1 /* 2 * STMicroelectronics sensors trigger library driver 3 * 4 * Copyright 2012-2013 STMicroelectronics Inc. 5 * 6 * Denis Ciocca <denis.ciocca@st.com> 7 * 8 * Licensed under the GPL-2. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <linux/iio/iio.h> 15 #include <linux/iio/trigger.h> 16 #include <linux/interrupt.h> 17 #include <linux/iio/common/st_sensors.h> 18 #include "st_sensors_core.h" 19 20 int st_sensors_allocate_trigger(struct iio_dev *indio_dev, 21 const struct iio_trigger_ops *trigger_ops) 22 { 23 int err, irq; 24 struct st_sensor_data *sdata = iio_priv(indio_dev); 25 unsigned long irq_trig; 26 27 sdata->trig = iio_trigger_alloc("%s-trigger", indio_dev->name); 28 if (sdata->trig == NULL) { 29 dev_err(&indio_dev->dev, "failed to allocate iio trigger.\n"); 30 return -ENOMEM; 31 } 32 33 irq = sdata->get_irq_data_ready(indio_dev); 34 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq)); 35 /* 36 * If the IRQ is triggered on falling edge, we need to mark the 37 * interrupt as active low, if the hardware supports this. 38 */ 39 if (irq_trig == IRQF_TRIGGER_FALLING) { 40 if (!sdata->sensor_settings->drdy_irq.addr_ihl) { 41 dev_err(&indio_dev->dev, 42 "falling edge specified for IRQ but hardware " 43 "only support rising edge, will request " 44 "rising edge\n"); 45 irq_trig = IRQF_TRIGGER_RISING; 46 } else { 47 /* Set up INT active low i.e. falling edge */ 48 err = st_sensors_write_data_with_mask(indio_dev, 49 sdata->sensor_settings->drdy_irq.addr_ihl, 50 sdata->sensor_settings->drdy_irq.mask_ihl, 1); 51 if (err < 0) 52 goto iio_trigger_free; 53 dev_info(&indio_dev->dev, 54 "interrupts on the falling edge\n"); 55 } 56 } else if (irq_trig == IRQF_TRIGGER_RISING) { 57 dev_info(&indio_dev->dev, 58 "interrupts on the rising edge\n"); 59 60 } else { 61 dev_err(&indio_dev->dev, 62 "unsupported IRQ trigger specified (%lx), only " 63 "rising and falling edges supported, enforce " 64 "rising edge\n", irq_trig); 65 irq_trig = IRQF_TRIGGER_RISING; 66 } 67 err = request_threaded_irq(irq, 68 iio_trigger_generic_data_rdy_poll, 69 NULL, 70 irq_trig, 71 sdata->trig->name, 72 sdata->trig); 73 if (err) { 74 dev_err(&indio_dev->dev, "failed to request trigger IRQ.\n"); 75 goto iio_trigger_free; 76 } 77 78 iio_trigger_set_drvdata(sdata->trig, indio_dev); 79 sdata->trig->ops = trigger_ops; 80 sdata->trig->dev.parent = sdata->dev; 81 82 err = iio_trigger_register(sdata->trig); 83 if (err < 0) { 84 dev_err(&indio_dev->dev, "failed to register iio trigger.\n"); 85 goto iio_trigger_register_error; 86 } 87 indio_dev->trig = iio_trigger_get(sdata->trig); 88 89 return 0; 90 91 iio_trigger_register_error: 92 free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig); 93 iio_trigger_free: 94 iio_trigger_free(sdata->trig); 95 return err; 96 } 97 EXPORT_SYMBOL(st_sensors_allocate_trigger); 98 99 void st_sensors_deallocate_trigger(struct iio_dev *indio_dev) 100 { 101 struct st_sensor_data *sdata = iio_priv(indio_dev); 102 103 iio_trigger_unregister(sdata->trig); 104 free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig); 105 iio_trigger_free(sdata->trig); 106 } 107 EXPORT_SYMBOL(st_sensors_deallocate_trigger); 108 109 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); 110 MODULE_DESCRIPTION("STMicroelectronics ST-sensors trigger"); 111 MODULE_LICENSE("GPL v2"); 112