| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame^] | 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/module.h> |
| 15 | #include <linux/platform_device.h> |
| 16 | |
| 17 | /* List Low-Power Timer triggers */ |
| 18 | static const char * const stm32_lptim_triggers[] = { |
| 19 | LPTIM1_OUT, |
| 20 | LPTIM2_OUT, |
| 21 | LPTIM3_OUT, |
| 22 | }; |
| 23 | |
| 24 | struct stm32_lptim_trigger { |
| 25 | struct device *dev; |
| 26 | const char *trg; |
| 27 | }; |
| 28 | |
| 29 | static int stm32_lptim_validate_device(struct iio_trigger *trig, |
| 30 | struct iio_dev *indio_dev) |
| 31 | { |
| 32 | if (indio_dev->modes & INDIO_HARDWARE_TRIGGERED) |
| 33 | return 0; |
| 34 | |
| 35 | return -EINVAL; |
| 36 | } |
| 37 | |
| 38 | static const struct iio_trigger_ops stm32_lptim_trigger_ops = { |
| 39 | .validate_device = stm32_lptim_validate_device, |
| 40 | }; |
| 41 | |
| 42 | /** |
| 43 | * is_stm32_lptim_trigger |
| 44 | * @trig: trigger to be checked |
| 45 | * |
| 46 | * return true if the trigger is a valid STM32 IIO Low-Power Timer Trigger |
| 47 | * either return false |
| 48 | */ |
| 49 | bool is_stm32_lptim_trigger(struct iio_trigger *trig) |
| 50 | { |
| 51 | return (trig->ops == &stm32_lptim_trigger_ops); |
| 52 | } |
| 53 | EXPORT_SYMBOL(is_stm32_lptim_trigger); |
| 54 | |
| 55 | static int stm32_lptim_setup_trig(struct stm32_lptim_trigger *priv) |
| 56 | { |
| 57 | struct iio_trigger *trig; |
| 58 | |
| 59 | trig = devm_iio_trigger_alloc(priv->dev, "%s", priv->trg); |
| 60 | if (!trig) |
| 61 | return -ENOMEM; |
| 62 | |
| 63 | trig->dev.parent = priv->dev->parent; |
| 64 | trig->ops = &stm32_lptim_trigger_ops; |
| 65 | iio_trigger_set_drvdata(trig, priv); |
| 66 | |
| 67 | return devm_iio_trigger_register(priv->dev, trig); |
| 68 | } |
| 69 | |
| 70 | static int stm32_lptim_trigger_probe(struct platform_device *pdev) |
| 71 | { |
| 72 | struct stm32_lptim_trigger *priv; |
| 73 | u32 index; |
| 74 | int ret; |
| 75 | |
| 76 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
| 77 | if (!priv) |
| 78 | return -ENOMEM; |
| 79 | |
| 80 | if (of_property_read_u32(pdev->dev.of_node, "reg", &index)) |
| 81 | return -EINVAL; |
| 82 | |
| 83 | if (index >= ARRAY_SIZE(stm32_lptim_triggers)) |
| 84 | return -EINVAL; |
| 85 | |
| 86 | priv->dev = &pdev->dev; |
| 87 | priv->trg = stm32_lptim_triggers[index]; |
| 88 | |
| 89 | ret = stm32_lptim_setup_trig(priv); |
| 90 | if (ret) |
| 91 | return ret; |
| 92 | |
| 93 | platform_set_drvdata(pdev, priv); |
| 94 | |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | static const struct of_device_id stm32_lptim_trig_of_match[] = { |
| 99 | { .compatible = "st,stm32-lptimer-trigger", }, |
| 100 | {}, |
| 101 | }; |
| 102 | MODULE_DEVICE_TABLE(of, stm32_lptim_trig_of_match); |
| 103 | |
| 104 | static struct platform_driver stm32_lptim_trigger_driver = { |
| 105 | .probe = stm32_lptim_trigger_probe, |
| 106 | .driver = { |
| 107 | .name = "stm32-lptimer-trigger", |
| 108 | .of_match_table = stm32_lptim_trig_of_match, |
| 109 | }, |
| 110 | }; |
| 111 | module_platform_driver(stm32_lptim_trigger_driver); |
| 112 | |
| 113 | MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); |
| 114 | MODULE_ALIAS("platform:stm32-lptimer-trigger"); |
| 115 | MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver"); |
| 116 | MODULE_LICENSE("GPL v2"); |