119 lines
2.7 KiB
C
119 lines
2.7 KiB
C
/*
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* STM32 Low-Power Timer Trigger driver
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*
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* Copyright (C) STMicroelectronics 2017
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*
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* Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
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*
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* License terms: GNU General Public License (GPL), version 2
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*
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* Inspired by Benjamin Gaignard's stm32-timer-trigger driver
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*/
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#include <linux/iio/timer/stm32-lptim-trigger.h>
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#include <linux/mfd/stm32-lptimer.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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/* List Low-Power Timer triggers */
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static const char * const stm32_lptim_triggers[] = {
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LPTIM1_OUT,
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LPTIM2_OUT,
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LPTIM3_OUT,
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};
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struct stm32_lptim_trigger {
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struct device *dev;
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const char *trg;
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};
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static int stm32_lptim_validate_device(struct iio_trigger *trig,
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struct iio_dev *indio_dev)
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{
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if (indio_dev->modes & INDIO_HARDWARE_TRIGGERED)
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return 0;
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return -EINVAL;
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}
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static const struct iio_trigger_ops stm32_lptim_trigger_ops = {
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.owner = THIS_MODULE,
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.validate_device = stm32_lptim_validate_device,
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};
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/**
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* is_stm32_lptim_trigger
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* @trig: trigger to be checked
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*
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* return true if the trigger is a valid STM32 IIO Low-Power Timer Trigger
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* either return false
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*/
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bool is_stm32_lptim_trigger(struct iio_trigger *trig)
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{
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return (trig->ops == &stm32_lptim_trigger_ops);
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}
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EXPORT_SYMBOL(is_stm32_lptim_trigger);
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static int stm32_lptim_setup_trig(struct stm32_lptim_trigger *priv)
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{
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struct iio_trigger *trig;
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trig = devm_iio_trigger_alloc(priv->dev, "%s", priv->trg);
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if (!trig)
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return -ENOMEM;
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trig->dev.parent = priv->dev->parent;
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trig->ops = &stm32_lptim_trigger_ops;
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iio_trigger_set_drvdata(trig, priv);
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return devm_iio_trigger_register(priv->dev, trig);
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}
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static int stm32_lptim_trigger_probe(struct platform_device *pdev)
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{
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struct stm32_lptim_trigger *priv;
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u32 index;
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int ret;
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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if (of_property_read_u32(pdev->dev.of_node, "reg", &index))
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return -EINVAL;
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if (index >= ARRAY_SIZE(stm32_lptim_triggers))
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return -EINVAL;
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priv->dev = &pdev->dev;
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priv->trg = stm32_lptim_triggers[index];
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ret = stm32_lptim_setup_trig(priv);
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if (ret)
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return ret;
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platform_set_drvdata(pdev, priv);
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return 0;
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}
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static const struct of_device_id stm32_lptim_trig_of_match[] = {
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{ .compatible = "st,stm32-lptimer-trigger", },
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{},
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};
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MODULE_DEVICE_TABLE(of, stm32_lptim_trig_of_match);
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static struct platform_driver stm32_lptim_trigger_driver = {
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.probe = stm32_lptim_trigger_probe,
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.driver = {
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.name = "stm32-lptimer-trigger",
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.of_match_table = stm32_lptim_trig_of_match,
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},
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};
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module_platform_driver(stm32_lptim_trigger_driver);
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MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
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MODULE_ALIAS("platform:stm32-lptimer-trigger");
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MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver");
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MODULE_LICENSE("GPL v2");
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