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

From: Fabrice Gasnier
Date: Tue May 02 2017 - 08:35:06 EST

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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>
---
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
--
1.9.1

Next message: Mark Rutland: "Re: [PATCH 1/1] arm64: Always provide "model name" in /proc/cpuinfo"
Previous message: Roberto Sassu: "[PATCH 3/3] tpm: move TPM 1.2 code of tpm_pcr_extend() to tpm1_pcr_extend()"
Next in thread: Jonathan Cameron: "Re: [PATCH v2] iio: stm32 trigger: Add support for TRGO2 triggers"
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