@@ -51,6 +51,384 @@ 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 == 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);
+
+ 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, 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, 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, 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, rate,
+ (u64)NSEC_PER_SEC * (wfhw->psc + 1));
+ duty = min_t(u64, duty, wfhw->arr + 1);
+
+ if (wf->duty_length && wf->duty_offset &&
+ wf->duty_length + wf->duty_offset >= wf->period_length) {
+ 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, wf->period_length, wf->duty_offset,
+ 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 = 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 =
+ stm32_pwm_mul_u64_u64_div_u64_roundup(((u64)wfhw->psc + 1) * (wfhw->arr + 1 - wfhw->ccr),
+ NSEC_PER_SEC, rate);
+
+ wf->duty_offset = ccr_ns;
+ } else {
+ wf->duty_length = ccr_ns;
+ wf->duty_offset = 0;
+ }
+ } else {
+ *wf = (struct pwm_waveform){
+ .period_length = 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 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;
+ }
+
+ 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)
@@ -308,228 +686,13 @@ static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
return ret;
}
-static int stm32_pwm_config(struct stm32_pwm *priv, unsigned int ch,
- u64 duty_ns, u64 period_ns)
-{
- unsigned long long prd, dty;
- unsigned long long prescaler;
- u32 ccmr, mask, shift;
-
- /*
- * .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
- */
-
- prescaler = mul_u64_u64_div_u64(period_ns, clk_get_rate(priv->clk),
- (u64)NSEC_PER_SEC * ((u64)priv->max_arr + 1));
- if (prescaler > MAX_TIM_PSC)
- return -EINVAL;
-
- prd = mul_u64_u64_div_u64(period_ns, clk_get_rate(priv->clk),
- (u64)NSEC_PER_SEC * (prescaler + 1));
- if (!prd)
- 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 = mul_u64_u64_div_u64(duty_ns, clk_get_rate(priv->clk),
- (u64)NSEC_PER_SEC * (prescaler + 1));
-
- regmap_write(priv->regmap, TIM_CCRx(ch + 1), 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_CCxP(ch + 1);
- if (priv->have_complementary_output)
- mask |= TIM_CCER_CCxNP(ch + 1);
-
- 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_CCxE(ch + 1);
- if (priv->have_complementary_output)
- mask |= TIM_CCER_CCxNE(ch);
-
- 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_CCxE(ch + 1);
- if (priv->have_complementary_output)
- mask |= TIM_CCER_CCxNE(ch + 1);
-
- 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 (!state->enabled) {
- if (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_CCxE(ch + 1);
- state->polarity = (ccer & TIM_CCER_CCxP(ch + 1)) ?
- 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_CCRx(ch + 1), &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,
};
Convert the stm32 pwm driver to use the new callbacks for hardware programming. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> --- drivers/pwm/pwm-stm32.c | 605 +++++++++++++++++++++++++--------------- 1 file changed, 384 insertions(+), 221 deletions(-)