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 68 /* 69 * If the interrupt pin is Open Drain, by definition this 70 * means that the interrupt line may be shared with other 71 * peripherals. But to do this we also need to have a status 72 * register and mask to figure out if this sensor was firing 73 * the IRQ or not, so we can tell the interrupt handle that 74 * it was "our" interrupt. 75 */ 76 if (sdata->int_pin_open_drain && 77 sdata->sensor_settings->drdy_irq.addr_stat_drdy) 78 irq_trig |= IRQF_SHARED; 79 80 err = request_threaded_irq(irq, 81 iio_trigger_generic_data_rdy_poll, 82 NULL, 83 irq_trig, 84 sdata->trig->name, 85 sdata->trig); 86 if (err) { 87 dev_err(&indio_dev->dev, "failed to request trigger IRQ.\n"); 88 goto iio_trigger_free; 89 } 90 91 iio_trigger_set_drvdata(sdata->trig, indio_dev); 92 sdata->trig->ops = trigger_ops; 93 sdata->trig->dev.parent = sdata->dev; 94 95 err = iio_trigger_register(sdata->trig); 96 if (err < 0) { 97 dev_err(&indio_dev->dev, "failed to register iio trigger.\n"); 98 goto iio_trigger_register_error; 99 } 100 indio_dev->trig = iio_trigger_get(sdata->trig); 101 102 return 0; 103 104 iio_trigger_register_error: 105 free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig); 106 iio_trigger_free: 107 iio_trigger_free(sdata->trig); 108 return err; 109 } 110 EXPORT_SYMBOL(st_sensors_allocate_trigger); 111 112 void st_sensors_deallocate_trigger(struct iio_dev *indio_dev) 113 { 114 struct st_sensor_data *sdata = iio_priv(indio_dev); 115 116 iio_trigger_unregister(sdata->trig); 117 free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig); 118 iio_trigger_free(sdata->trig); 119 } 120 EXPORT_SYMBOL(st_sensors_deallocate_trigger); 121 122 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); 123 MODULE_DESCRIPTION("STMicroelectronics ST-sensors trigger"); 124 MODULE_LICENSE("GPL v2"); 125