Re: [PATCH v3 6/7] IIO: add STM32 timer trigger driver

From: Lee Jones
Date: Fri Dec 02 2016 - 08:54:21 EST


On Fri, 02 Dec 2016, Benjamin Gaignard wrote:

> Timers IPs can be used to generate triggers for other IPs like
> DAC, ADC or other timers.
> Each trigger may result of timer internals signals like counter enable,
> reset or edge, this configuration could be done through "master_mode"
> device attribute.
>
> A timer device could be triggered by other timers, we use the trigger
> name and is_stm32_iio_timer_trigger() function to distinguish them
> and configure IP input switch.
>
> Timer may also decide on which event (edge, level) they could
> be activated by a trigger, this configuration is done by writing in
> "slave_mode" device attribute.
>
> Since triggers could also be used by DAC or ADC their names are defined
> in include/dt-bindings/iio/timer/st,stm32-iio-timer.h so those IPs will be able
> to configure themselves in valid_trigger function
>
> Trigger have a "sampling_frequency" attribute which allow to configure
> timer sampling frequency without using pwm interface
>
> version 3:
> - change compatible to "st,stm32-timer-trigger"
> - fix attributes access right
> - use string instead of int for master_mode and slave_mode
> - document device attributes in sysfs-bus-iio-timer-stm32
>
> version 2:
> - keep only one compatible
> - use st,input-triggers-names and st,output-triggers-names
> to know which triggers are accepted and/or create by the device
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxx>
> ---
> .../ABI/testing/sysfs-bus-iio-timer-stm32 | 47 ++
> drivers/iio/Kconfig | 2 +-
> drivers/iio/Makefile | 1 +
> drivers/iio/timer/Kconfig | 15 +
> drivers/iio/timer/Makefile | 1 +
> drivers/iio/timer/stm32-timer-trigger.c | 477 +++++++++++++++++++++
> drivers/iio/trigger/Kconfig | 1 -
> .../iio/timer/st,stm32-timer-triggers.h | 60 +++
> include/linux/iio/timer/stm32-timer-trigger.h | 16 +
> 9 files changed, 618 insertions(+), 2 deletions(-)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
> create mode 100644 drivers/iio/timer/Kconfig
> create mode 100644 drivers/iio/timer/Makefile
> create mode 100644 drivers/iio/timer/stm32-timer-trigger.c
> create mode 100644 include/dt-bindings/iio/timer/st,stm32-timer-triggers.h
> create mode 100644 include/linux/iio/timer/stm32-timer-trigger.h
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
> new file mode 100644
> index 0000000..b70bb2a
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
> @@ -0,0 +1,47 @@
> +What: /sys/bus/iio/devices/iio:deviceX/master_mode_available
> +KernelVersion: 4.10
> +Contact: benjamin.gaignard@xxxxxx
> +Description:
> + Reading returns the list possible master modes which are:
> + - "reset" : The UG bit from the TIMx_EGR register is used as trigger output (TRGO).
> + - "enable" : The Counter Enable signal CNT_EN is used as trigger output.
> + - "update" : The update event is selected as trigger output.
> + For instance a master timer can then be used as a prescaler for a slave timer.
> + - "compare_pulse" : The trigger output send a positive pulse when the CC1IF flag is to be set.
> + - "OC1REF" : OC1REF signal is used as trigger output.
> + - "OC2REF" : OC2REF signal is used as trigger output.
> + - "OC3REF" : OC3REF signal is used as trigger output.
> + - "OC4REF" : OC4REF signal is used as trigger output.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/master_mode
> +KernelVersion: 4.10
> +Contact: benjamin.gaignard@xxxxxx
> +Description:
> + Reading returns the current master modes.
> + Writing set the master mode
> +
> +What: /sys/bus/iio/devices/iio:deviceX/slave_mode_available
> +KernelVersion: 4.10
> +Contact: benjamin.gaignard@xxxxxx
> +Description:
> + Reading returns the list possible slave modes which are:
> + - "disabled" : The prescaler is clocked directly by the internal clock.
> + - "encoder_1" : Counter counts up/down on TI2FP1 edge depending on TI1FP2 level.
> + - "encoder_2" : Counter counts up/down on TI1FP2 edge depending on TI2FP1 level.
> + - "encoder_3" : Counter counts up/down on both TI1FP1 and TI2FP2 edges depending
> + on the level of the other input.
> + - "reset" : Rising edge of the selected trigger input reinitializes the counter
> + and generates an update of the registers.
> + - "gated" : The counter clock is enabled when the trigger input is high.
> + The counter stops (but is not reset) as soon as the trigger becomes low.
> + Both start and stop of the counter are controlled.
> + - "trigger" : The counter starts at a rising edge of the trigger TRGI (but it is not
> + reset). Only the start of the counter is controlled.
> + - "external_clock": Rising edges of the selected trigger (TRGI) clock the counter.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/slave_mode
> +KernelVersion: 4.10
> +Contact: benjamin.gaignard@xxxxxx
> +Description:
> + Reading returns the current slave mode.
> + Writing set the slave mode
> diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
> index 6743b18..2de2a80 100644
> --- a/drivers/iio/Kconfig
> +++ b/drivers/iio/Kconfig
> @@ -90,5 +90,5 @@ source "drivers/iio/potentiometer/Kconfig"
> source "drivers/iio/pressure/Kconfig"
> source "drivers/iio/proximity/Kconfig"
> source "drivers/iio/temperature/Kconfig"
> -
> +source "drivers/iio/timer/Kconfig"
> endif # IIO
> diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
> index 87e4c43..b797c08 100644
> --- a/drivers/iio/Makefile
> +++ b/drivers/iio/Makefile
> @@ -32,4 +32,5 @@ obj-y += potentiometer/
> obj-y += pressure/
> obj-y += proximity/
> obj-y += temperature/
> +obj-y += timer/
> obj-y += trigger/
> diff --git a/drivers/iio/timer/Kconfig b/drivers/iio/timer/Kconfig
> new file mode 100644
> index 0000000..149a917
> --- /dev/null
> +++ b/drivers/iio/timer/Kconfig
> @@ -0,0 +1,15 @@
> +#
> +# Timers drivers
> +
> +menu "Timers"
> +
> +config IIO_STM32_TIMER_TRIGGER
> + tristate "stm32 timer trigger"

"STM32 Timer Trigger"

> + depends on ARCH_STM32
> + depends on OF

Are these build or run time dependencies?

If they are only run-time, add "|| COMPILE_TEST".

> + select IIO_TRIGGERED_EVENT
> + select MFD_STM32_GP_TIMER
> + help
> + Select this option to enable stm32 timer trigger
> +
> +endmenu
> diff --git a/drivers/iio/timer/Makefile b/drivers/iio/timer/Makefile
> new file mode 100644
> index 0000000..4ad95ec9
> --- /dev/null
> +++ b/drivers/iio/timer/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_IIO_STM32_TIMER_TRIGGER) += stm32-timer-trigger.o
> diff --git a/drivers/iio/timer/stm32-timer-trigger.c b/drivers/iio/timer/stm32-timer-trigger.c
> new file mode 100644
> index 0000000..0c51601
> --- /dev/null
> +++ b/drivers/iio/timer/stm32-timer-trigger.c
> @@ -0,0 +1,477 @@
> +/*
> + * stm32-iio-timer.c

Swap this out for a description.

Filenames have a habit of becoming out-of-date.

> + * Copyright (C) STMicroelectronics 2016

'\n'

> + * Author: Benjamin Gaignard <benjamin.gaignard@xxxxxx> for STMicroelectronics.

You don't need to put the "for" bit. That's just what we do when
Linaro are writing drivers for other companies. Your email address
says enough.

> + * License terms: GNU General Public License (GPL), version 2
> + */
> +
> +#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/iio/triggered_event.h>
> +#include <linux/interrupt.h>
> +#include <linux/mfd/stm32-gptimer.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#define DRIVER_NAME "stm32-timer-trigger"

Just use the name in the correct places. Defining device names is an
ugly practice IMHO.

> +#define MAX_MODES 8
> +
> +struct stm32_timer_trigger_dev {
> + struct device *dev;
> + struct regmap *regmap;
> + struct clk *clk;
> + int irq;
> + bool own_timer;
> + unsigned int sampling_frequency;
> + struct iio_trigger *active_trigger;
> +};
> +
> +static ssize_t _store_frequency(struct device *dev,

What's with the '_' naming scheme?

> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct iio_trigger *trig = to_iio_trigger(dev);
> + struct stm32_timer_trigger_dev *stm32 = iio_trigger_get_drvdata(trig);
> + unsigned int freq;
> + int ret;
> +
> + ret = kstrtouint(buf, 10, &freq);
> + if (ret)
> + return ret;

No bounds checking required?

> + stm32->sampling_frequency = freq;

Where is this value placed into the registers?

> + return len;
> +}
> +
> +static ssize_t _read_frequency(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct iio_trigger *trig = to_iio_trigger(dev);
> + struct stm32_timer_trigger_dev *stm32 = iio_trigger_get_drvdata(trig);
> + unsigned long long freq = stm32->sampling_frequency;
> + u32 psc, arr, cr1;
> +
> + regmap_read(stm32->regmap, TIM_CR1, &cr1);
> + regmap_read(stm32->regmap, TIM_PSC, &psc);
> + regmap_read(stm32->regmap, TIM_ARR, &arr);
> +
> + if (psc && arr && (cr1 & TIM_CR1_CEN)) {
> + freq = (unsigned long long)clk_get_rate(stm32->clk);
> + do_div(freq, psc);
> + do_div(freq, arr);
> + }
> +
> + return sprintf(buf, "%d\n", (unsigned int)freq);
> +}
> +
> +static IIO_DEV_ATTR_SAMP_FREQ(0660, _read_frequency, _store_frequency);
> +
> +static struct attribute *stm32_trigger_attrs[] = {
> + &iio_dev_attr_sampling_frequency.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,
> +};

A lot of generic code here.

Are there macros that could help with this?

> +static char *master_mode_table[] = {
> + "reset",
> + "enable",
> + "update",
> + "compare_pulse",
> + "OC1REF",
> + "OC2REF",
> + "OC3REF",
> + "OC4REF"
> +};
> +
> +static

Why the line break here?

[and the ones below]

> +ssize_t _show_master_mode(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct stm32_timer_trigger_dev *stm32 = iio_priv(indio_dev);
> + u32 cr2;
> +
> + regmap_read(stm32->regmap, TIM_CR2, &cr2);
> + cr2 = (cr2 >> 4) & 0x7;

Define these SHIFT and MASK values.

> + return snprintf(buf, PAGE_SIZE, "%s\n", master_mode_table[cr2]);
> +}
> +
> +static
> +ssize_t _store_master_mode(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct stm32_timer_trigger_dev *stm32 = iio_priv(indio_dev);
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(master_mode_table); i++) {
> + if (!strncmp(master_mode_table[i], buf,
> + strlen(master_mode_table[i]))) {
> + regmap_update_bits(stm32->regmap, TIM_CR2,
> + TIM_CR2_MMS, i << 4);

Define all of the SHIFT and MASK values in this set.

> + return len;
> + }
> + }
> +
> + return -EINVAL;
> +}
> +
> +static IIO_CONST_ATTR(master_mode_available,
> + "reset enable update compare_pulse OC1REF OC2REF OC3REF OC4REF");
> +
> +static IIO_DEVICE_ATTR(master_mode, 0660,
> + _show_master_mode,
> + _store_master_mode,
> + 0);
> +
> +static char *slave_mode_table[] = {
> + "disabled",
> + "encoder_1",
> + "encoder_2",
> + "encoder_3",
> + "reset",
> + "gated",
> + "trigger",
> + "external_clock",
> +};
> +
> +static
> +ssize_t _show_slave_mode(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct stm32_timer_trigger_dev *stm32 = iio_priv(indio_dev);
> + u32 smcr;
> +
> + regmap_read(stm32->regmap, TIM_SMCR, &smcr);
> + smcr &= 0x7;
> +
> + return snprintf(buf, PAGE_SIZE, "%s\n", slave_mode_table[smcr]);
> +}
> +
> +static
> +ssize_t _store_slave_mode(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct stm32_timer_trigger_dev *stm32 = iio_priv(indio_dev);
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(slave_mode_table); i++) {
> + if (!strncmp(slave_mode_table[i], buf,
> + strlen(slave_mode_table[i]))) {
> + regmap_update_bits(stm32->regmap,
> + TIM_SMCR, TIM_SMCR_SMS, i);
> + return len;
> + }
> + }
> +
> + return -EINVAL;
> +}
> +
> +static IIO_CONST_ATTR(slave_mode_available,
> + "disabled encoder_1 encoder_2 encoder_3 reset gated trigger external_clock");
> +
> +static IIO_DEVICE_ATTR(slave_mode, 0660,
> + _show_slave_mode,
> + _store_slave_mode,
> + 0);
> +
> +static struct attribute *stm32_timer_attrs[] = {
> + &iio_dev_attr_master_mode.dev_attr.attr,
> + &iio_const_attr_master_mode_available.dev_attr.attr,
> + &iio_dev_attr_slave_mode.dev_attr.attr,
> + &iio_const_attr_slave_mode_available.dev_attr.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group stm32_timer_attr_group = {
> + .attrs = stm32_timer_attrs,
> +};
> +
> +static int stm32_timer_start(struct stm32_timer_trigger_dev *stm32)
> +{
> + unsigned long long prd, div;
> + int prescaler = 0;
> + u32 max_arr = 0xFFFF, cr1;

Since this is const, it'll be better of as a define.

> + if (stm32->sampling_frequency == 0)
> + return 0;

Is this okay? Or is this an error?

> + /* Period and prescaler values depends of clock rate */
> + div = (unsigned long long)clk_get_rate(stm32->clk);
> +
> + do_div(div, stm32->sampling_frequency);
> +
> + prd = div;
> +
> + while (div > max_arr) {
> + prescaler++;
> + div = prd;
> + do_div(div, (prescaler + 1));
> + }
> + prd = div;

Best to place a comment here. Saves the reader having to work it out.

> + if (prescaler > MAX_TIM_PSC) {
> + dev_err(stm32->dev, "prescaler exceeds the maximum value\n");
> + return -EINVAL;
> + }
> +
> + /* Check that we own the timer */
> + regmap_read(stm32->regmap, TIM_CR1, &cr1);
> + if ((cr1 & TIM_CR1_CEN) && !stm32->own_timer)
> + return -EBUSY;

What happens if the timer is already enabled and you do own it?

I guess this *re*-starts it?

> + if (!stm32->own_timer) {
> + stm32->own_timer = true;
> + clk_enable(stm32->clk);
> + }

At the very least you're going to require some shared locking here.

At best you should have a shared "device held" flag.

> + regmap_write(stm32->regmap, TIM_PSC, prescaler);
> + regmap_write(stm32->regmap, TIM_ARR, prd - 1);
> + regmap_update_bits(stm32->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE);
> +
> + /* Force master mode to update mode */
> + regmap_update_bits(stm32->regmap, TIM_CR2, TIM_CR2_MMS, 0x20);
> +
> + /* Make sure that registers are updated */
> + regmap_update_bits(stm32->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);
> +
> + /* Enable interrupt */
> + regmap_write(stm32->regmap, TIM_SR, 0);
> + regmap_update_bits(stm32->regmap, TIM_DIER, TIM_DIER_UIE, TIM_DIER_UIE);
> +
> + /* Enable controller */
> + regmap_update_bits(stm32->regmap, TIM_CR1, TIM_CR1_CEN, TIM_CR1_CEN);
> +
> + return 0;
> +}
> +
> +static int stm32_timer_stop(struct stm32_timer_trigger_dev *stm32)
> +{
> + if (!stm32->own_timer)
> + return 0;
> +
> + /* Stop timer */
> + regmap_update_bits(stm32->regmap, TIM_DIER, TIM_DIER_UIE, 0);
> + regmap_update_bits(stm32->regmap, TIM_CR1, TIM_CR1_CEN, 0);
> + regmap_write(stm32->regmap, TIM_PSC, 0);
> + regmap_write(stm32->regmap, TIM_ARR, 0);
> +
> + clk_disable(stm32->clk);
> +
> + stm32->own_timer = false;
> + stm32->active_trigger = NULL;
> +
> + return 0;
> +}
> +
> +static int stm32_set_trigger_state(struct iio_trigger *trig, bool state)
> +{
> + struct stm32_timer_trigger_dev *stm32 = iio_trigger_get_drvdata(trig);
> +
> + stm32->active_trigger = trig;
> +
> + if (state)
> + return stm32_timer_start(stm32);
> + else
> + return stm32_timer_stop(stm32);
> +}
> +
> +static irqreturn_t stm32_timer_irq_handler(int irq, void *private)
> +{
> + struct stm32_timer_trigger_dev *stm32 = private;
> + u32 sr;
> +
> + regmap_read(stm32->regmap, TIM_SR, &sr);
> + regmap_write(stm32->regmap, TIM_SR, 0);
> +
> + if ((sr & TIM_SR_UIF) && stm32->active_trigger)
> + iio_trigger_poll(stm32->active_trigger);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static const struct iio_trigger_ops timer_trigger_ops = {
> + .owner = THIS_MODULE,
> + .set_trigger_state = stm32_set_trigger_state,
> +};
> +
> +static int stm32_setup_iio_triggers(struct stm32_timer_trigger_dev *stm32)
> +{
> + int ret;
> + struct property *p;
> + const char *cur = NULL;
> +
> + p = of_find_property(stm32->dev->of_node,
> + "st,output-triggers-names", NULL);
> +
> + while ((cur = of_prop_next_string(p, cur)) != NULL) {
> + struct iio_trigger *trig;
> +
> + trig = devm_iio_trigger_alloc(stm32->dev, "%s", cur);
> + if (!trig)
> + return -ENOMEM;
> +
> + trig->dev.parent = stm32->dev->parent;
> + trig->ops = &timer_trigger_ops;
> + trig->dev.groups = stm32_trigger_attr_groups;
> + iio_trigger_set_drvdata(trig, stm32);
> +
> + ret = devm_iio_trigger_register(stm32->dev, trig);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * 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 int stm32_validate_trigger(struct iio_dev *indio_dev,
> + struct iio_trigger *trig)
> +{
> + struct stm32_timer_trigger_dev *dev = iio_priv(indio_dev);
> + int ret;
> +
> + if (!is_stm32_timer_trigger(trig))
> + return -EINVAL;
> +
> + ret = of_property_match_string(dev->dev->of_node,
> + "st,input-triggers-names",
> + trig->name);
> +
> + if (ret < 0)
> + return ret;
> +
> + regmap_update_bits(dev->regmap, TIM_SMCR, TIM_SMCR_TS, ret << 4);
> +
> + return 0;
> +}
> +
> +static const struct iio_info stm32_trigger_info = {
> + .driver_module = THIS_MODULE,
> + .validate_trigger = stm32_validate_trigger,
> + .attrs = &stm32_timer_attr_group,
> +};
> +
> +static struct stm32_timer_trigger_dev *stm32_setup_iio_device(struct device *dev)
> +{
> + struct iio_dev *indio_dev;
> + int ret;

> + indio_dev = devm_iio_device_alloc(dev, sizeof(struct stm32_timer_trigger_dev));

Did you run checkpatch.pl?

> + if (!indio_dev)
> + return NULL;
> +
> + indio_dev->name = dev_name(dev);
> + indio_dev->dev.parent = dev;
> + indio_dev->info = &stm32_trigger_info;
> + indio_dev->modes = INDIO_EVENT_TRIGGERED;
> + indio_dev->num_channels = 0;
> + indio_dev->dev.of_node = dev->of_node;
> +
> + ret = iio_triggered_event_setup(indio_dev,
> + NULL,
> + stm32_timer_irq_handler);
> + if (ret)
> + return NULL;

Return ERR_PTR(ret).

> + ret = devm_iio_device_register(dev, indio_dev);
> + if (ret) {
> + iio_triggered_event_cleanup(indio_dev);
> + return NULL;

Return ERR_PTR(ret).

> + }
> +
> + return iio_priv(indio_dev);
> +}
> +
> +static int stm32_timer_trigger_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct stm32_timer_trigger_dev *stm32;
> + struct stm32_gptimer_dev *mfd = dev_get_drvdata(pdev->dev.parent);
> + int ret;
> +
> + stm32 = stm32_setup_iio_device(dev);
> + if (!stm32)
> + return -ENOMEM;

Return stm32.

> + stm32->dev = dev;
> + stm32->regmap = mfd->regmap;
> + stm32->clk = mfd->clk;
> +
> + stm32->irq = platform_get_irq(pdev, 0);
> + if (stm32->irq < 0)
> + return -EINVAL;

return stm32->irq.

> + ret = devm_request_irq(stm32->dev, stm32->irq,
> + stm32_timer_irq_handler, IRQF_SHARED,
> + "timer_event", stm32);
> + if (ret)
> + return ret;
> +
> + ret = stm32_setup_iio_triggers(stm32);
> + if (ret)
> + return ret;
> +
> + platform_set_drvdata(pdev, stm32);
> +
> + return 0;
> +}
> +
> +static int stm32_timer_trigger_remove(struct platform_device *pdev)
> +{
> + struct stm32_timer_trigger_dev *stm32 = platform_get_drvdata(pdev);
> +
> + iio_triggered_event_cleanup((struct iio_dev *)stm32);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id stm32_trig_of_match[] = {
> + {
> + .compatible = "st,stm32-timer-trigger",
> + },
> +};

Make this one line.

{ .compatible = "st,stm32-timer-trigger" },

> +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 = DRIVER_NAME,

Yuk!

> + .of_match_table = stm32_trig_of_match,
> + },
> +};
> +module_platform_driver(stm32_timer_trigger_driver);
> +
> +MODULE_ALIAS("platform:" DRIVER_NAME);
> +MODULE_DESCRIPTION("STMicroelectronics STM32 timer trigger driver");
> +MODULE_LICENSE("GPL");

I thought this was "GPL v2"?

> diff --git a/drivers/iio/trigger/Kconfig b/drivers/iio/trigger/Kconfig
> index 809b2e7..f2af4fe 100644
> --- a/drivers/iio/trigger/Kconfig
> +++ b/drivers/iio/trigger/Kconfig
> @@ -46,5 +46,4 @@ config IIO_SYSFS_TRIGGER
>
> To compile this driver as a module, choose M here: the
> module will be called iio-trig-sysfs.
> -
> endmenu
> diff --git a/include/dt-bindings/iio/timer/st,stm32-timer-triggers.h b/include/dt-bindings/iio/timer/st,stm32-timer-triggers.h
> new file mode 100644
> index 0000000..a13db63
> --- /dev/null
> +++ b/include/dt-bindings/iio/timer/st,stm32-timer-triggers.h
> @@ -0,0 +1,60 @@
> +/*
> + * st,stm32-timer-triggers.h
> + * Copyright (C) STMicroelectronics 2016
> + * Author: Benjamin Gaignard <benjamin.gaignard@xxxxxx> for STMicroelectronics.
> + * License terms: GNU General Public License (GPL), version 2
> + */

Same comments as the top header.

> +#ifndef _DT_BINDINGS_STM32_TIMER_TRIGGERS_H_
> +#define _DT_BINDINGS_STM32_TIMER_TRIGGERS_H_
> +
> +#define TIM1_TRGO "tim1_trgo"
> +#define TIM1_CH1 "tim1_ch1"
> +#define TIM1_CH2 "tim1_ch2"
> +#define TIM1_CH3 "tim1_ch3"
> +#define TIM1_CH4 "tim1_ch4"
> +
> +#define TIM2_TRGO "tim2_trgo"
> +#define TIM2_CH1 "tim2_ch1"
> +#define TIM2_CH2 "tim2_ch2"
> +#define TIM2_CH3 "tim2_ch3"
> +#define TIM2_CH4 "tim2_ch4"
> +
> +#define TIM3_TRGO "tim3_trgo"
> +#define TIM3_CH1 "tim3_ch1"
> +#define TIM3_CH2 "tim3_ch2"
> +#define TIM3_CH3 "tim3_ch3"
> +#define TIM3_CH4 "tim3_ch4"
> +
> +#define TIM4_TRGO "tim4_trgo"
> +#define TIM4_CH1 "tim4_ch1"
> +#define TIM4_CH2 "tim4_ch2"
> +#define TIM4_CH3 "tim4_ch3"
> +#define TIM4_CH4 "tim4_ch4"
> +
> +#define TIM5_TRGO "tim5_trgo"
> +#define TIM5_CH1 "tim5_ch1"
> +#define TIM5_CH2 "tim5_ch2"
> +#define TIM5_CH3 "tim5_ch3"
> +#define TIM5_CH4 "tim5_ch4"
> +
> +#define TIM6_TRGO "tim6_trgo"
> +
> +#define TIM7_TRGO "tim7_trgo"
> +
> +#define TIM8_TRGO "tim8_trgo"
> +#define TIM8_CH1 "tim8_ch1"
> +#define TIM8_CH2 "tim8_ch2"
> +#define TIM8_CH3 "tim8_ch3"
> +#define TIM8_CH4 "tim8_ch4"
> +
> +#define TIM9_TRGO "tim9_trgo"
> +#define TIM9_CH1 "tim9_ch1"
> +#define TIM9_CH2 "tim9_ch2"
> +
> +#define TIM12_TRGO "tim12_trgo"
> +#define TIM12_CH1 "tim12_ch1"
> +#define TIM12_CH2 "tim12_ch2"

Grim!

uint8 valid_timers[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 12 };
uint8 valid_channels[] = { 0, 1, 2, 3, 4 };

> +#endif
> diff --git a/include/linux/iio/timer/stm32-timer-trigger.h b/include/linux/iio/timer/stm32-timer-trigger.h
> new file mode 100644
> index 0000000..c22fb3b
> --- /dev/null
> +++ b/include/linux/iio/timer/stm32-timer-trigger.h
> @@ -0,0 +1,16 @@
> +/*
> + * stm32-timer-trigger.h
> + * Copyright (C) STMicroelectronics 2016
> + * Author: Benjamin Gaignard <benjamin.gaignard@xxxxxx> for STMicroelectronics.
> + * License terms: GNU General Public License (GPL), version 2
> + */

Same comments as the top header.

> +#ifndef _STM32_TIMER_TRIGGER_H_
> +#define _STM32_TIMER_TRIGGER_H_
> +
> +#include <dt-bindings/iio/timer/st,stm32-timer-triggers.h>
> +
> +bool is_stm32_timer_trigger(struct iio_trigger *trig);
> +
> +#endif

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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