1 /* 2 * Industrial I/O - generic interrupt based trigger support 3 * 4 * Copyright (c) 2008-2013 Jonathan Cameron 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/platform_device.h> 14 #include <linux/interrupt.h> 15 #include <linux/slab.h> 16 17 #include <linux/iio/iio.h> 18 #include <linux/iio/trigger.h> 19 20 21 struct iio_interrupt_trigger_info { 22 unsigned int irq; 23 }; 24 25 static irqreturn_t iio_interrupt_trigger_poll(int irq, void *private) 26 { 27 iio_trigger_poll(private); 28 return IRQ_HANDLED; 29 } 30 31 static const struct iio_trigger_ops iio_interrupt_trigger_ops = { 32 .owner = THIS_MODULE, 33 }; 34 35 static int iio_interrupt_trigger_probe(struct platform_device *pdev) 36 { 37 struct iio_interrupt_trigger_info *trig_info; 38 struct iio_trigger *trig; 39 unsigned long irqflags; 40 struct resource *irq_res; 41 int irq, ret = 0; 42 43 irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 44 45 if (irq_res == NULL) 46 return -ENODEV; 47 48 irqflags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED; 49 50 irq = irq_res->start; 51 52 trig = iio_trigger_alloc("irqtrig%d", irq); 53 if (!trig) { 54 ret = -ENOMEM; 55 goto error_ret; 56 } 57 58 trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL); 59 if (!trig_info) { 60 ret = -ENOMEM; 61 goto error_put_trigger; 62 } 63 iio_trigger_set_drvdata(trig, trig_info); 64 trig_info->irq = irq; 65 trig->ops = &iio_interrupt_trigger_ops; 66 ret = request_irq(irq, iio_interrupt_trigger_poll, 67 irqflags, trig->name, trig); 68 if (ret) { 69 dev_err(&pdev->dev, 70 "request IRQ-%d failed", irq); 71 goto error_free_trig_info; 72 } 73 74 ret = iio_trigger_register(trig); 75 if (ret) 76 goto error_release_irq; 77 platform_set_drvdata(pdev, trig); 78 79 return 0; 80 81 /* First clean up the partly allocated trigger */ 82 error_release_irq: 83 free_irq(irq, trig); 84 error_free_trig_info: 85 kfree(trig_info); 86 error_put_trigger: 87 iio_trigger_put(trig); 88 error_ret: 89 return ret; 90 } 91 92 static int iio_interrupt_trigger_remove(struct platform_device *pdev) 93 { 94 struct iio_trigger *trig; 95 struct iio_interrupt_trigger_info *trig_info; 96 97 trig = platform_get_drvdata(pdev); 98 trig_info = iio_trigger_get_drvdata(trig); 99 iio_trigger_unregister(trig); 100 free_irq(trig_info->irq, trig); 101 kfree(trig_info); 102 iio_trigger_put(trig); 103 104 return 0; 105 } 106 107 static struct platform_driver iio_interrupt_trigger_driver = { 108 .probe = iio_interrupt_trigger_probe, 109 .remove = iio_interrupt_trigger_remove, 110 .driver = { 111 .name = "iio_interrupt_trigger", 112 .owner = THIS_MODULE, 113 }, 114 }; 115 116 module_platform_driver(iio_interrupt_trigger_driver); 117 118 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); 119 MODULE_DESCRIPTION("Interrupt trigger for the iio subsystem"); 120 MODULE_LICENSE("GPL v2"); 121