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1// SPDX-License-Identifier: GPL-2.02/*3 * STM32 Low-Power Timer Trigger driver4 *5 * Copyright (C) STMicroelectronics 20176 *7 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.8 *9 * Inspired by Benjamin Gaignard's stm32-timer-trigger driver10 */11 12#include <linux/iio/timer/stm32-lptim-trigger.h>13#include <linux/mfd/stm32-lptimer.h>14#include <linux/mod_devicetable.h>15#include <linux/module.h>16#include <linux/platform_device.h>17#include <linux/property.h>18 19/* List Low-Power Timer triggers */20static const char * const stm32_lptim_triggers[] = {21 LPTIM1_OUT,22 LPTIM2_OUT,23 LPTIM3_OUT,24};25 26struct stm32_lptim_trigger {27 struct device *dev;28 const char *trg;29};30 31static int stm32_lptim_validate_device(struct iio_trigger *trig,32 struct iio_dev *indio_dev)33{34 if (indio_dev->modes & INDIO_HARDWARE_TRIGGERED)35 return 0;36 37 return -EINVAL;38}39 40static const struct iio_trigger_ops stm32_lptim_trigger_ops = {41 .validate_device = stm32_lptim_validate_device,42};43 44/**45 * is_stm32_lptim_trigger46 * @trig: trigger to be checked47 *48 * return true if the trigger is a valid STM32 IIO Low-Power Timer Trigger49 * either return false50 */51bool is_stm32_lptim_trigger(struct iio_trigger *trig)52{53 return (trig->ops == &stm32_lptim_trigger_ops);54}55EXPORT_SYMBOL(is_stm32_lptim_trigger);56 57static int stm32_lptim_setup_trig(struct stm32_lptim_trigger *priv)58{59 struct iio_trigger *trig;60 61 trig = devm_iio_trigger_alloc(priv->dev, "%s", priv->trg);62 if (!trig)63 return -ENOMEM;64 65 trig->dev.parent = priv->dev->parent;66 trig->ops = &stm32_lptim_trigger_ops;67 iio_trigger_set_drvdata(trig, priv);68 69 return devm_iio_trigger_register(priv->dev, trig);70}71 72static int stm32_lptim_trigger_probe(struct platform_device *pdev)73{74 struct stm32_lptim_trigger *priv;75 u32 index;76 77 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);78 if (!priv)79 return -ENOMEM;80 81 if (device_property_read_u32(&pdev->dev, "reg", &index))82 return -EINVAL;83 84 if (index >= ARRAY_SIZE(stm32_lptim_triggers))85 return -EINVAL;86 87 priv->dev = &pdev->dev;88 priv->trg = stm32_lptim_triggers[index];89 90 return stm32_lptim_setup_trig(priv);91}92 93static const struct of_device_id stm32_lptim_trig_of_match[] = {94 { .compatible = "st,stm32-lptimer-trigger", },95 {},96};97MODULE_DEVICE_TABLE(of, stm32_lptim_trig_of_match);98 99static struct platform_driver stm32_lptim_trigger_driver = {100 .probe = stm32_lptim_trigger_probe,101 .driver = {102 .name = "stm32-lptimer-trigger",103 .of_match_table = stm32_lptim_trig_of_match,104 },105};106module_platform_driver(stm32_lptim_trigger_driver);107 108MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");109MODULE_ALIAS("platform:stm32-lptimer-trigger");110MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver");111MODULE_LICENSE("GPL v2");112