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"); 117