1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2012 Analog Devices, Inc. 4 * Author: Lars-Peter Clausen <lars@metafoo.de> 5 */ 6 7 #include <linux/kernel.h> 8 #include <linux/export.h> 9 #include <linux/module.h> 10 #include <linux/iio/iio.h> 11 #include <linux/iio/buffer.h> 12 #include <linux/iio/buffer_impl.h> 13 #include <linux/iio/kfifo_buf.h> 14 #include <linux/iio/triggered_buffer.h> 15 #include <linux/iio/trigger_consumer.h> 16 17 /** 18 * iio_triggered_buffer_setup_ext() - Setup triggered buffer and pollfunc 19 * @indio_dev: IIO device structure 20 * @h: Function which will be used as pollfunc top half 21 * @thread: Function which will be used as pollfunc bottom half 22 * @direction: Direction of the data stream (in/out). 23 * @setup_ops: Buffer setup functions to use for this device. 24 * If NULL the default setup functions for triggered 25 * buffers will be used. 26 * @buffer_attrs: Extra sysfs buffer attributes for this IIO buffer 27 * 28 * This function combines some common tasks which will normally be performed 29 * when setting up a triggered buffer. It will allocate the buffer and the 30 * pollfunc. 31 * 32 * Before calling this function the indio_dev structure should already be 33 * completely initialized, but not yet registered. In practice this means that 34 * this function should be called right before iio_device_register(). 35 * 36 * To free the resources allocated by this function call 37 * iio_triggered_buffer_cleanup(). 38 */ 39 int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev, 40 irqreturn_t (*h)(int irq, void *p), 41 irqreturn_t (*thread)(int irq, void *p), 42 enum iio_buffer_direction direction, 43 const struct iio_buffer_setup_ops *setup_ops, 44 const struct iio_dev_attr **buffer_attrs) 45 { 46 struct iio_buffer *buffer; 47 int ret; 48 49 /* 50 * iio_triggered_buffer_cleanup() assumes that the buffer allocated here 51 * is assigned to indio_dev->buffer but this is only the case if this 52 * function is the first caller to iio_device_attach_buffer(). If 53 * indio_dev->buffer is already set then we can't proceed otherwise the 54 * cleanup function will try to free a buffer that was not allocated here. 55 */ 56 if (indio_dev->buffer) 57 return -EADDRINUSE; 58 59 buffer = iio_kfifo_allocate(); 60 if (!buffer) { 61 ret = -ENOMEM; 62 goto error_ret; 63 } 64 65 indio_dev->pollfunc = iio_alloc_pollfunc(h, 66 thread, 67 IRQF_ONESHOT, 68 indio_dev, 69 "%s_consumer%d", 70 indio_dev->name, 71 iio_device_id(indio_dev)); 72 if (indio_dev->pollfunc == NULL) { 73 ret = -ENOMEM; 74 goto error_kfifo_free; 75 } 76 77 /* Ring buffer functions - here trigger setup related */ 78 indio_dev->setup_ops = setup_ops; 79 80 /* Flag that polled ring buffering is possible */ 81 indio_dev->modes |= INDIO_BUFFER_TRIGGERED; 82 83 buffer->direction = direction; 84 buffer->attrs = buffer_attrs; 85 86 ret = iio_device_attach_buffer(indio_dev, buffer); 87 if (ret < 0) 88 goto error_dealloc_pollfunc; 89 90 return 0; 91 92 error_dealloc_pollfunc: 93 iio_dealloc_pollfunc(indio_dev->pollfunc); 94 error_kfifo_free: 95 iio_kfifo_free(buffer); 96 error_ret: 97 return ret; 98 } 99 EXPORT_SYMBOL(iio_triggered_buffer_setup_ext); 100 101 /** 102 * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext() 103 * @indio_dev: IIO device structure 104 */ 105 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev) 106 { 107 iio_dealloc_pollfunc(indio_dev->pollfunc); 108 iio_kfifo_free(indio_dev->buffer); 109 } 110 EXPORT_SYMBOL(iio_triggered_buffer_cleanup); 111 112 static void devm_iio_triggered_buffer_clean(void *indio_dev) 113 { 114 iio_triggered_buffer_cleanup(indio_dev); 115 } 116 117 int devm_iio_triggered_buffer_setup_ext(struct device *dev, 118 struct iio_dev *indio_dev, 119 irqreturn_t (*h)(int irq, void *p), 120 irqreturn_t (*thread)(int irq, void *p), 121 enum iio_buffer_direction direction, 122 const struct iio_buffer_setup_ops *ops, 123 const struct iio_dev_attr **buffer_attrs) 124 { 125 int ret; 126 127 ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, direction, 128 ops, buffer_attrs); 129 if (ret) 130 return ret; 131 132 return devm_add_action_or_reset(dev, devm_iio_triggered_buffer_clean, 133 indio_dev); 134 } 135 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext); 136 137 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 138 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers"); 139 MODULE_LICENSE("GPL"); 140