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-rw-r--r--drivers/iio/trigger/stm32-timer-trigger.c918
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");