask = BIT(SAMSUNG_PWM_NUM) - 1;  in pwm_samsung_probe()
527 	if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {  in pwm_samsung_probe()
532 		chip->chip.of_xlate = of_pwm_xlate_with_flags;  in pwm_samsung_probe()
533 		chip->chip.of_pwm_n_cells = 3;  in pwm_samsung_probe()
535 		if (!pdev->dev.platform_data) {  in pwm_samsung_probe()
536 			dev_err(&pdev->dev, "no platform data specified\n");  in pwm_samsung_probe()
537 			return -EINVAL;  in pwm_samsung_probe()
540 		memcpy(&chip->variant, pdev->dev.platform_data,  in pwm_samsung_probe()
541 							sizeof(chip->variant));  in pwm_samsung_probe()
545 	chip->base = devm_ioremap_resource(&pdev->dev, res);  in pwm_samsung_probe()
546 	if (IS_ERR(chip->base))  in pwm_samsung_probe()
547 		return PTR_ERR(chip->base);  in pwm_samsung_probe()
549 	chip->base_clk = devm_clk_get(&pdev->dev, "timers");  in pwm_samsung_probe()
550 	if (IS_ERR(chip->base_clk)) {  in pwm_samsung_probe()
552 		return PTR_ERR(chip->base_clk);  in pwm_samsung_probe()
555 	ret = clk_prepare_enable(chip->base_clk);  in pwm_samsung_probe()
562 		if (chip->variant.output_mask & BIT(chan))  in pwm_samsung_probe()
566 	chip->tclk0 = devm_clk_get(&pdev->dev, "pwm-tclk0");  in pwm_samsung_probe()
567 	chip->tclk1 = devm_clk_get(&pdev->dev, "pwm-tclk1");  in pwm_samsung_probe()
571 	ret = pwmchip_add(&chip->chip);  in pwm_samsung_probe()
573 		dev_err(dev, "failed to register PWM chip\n");  in pwm_samsung_probe()
574 		clk_disable_unprepare(chip->base_clk);  in pwm_samsung_probe()
579 		clk_get_rate(chip->base_clk),  in pwm_samsung_probe()
580 		!IS_ERR(chip->tclk0) ? clk_get_rate(chip->tclk0) : 0,  in pwm_samsung_probe()
581 		!IS_ERR(chip->tclk1) ? clk_get_rate(chip->tclk1) : 0);  in pwm_samsung_probe()
591 	ret = pwmchip_remove(&chip->chip);  in pwm_samsung_remove()
595 	clk_disable_unprepare(chip->base_clk);  in pwm_samsung_remove()
604 	struct pwm_chip *chip = &our_chip->chip;  in pwm_samsung_resume()
608 		struct pwm_device *pwm = &chip->pwms[i];  in pwm_samsung_resume()  local
609 		struct samsung_pwm_channel *chan = pwm_get_chip_data(pwm);  in pwm_samsung_resume()
614 		if (our_chip->variant.output_mask & BIT(i))  in pwm_samsung_resume()
616 					our_chip->inverter_mask & BIT(i));  in pwm_samsung_resume()
618 		if (chan->period_ns) {  in pwm_samsung_resume()
619 			__pwm_samsung_config(chip, pwm, chan->duty_ns,  in pwm_samsung_resume()
620 					     chan->period_ns, true);  in pwm_samsung_resume()
621 			/* needed to make PWM disable work on Odroid-XU3 */  in pwm_samsung_resume()
622 			pwm_samsung_manual_update(our_chip, pwm);  in pwm_samsung_resume()
625 		if (our_chip->disabled_mask & BIT(i))  in pwm_samsung_resume()
626 			pwm_samsung_disable(chip, pwm);  in pwm_samsung_resume()
628 			pwm_samsung_enable(chip, pwm);  in pwm_samsung_resume()
639 		.name	= "samsung-pwm",
650 MODULE_ALIAS("platform:samsung-pwm");