Re: [PATCH v2] iio: stm32 trigger: Add support for TRGO2 triggers

From: Jonathan Cameron
Date: Sun May 07 2017 - 18:16:07 EST

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Previous message: Jonathan Cameron: "Re: [PATCH v2 2/3] iio: adc: at91-sama5d2_adc: add hw trigger and buffer support"
In reply to: Fabrice Gasnier: "[PATCH v2] iio: stm32 trigger: Add support for TRGO2 triggers"
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On 02/05/17 13:33, Fabrice Gasnier wrote:
> Add support for TRGO2 trigger that can be found on STM32F7.
> Add additional master modes supported by TRGO2.
> 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>
> Acked-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx>
This definitely strikes me a stuff we may want to revisit sometime
in the future once we have a few similar bits of hardware supported.

I don't see this particularly interface being hard to support
even if we add something more general so:

Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan
> ---
> Changes in v2:
> - Improve ABI documentation by adding ascii art
> ---
> .../ABI/testing/sysfs-bus-iio-timer-stm32 | 48 +++++++++
> 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, 151 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..deb0159 100644
> --- a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
> @@ -16,6 +16,54 @@ 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.
> + - "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.
> +
> + +-----------+ +-------------+ +---------+
> + | 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 | | | |
> + +-+ +---+ +---------+
>
> 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
>

Next message: Andy Shevchenko: "Re: [PATCH 1/5] PCI: add a define for the PCI resource type mask"
Previous message: Jonathan Cameron: "Re: [PATCH v2 2/3] iio: adc: at91-sama5d2_adc: add hw trigger and buffer support"
In reply to: Fabrice Gasnier: "[PATCH v2] iio: stm32 trigger: Add support for TRGO2 triggers"
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