linux/drivers/iio/trigger/stm32-lptimer-trigger.c

118 lines
2.7 KiB
C

/*
* STM32 Low-Power Timer Trigger driver
*
* Copyright (C) STMicroelectronics 2017
*
* Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
*
* License terms: GNU General Public License (GPL), version 2
*
* Inspired by Benjamin Gaignard's stm32-timer-trigger driver
*/
#include <linux/iio/timer/stm32-lptim-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 int stm32_lptim_validate_device(struct iio_trigger *trig,
struct iio_dev *indio_dev)
{
if (indio_dev->modes & INDIO_HARDWARE_TRIGGERED)
return 0;
return -EINVAL;
}
static const struct iio_trigger_ops stm32_lptim_trigger_ops = {
.validate_device = stm32_lptim_validate_device,
};
/**
* 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 <fabrice.gasnier@st.com>");
MODULE_ALIAS("platform:stm32-lptimer-trigger");
MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver");
MODULE_LICENSE("GPL v2");