1 files changed, 446 insertions, 239 deletions

diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index 5f10cba492ec..a59de4de18b6 100644
--- a/drivers/pwm/pwm-stm32.c
+++ b/drivers/pwm/pwm-stm32.c
@@ -27,7 +27,6 @@ struct stm32_breakinput {
 };
 
 struct stm32_pwm {
-	struct pwm_chip chip;
 	struct mutex lock; /* protect pwm config/enable */
 	struct clk *clk;
 	struct regmap *regmap;
@@ -40,7 +39,7 @@ struct stm32_pwm {
 
 static inline struct stm32_pwm *to_stm32_pwm_dev(struct pwm_chip *chip)
 {
-	return container_of(chip, struct stm32_pwm, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static u32 active_channels(struct stm32_pwm *dev)
@@ -52,6 +51,391 @@ static u32 active_channels(struct stm32_pwm *dev)
 	return ccer & TIM_CCER_CCXE;
 }
 
+struct stm32_pwm_waveform {
+	u32 ccer;
+	u32 psc;
+	u32 arr;
+	u32 ccr;
+};
+
+static int stm32_pwm_round_waveform_tohw(struct pwm_chip *chip,
+					 struct pwm_device *pwm,
+					 const struct pwm_waveform *wf,
+					 void *_wfhw)
+{
+	struct stm32_pwm_waveform *wfhw = _wfhw;
+	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+	unsigned int ch = pwm->hwpwm;
+	unsigned long rate;
+	u64 ccr, duty;
+	int ret;
+
+	if (wf->period_length_ns == 0) {
+		*wfhw = (struct stm32_pwm_waveform){
+			.ccer = 0,
+		};
+
+		return 0;
+	}
+
+	ret = clk_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	wfhw->ccer = TIM_CCER_CCxE(ch + 1);
+	if (priv->have_complementary_output)
+		wfhw->ccer |= TIM_CCER_CCxNE(ch + 1);
+
+	rate = clk_get_rate(priv->clk);
+
+	if (active_channels(priv) & ~(1 << ch * 4)) {
+		u64 arr;
+
+		/*
+		 * Other channels are already enabled, so the configured PSC and
+		 * ARR must be used for this channel, too.
+		 */
+		ret = regmap_read(priv->regmap, TIM_PSC, &wfhw->psc);
+		if (ret)
+			goto out;
+
+		ret = regmap_read(priv->regmap, TIM_ARR, &wfhw->arr);
+		if (ret)
+			goto out;
+
+		/*
+		 * calculate the best value for ARR for the given PSC, refuse if
+		 * the resulting period gets bigger than the requested one.
+		 */
+		arr = mul_u64_u64_div_u64(wf->period_length_ns, rate,
+					  (u64)NSEC_PER_SEC * (wfhw->psc + 1));
+		if (arr <= wfhw->arr) {
+			/*
+			 * requested period is small than the currently
+			 * configured and unchangable period, report back the smallest
+			 * possible period, i.e. the current state; Initialize
+			 * ccr to anything valid.
+			 */
+			wfhw->ccr = 0;
+			ret = 1;
+			goto out;
+		}
+
+	} else {
+		/*
+		 * .probe() asserted that clk_get_rate() is not bigger than 1 GHz, so
+		 * the calculations here won't overflow.
+		 * First we need to find the minimal value for prescaler such that
+		 *
+		 *        period_ns * clkrate
+		 *   ------------------------------ < max_arr + 1
+		 *   NSEC_PER_SEC * (prescaler + 1)
+		 *
+		 * This equation is equivalent to
+		 *
+		 *        period_ns * clkrate
+		 *   ---------------------------- < prescaler + 1
+		 *   NSEC_PER_SEC * (max_arr + 1)
+		 *
+		 * Using integer division and knowing that the right hand side is
+		 * integer, this is further equivalent to
+		 *
+		 *   (period_ns * clkrate) // (NSEC_PER_SEC * (max_arr + 1)) ≤ prescaler
+		 */
+		u64 psc = mul_u64_u64_div_u64(wf->period_length_ns, rate,
+					      (u64)NSEC_PER_SEC * ((u64)priv->max_arr + 1));
+		u64 arr;
+
+		wfhw->psc = min_t(u64, psc, MAX_TIM_PSC);
+
+		arr = mul_u64_u64_div_u64(wf->period_length_ns, rate,
+					  (u64)NSEC_PER_SEC * (wfhw->psc + 1));
+		if (!arr) {
+			/*
+			 * requested period is too small, report back the smallest
+			 * possible period, i.e. ARR = 0. The only valid CCR
+			 * value is then zero, too.
+			 */
+			wfhw->arr = 0;
+			wfhw->ccr = 0;
+			ret = 1;
+			goto out;
+		}
+
+		/*
+		 * ARR is limited intentionally to values less than
+		 * priv->max_arr to allow 100% duty cycle.
+		 */
+		wfhw->arr = min_t(u64, arr, priv->max_arr) - 1;
+	}
+
+	duty = mul_u64_u64_div_u64(wf->duty_length_ns, rate,
+				   (u64)NSEC_PER_SEC * (wfhw->psc + 1));
+	duty = min_t(u64, duty, wfhw->arr + 1);
+
+	if (wf->duty_length_ns && wf->duty_offset_ns &&
+	    wf->duty_length_ns + wf->duty_offset_ns >= wf->period_length_ns) {
+		wfhw->ccer |= TIM_CCER_CCxP(ch + 1);
+		if (priv->have_complementary_output)
+			wfhw->ccer |= TIM_CCER_CCxNP(ch + 1);
+
+		ccr = wfhw->arr + 1 - duty;
+	} else {
+		ccr = duty;
+	}
+
+	wfhw->ccr = min_t(u64, ccr, wfhw->arr + 1);
+
+	dev_dbg(&chip->dev, "pwm#%u: %lld/%lld [+%lld] @%lu -> CCER: %08x, PSC: %08x, ARR: %08x, CCR: %08x\n",
+		pwm->hwpwm, wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,
+		rate, wfhw->ccer, wfhw->psc, wfhw->arr, wfhw->ccr);
+
+out:
+	clk_disable(priv->clk);
+
+	return ret;
+}
+
+/*
+ * This should be moved to lib/math/div64.c. Currently there are some changes
+ * pending to mul_u64_u64_div_u64. Uwe will care for that when the dust settles.
+ */
+static u64 stm32_pwm_mul_u64_u64_div_u64_roundup(u64 a, u64 b, u64 c)
+{
+	u64 res = mul_u64_u64_div_u64(a, b, c);
+	/* Those multiplications might overflow but it doesn't matter */
+	u64 rem = a * b - c * res;
+
+	if (rem)
+		res += 1;
+
+	return res;
+}
+
+static int stm32_pwm_round_waveform_fromhw(struct pwm_chip *chip,
+					   struct pwm_device *pwm,
+					   const void *_wfhw,
+					   struct pwm_waveform *wf)
+{
+	const struct stm32_pwm_waveform *wfhw = _wfhw;
+	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+	unsigned int ch = pwm->hwpwm;
+
+	if (wfhw->ccer & TIM_CCER_CCxE(ch + 1)) {
+		unsigned long rate = clk_get_rate(priv->clk);
+		u64 ccr_ns;
+
+		/* The result doesn't overflow for rate >= 15259 */
+		wf->period_length_ns = stm32_pwm_mul_u64_u64_div_u64_roundup(((u64)wfhw->psc + 1) * (wfhw->arr + 1),
+									     NSEC_PER_SEC, rate);
+
+		ccr_ns = stm32_pwm_mul_u64_u64_div_u64_roundup(((u64)wfhw->psc + 1) * wfhw->ccr,
+							       NSEC_PER_SEC, rate);
+
+		if (wfhw->ccer & TIM_CCER_CCxP(ch + 1)) {
+			wf->duty_length_ns =
+				stm32_pwm_mul_u64_u64_div_u64_roundup(((u64)wfhw->psc + 1) * (wfhw->arr + 1 - wfhw->ccr),
+								      NSEC_PER_SEC, rate);
+
+			wf->duty_offset_ns = ccr_ns;
+		} else {
+			wf->duty_length_ns = ccr_ns;
+			wf->duty_offset_ns = 0;
+		}
+
+		dev_dbg(&chip->dev, "pwm#%u: CCER: %08x, PSC: %08x, ARR: %08x, CCR: %08x @%lu -> %lld/%lld [+%lld]\n",
+			pwm->hwpwm, wfhw->ccer, wfhw->psc, wfhw->arr, wfhw->ccr, rate,
+			wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns);
+
+	} else {
+		*wf = (struct pwm_waveform){
+			.period_length_ns = 0,
+		};
+	}
+
+	return 0;
+}
+
+static int stm32_pwm_read_waveform(struct pwm_chip *chip,
+				     struct pwm_device *pwm,
+				     void *_wfhw)
+{
+	struct stm32_pwm_waveform *wfhw = _wfhw;
+	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+	unsigned int ch = pwm->hwpwm;
+	int ret;
+
+	ret = clk_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(priv->regmap, TIM_CCER, &wfhw->ccer);
+	if (ret)
+		goto out;
+
+	if (wfhw->ccer & TIM_CCER_CCxE(ch + 1)) {
+		ret = regmap_read(priv->regmap, TIM_PSC, &wfhw->psc);
+		if (ret)
+			goto out;
+
+		ret = regmap_read(priv->regmap, TIM_ARR, &wfhw->arr);
+		if (ret)
+			goto out;
+
+		if (wfhw->arr == U32_MAX)
+			wfhw->arr -= 1;
+
+		ret = regmap_read(priv->regmap, TIM_CCRx(ch + 1), &wfhw->ccr);
+		if (ret)
+			goto out;
+
+		if (wfhw->ccr > wfhw->arr + 1)
+			wfhw->ccr = wfhw->arr + 1;
+	}
+
+out:
+	clk_disable(priv->clk);
+
+	return ret;
+}
+
+static int stm32_pwm_write_waveform(struct pwm_chip *chip,
+				      struct pwm_device *pwm,
+				      const void *_wfhw)
+{
+	const struct stm32_pwm_waveform *wfhw = _wfhw;
+	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+	unsigned int ch = pwm->hwpwm;
+	int ret;
+
+	ret = clk_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	if (wfhw->ccer & TIM_CCER_CCxE(ch + 1)) {
+		u32 ccer, mask;
+		unsigned int shift;
+		u32 ccmr;
+
+		ret = regmap_read(priv->regmap, TIM_CCER, &ccer);
+		if (ret)
+			goto out;
+
+		/* If there are other channels enabled, don't update PSC and ARR */
+		if (ccer & ~TIM_CCER_CCxE(ch + 1) & TIM_CCER_CCXE) {
+			u32 psc, arr;
+
+			ret = regmap_read(priv->regmap, TIM_PSC, &psc);
+			if (ret)
+				goto out;
+
+			if (psc != wfhw->psc) {
+				ret = -EBUSY;
+				goto out;
+			}
+
+			ret = regmap_read(priv->regmap, TIM_ARR, &arr);
+			if (ret)
+				goto out;
+
+			if (arr != wfhw->arr) {
+				ret = -EBUSY;
+				goto out;
+			}
+		} else {
+			ret = regmap_write(priv->regmap, TIM_PSC, wfhw->psc);
+			if (ret)
+				goto out;
+
+			ret = regmap_write(priv->regmap, TIM_ARR, wfhw->arr);
+			if (ret)
+				goto out;
+
+			ret = regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE);
+			if (ret)
+				goto out;
+
+		}
+
+		/* set polarity */
+		mask = TIM_CCER_CCxP(ch + 1) | TIM_CCER_CCxNP(ch + 1);
+		ret = regmap_update_bits(priv->regmap, TIM_CCER, mask, wfhw->ccer);
+		if (ret)
+			goto out;
+
+		ret = regmap_write(priv->regmap, TIM_CCRx(ch + 1), wfhw->ccr);
+		if (ret)
+			goto out;
+
+		/* Configure output mode */
+		shift = (ch & 0x1) * CCMR_CHANNEL_SHIFT;
+		ccmr = (TIM_CCMR_PE | TIM_CCMR_M1) << shift;
+		mask = CCMR_CHANNEL_MASK << shift;
+
+		if (ch < 2)
+			ret = regmap_update_bits(priv->regmap, TIM_CCMR1, mask, ccmr);
+		else
+			ret = regmap_update_bits(priv->regmap, TIM_CCMR2, mask, ccmr);
+		if (ret)
+			goto out;
+
+		ret = regmap_set_bits(priv->regmap, TIM_BDTR, TIM_BDTR_MOE);
+		if (ret)
+			goto out;
+
+		if (!(ccer & TIM_CCER_CCxE(ch + 1))) {
+			mask = TIM_CCER_CCxE(ch + 1) | TIM_CCER_CCxNE(ch + 1);
+
+			ret = clk_enable(priv->clk);
+			if (ret)
+				goto out;
+
+			ccer = (ccer & ~mask) | (wfhw->ccer & mask);
+			regmap_write(priv->regmap, TIM_CCER, ccer);
+
+			/* Make sure that registers are updated */
+			regmap_set_bits(priv->regmap, TIM_EGR, TIM_EGR_UG);
+
+			/* Enable controller */
+			regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
+		}
+
+	} else {
+		/* disable channel */
+		u32 mask, ccer;
+
+		mask = TIM_CCER_CCxE(ch + 1);
+		if (priv->have_complementary_output)
+			mask |= TIM_CCER_CCxNE(ch + 1);
+
+		ret = regmap_read(priv->regmap, TIM_CCER, &ccer);
+		if (ret)
+			goto out;
+
+		if (ccer & mask) {
+			ccer = ccer & ~mask;
+
+			ret = regmap_write(priv->regmap, TIM_CCER, ccer);
+			if (ret)
+				goto out;
+
+			if (!(ccer & TIM_CCER_CCXE)) {
+				/* When all channels are disabled, we can disable the controller */
+				ret = regmap_clear_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
+				if (ret)
+					goto out;
+			}
+
+			clk_disable(priv->clk);
+		}
+	}
+
+out:
+	clk_disable(priv->clk);
+
+	return ret;
+}
+
 #define TIM_CCER_CC12P (TIM_CCER_CC1P | TIM_CCER_CC2P)
 #define TIM_CCER_CC12E (TIM_CCER_CC1E | TIM_CCER_CC2E)
 #define TIM_CCER_CC34P (TIM_CCER_CC3P | TIM_CCER_CC4P)
@@ -90,11 +474,12 @@ static u32 active_channels(struct stm32_pwm *dev)
  * - Period     = t2 - t0
  * - Duty cycle = t1 - t0
  */
-static int stm32_pwm_raw_capture(struct stm32_pwm *priv, struct pwm_device *pwm,
+static int stm32_pwm_raw_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 				 unsigned long tmo_ms, u32 *raw_prd,
 				 u32 *raw_dty)
 {
-	struct device *parent = priv->chip.dev->parent;
+	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+	struct device *parent = pwmchip_parent(chip)->parent;
 	enum stm32_timers_dmas dma_id;
 	u32 ccen, ccr;
 	int ret;
@@ -170,7 +555,7 @@ static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	ret = clk_enable(priv->clk);
 	if (ret) {
-		dev_err(priv->chip.dev, "failed to enable counter clock\n");
+		dev_err(pwmchip_parent(chip), "failed to enable counter clock\n");
 		goto unlock;
 	}
 
@@ -208,7 +593,7 @@ static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 			   TIM_CCER_CC12P : TIM_CCER_CC34P, pwm->hwpwm < 2 ?
 			   TIM_CCER_CC2P : TIM_CCER_CC4P);
 
-	ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd, &raw_dty);
+	ret = stm32_pwm_raw_capture(chip, pwm, tmo_ms, &raw_prd, &raw_dty);
 	if (ret)
 		goto stop;
 
@@ -222,14 +607,14 @@ static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 
 		scale = max_arr / min(max_arr, raw_prd);
 	} else {
-		scale = priv->max_arr; /* bellow resolution, use max scale */
+		scale = priv->max_arr; /* below resolution, use max scale */
 	}
 
 	if (psc && scale > 1) {
 		/* 2nd measure with new scale */
 		psc /= scale;
 		regmap_write(priv->regmap, TIM_PSC, psc);
-		ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd,
+		ret = stm32_pwm_raw_capture(chip, pwm, tmo_ms, &raw_prd,
 					    &raw_dty);
 		if (ret)
 			goto stop;
@@ -257,7 +642,7 @@ static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
 			   FIELD_PREP(TIM_CCMR_IC1PSC, icpsc) |
 			   FIELD_PREP(TIM_CCMR_IC2PSC, icpsc));
 
-	ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd, &raw_dty);
+	ret = stm32_pwm_raw_capture(chip, pwm, tmo_ms, &raw_prd, &raw_dty);
 	if (ret)
 		goto stop;
 
@@ -308,213 +693,13 @@ unlock:
 	return ret;
 }
 
-static int stm32_pwm_config(struct stm32_pwm *priv, unsigned int ch,
-			    int duty_ns, int period_ns)
-{
-	unsigned long long prd, div, dty;
-	unsigned int prescaler = 0;
-	u32 ccmr, mask, shift;
-
-	/* Period and prescaler values depends on clock rate */
-	div = (unsigned long long)clk_get_rate(priv->clk) * period_ns;
-
-	do_div(div, NSEC_PER_SEC);
-	prd = div;
-
-	while (div > priv->max_arr) {
-		prescaler++;
-		div = prd;
-		do_div(div, prescaler + 1);
-	}
-
-	prd = div;
-
-	if (prescaler > MAX_TIM_PSC)
-		return -EINVAL;
-
-	/*
-	 * All channels share the same prescaler and counter so when two
-	 * channels are active at the same time we can't change them
-	 */
-	if (active_channels(priv) & ~(1 << ch * 4)) {
-		u32 psc, arr;
-
-		regmap_read(priv->regmap, TIM_PSC, &psc);
-		regmap_read(priv->regmap, TIM_ARR, &arr);
-
-		if ((psc != prescaler) || (arr != prd - 1))
-			return -EBUSY;
-	}
-
-	regmap_write(priv->regmap, TIM_PSC, prescaler);
-	regmap_write(priv->regmap, TIM_ARR, prd - 1);
-	regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE);
-
-	/* Calculate the duty cycles */
-	dty = prd * duty_ns;
-	do_div(dty, period_ns);
-
-	regmap_write(priv->regmap, TIM_CCR1 + 4 * ch, dty);
-
-	/* Configure output mode */
-	shift = (ch & 0x1) * CCMR_CHANNEL_SHIFT;
-	ccmr = (TIM_CCMR_PE | TIM_CCMR_M1) << shift;
-	mask = CCMR_CHANNEL_MASK << shift;
-
-	if (ch < 2)
-		regmap_update_bits(priv->regmap, TIM_CCMR1, mask, ccmr);
-	else
-		regmap_update_bits(priv->regmap, TIM_CCMR2, mask, ccmr);
-
-	regmap_set_bits(priv->regmap, TIM_BDTR, TIM_BDTR_MOE);
-
-	return 0;
-}
-
-static int stm32_pwm_set_polarity(struct stm32_pwm *priv, unsigned int ch,
-				  enum pwm_polarity polarity)
-{
-	u32 mask;
-
-	mask = TIM_CCER_CC1P << (ch * 4);
-	if (priv->have_complementary_output)
-		mask |= TIM_CCER_CC1NP << (ch * 4);
-
-	regmap_update_bits(priv->regmap, TIM_CCER, mask,
-			   polarity == PWM_POLARITY_NORMAL ? 0 : mask);
-
-	return 0;
-}
-
-static int stm32_pwm_enable(struct stm32_pwm *priv, unsigned int ch)
-{
-	u32 mask;
-	int ret;
-
-	ret = clk_enable(priv->clk);
-	if (ret)
-		return ret;
-
-	/* Enable channel */
-	mask = TIM_CCER_CC1E << (ch * 4);
-	if (priv->have_complementary_output)
-		mask |= TIM_CCER_CC1NE << (ch * 4);
-
-	regmap_set_bits(priv->regmap, TIM_CCER, mask);
-
-	/* Make sure that registers are updated */
-	regmap_set_bits(priv->regmap, TIM_EGR, TIM_EGR_UG);
-
-	/* Enable controller */
-	regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
-
-	return 0;
-}
-
-static void stm32_pwm_disable(struct stm32_pwm *priv, unsigned int ch)
-{
-	u32 mask;
-
-	/* Disable channel */
-	mask = TIM_CCER_CC1E << (ch * 4);
-	if (priv->have_complementary_output)
-		mask |= TIM_CCER_CC1NE << (ch * 4);
-
-	regmap_clear_bits(priv->regmap, TIM_CCER, mask);
-
-	/* When all channels are disabled, we can disable the controller */
-	if (!active_channels(priv))
-		regmap_clear_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
-
-	clk_disable(priv->clk);
-}
-
-static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
-			   const struct pwm_state *state)
-{
-	bool enabled;
-	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
-	int ret;
-
-	enabled = pwm->state.enabled;
-
-	if (enabled && !state->enabled) {
-		stm32_pwm_disable(priv, pwm->hwpwm);
-		return 0;
-	}
-
-	if (state->polarity != pwm->state.polarity)
-		stm32_pwm_set_polarity(priv, pwm->hwpwm, state->polarity);
-
-	ret = stm32_pwm_config(priv, pwm->hwpwm,
-			       state->duty_cycle, state->period);
-	if (ret)
-		return ret;
-
-	if (!enabled && state->enabled)
-		ret = stm32_pwm_enable(priv, pwm->hwpwm);
-
-	return ret;
-}
-
-static int stm32_pwm_apply_locked(struct pwm_chip *chip, struct pwm_device *pwm,
-				  const struct pwm_state *state)
-{
-	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
-	int ret;
-
-	/* protect common prescaler for all active channels */
-	mutex_lock(&priv->lock);
-	ret = stm32_pwm_apply(chip, pwm, state);
-	mutex_unlock(&priv->lock);
-
-	return ret;
-}
-
-static int stm32_pwm_get_state(struct pwm_chip *chip,
-			       struct pwm_device *pwm, struct pwm_state *state)
-{
-	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
-	int ch = pwm->hwpwm;
-	unsigned long rate;
-	u32 ccer, psc, arr, ccr;
-	u64 dty, prd;
-	int ret;
-
-	mutex_lock(&priv->lock);
-
-	ret = regmap_read(priv->regmap, TIM_CCER, &ccer);
-	if (ret)
-		goto out;
-
-	state->enabled = ccer & (TIM_CCER_CC1E << (ch * 4));
-	state->polarity = (ccer & (TIM_CCER_CC1P << (ch * 4))) ?
-			  PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
-	ret = regmap_read(priv->regmap, TIM_PSC, &psc);
-	if (ret)
-		goto out;
-	ret = regmap_read(priv->regmap, TIM_ARR, &arr);
-	if (ret)
-		goto out;
-	ret = regmap_read(priv->regmap, TIM_CCR1 + 4 * ch, &ccr);
-	if (ret)
-		goto out;
-
-	rate = clk_get_rate(priv->clk);
-
-	prd = (u64)NSEC_PER_SEC * (psc + 1) * (arr + 1);
-	state->period = DIV_ROUND_UP_ULL(prd, rate);
-	dty = (u64)NSEC_PER_SEC * (psc + 1) * ccr;
-	state->duty_cycle = DIV_ROUND_UP_ULL(dty, rate);
-
-out:
-	mutex_unlock(&priv->lock);
-	return ret;
-}
-
 static const struct pwm_ops stm32pwm_ops = {
-	.apply = stm32_pwm_apply_locked,
-	.get_state = stm32_pwm_get_state,
+	.sizeof_wfhw = sizeof(struct stm32_pwm_waveform),
+	.round_waveform_tohw = stm32_pwm_round_waveform_tohw,
+	.round_waveform_fromhw = stm32_pwm_round_waveform_fromhw,
+	.read_waveform = stm32_pwm_read_waveform,
+	.write_waveform = stm32_pwm_write_waveform,
+
 	.capture = IS_ENABLED(CONFIG_DMA_ENGINE) ? stm32_pwm_capture : NULL,
 };
 
@@ -605,7 +790,7 @@ static void stm32_pwm_detect_complementary(struct stm32_pwm *priv)
 	priv->have_complementary_output = (ccer != 0);
 }
 
-static unsigned int stm32_pwm_detect_channels(struct stm32_pwm *priv,
+static unsigned int stm32_pwm_detect_channels(struct regmap *regmap,
 					      unsigned int *num_enabled)
 {
 	u32 ccer, ccer_backup;
@@ -614,10 +799,10 @@ static unsigned int stm32_pwm_detect_channels(struct stm32_pwm *priv,
 	 * If channels enable bits don't exist writing 1 will have no
 	 * effect so we can detect and count them.
 	 */
-	regmap_read(priv->regmap, TIM_CCER, &ccer_backup);
-	regmap_set_bits(priv->regmap, TIM_CCER, TIM_CCER_CCXE);
-	regmap_read(priv->regmap, TIM_CCER, &ccer);
-	regmap_write(priv->regmap, TIM_CCER, ccer_backup);
+	regmap_read(regmap, TIM_CCER, &ccer_backup);
+	regmap_set_bits(regmap, TIM_CCER, TIM_CCER_CCXE);
+	regmap_read(regmap, TIM_CCER, &ccer);
+	regmap_write(regmap, TIM_CCER, ccer_backup);
 
 	*num_enabled = hweight32(ccer_backup & TIM_CCER_CCXE);
 
@@ -629,14 +814,18 @@ static int stm32_pwm_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
+	struct pwm_chip *chip;
 	struct stm32_pwm *priv;
-	unsigned int num_enabled;
+	unsigned int npwm, num_enabled;
 	unsigned int i;
 	int ret;
 
-	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
+	npwm = stm32_pwm_detect_channels(ddata->regmap, &num_enabled);
+
+	chip = devm_pwmchip_alloc(dev, npwm, sizeof(*priv));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	priv = to_stm32_pwm_dev(chip);
 
 	mutex_init(&priv->lock);
 	priv->regmap = ddata->regmap;
@@ -644,45 +833,62 @@ static int stm32_pwm_probe(struct platform_device *pdev)
 	priv->max_arr = ddata->max_arr;
 
 	if (!priv->regmap || !priv->clk)
-		return -EINVAL;
+		return dev_err_probe(dev, -EINVAL, "Failed to get %s\n",
+				     priv->regmap ? "clk" : "regmap");
 
 	ret = stm32_pwm_probe_breakinputs(priv, np);
 	if (ret)
-		return ret;
+		return dev_err_probe(dev, ret,
+				     "Failed to configure breakinputs\n");
 
 	stm32_pwm_detect_complementary(priv);
 
-	priv->chip.dev = dev;
-	priv->chip.ops = &stm32pwm_ops;
-	priv->chip.npwm = stm32_pwm_detect_channels(priv, &num_enabled);
+	ret = devm_clk_rate_exclusive_get(dev, priv->clk);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to lock clock\n");
+
+	/*
+	 * With the clk running with not more than 1 GHz the calculations in
+	 * .apply() won't overflow.
+	 */
+	if (clk_get_rate(priv->clk) > 1000000000)
+		return dev_err_probe(dev, -EINVAL, "Clock freq too high (%lu)\n",
+				     clk_get_rate(priv->clk));
+
+	chip->ops = &stm32pwm_ops;
 
 	/* Initialize clock refcount to number of enabled PWM channels. */
-	for (i = 0; i < num_enabled; i++)
-		clk_enable(priv->clk);
+	for (i = 0; i < num_enabled; i++) {
+		ret = clk_enable(priv->clk);
+		if (ret)
+			return ret;
+	}
 
-	ret = devm_pwmchip_add(dev, &priv->chip);
+	ret = devm_pwmchip_add(dev, chip);
 	if (ret < 0)
-		return ret;
+		return dev_err_probe(dev, ret,
+				     "Failed to register pwmchip\n");
 
-	platform_set_drvdata(pdev, priv);
+	platform_set_drvdata(pdev, chip);
 
 	return 0;
 }
 
 static int stm32_pwm_suspend(struct device *dev)
 {
-	struct stm32_pwm *priv = dev_get_drvdata(dev);
+	struct pwm_chip *chip = dev_get_drvdata(dev);
+	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
 	unsigned int i;
 	u32 ccer, mask;
 
 	/* Look for active channels */
 	ccer = active_channels(priv);
 
-	for (i = 0; i < priv->chip.npwm; i++) {
-		mask = TIM_CCER_CC1E << (i * 4);
+	for (i = 0; i < chip->npwm; i++) {
+		mask = TIM_CCER_CCxE(i + 1);
 		if (ccer & mask) {
 			dev_err(dev, "PWM %u still in use by consumer %s\n",
-				i, priv->chip.pwms[i].label);
+				i, chip->pwms[i].label);
 			return -EBUSY;
 		}
 	}
@@ -692,7 +898,8 @@ static int stm32_pwm_suspend(struct device *dev)
 
 static int stm32_pwm_resume(struct device *dev)
 {
-	struct stm32_pwm *priv = dev_get_drvdata(dev);
+	struct pwm_chip *chip = dev_get_drvdata(dev);
+	struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
 	int ret;
 
 	ret = pinctrl_pm_select_default_state(dev);