Re: [PATCH] iio: stm32 trigger: Add support for TRGO2 triggers

From: Fabrice Gasnier
Date: Fri Apr 28 2017 - 10:54:09 EST

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In reply to: Jonathan Cameron: "Re: [PATCH] iio: stm32 trigger: Add support for TRGO2 triggers"
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On 04/27/2017 07:49 AM, Jonathan Cameron wrote:
> On 26/04/17 09:55, Benjamin Gaignard wrote:
>> 2017-04-26 10:17 GMT+02:00 Fabrice Gasnier <fabrice.gasnier@xxxxxx>:
>>> Add support for TRGO2 trigger that can be found on STM32F7.
>>> Add additional master modes supported by TRGO2.
> These additional modes would benefit from more information in the
> ABI docs. Otherwise patch seems fine, though this may win
> the award for hardest hardware to come up with a generic
> interface for...
>>> Register additional "tim[1/8]_trgo2" triggers for timer1 & timer8.
>>> Detect TRGO2 timer capability (master mode selection 2).
>>>
>>> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
>>> ---
>>> .../ABI/testing/sysfs-bus-iio-timer-stm32 | 15 +++
>>> drivers/iio/trigger/stm32-timer-trigger.c | 113 ++++++++++++++++++---
>>> include/linux/iio/timer/stm32-timer-trigger.h | 2 +
>>> include/linux/mfd/stm32-timers.h | 2 +
>>> 4 files changed, 118 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
>>> index 230020e..47647b4 100644
>>> --- a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
>>> +++ b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
>>> @@ -16,6 +16,21 @@ Description:
>>> - "OC2REF" : OC2REF signal is used as trigger output.
>>> - "OC3REF" : OC3REF signal is used as trigger output.
>>> - "OC4REF" : OC4REF signal is used as trigger output.
>>> + Additional modes (on TRGO2 only):
>>> + - "OC5REF" : OC5REF signal is used as trigger output.
>>> + - "OC6REF" : OC6REF signal is used as trigger output.
>>> + - "compare_pulse_OC4REF":
>>> + OC4REF rising or falling edges generate pulses.
> I'd like this to be fairly understandable without resorting to reading the
> datasheet. As I understand it you get a fixed term pulse on both edges
> of the waveform? Perhaps this calls for some ascii art :)

Hi Jonathan,

If you feel like it needs more documentation, I'd rather prefer to add
reference or link to the datasheet... That will be more accurate,
up-to-date (e.g. like RM0385 pdf). Does this sound ok ? Or...

Just in case, I prepared some ascii art, hope it clarify things.
I'm wondering if this is best place to put it ?
Shouldn't this be added in source code, instead of ABI Doc ?
Maybe I can skip 1st part of it, heading boxes? (only example is enough?
or not...)

+-----------+ +-------------+ +---------+
| Prescaler +-> | Counter | +-> | Master | TRGO(2)
+-----------+ +--+--------+-+ |-> | Control +-->
| | || +---------+
+--v--------+-+ OCxREF || +---------+
| Chx compare +----------> | Output | ChX
+-----------+-+ | | Control +-->
. | | +---------+
. | | .
+-----------v-+ OC6REF | .
| Ch6 compare +---------+>
+-------------+

Example with: "compare_pulse_OC4REF_r_or_OC6REF_r":

X
X X
X . . X
X . . X
X . . X
count X . . . . X
. . . .
. . . .
+---------------+
OC4REF | . . |
+-+ . . +-+
. +---+ .
OC6REF . | | .
+-------+ +-------+
+-+ +-+
TRGO2 | | | |
+-+ +---+ +---------+

side note: this isn't my house ;-)

Please advise,
Thanks,
Fabrice

>>> + - "compare_pulse_OC6REF":
>>> + OC6REF rising or falling edges generate pulses.
>>> + - "compare_pulse_OC4REF_r_or_OC6REF_r":
>>> + OC4REF or OC6REF rising edges generate pulses.
>>> + - "compare_pulse_OC4REF_r_or_OC6REF_f":
>>> + OC4REF rising or OC6REF falling edges generate pulses.
>>> + - "compare_pulse_OC5REF_r_or_OC6REF_r":
>>> + OC5REF or OC6REF rising edges generate pulses.
>>> + - "compare_pulse_OC5REF_r_or_OC6REF_f":
>>> + OC5REF rising or OC6REF falling edges generate pulses.
>>>
>>> What: /sys/bus/iio/devices/triggerX/master_mode
>>> KernelVersion: 4.11
>>> diff --git a/drivers/iio/trigger/stm32-timer-trigger.c b/drivers/iio/trigger/stm32-timer-trigger.c
>>> index 0f1a2cf..a0031b7 100644
>>> --- a/drivers/iio/trigger/stm32-timer-trigger.c
>>> +++ b/drivers/iio/trigger/stm32-timer-trigger.c
>>> @@ -14,19 +14,19 @@
>>> #include <linux/module.h>
>>> #include <linux/platform_device.h>
>>>
>>> -#define MAX_TRIGGERS 6
>>> +#define MAX_TRIGGERS 7
>>> #define MAX_VALIDS 5
>>>
>>> /* List the triggers created by each timer */
>>> static const void *triggers_table[][MAX_TRIGGERS] = {
>>> - { TIM1_TRGO, TIM1_CH1, TIM1_CH2, TIM1_CH3, TIM1_CH4,},
>>> + { TIM1_TRGO, TIM1_TRGO2, TIM1_CH1, TIM1_CH2, TIM1_CH3, TIM1_CH4,},
>>> { TIM2_TRGO, TIM2_CH1, TIM2_CH2, TIM2_CH3, TIM2_CH4,},
>>> { TIM3_TRGO, TIM3_CH1, TIM3_CH2, TIM3_CH3, TIM3_CH4,},
>>> { TIM4_TRGO, TIM4_CH1, TIM4_CH2, TIM4_CH3, TIM4_CH4,},
>>> { TIM5_TRGO, TIM5_CH1, TIM5_CH2, TIM5_CH3, TIM5_CH4,},
>>> { TIM6_TRGO,},
>>> { TIM7_TRGO,},
>>> - { TIM8_TRGO, TIM8_CH1, TIM8_CH2, TIM8_CH3, TIM8_CH4,},
>>> + { TIM8_TRGO, TIM8_TRGO2, TIM8_CH1, TIM8_CH2, TIM8_CH3, TIM8_CH4,},
>>> { TIM9_TRGO, TIM9_CH1, TIM9_CH2,},
>>> { }, /* timer 10 */
>>> { }, /* timer 11 */
>>> @@ -56,9 +56,16 @@ struct stm32_timer_trigger {
>>> u32 max_arr;
>>> const void *triggers;
>>> const void *valids;
>>> + bool has_trgo2;
>>> };
>>>
>>> +static bool stm32_timer_is_trgo2_name(const char *name)
>>> +{
>>> + return !!strstr(name, "trgo2");
>>> +}
>>> +
>>> static int stm32_timer_start(struct stm32_timer_trigger *priv,
>>> + struct iio_trigger *trig,
>>> unsigned int frequency)
>>> {
>>> unsigned long long prd, div;
>>> @@ -102,7 +109,12 @@ static int stm32_timer_start(struct stm32_timer_trigger *priv,
>>> regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE);
>>>
>>> /* Force master mode to update mode */
>>> - regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS, 0x20);
>>> + if (stm32_timer_is_trgo2_name(trig->name))
>>> + regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS2,
>>> + 0x2 << TIM_CR2_MMS2_SHIFT);
>>> + else
>>> + regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS,
>>> + 0x2 << TIM_CR2_MMS_SHIFT);
>>>
>>> /* Make sure that registers are updated */
>>> regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);
>>> @@ -150,7 +162,7 @@ static ssize_t stm32_tt_store_frequency(struct device *dev,
>>> if (freq == 0) {
>>> stm32_timer_stop(priv);
>>> } else {
>>> - ret = stm32_timer_start(priv, freq);
>>> + ret = stm32_timer_start(priv, trig, freq);
>>> if (ret)
>>> return ret;
>>> }
>>> @@ -183,6 +195,9 @@ static IIO_DEV_ATTR_SAMP_FREQ(0660,
>>> stm32_tt_read_frequency,
>>> stm32_tt_store_frequency);
>>>
>>> +#define MASTER_MODE_MAX 7
>>> +#define MASTER_MODE2_MAX 15
>>> +
>>> static char *master_mode_table[] = {
>>> "reset",
>>> "enable",
>>> @@ -191,7 +206,16 @@ static IIO_DEV_ATTR_SAMP_FREQ(0660,
>>> "OC1REF",
>>> "OC2REF",
>>> "OC3REF",
>>> - "OC4REF"
>>> + "OC4REF",
>>> + /* Master mode selection 2 only */
>>> + "OC5REF",
>>> + "OC6REF",
>>> + "compare_pulse_OC4REF",
>>> + "compare_pulse_OC6REF",
>>> + "compare_pulse_OC4REF_r_or_OC6REF_r",
>>> + "compare_pulse_OC4REF_r_or_OC6REF_f",
>>> + "compare_pulse_OC5REF_r_or_OC6REF_r",
>>> + "compare_pulse_OC5REF_r_or_OC6REF_f",
>>> };
>>>
>>> static ssize_t stm32_tt_show_master_mode(struct device *dev,
>>> @@ -199,10 +223,15 @@ static ssize_t stm32_tt_show_master_mode(struct device *dev,
>>> char *buf)
>>> {
>>> struct stm32_timer_trigger *priv = dev_get_drvdata(dev);
>>> + struct iio_trigger *trig = to_iio_trigger(dev);
>>> u32 cr2;
>>>
>>> regmap_read(priv->regmap, TIM_CR2, &cr2);
>>> - cr2 = (cr2 & TIM_CR2_MMS) >> TIM_CR2_MMS_SHIFT;
>>> +
>>> + if (stm32_timer_is_trgo2_name(trig->name))
>>> + cr2 = (cr2 & TIM_CR2_MMS2) >> TIM_CR2_MMS2_SHIFT;
>>> + else
>>> + cr2 = (cr2 & TIM_CR2_MMS) >> TIM_CR2_MMS_SHIFT;
>>>
>>> return snprintf(buf, PAGE_SIZE, "%s\n", master_mode_table[cr2]);
>>> }
>>> @@ -212,13 +241,25 @@ static ssize_t stm32_tt_store_master_mode(struct device *dev,
>>> const char *buf, size_t len)
>>> {
>>> struct stm32_timer_trigger *priv = dev_get_drvdata(dev);
>>> + struct iio_trigger *trig = to_iio_trigger(dev);
>>> + u32 mask, shift, master_mode_max;
>>> int i;
>>>
>>> - for (i = 0; i < ARRAY_SIZE(master_mode_table); i++) {
>>> + if (stm32_timer_is_trgo2_name(trig->name)) {
>>> + mask = TIM_CR2_MMS2;
>>> + shift = TIM_CR2_MMS2_SHIFT;
>>> + master_mode_max = MASTER_MODE2_MAX;
>>> + } else {
>>> + mask = TIM_CR2_MMS;
>>> + shift = TIM_CR2_MMS_SHIFT;
>>> + master_mode_max = MASTER_MODE_MAX;
>>> + }
>>> +
>>> + for (i = 0; i <= master_mode_max; i++) {
>>> if (!strncmp(master_mode_table[i], buf,
>>> strlen(master_mode_table[i]))) {
>>> - regmap_update_bits(priv->regmap, TIM_CR2,
>>> - TIM_CR2_MMS, i << TIM_CR2_MMS_SHIFT);
>>> + regmap_update_bits(priv->regmap, TIM_CR2, mask,
>>> + i << shift);
>>> /* Make sure that registers are updated */
>>> regmap_update_bits(priv->regmap, TIM_EGR,
>>> TIM_EGR_UG, TIM_EGR_UG);
>>> @@ -229,8 +270,31 @@ static ssize_t stm32_tt_store_master_mode(struct device *dev,
>>> return -EINVAL;
>>> }
>>>
>>> -static IIO_CONST_ATTR(master_mode_available,
>>> - "reset enable update compare_pulse OC1REF OC2REF OC3REF OC4REF");
>>> +static ssize_t stm32_tt_show_master_mode_avail(struct device *dev,
>>> + struct device_attribute *attr,
>>> + char *buf)
>>> +{
>>> + struct iio_trigger *trig = to_iio_trigger(dev);
>>> + unsigned int i, master_mode_max;
>>> + size_t len = 0;
>>> +
>>> + if (stm32_timer_is_trgo2_name(trig->name))
>>> + master_mode_max = MASTER_MODE2_MAX;
>>> + else
>>> + master_mode_max = MASTER_MODE_MAX;
>>> +
>>> + for (i = 0; i <= master_mode_max; i++)
>>> + len += scnprintf(buf + len, PAGE_SIZE - len,
>>> + "%s ", master_mode_table[i]);
>>> +
>>> + /* replace trailing space by newline */
>>> + buf[len - 1] = '\n';
>>> +
>>> + return len;
>>> +}
>>> +
>>> +static IIO_DEVICE_ATTR(master_mode_available, 0444,
>>> + stm32_tt_show_master_mode_avail, NULL, 0);
>>>
>>> static IIO_DEVICE_ATTR(master_mode, 0660,
>>> stm32_tt_show_master_mode,
>>> @@ -240,7 +304,7 @@ static IIO_DEVICE_ATTR(master_mode, 0660,
>>> static struct attribute *stm32_trigger_attrs[] = {
>>> &iio_dev_attr_sampling_frequency.dev_attr.attr,
>>> &iio_dev_attr_master_mode.dev_attr.attr,
>>> - &iio_const_attr_master_mode_available.dev_attr.attr,
>>> + &iio_dev_attr_master_mode_available.dev_attr.attr,
>>> NULL,
>>> };
>>>
>>> @@ -264,6 +328,12 @@ static int stm32_setup_iio_triggers(struct stm32_timer_trigger *priv)
>>>
>>> while (cur && *cur) {
>>> struct iio_trigger *trig;
>>> + bool cur_is_trgo2 = stm32_timer_is_trgo2_name(*cur);
>>> +
>>> + if (cur_is_trgo2 && !priv->has_trgo2) {
>>> + cur++;
>>> + continue;
>>> + }
>>>
>>> trig = devm_iio_trigger_alloc(priv->dev, "%s", *cur);
>>> if (!trig)
>>> @@ -277,7 +347,7 @@ static int stm32_setup_iio_triggers(struct stm32_timer_trigger *priv)
>>> * should only be available on trgo trigger which
>>> * is always the first in the list.
>>> */
>>> - if (cur == priv->triggers)
>>> + if (cur == priv->triggers || cur_is_trgo2)
>>> trig->dev.groups = stm32_trigger_attr_groups;
>>>
>>> iio_trigger_set_drvdata(trig, priv);
>>> @@ -584,6 +654,20 @@ bool is_stm32_timer_trigger(struct iio_trigger *trig)
>>> }
>>> EXPORT_SYMBOL(is_stm32_timer_trigger);
>>>
>>> +static void stm32_timer_detect_trgo2(struct stm32_timer_trigger *priv)
>>> +{
>>> + u32 val;
>>> +
>>> + /*
>>> + * Master mode selection 2 bits can only be written and read back when
>>> + * timer supports it.
>>> + */
>>> + regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS2, TIM_CR2_MMS2);
>>> + regmap_read(priv->regmap, TIM_CR2, &val);
>>> + regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS2, 0);
>>> + priv->has_trgo2 = !!val;
>>> +}
>>> +
>>> static int stm32_timer_trigger_probe(struct platform_device *pdev)
>>> {
>>> struct device *dev = &pdev->dev;
>>> @@ -614,6 +698,7 @@ static int stm32_timer_trigger_probe(struct platform_device *pdev)
>>> priv->max_arr = ddata->max_arr;
>>> priv->triggers = triggers_table[index];
>>> priv->valids = valids_table[index];
>>> + stm32_timer_detect_trgo2(priv);
>>>
>>> ret = stm32_setup_iio_triggers(priv);
>>> if (ret)
>>> diff --git a/include/linux/iio/timer/stm32-timer-trigger.h b/include/linux/iio/timer/stm32-timer-trigger.h
>>> index 55535ae..fa7d786 100644
>>> --- a/include/linux/iio/timer/stm32-timer-trigger.h
>>> +++ b/include/linux/iio/timer/stm32-timer-trigger.h
>>> @@ -10,6 +10,7 @@
>>> #define _STM32_TIMER_TRIGGER_H_
>>>
>>> #define TIM1_TRGO "tim1_trgo"
>>> +#define TIM1_TRGO2 "tim1_trgo2"
>>> #define TIM1_CH1 "tim1_ch1"
>>> #define TIM1_CH2 "tim1_ch2"
>>> #define TIM1_CH3 "tim1_ch3"
>>> @@ -44,6 +45,7 @@
>>> #define TIM7_TRGO "tim7_trgo"
>>>
>>> #define TIM8_TRGO "tim8_trgo"
>>> +#define TIM8_TRGO2 "tim8_trgo2"
>>> #define TIM8_CH1 "tim8_ch1"
>>> #define TIM8_CH2 "tim8_ch2"
>>> #define TIM8_CH3 "tim8_ch3"
>>> diff --git a/include/linux/mfd/stm32-timers.h b/include/linux/mfd/stm32-timers.h
>>> index 4a0abbc..ce7346e 100644
>>> --- a/include/linux/mfd/stm32-timers.h
>>> +++ b/include/linux/mfd/stm32-timers.h
>>> @@ -34,6 +34,7 @@
>>> #define TIM_CR1_DIR BIT(4) /* Counter Direction */
>>> #define TIM_CR1_ARPE BIT(7) /* Auto-reload Preload Ena */
>>> #define TIM_CR2_MMS (BIT(4) | BIT(5) | BIT(6)) /* Master mode selection */
>>> +#define TIM_CR2_MMS2 GENMASK(23, 20) /* Master mode selection 2 */
>>> #define TIM_SMCR_SMS (BIT(0) | BIT(1) | BIT(2)) /* Slave mode selection */
>>> #define TIM_SMCR_TS (BIT(4) | BIT(5) | BIT(6)) /* Trigger selection */
>>> #define TIM_DIER_UIE BIT(0) /* Update interrupt */
>>> @@ -60,6 +61,7 @@
>>>
>>> #define MAX_TIM_PSC 0xFFFF
>>> #define TIM_CR2_MMS_SHIFT 4
>>> +#define TIM_CR2_MMS2_SHIFT 20
>>> #define TIM_SMCR_TS_SHIFT 4
>>> #define TIM_BDTR_BKF_MASK 0xF
>>> #define TIM_BDTR_BKF_SHIFT 16
>>> --
>>> 1.9.1
>>>
>>
>> Acked-by: Benjamin Gaiganrd <benjamin.gaignard@xxxxxxxxxx>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
>> the body of a message to majordomo@xxxxxxxxxxxxxxx
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>>
>

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In reply to: Jonathan Cameron: "Re: [PATCH] iio: stm32 trigger: Add support for TRGO2 triggers"
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