On Wed, 21 Jun 2017 16:30:13 +0200 Fabrice Gasnier <[email protected]> wrote:
> Add support for LPTIMx_OUT triggers that can be found on some STM32 > devices. These triggers can be used then by ADC or DAC. > Typical usage is to configure LPTimer as PWM output (via pwm-stm32-lp) > and have synchronised analog conversions with these triggers. > > Signed-off-by: Fabrice Gasnier <[email protected]> Given this can't be used as a trigger for other devices (no exposed interrupt?) I'd expect to see a validate_device callback provided for the trigger ops. That would prevent other devices trying to use it. Otherwise, looks good. Jonathan > --- > Changes in v2: > - s/Low Power/Low-Power > - update few comments > --- > drivers/iio/trigger/Kconfig | 11 +++ > drivers/iio/trigger/Makefile | 1 + > drivers/iio/trigger/stm32-lptimer-trigger.c | 110 > ++++++++++++++++++++++++++ > include/linux/iio/timer/stm32-lptim-trigger.h | 24 ++++++ > 4 files changed, 146 insertions(+) > create mode 100644 drivers/iio/trigger/stm32-lptimer-trigger.c > create mode 100644 include/linux/iio/timer/stm32-lptim-trigger.h > > diff --git a/drivers/iio/trigger/Kconfig b/drivers/iio/trigger/Kconfig > index e4d4e63..a633d2c 100644 > --- a/drivers/iio/trigger/Kconfig > +++ b/drivers/iio/trigger/Kconfig > @@ -24,6 +24,17 @@ config IIO_INTERRUPT_TRIGGER > To compile this driver as a module, choose M here: the > module will be called iio-trig-interrupt. > > +config IIO_STM32_LPTIMER_TRIGGER > + tristate "STM32 Low-Power Timer Trigger" > + depends on MFD_STM32_LPTIMER || COMPILE_TEST > + help > + Select this option to enable STM32 Low-Power Timer Trigger. > + This can be used as trigger source for STM32 internal ADC > + and/or DAC. > + > + To compile this driver as a module, choose M here: the > + module will be called stm32-lptimer-trigger. > + > config IIO_STM32_TIMER_TRIGGER > tristate "STM32 Timer Trigger" > depends on (ARCH_STM32 && OF && MFD_STM32_TIMERS) || COMPILE_TEST > diff --git a/drivers/iio/trigger/Makefile b/drivers/iio/trigger/Makefile > index 5c4ecd3..0a72a2a 100644 > --- a/drivers/iio/trigger/Makefile > +++ b/drivers/iio/trigger/Makefile > @@ -6,6 +6,7 @@ > > obj-$(CONFIG_IIO_HRTIMER_TRIGGER) += iio-trig-hrtimer.o > obj-$(CONFIG_IIO_INTERRUPT_TRIGGER) += iio-trig-interrupt.o > +obj-$(CONFIG_IIO_STM32_LPTIMER_TRIGGER) += stm32-lptimer-trigger.o > obj-$(CONFIG_IIO_STM32_TIMER_TRIGGER) += stm32-timer-trigger.o > obj-$(CONFIG_IIO_SYSFS_TRIGGER) += iio-trig-sysfs.o > obj-$(CONFIG_IIO_TIGHTLOOP_TRIGGER) += iio-trig-loop.o > diff --git a/drivers/iio/trigger/stm32-lptimer-trigger.c > b/drivers/iio/trigger/stm32-lptimer-trigger.c > new file mode 100644 > index 0000000..bcb9aa2 > --- /dev/null > +++ b/drivers/iio/trigger/stm32-lptimer-trigger.c > @@ -0,0 +1,110 @@ > +/* > + * STM32 Low-Power Timer Trigger driver > + * > + * Copyright (C) STMicroelectronics 2017 > + * > + * Author: Fabrice Gasnier <[email protected]>. > + * > + * License terms: GNU General Public License (GPL), version 2 > + * > + * Inspired by Benjamin Gaignard's stm32-timer-trigger driver > + */ > + > +#include <linux/iio/iio.h> > +#include <linux/iio/timer/stm32-lptim-trigger.h> > +#include <linux/iio/trigger.h> > +#include <linux/mfd/stm32-lptimer.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > + > +/* List Low-Power Timer triggers */ > +static const char * const stm32_lptim_triggers[] = { > + LPTIM1_OUT, > + LPTIM2_OUT, > + LPTIM3_OUT, > +}; > + > +struct stm32_lptim_trigger { > + struct device *dev; > + const char *trg; > +}; > + > +static const struct iio_trigger_ops stm32_lptim_trigger_ops = { > + .owner = THIS_MODULE, > +}; > + > +/** > + * is_stm32_lptim_trigger > + * @trig: trigger to be checked > + * > + * return true if the trigger is a valid STM32 IIO Low-Power Timer Trigger > + * either return false > + */ > +bool is_stm32_lptim_trigger(struct iio_trigger *trig) > +{ > + return (trig->ops == &stm32_lptim_trigger_ops); > +} > +EXPORT_SYMBOL(is_stm32_lptim_trigger); > + > +static int stm32_lptim_setup_trig(struct stm32_lptim_trigger *priv) > +{ > + struct iio_trigger *trig; > + > + trig = devm_iio_trigger_alloc(priv->dev, "%s", priv->trg); > + if (!trig) > + return -ENOMEM; > + > + trig->dev.parent = priv->dev->parent; > + trig->ops = &stm32_lptim_trigger_ops; > + iio_trigger_set_drvdata(trig, priv); > + > + return devm_iio_trigger_register(priv->dev, trig); > +} > + > +static int stm32_lptim_trigger_probe(struct platform_device *pdev) > +{ > + struct stm32_lptim_trigger *priv; > + u32 index; > + int ret; > + > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + if (of_property_read_u32(pdev->dev.of_node, "reg", &index)) > + return -EINVAL; > + > + if (index >= ARRAY_SIZE(stm32_lptim_triggers)) > + return -EINVAL; > + > + priv->dev = &pdev->dev; > + priv->trg = stm32_lptim_triggers[index]; > + > + ret = stm32_lptim_setup_trig(priv); > + if (ret) > + return ret; > + > + platform_set_drvdata(pdev, priv); > + > + return 0; > +} > + > +static const struct of_device_id stm32_lptim_trig_of_match[] = { > + { .compatible = "st,stm32-lptimer-trigger", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, stm32_lptim_trig_of_match); > + > +static struct platform_driver stm32_lptim_trigger_driver = { > + .probe = stm32_lptim_trigger_probe, > + .driver = { > + .name = "stm32-lptimer-trigger", > + .of_match_table = stm32_lptim_trig_of_match, > + }, > +}; > +module_platform_driver(stm32_lptim_trigger_driver); > + > +MODULE_AUTHOR("Fabrice Gasnier <[email protected]>"); > +MODULE_ALIAS("platform:stm32-lptimer-trigger"); > +MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver"); > +MODULE_LICENSE("GPL v2"); > diff --git a/include/linux/iio/timer/stm32-lptim-trigger.h > b/include/linux/iio/timer/stm32-lptim-trigger.h > new file mode 100644 > index 0000000..cb795b1 > --- /dev/null > +++ b/include/linux/iio/timer/stm32-lptim-trigger.h > @@ -0,0 +1,24 @@ > +/* > + * Copyright (C) STMicroelectronics 2017 > + * > + * Author: Fabrice Gasnier <[email protected]> > + * > + * License terms: GNU General Public License (GPL), version 2 > + */ > + > +#ifndef _STM32_LPTIM_TRIGGER_H_ > +#define _STM32_LPTIM_TRIGGER_H_ > + > +#define LPTIM1_OUT "lptim1_out" > +#define LPTIM2_OUT "lptim2_out" > +#define LPTIM3_OUT "lptim3_out" > + > +#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER) > +bool is_stm32_lptim_trigger(struct iio_trigger *trig); > +#else > +static inline bool is_stm32_lptim_trigger(struct iio_trigger *trig) > +{ > + return false; > +} > +#endif > +#endif
