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/export.h> 13 #include <linux/iio/timer/stm32-lptim-trigger.h> 14 #include <linux/mfd/stm32-lptimer.h> 15 #include <linux/mod_devicetable.h> 16 #include <linux/module.h> 17 #include <linux/platform_device.h> 18 #include <linux/property.h> 19 20 /* Maximum triggers + one trailing null entry to indicate the end of array */ 21 #define MAX_TRIGGERS 3 22 23 struct stm32_lptim_cfg { 24 const char * const (*triggers)[MAX_TRIGGERS]; 25 unsigned int nb_triggers; 26 }; 27 28 /* List Low-Power Timer triggers for H7, MP13, MP15 */ 29 static const char * const stm32_lptim_triggers[][MAX_TRIGGERS] = { 30 { LPTIM1_OUT,}, 31 { LPTIM2_OUT,}, 32 { LPTIM3_OUT,}, 33 }; 34 35 /* List Low-Power Timer triggers for STM32MP25 */ 36 static const char * const stm32mp25_lptim_triggers[][MAX_TRIGGERS] = { 37 { LPTIM1_CH1, LPTIM1_CH2, }, 38 { LPTIM2_CH1, LPTIM2_CH2, }, 39 { LPTIM3_CH1,}, 40 { LPTIM4_CH1,}, 41 { LPTIM5_OUT,}, 42 }; 43 44 static const struct stm32_lptim_cfg stm32mp15_lptim_cfg = { 45 .triggers = stm32_lptim_triggers, 46 .nb_triggers = ARRAY_SIZE(stm32_lptim_triggers), 47 }; 48 49 static const struct stm32_lptim_cfg stm32mp25_lptim_cfg = { 50 .triggers = stm32mp25_lptim_triggers, 51 .nb_triggers = ARRAY_SIZE(stm32mp25_lptim_triggers), 52 }; 53 54 struct stm32_lptim_trigger { 55 struct device *dev; 56 const char * const *triggers; 57 }; 58 59 static int stm32_lptim_validate_device(struct iio_trigger *trig, 60 struct iio_dev *indio_dev) 61 { 62 if (indio_dev->modes & INDIO_HARDWARE_TRIGGERED) 63 return 0; 64 65 return -EINVAL; 66 } 67 68 static const struct iio_trigger_ops stm32_lptim_trigger_ops = { 69 .validate_device = stm32_lptim_validate_device, 70 }; 71 72 /** 73 * is_stm32_lptim_trigger 74 * @trig: trigger to be checked 75 * 76 * return true if the trigger is a valid STM32 IIO Low-Power Timer Trigger 77 * either return false 78 */ 79 bool is_stm32_lptim_trigger(struct iio_trigger *trig) 80 { 81 return (trig->ops == &stm32_lptim_trigger_ops); 82 } 83 EXPORT_SYMBOL(is_stm32_lptim_trigger); 84 85 static int stm32_lptim_setup_trig(struct stm32_lptim_trigger *priv) 86 { 87 const char * const *cur = priv->triggers; 88 int ret; 89 90 while (cur && *cur) { 91 struct iio_trigger *trig; 92 93 trig = devm_iio_trigger_alloc(priv->dev, "%s", *cur); 94 if (!trig) 95 return -ENOMEM; 96 97 trig->dev.parent = priv->dev->parent; 98 trig->ops = &stm32_lptim_trigger_ops; 99 iio_trigger_set_drvdata(trig, priv); 100 101 ret = devm_iio_trigger_register(priv->dev, trig); 102 if (ret) 103 return ret; 104 cur++; 105 } 106 107 return 0; 108 } 109 110 static int stm32_lptim_trigger_probe(struct platform_device *pdev) 111 { 112 struct stm32_lptim_trigger *priv; 113 struct stm32_lptim_cfg const *lptim_cfg; 114 u32 index; 115 116 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 117 if (!priv) 118 return -ENOMEM; 119 120 if (device_property_read_u32(&pdev->dev, "reg", &index)) 121 return -EINVAL; 122 123 lptim_cfg = device_get_match_data(&pdev->dev); 124 125 if (index >= lptim_cfg->nb_triggers) 126 return -EINVAL; 127 128 priv->dev = &pdev->dev; 129 priv->triggers = lptim_cfg->triggers[index]; 130 131 return stm32_lptim_setup_trig(priv); 132 } 133 134 static const struct of_device_id stm32_lptim_trig_of_match[] = { 135 { .compatible = "st,stm32-lptimer-trigger", .data = &stm32mp15_lptim_cfg }, 136 { .compatible = "st,stm32mp25-lptimer-trigger", .data = &stm32mp25_lptim_cfg}, 137 { } 138 }; 139 MODULE_DEVICE_TABLE(of, stm32_lptim_trig_of_match); 140 141 static struct platform_driver stm32_lptim_trigger_driver = { 142 .probe = stm32_lptim_trigger_probe, 143 .driver = { 144 .name = "stm32-lptimer-trigger", 145 .of_match_table = stm32_lptim_trig_of_match, 146 }, 147 }; 148 module_platform_driver(stm32_lptim_trigger_driver); 149 150 MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); 151 MODULE_ALIAS("platform:stm32-lptimer-trigger"); 152 MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver"); 153 MODULE_LICENSE("GPL v2"); 154