| Message ID | 20231220145726.640627-11-fabrice.gasnier@foss.st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | counter: Add stm32 timer events support | expand |
On Wed, Dec 20, 2023 at 03:57:26PM +0100, Fabrice Gasnier wrote: > + /* > + * configure channel in input capture mode, map channel 1 on TI1, channel2 on TI2... > + * Select both edges / non-inverted to trigger a capture. > + */ I suggest defining a new local variable 'cc' to point to stm32_cc[ch]. I think that's make the code look nicer here to avoid all the array index syntax every time you access stm32_cc[ch]. > + if (enable) { > + /* first clear possibly latched capture flag upon enabling */ > + regmap_read(priv->regmap, TIM_CCER, &ccer); > + if (!(ccer & stm32_cc[ch].ccer_bits)) { Try regmap_test_bits() here instead of using regmap_read(). > + sr = ~TIM_SR_CC_IF(ch); > + regmap_write(priv->regmap, TIM_SR, sr); Eliminate 'sr' by regmap_write(priv->regmap, TIM_SR, ~TIM_SR_CC_IF(ch)). > @@ -366,6 +460,12 @@ static int stm32_count_events_configure(struct counter_device *counter) > regmap_write(priv->regmap, TIM_SR, (u32)~TIM_SR_UIF); > dier |= TIM_DIER_UIE; > break; > + case COUNTER_EVENT_CAPTURE: > + ret = stm32_count_capture_configure(counter, event_node->channel, true); > + if (ret) > + return ret; > + dier |= TIM_DIER_CC_IE(event_node->channel); Ah, now I understand why the previous patch OR'd TIM_DIER_UIE to dier. Apologies for the noise. > @@ -374,6 +474,15 @@ static int stm32_count_events_configure(struct counter_device *counter) > > regmap_write(priv->regmap, TIM_DIER, dier); > > + /* check for disabled capture events */ > + for (i = 0 ; i < priv->nchannels; i++) { > + if (!(dier & TIM_DIER_CC_IE(i))) { > + ret = stm32_count_capture_configure(counter, i, false); > + if (ret) > + return ret; > + } Would for_each_clear_bitrange() in linux/find.h work for this loop? > @@ -504,7 +620,7 @@ static irqreturn_t stm32_timer_cnt_isr(int irq, void *ptr) > * Some status bits in SR don't match with the enable bits in DIER. Only take care of > * the possibly enabled bits in DIER (that matches in between SR and DIER). > */ > - dier &= TIM_DIER_UIE; > + dier &= (TIM_DIER_UIE | TIM_DIER_CC1IE | TIM_DIER_CC2IE | TIM_DIER_CC3IE | TIM_DIER_CC4IE); Again, sorry for the noise on the previous patch; this makes sense now. > @@ -515,6 +631,15 @@ static irqreturn_t stm32_timer_cnt_isr(int irq, void *ptr) > clr &= ~TIM_SR_UIF; > } > > + /* Check capture events */ > + for (i = 0 ; i < priv->nchannels; i++) { > + if (sr & TIM_SR_CC_IF(i)) { Would for_each_set_bitrange() in linux/find.h work for this loop? > + counter_push_event(counter, COUNTER_EVENT_CAPTURE, i); > + clr &= ~TIM_SR_CC_IF(i); Perhaps u32p_replace_bits(&clr, 0, TIM_SR_CC_IF(i)) is clearer here. > @@ -627,8 +752,11 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev) > } > } else { > for (i = 0; i < priv->nr_irqs; i++) { > - /* Only take care of update IRQ for overflow events */ > - if (i != STM32_TIMERS_IRQ_UP) > + /* > + * Only take care of update IRQ for overflow events, and cc for > + * capture events. > + */ > + if (i != STM32_TIMERS_IRQ_UP && i != STM32_TIMERS_IRQ_CC) > continue; Okay, I see now why you have this check. This should be fine as it'll makes adding support in the future for the other IRQs a less invasive change. William Breathitt Gray
On 1/8/24 23:07, William Breathitt Gray wrote: > On Wed, Dec 20, 2023 at 03:57:26PM +0100, Fabrice Gasnier wrote: >> + /* >> + * configure channel in input capture mode, map channel 1 on TI1, channel2 on TI2... >> + * Select both edges / non-inverted to trigger a capture. >> + */ > > I suggest defining a new local variable 'cc' to point to stm32_cc[ch]. I > think that's make the code look nicer here to avoid all the array index > syntax every time you access stm32_cc[ch]. Hi William, Thanks for suggesting. Done. > >> + if (enable) { >> + /* first clear possibly latched capture flag upon enabling */ >> + regmap_read(priv->regmap, TIM_CCER, &ccer); >> + if (!(ccer & stm32_cc[ch].ccer_bits)) { > > Try regmap_test_bits() here instead of using regmap_read(). Done, > >> + sr = ~TIM_SR_CC_IF(ch); >> + regmap_write(priv->regmap, TIM_SR, sr); > > Eliminate 'sr' by regmap_write(priv->regmap, TIM_SR, ~TIM_SR_CC_IF(ch)). > >> @@ -366,6 +460,12 @@ static int stm32_count_events_configure(struct counter_device *counter) >> regmap_write(priv->regmap, TIM_SR, (u32)~TIM_SR_UIF); >> dier |= TIM_DIER_UIE; >> break; >> + case COUNTER_EVENT_CAPTURE: >> + ret = stm32_count_capture_configure(counter, event_node->channel, true); >> + if (ret) >> + return ret; >> + dier |= TIM_DIER_CC_IE(event_node->channel); > > Ah, now I understand why the previous patch OR'd TIM_DIER_UIE to dier. > Apologies for the noise. > >> @@ -374,6 +474,15 @@ static int stm32_count_events_configure(struct counter_device *counter) >> >> regmap_write(priv->regmap, TIM_DIER, dier); >> >> + /* check for disabled capture events */ >> + for (i = 0 ; i < priv->nchannels; i++) { >> + if (!(dier & TIM_DIER_CC_IE(i))) { >> + ret = stm32_count_capture_configure(counter, i, false); >> + if (ret) >> + return ret; >> + } > > Would for_each_clear_bitrange() in linux/find.h work for this loop? I had a look, but it requires to add some variables, for start and stop bit in the bitmap. For now, I've kept the simple BIT macro and bit ops. > >> @@ -504,7 +620,7 @@ static irqreturn_t stm32_timer_cnt_isr(int irq, void *ptr) >> * Some status bits in SR don't match with the enable bits in DIER. Only take care of >> * the possibly enabled bits in DIER (that matches in between SR and DIER). >> */ >> - dier &= TIM_DIER_UIE; >> + dier &= (TIM_DIER_UIE | TIM_DIER_CC1IE | TIM_DIER_CC2IE | TIM_DIER_CC3IE | TIM_DIER_CC4IE); > > Again, sorry for the noise on the previous patch; this makes sense now. > >> @@ -515,6 +631,15 @@ static irqreturn_t stm32_timer_cnt_isr(int irq, void *ptr) >> clr &= ~TIM_SR_UIF; >> } >> >> + /* Check capture events */ >> + for (i = 0 ; i < priv->nchannels; i++) { >> + if (sr & TIM_SR_CC_IF(i)) { > > Would for_each_set_bitrange() in linux/find.h work for this loop? same. > >> + counter_push_event(counter, COUNTER_EVENT_CAPTURE, i); >> + clr &= ~TIM_SR_CC_IF(i); > > Perhaps u32p_replace_bits(&clr, 0, TIM_SR_CC_IF(i)) is clearer here. I've hit some build issue with TIM_SR_CC_IF(i) macro, e.g.: ./include/linux/bitfield.h:165:17: error: call to ‘__bad_mask’ declared with attribute error: bad bitfield mask 165 | __bad_mask(); So I've kept the simple bit operation here. Thanks & Best Regards, Fabrice > >> @@ -627,8 +752,11 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev) >> } >> } else { >> for (i = 0; i < priv->nr_irqs; i++) { >> - /* Only take care of update IRQ for overflow events */ >> - if (i != STM32_TIMERS_IRQ_UP) >> + /* >> + * Only take care of update IRQ for overflow events, and cc for >> + * capture events. >> + */ >> + if (i != STM32_TIMERS_IRQ_UP && i != STM32_TIMERS_IRQ_CC) >> continue; > > Okay, I see now why you have this check. This should be fine as it'll > makes adding support in the future for the other IRQs a less invasive > change. > > William Breathitt Gray
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c index d13e4c427965..0b131ca71de6 100644 --- a/drivers/counter/stm32-timer-cnt.c +++ b/drivers/counter/stm32-timer-cnt.c @@ -263,6 +263,40 @@ static int stm32_count_prescaler_write(struct counter_device *counter, return regmap_write(priv->regmap, TIM_PSC, psc); } +static int stm32_count_cap_read(struct counter_device *counter, + struct counter_count *count, + size_t ch, u64 *cap) +{ + struct stm32_timer_cnt *const priv = counter_priv(counter); + u32 ccrx; + + if (ch >= priv->nchannels) + return -EOPNOTSUPP; + + switch (ch) { + case 0: + regmap_read(priv->regmap, TIM_CCR1, &ccrx); + break; + case 1: + regmap_read(priv->regmap, TIM_CCR2, &ccrx); + break; + case 2: + regmap_read(priv->regmap, TIM_CCR3, &ccrx); + break; + case 3: + regmap_read(priv->regmap, TIM_CCR4, &ccrx); + break; + default: + return -EINVAL; + } + + dev_dbg(counter->parent, "CCR%zu: 0x%08x\n", ch + 1, ccrx); + + *cap = ccrx; + + return 0; +} + static int stm32_count_nb_ovf_read(struct counter_device *counter, struct counter_count *count, u64 *val) { @@ -286,6 +320,8 @@ static int stm32_count_nb_ovf_write(struct counter_device *counter, return 0; } +static DEFINE_COUNTER_ARRAY_CAPTURE(stm32_count_cap_array, 4); + static struct counter_comp stm32_count_ext[] = { COUNTER_COMP_DIRECTION(stm32_count_direction_read), COUNTER_COMP_ENABLE(stm32_count_enable_read, stm32_count_enable_write), @@ -293,6 +329,7 @@ static struct counter_comp stm32_count_ext[] = { stm32_count_ceiling_write), COUNTER_COMP_COUNT_U64("prescaler", stm32_count_prescaler_read, stm32_count_prescaler_write), + COUNTER_COMP_ARRAY_CAPTURE(stm32_count_cap_read, NULL, stm32_count_cap_array), COUNTER_COMP_COUNT_U64("num_overflows", stm32_count_nb_ovf_read, stm32_count_nb_ovf_write), }; @@ -351,11 +388,68 @@ static int stm32_action_read(struct counter_device *counter, } } +struct stm32_count_cc_regs { + u32 ccmr_reg; + u32 ccmr_mask; + u32 ccmr_bits; + u32 ccer_bits; +}; + +static const struct stm32_count_cc_regs stm32_cc[] = { + { TIM_CCMR1, TIM_CCMR_CC1S, TIM_CCMR_CC1S_TI1, + TIM_CCER_CC1E | TIM_CCER_CC1P | TIM_CCER_CC1NP }, + { TIM_CCMR1, TIM_CCMR_CC2S, TIM_CCMR_CC2S_TI2, + TIM_CCER_CC2E | TIM_CCER_CC2P | TIM_CCER_CC2NP }, + { TIM_CCMR2, TIM_CCMR_CC3S, TIM_CCMR_CC3S_TI3, + TIM_CCER_CC3E | TIM_CCER_CC3P | TIM_CCER_CC3NP }, + { TIM_CCMR2, TIM_CCMR_CC4S, TIM_CCMR_CC4S_TI4, + TIM_CCER_CC4E | TIM_CCER_CC4P | TIM_CCER_CC4NP }, +}; + +static int stm32_count_capture_configure(struct counter_device *counter, unsigned int ch, + bool enable) +{ + struct stm32_timer_cnt *const priv = counter_priv(counter); + u32 ccmr, ccer, sr; + + if (ch >= ARRAY_SIZE(stm32_cc) || ch >= priv->nchannels) { + dev_err(counter->parent, "invalid ch: %d\n", ch); + return -EINVAL; + } + + /* + * configure channel in input capture mode, map channel 1 on TI1, channel2 on TI2... + * Select both edges / non-inverted to trigger a capture. + */ + if (enable) { + /* first clear possibly latched capture flag upon enabling */ + regmap_read(priv->regmap, TIM_CCER, &ccer); + if (!(ccer & stm32_cc[ch].ccer_bits)) { + sr = ~TIM_SR_CC_IF(ch); + regmap_write(priv->regmap, TIM_SR, sr); + } + regmap_update_bits(priv->regmap, stm32_cc[ch].ccmr_reg, stm32_cc[ch].ccmr_mask, + stm32_cc[ch].ccmr_bits); + regmap_set_bits(priv->regmap, TIM_CCER, stm32_cc[ch].ccer_bits); + } else { + regmap_clear_bits(priv->regmap, TIM_CCER, stm32_cc[ch].ccer_bits); + regmap_clear_bits(priv->regmap, stm32_cc[ch].ccmr_reg, stm32_cc[ch].ccmr_mask); + } + + regmap_read(priv->regmap, stm32_cc[ch].ccmr_reg, &ccmr); + regmap_read(priv->regmap, TIM_CCER, &ccer); + dev_dbg(counter->parent, "%s(%s) ch%d 0x%08x 0x%08x\n", __func__, enable ? "ena" : "dis", + ch, ccmr, ccer); + + return 0; +} + static int stm32_count_events_configure(struct counter_device *counter) { struct stm32_timer_cnt *const priv = counter_priv(counter); struct counter_event_node *event_node; u32 val, dier = 0; + int i, ret; list_for_each_entry(event_node, &counter->events_list, l) { switch (event_node->event) { @@ -366,6 +460,12 @@ static int stm32_count_events_configure(struct counter_device *counter) regmap_write(priv->regmap, TIM_SR, (u32)~TIM_SR_UIF); dier |= TIM_DIER_UIE; break; + case COUNTER_EVENT_CAPTURE: + ret = stm32_count_capture_configure(counter, event_node->channel, true); + if (ret) + return ret; + dier |= TIM_DIER_CC_IE(event_node->channel); + break; default: /* should never reach this path */ return -EINVAL; @@ -374,6 +474,15 @@ static int stm32_count_events_configure(struct counter_device *counter) regmap_write(priv->regmap, TIM_DIER, dier); + /* check for disabled capture events */ + for (i = 0 ; i < priv->nchannels; i++) { + if (!(dier & TIM_DIER_CC_IE(i))) { + ret = stm32_count_capture_configure(counter, i, false); + if (ret) + return ret; + } + } + return 0; } @@ -387,6 +496,12 @@ static int stm32_count_watch_validate(struct counter_device *counter, return -EOPNOTSUPP; switch (watch->event) { + case COUNTER_EVENT_CAPTURE: + if (watch->channel >= priv->nchannels) { + dev_err(counter->parent, "Invalid channel %d\n", watch->channel); + return -EINVAL; + } + return 0; case COUNTER_EVENT_OVERFLOW_UNDERFLOW: return 0; default: @@ -497,6 +612,7 @@ static irqreturn_t stm32_timer_cnt_isr(int irq, void *ptr) struct stm32_timer_cnt *const priv = counter_priv(counter); u32 clr = GENMASK(31, 0); /* SR flags can be cleared by writing 0 (wr 1 has no effect) */ u32 sr, dier; + int i; regmap_read(priv->regmap, TIM_SR, &sr); regmap_read(priv->regmap, TIM_DIER, &dier); @@ -504,7 +620,7 @@ static irqreturn_t stm32_timer_cnt_isr(int irq, void *ptr) * Some status bits in SR don't match with the enable bits in DIER. Only take care of * the possibly enabled bits in DIER (that matches in between SR and DIER). */ - dier &= TIM_DIER_UIE; + dier &= (TIM_DIER_UIE | TIM_DIER_CC1IE | TIM_DIER_CC2IE | TIM_DIER_CC3IE | TIM_DIER_CC4IE); sr &= dier; if (sr & TIM_SR_UIF) { @@ -515,6 +631,15 @@ static irqreturn_t stm32_timer_cnt_isr(int irq, void *ptr) clr &= ~TIM_SR_UIF; } + /* Check capture events */ + for (i = 0 ; i < priv->nchannels; i++) { + if (sr & TIM_SR_CC_IF(i)) { + counter_push_event(counter, COUNTER_EVENT_CAPTURE, i); + clr &= ~TIM_SR_CC_IF(i); + dev_dbg(counter->parent, "COUNTER_EVENT_CAPTURE, %d\n", i); + } + } + regmap_write(priv->regmap, TIM_SR, clr); return IRQ_HANDLED; @@ -627,8 +752,11 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev) } } else { for (i = 0; i < priv->nr_irqs; i++) { - /* Only take care of update IRQ for overflow events */ - if (i != STM32_TIMERS_IRQ_UP) + /* + * Only take care of update IRQ for overflow events, and cc for + * capture events. + */ + if (i != STM32_TIMERS_IRQ_UP && i != STM32_TIMERS_IRQ_CC) continue; ret = devm_request_irq(&pdev->dev, priv->irq[i], stm32_timer_cnt_isr,
Add support for capture events. Captured counter value for each channel can be retrieved through CCRx register. STM32 timers can have up to 4 capture channels (on input channel 1 to channel 4), hence need to check the number of channels before reading the capture data. The capture configuration is hard-coded to capture signals on both edges (non-inverted). Interrupts are used to report events independently for each channel. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com> --- Changes in v3: - patch split from: "counter: stm32-timer-cnt: add support for events", to focus on the capture events only here. - only get relevant interrupt line --- drivers/counter/stm32-timer-cnt.c | 134 +++++++++++++++++++++++++++++- 1 file changed, 131 insertions(+), 3 deletions(-)