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 */ 20 static const char * const stm32_lptim_triggers[] = { 21 LPTIM1_OUT, 22 LPTIM2_OUT, 23 LPTIM3_OUT, 24 }; 25 26 struct stm32_lptim_trigger { 27 struct device *dev; 28 const char *trg; 29 }; 30 31 static 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 40 static 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 */ 51 bool is_stm32_lptim_trigger(struct iio_trigger *trig) 52 { 53 return (trig->ops == &stm32_lptim_trigger_ops); 54 } 55 EXPORT_SYMBOL(is_stm32_lptim_trigger); 56 57 static 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 72 static 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 93 static const struct of_device_id stm32_lptim_trig_of_match[] = { 94 { .compatible = "st,stm32-lptimer-trigger", }, 95 {}, 96 }; 97 MODULE_DEVICE_TABLE(of, stm32_lptim_trig_of_match); 98 99 static 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 }; 106 module_platform_driver(stm32_lptim_trigger_driver); 107 108 MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); 109 MODULE_ALIAS("platform:stm32-lptimer-trigger"); 110 MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver"); 111 MODULE_LICENSE("GPL v2"); 112