diff options
Diffstat (limited to 'drivers/iio/trigger/stm32-lptimer-trigger.c')
| -rw-r--r-- | drivers/iio/trigger/stm32-lptimer-trigger.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/iio/trigger/stm32-lptimer-trigger.c b/drivers/iio/trigger/stm32-lptimer-trigger.c new file mode 100644 index 000000000000..c7bab18221c7 --- /dev/null +++ b/drivers/iio/trigger/stm32-lptimer-trigger.c @@ -0,0 +1,153 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * STM32 Low-Power Timer Trigger driver + * + * Copyright (C) STMicroelectronics 2017 + * + * Author: Fabrice Gasnier <fabrice.gasnier@st.com>. + * + * Inspired by Benjamin Gaignard's stm32-timer-trigger driver + */ + +#include <linux/export.h> +#include <linux/iio/timer/stm32-lptim-trigger.h> +#include <linux/mfd/stm32-lptimer.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/property.h> + +/* Maximum triggers + one trailing null entry to indicate the end of array */ +#define MAX_TRIGGERS 3 + +struct stm32_lptim_cfg { + const char * const (*triggers)[MAX_TRIGGERS]; + unsigned int nb_triggers; +}; + +/* List Low-Power Timer triggers for H7, MP13, MP15 */ +static const char * const stm32_lptim_triggers[][MAX_TRIGGERS] = { + { LPTIM1_OUT,}, + { LPTIM2_OUT,}, + { LPTIM3_OUT,}, +}; + +/* List Low-Power Timer triggers for STM32MP25 */ +static const char * const stm32mp25_lptim_triggers[][MAX_TRIGGERS] = { + { LPTIM1_CH1, LPTIM1_CH2, }, + { LPTIM2_CH1, LPTIM2_CH2, }, + { LPTIM3_CH1,}, + { LPTIM4_CH1,}, + { LPTIM5_OUT,}, +}; + +static const struct stm32_lptim_cfg stm32mp15_lptim_cfg = { + .triggers = stm32_lptim_triggers, + .nb_triggers = ARRAY_SIZE(stm32_lptim_triggers), +}; + +static const struct stm32_lptim_cfg stm32mp25_lptim_cfg = { + .triggers = stm32mp25_lptim_triggers, + .nb_triggers = ARRAY_SIZE(stm32mp25_lptim_triggers), +}; + +struct stm32_lptim_trigger { + struct device *dev; + const char * const *triggers; +}; + +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) +{ + const char * const *cur = priv->triggers; + int ret; + + while (cur && *cur) { + struct iio_trigger *trig; + + trig = devm_iio_trigger_alloc(priv->dev, "%s", *cur); + if (!trig) + return -ENOMEM; + + trig->dev.parent = priv->dev->parent; + trig->ops = &stm32_lptim_trigger_ops; + iio_trigger_set_drvdata(trig, priv); + + ret = devm_iio_trigger_register(priv->dev, trig); + if (ret) + return ret; + cur++; + } + + return 0; +} + +static int stm32_lptim_trigger_probe(struct platform_device *pdev) +{ + struct stm32_lptim_trigger *priv; + struct stm32_lptim_cfg const *lptim_cfg; + u32 index; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + if (device_property_read_u32(&pdev->dev, "reg", &index)) + return -EINVAL; + + lptim_cfg = device_get_match_data(&pdev->dev); + + if (index >= lptim_cfg->nb_triggers) + return -EINVAL; + + priv->dev = &pdev->dev; + priv->triggers = lptim_cfg->triggers[index]; + + return stm32_lptim_setup_trig(priv); +} + +static const struct of_device_id stm32_lptim_trig_of_match[] = { + { .compatible = "st,stm32-lptimer-trigger", .data = &stm32mp15_lptim_cfg }, + { .compatible = "st,stm32mp25-lptimer-trigger", .data = &stm32mp25_lptim_cfg}, + { } +}; +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"); |