Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 918 insertions, 0 deletions

diff --git a/drivers/iio/trigger/stm32-timer-trigger.c b/drivers/iio/trigger/stm32-timer-trigger.c
new file mode 100644
index 000000000..3643c4afa
--- /dev/null
+++ b/drivers/iio/trigger/stm32-timer-trigger.c
@@ -0,0 +1,918 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2016
+ *
+ * Author: Benjamin Gaignard <benjamin.gaignard@st.com>
+ *
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/timer/stm32-timer-trigger.h>
+#include <linux/iio/trigger.h>
+#include <linux/mfd/stm32-timers.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+
+#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_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_TRGO2, TIM8_CH1, TIM8_CH2, TIM8_CH3, TIM8_CH4,},
+	{ TIM9_TRGO, TIM9_CH1, TIM9_CH2,},
+	{ TIM10_OC1,},
+	{ TIM11_OC1,},
+	{ TIM12_TRGO, TIM12_CH1, TIM12_CH2,},
+	{ TIM13_OC1,},
+	{ TIM14_OC1,},
+	{ TIM15_TRGO,},
+	{ TIM16_OC1,},
+	{ TIM17_OC1,},
+};
+
+/* List the triggers accepted by each timer */
+static const void *valids_table[][MAX_VALIDS] = {
+	{ TIM5_TRGO, TIM2_TRGO, TIM3_TRGO, TIM4_TRGO,},
+	{ TIM1_TRGO, TIM8_TRGO, TIM3_TRGO, TIM4_TRGO,},
+	{ TIM1_TRGO, TIM2_TRGO, TIM5_TRGO, TIM4_TRGO,},
+	{ TIM1_TRGO, TIM2_TRGO, TIM3_TRGO, TIM8_TRGO,},
+	{ TIM2_TRGO, TIM3_TRGO, TIM4_TRGO, TIM8_TRGO,},
+	{ }, /* timer 6 */
+	{ }, /* timer 7 */
+	{ TIM1_TRGO, TIM2_TRGO, TIM4_TRGO, TIM5_TRGO,},
+	{ TIM2_TRGO, TIM3_TRGO, TIM10_OC1, TIM11_OC1,},
+	{ }, /* timer 10 */
+	{ }, /* timer 11 */
+	{ TIM4_TRGO, TIM5_TRGO, TIM13_OC1, TIM14_OC1,},
+};
+
+static const void *stm32h7_valids_table[][MAX_VALIDS] = {
+	{ TIM15_TRGO, TIM2_TRGO, TIM3_TRGO, TIM4_TRGO,},
+	{ TIM1_TRGO, TIM8_TRGO, TIM3_TRGO, TIM4_TRGO,},
+	{ TIM1_TRGO, TIM2_TRGO, TIM15_TRGO, TIM4_TRGO,},
+	{ TIM1_TRGO, TIM2_TRGO, TIM3_TRGO, TIM8_TRGO,},
+	{ TIM1_TRGO, TIM8_TRGO, TIM3_TRGO, TIM4_TRGO,},
+	{ }, /* timer 6 */
+	{ }, /* timer 7 */
+	{ TIM1_TRGO, TIM2_TRGO, TIM4_TRGO, TIM5_TRGO,},
+	{ }, /* timer 9 */
+	{ }, /* timer 10 */
+	{ }, /* timer 11 */
+	{ TIM4_TRGO, TIM5_TRGO, TIM13_OC1, TIM14_OC1,},
+	{ }, /* timer 13 */
+	{ }, /* timer 14 */
+	{ TIM1_TRGO, TIM3_TRGO, TIM16_OC1, TIM17_OC1,},
+	{ }, /* timer 16 */
+	{ }, /* timer 17 */
+};
+
+struct stm32_timer_trigger_regs {
+	u32 cr1;
+	u32 cr2;
+	u32 psc;
+	u32 arr;
+	u32 cnt;
+	u32 smcr;
+};
+
+struct stm32_timer_trigger {
+	struct device *dev;
+	struct regmap *regmap;
+	struct clk *clk;
+	bool enabled;
+	u32 max_arr;
+	const void *triggers;
+	const void *valids;
+	bool has_trgo2;
+	struct mutex lock; /* concurrent sysfs configuration */
+	struct list_head tr_list;
+	struct stm32_timer_trigger_regs bak;
+};
+
+struct stm32_timer_trigger_cfg {
+	const void *(*valids_table)[MAX_VALIDS];
+	const unsigned int num_valids_table;
+};
+
+static bool stm32_timer_is_trgo2_name(const char *name)
+{
+	return !!strstr(name, "trgo2");
+}
+
+static bool stm32_timer_is_trgo_name(const char *name)
+{
+	return (!!strstr(name, "trgo") && !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;
+	int prescaler = 0;
+	u32 ccer;
+
+	/* Period and prescaler values depends of clock rate */
+	div = (unsigned long long)clk_get_rate(priv->clk);
+
+	do_div(div, frequency);
+
+	prd = div;
+
+	/*
+	 * Increase prescaler value until we get a result that fit
+	 * with auto reload register maximum value.
+	 */
+	while (div > priv->max_arr) {
+		prescaler++;
+		div = prd;
+		do_div(div, (prescaler + 1));
+	}
+	prd = div;
+
+	if (prescaler > MAX_TIM_PSC) {
+		dev_err(priv->dev, "prescaler exceeds the maximum value\n");
+		return -EINVAL;
+	}
+
+	/* Check if nobody else use the timer */
+	regmap_read(priv->regmap, TIM_CCER, &ccer);
+	if (ccer & TIM_CCER_CCXE)
+		return -EBUSY;
+
+	mutex_lock(&priv->lock);
+	if (!priv->enabled) {
+		priv->enabled = true;
+		clk_enable(priv->clk);
+	}
+
+	regmap_write(priv->regmap, TIM_PSC, prescaler);
+	regmap_write(priv->regmap, TIM_ARR, prd - 1);
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE);
+
+	/* Force master mode to update mode */
+	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);
+
+	/* Enable controller */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, TIM_CR1_CEN);
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static void stm32_timer_stop(struct stm32_timer_trigger *priv,
+			     struct iio_trigger *trig)
+{
+	u32 ccer;
+
+	regmap_read(priv->regmap, TIM_CCER, &ccer);
+	if (ccer & TIM_CCER_CCXE)
+		return;
+
+	mutex_lock(&priv->lock);
+	/* Stop timer */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
+	regmap_write(priv->regmap, TIM_PSC, 0);
+	regmap_write(priv->regmap, TIM_ARR, 0);
+
+	/* Force disable master mode */
+	if (stm32_timer_is_trgo2_name(trig->name))
+		regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS2, 0);
+	else
+		regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS, 0);
+
+	/* Make sure that registers are updated */
+	regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);
+
+	if (priv->enabled) {
+		priv->enabled = false;
+		clk_disable(priv->clk);
+	}
+	mutex_unlock(&priv->lock);
+}
+
+static ssize_t stm32_tt_store_frequency(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t len)
+{
+	struct iio_trigger *trig = to_iio_trigger(dev);
+	struct stm32_timer_trigger *priv = iio_trigger_get_drvdata(trig);
+	unsigned int freq;
+	int ret;
+
+	ret = kstrtouint(buf, 10, &freq);
+	if (ret)
+		return ret;
+
+	if (freq == 0) {
+		stm32_timer_stop(priv, trig);
+	} else {
+		ret = stm32_timer_start(priv, trig, freq);
+		if (ret)
+			return ret;
+	}
+
+	return len;
+}
+
+static ssize_t stm32_tt_read_frequency(struct device *dev,
+				       struct device_attribute *attr, char *buf)
+{
+	struct iio_trigger *trig = to_iio_trigger(dev);
+	struct stm32_timer_trigger *priv = iio_trigger_get_drvdata(trig);
+	u32 psc, arr, cr1;
+	unsigned long long freq = 0;
+
+	regmap_read(priv->regmap, TIM_CR1, &cr1);
+	regmap_read(priv->regmap, TIM_PSC, &psc);
+	regmap_read(priv->regmap, TIM_ARR, &arr);
+
+	if (cr1 & TIM_CR1_CEN) {
+		freq = (unsigned long long)clk_get_rate(priv->clk);
+		do_div(freq, psc + 1);
+		do_div(freq, arr + 1);
+	}
+
+	return sprintf(buf, "%d\n", (unsigned int)freq);
+}
+
+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",
+	"update",
+	"compare_pulse",
+	"OC1REF",
+	"OC2REF",
+	"OC3REF",
+	"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,
+					 struct device_attribute *attr,
+					 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);
+
+	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 sysfs_emit(buf, "%s\n", master_mode_table[cr2]);
+}
+
+static ssize_t stm32_tt_store_master_mode(struct device *dev,
+					  struct device_attribute *attr,
+					  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;
+
+	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]))) {
+			mutex_lock(&priv->lock);
+			if (!priv->enabled) {
+				/* Clock should be enabled first */
+				priv->enabled = true;
+				clk_enable(priv->clk);
+			}
+			regmap_update_bits(priv->regmap, TIM_CR2, mask,
+					   i << shift);
+			mutex_unlock(&priv->lock);
+			return len;
+		}
+	}
+
+	return -EINVAL;
+}
+
+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,
+		       stm32_tt_store_master_mode,
+		       0);
+
+static struct attribute *stm32_trigger_attrs[] = {
+	&iio_dev_attr_sampling_frequency.dev_attr.attr,
+	&iio_dev_attr_master_mode.dev_attr.attr,
+	&iio_dev_attr_master_mode_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group stm32_trigger_attr_group = {
+	.attrs = stm32_trigger_attrs,
+};
+
+static const struct attribute_group *stm32_trigger_attr_groups[] = {
+	&stm32_trigger_attr_group,
+	NULL,
+};
+
+static const struct iio_trigger_ops timer_trigger_ops = {
+};
+
+static void stm32_unregister_iio_triggers(struct stm32_timer_trigger *priv)
+{
+	struct iio_trigger *tr;
+
+	list_for_each_entry(tr, &priv->tr_list, alloc_list)
+		iio_trigger_unregister(tr);
+}
+
+static int stm32_register_iio_triggers(struct stm32_timer_trigger *priv)
+{
+	int ret;
+	const char * const *cur = priv->triggers;
+
+	INIT_LIST_HEAD(&priv->tr_list);
+
+	while (cur && *cur) {
+		struct iio_trigger *trig;
+		bool cur_is_trgo = stm32_timer_is_trgo_name(*cur);
+		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)
+			return -ENOMEM;
+
+		trig->dev.parent = priv->dev->parent;
+		trig->ops = &timer_trigger_ops;
+
+		/*
+		 * sampling frequency and master mode attributes
+		 * should only be available on trgo/trgo2 triggers
+		 */
+		if (cur_is_trgo || cur_is_trgo2)
+			trig->dev.groups = stm32_trigger_attr_groups;
+
+		iio_trigger_set_drvdata(trig, priv);
+
+		ret = iio_trigger_register(trig);
+		if (ret) {
+			stm32_unregister_iio_triggers(priv);
+			return ret;
+		}
+
+		list_add_tail(&trig->alloc_list, &priv->tr_list);
+		cur++;
+	}
+
+	return 0;
+}
+
+static int stm32_counter_read_raw(struct iio_dev *indio_dev,
+				  struct iio_chan_spec const *chan,
+				  int *val, int *val2, long mask)
+{
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	u32 dat;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		regmap_read(priv->regmap, TIM_CNT, &dat);
+		*val = dat;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_ENABLE:
+		regmap_read(priv->regmap, TIM_CR1, &dat);
+		*val = (dat & TIM_CR1_CEN) ? 1 : 0;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		regmap_read(priv->regmap, TIM_SMCR, &dat);
+		dat &= TIM_SMCR_SMS;
+
+		*val = 1;
+		*val2 = 0;
+
+		/* in quadrature case scale = 0.25 */
+		if (dat == 3)
+			*val2 = 2;
+
+		return IIO_VAL_FRACTIONAL_LOG2;
+	}
+
+	return -EINVAL;
+}
+
+static int stm32_counter_write_raw(struct iio_dev *indio_dev,
+				   struct iio_chan_spec const *chan,
+				   int val, int val2, long mask)
+{
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		return regmap_write(priv->regmap, TIM_CNT, val);
+
+	case IIO_CHAN_INFO_SCALE:
+		/* fixed scale */
+		return -EINVAL;
+
+	case IIO_CHAN_INFO_ENABLE:
+		mutex_lock(&priv->lock);
+		if (val) {
+			if (!priv->enabled) {
+				priv->enabled = true;
+				clk_enable(priv->clk);
+			}
+			regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN,
+					   TIM_CR1_CEN);
+		} else {
+			regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN,
+					   0);
+			if (priv->enabled) {
+				priv->enabled = false;
+				clk_disable(priv->clk);
+			}
+		}
+		mutex_unlock(&priv->lock);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int stm32_counter_validate_trigger(struct iio_dev *indio_dev,
+					  struct iio_trigger *trig)
+{
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	const char * const *cur = priv->valids;
+	unsigned int i = 0;
+
+	if (!is_stm32_timer_trigger(trig))
+		return -EINVAL;
+
+	while (cur && *cur) {
+		if (!strncmp(trig->name, *cur, strlen(trig->name))) {
+			regmap_update_bits(priv->regmap,
+					   TIM_SMCR, TIM_SMCR_TS,
+					   i << TIM_SMCR_TS_SHIFT);
+			return 0;
+		}
+		cur++;
+		i++;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info stm32_trigger_info = {
+	.validate_trigger = stm32_counter_validate_trigger,
+	.read_raw = stm32_counter_read_raw,
+	.write_raw = stm32_counter_write_raw
+};
+
+static const char *const stm32_trigger_modes[] = {
+	"trigger",
+};
+
+static int stm32_set_trigger_mode(struct iio_dev *indio_dev,
+				  const struct iio_chan_spec *chan,
+				  unsigned int mode)
+{
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+
+	regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, TIM_SMCR_SMS);
+
+	return 0;
+}
+
+static int stm32_get_trigger_mode(struct iio_dev *indio_dev,
+				  const struct iio_chan_spec *chan)
+{
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	u32 smcr;
+
+	regmap_read(priv->regmap, TIM_SMCR, &smcr);
+
+	return (smcr & TIM_SMCR_SMS) == TIM_SMCR_SMS ? 0 : -EINVAL;
+}
+
+static const struct iio_enum stm32_trigger_mode_enum = {
+	.items = stm32_trigger_modes,
+	.num_items = ARRAY_SIZE(stm32_trigger_modes),
+	.set = stm32_set_trigger_mode,
+	.get = stm32_get_trigger_mode
+};
+
+static const char *const stm32_enable_modes[] = {
+	"always",
+	"gated",
+	"triggered",
+};
+
+static int stm32_enable_mode2sms(int mode)
+{
+	switch (mode) {
+	case 0:
+		return 0;
+	case 1:
+		return 5;
+	case 2:
+		return 6;
+	}
+
+	return -EINVAL;
+}
+
+static int stm32_set_enable_mode(struct iio_dev *indio_dev,
+				 const struct iio_chan_spec *chan,
+				 unsigned int mode)
+{
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	int sms = stm32_enable_mode2sms(mode);
+
+	if (sms < 0)
+		return sms;
+	/*
+	 * Triggered mode sets CEN bit automatically by hardware. So, first
+	 * enable counter clock, so it can use it. Keeps it in sync with CEN.
+	 */
+	mutex_lock(&priv->lock);
+	if (sms == 6 && !priv->enabled) {
+		clk_enable(priv->clk);
+		priv->enabled = true;
+	}
+	mutex_unlock(&priv->lock);
+
+	regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, sms);
+
+	return 0;
+}
+
+static int stm32_sms2enable_mode(int mode)
+{
+	switch (mode) {
+	case 0:
+		return 0;
+	case 5:
+		return 1;
+	case 6:
+		return 2;
+	}
+
+	return -EINVAL;
+}
+
+static int stm32_get_enable_mode(struct iio_dev *indio_dev,
+				 const struct iio_chan_spec *chan)
+{
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	u32 smcr;
+
+	regmap_read(priv->regmap, TIM_SMCR, &smcr);
+	smcr &= TIM_SMCR_SMS;
+
+	return stm32_sms2enable_mode(smcr);
+}
+
+static const struct iio_enum stm32_enable_mode_enum = {
+	.items = stm32_enable_modes,
+	.num_items = ARRAY_SIZE(stm32_enable_modes),
+	.set = stm32_set_enable_mode,
+	.get = stm32_get_enable_mode
+};
+
+static ssize_t stm32_count_get_preset(struct iio_dev *indio_dev,
+				      uintptr_t private,
+				      const struct iio_chan_spec *chan,
+				      char *buf)
+{
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	u32 arr;
+
+	regmap_read(priv->regmap, TIM_ARR, &arr);
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", arr);
+}
+
+static ssize_t stm32_count_set_preset(struct iio_dev *indio_dev,
+				      uintptr_t private,
+				      const struct iio_chan_spec *chan,
+				      const char *buf, size_t len)
+{
+	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	unsigned int preset;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &preset);
+	if (ret)
+		return ret;
+
+	/* TIMx_ARR register shouldn't be buffered (ARPE=0) */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
+	regmap_write(priv->regmap, TIM_ARR, preset);
+
+	return len;
+}
+
+static const struct iio_chan_spec_ext_info stm32_trigger_count_info[] = {
+	{
+		.name = "preset",
+		.shared = IIO_SEPARATE,
+		.read = stm32_count_get_preset,
+		.write = stm32_count_set_preset
+	},
+	IIO_ENUM("enable_mode", IIO_SEPARATE, &stm32_enable_mode_enum),
+	IIO_ENUM_AVAILABLE("enable_mode", IIO_SHARED_BY_TYPE, &stm32_enable_mode_enum),
+	IIO_ENUM("trigger_mode", IIO_SEPARATE, &stm32_trigger_mode_enum),
+	IIO_ENUM_AVAILABLE("trigger_mode", IIO_SHARED_BY_TYPE, &stm32_trigger_mode_enum),
+	{}
+};
+
+static const struct iio_chan_spec stm32_trigger_channel = {
+	.type = IIO_COUNT,
+	.channel = 0,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+			      BIT(IIO_CHAN_INFO_ENABLE) |
+			      BIT(IIO_CHAN_INFO_SCALE),
+	.ext_info = stm32_trigger_count_info,
+	.indexed = 1
+};
+
+static struct stm32_timer_trigger *stm32_setup_counter_device(struct device *dev)
+{
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev,
+					  sizeof(struct stm32_timer_trigger));
+	if (!indio_dev)
+		return NULL;
+
+	indio_dev->name = dev_name(dev);
+	indio_dev->info = &stm32_trigger_info;
+	indio_dev->modes = INDIO_HARDWARE_TRIGGERED;
+	indio_dev->num_channels = 1;
+	indio_dev->channels = &stm32_trigger_channel;
+
+	ret = devm_iio_device_register(dev, indio_dev);
+	if (ret)
+		return NULL;
+
+	return iio_priv(indio_dev);
+}
+
+/**
+ * is_stm32_timer_trigger
+ * @trig: trigger to be checked
+ *
+ * return true if the trigger is a valid stm32 iio timer trigger
+ * either return false
+ */
+bool is_stm32_timer_trigger(struct iio_trigger *trig)
+{
+	return (trig->ops == &timer_trigger_ops);
+}
+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;
+	struct stm32_timer_trigger *priv;
+	struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
+	const struct stm32_timer_trigger_cfg *cfg;
+	unsigned int index;
+	int ret;
+
+	ret = device_property_read_u32(dev, "reg", &index);
+	if (ret)
+		return ret;
+
+	cfg = device_get_match_data(dev);
+
+	if (index >= ARRAY_SIZE(triggers_table) ||
+	    index >= cfg->num_valids_table)
+		return -EINVAL;
+
+	/* Create an IIO device only if we have triggers to be validated */
+	if (*cfg->valids_table[index])
+		priv = stm32_setup_counter_device(dev);
+	else
+		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	priv->regmap = ddata->regmap;
+	priv->clk = ddata->clk;
+	priv->max_arr = ddata->max_arr;
+	priv->triggers = triggers_table[index];
+	priv->valids = cfg->valids_table[index];
+	stm32_timer_detect_trgo2(priv);
+	mutex_init(&priv->lock);
+
+	ret = stm32_register_iio_triggers(priv);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static int stm32_timer_trigger_remove(struct platform_device *pdev)
+{
+	struct stm32_timer_trigger *priv = platform_get_drvdata(pdev);
+	u32 val;
+
+	/* Unregister triggers before everything can be safely turned off */
+	stm32_unregister_iio_triggers(priv);
+
+	/* Check if nobody else use the timer, then disable it */
+	regmap_read(priv->regmap, TIM_CCER, &val);
+	if (!(val & TIM_CCER_CCXE))
+		regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
+
+	if (priv->enabled)
+		clk_disable(priv->clk);
+
+	return 0;
+}
+
+static int stm32_timer_trigger_suspend(struct device *dev)
+{
+	struct stm32_timer_trigger *priv = dev_get_drvdata(dev);
+
+	/* Only take care of enabled timer: don't disturb other MFD child */
+	if (priv->enabled) {
+		/* Backup registers that may get lost in low power mode */
+		regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1);
+		regmap_read(priv->regmap, TIM_CR2, &priv->bak.cr2);
+		regmap_read(priv->regmap, TIM_PSC, &priv->bak.psc);
+		regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr);
+		regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt);
+		regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr);
+
+		/* Disable the timer */
+		regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
+		clk_disable(priv->clk);
+	}
+
+	return 0;
+}
+
+static int stm32_timer_trigger_resume(struct device *dev)
+{
+	struct stm32_timer_trigger *priv = dev_get_drvdata(dev);
+	int ret;
+
+	if (priv->enabled) {
+		ret = clk_enable(priv->clk);
+		if (ret)
+			return ret;
+
+		/* restore master/slave modes */
+		regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr);
+		regmap_write(priv->regmap, TIM_CR2, priv->bak.cr2);
+
+		/* restore sampling_frequency (trgo / trgo2 triggers) */
+		regmap_write(priv->regmap, TIM_PSC, priv->bak.psc);
+		regmap_write(priv->regmap, TIM_ARR, priv->bak.arr);
+		regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt);
+
+		/* Also re-enables the timer */
+		regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1);
+	}
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(stm32_timer_trigger_pm_ops,
+				stm32_timer_trigger_suspend,
+				stm32_timer_trigger_resume);
+
+static const struct stm32_timer_trigger_cfg stm32_timer_trg_cfg = {
+	.valids_table = valids_table,
+	.num_valids_table = ARRAY_SIZE(valids_table),
+};
+
+static const struct stm32_timer_trigger_cfg stm32h7_timer_trg_cfg = {
+	.valids_table = stm32h7_valids_table,
+	.num_valids_table = ARRAY_SIZE(stm32h7_valids_table),
+};
+
+static const struct of_device_id stm32_trig_of_match[] = {
+	{
+		.compatible = "st,stm32-timer-trigger",
+		.data = (void *)&stm32_timer_trg_cfg,
+	}, {
+		.compatible = "st,stm32h7-timer-trigger",
+		.data = (void *)&stm32h7_timer_trg_cfg,
+	},
+	{ /* end node */ },
+};
+MODULE_DEVICE_TABLE(of, stm32_trig_of_match);
+
+static struct platform_driver stm32_timer_trigger_driver = {
+	.probe = stm32_timer_trigger_probe,
+	.remove = stm32_timer_trigger_remove,
+	.driver = {
+		.name = "stm32-timer-trigger",
+		.of_match_table = stm32_trig_of_match,
+		.pm = pm_sleep_ptr(&stm32_timer_trigger_pm_ops),
+	},
+};
+module_platform_driver(stm32_timer_trigger_driver);
+
+MODULE_ALIAS("platform:stm32-timer-trigger");
+MODULE_DESCRIPTION("STMicroelectronics STM32 Timer Trigger driver");
+MODULE_LICENSE("GPL v2");