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

From: Jonathan Cameron
Date: Thu Apr 27 2017 - 01:49:41 EST

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 :)
>> + - "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
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>