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Linux kernel mirror (for testing)
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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * STM32 Low-Power Timer Trigger driver
4 *
5 * Copyright (C) STMicroelectronics 2017
6 *
7 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
8 *
9 * Inspired by Benjamin Gaignard's stm32-timer-trigger driver
10 */
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_trigger
46 * @trig: trigger to be checked
47 *
48 * return true if the trigger is a valid STM32 IIO Low-Power Timer Trigger
49 * either return false
50 */
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 int ret;
77
78 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
79 if (!priv)
80 return -ENOMEM;
81
82 if (device_property_read_u32(&pdev->dev, "reg", &index))
83 return -EINVAL;
84
85 if (index >= ARRAY_SIZE(stm32_lptim_triggers))
86 return -EINVAL;
87
88 priv->dev = &pdev->dev;
89 priv->trg = stm32_lptim_triggers[index];
90
91 ret = stm32_lptim_setup_trig(priv);
92 if (ret)
93 return ret;
94
95 platform_set_drvdata(pdev, priv);
96
97 return 0;
98}
99
100static const struct of_device_id stm32_lptim_trig_of_match[] = {
101 { .compatible = "st,stm32-lptimer-trigger", },
102 {},
103};
104MODULE_DEVICE_TABLE(of, stm32_lptim_trig_of_match);
105
106static struct platform_driver stm32_lptim_trigger_driver = {
107 .probe = stm32_lptim_trigger_probe,
108 .driver = {
109 .name = "stm32-lptimer-trigger",
110 .of_match_table = stm32_lptim_trig_of_match,
111 },
112};
113module_platform_driver(stm32_lptim_trigger_driver);
114
115MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
116MODULE_ALIAS("platform:stm32-lptimer-trigger");
117MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver");
118MODULE_LICENSE("GPL v2");