diff options
Diffstat (limited to 'drivers/iio/industrialio-triggered-buffer.c')
| -rw-r--r-- | drivers/iio/industrialio-triggered-buffer.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-triggered-buffer.c b/drivers/iio/industrialio-triggered-buffer.c new file mode 100644 index 00000000000..46c619b0d8c --- /dev/null +++ b/drivers/iio/industrialio-triggered-buffer.c @@ -0,0 +1,110 @@ + /* + * Copyright (c) 2012 Analog Devices, Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/module.h> +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/kfifo_buf.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger_consumer.h> + +static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = { + .preenable = &iio_sw_buffer_preenable, + .postenable = &iio_triggered_buffer_postenable, + .predisable = &iio_triggered_buffer_predisable, +}; + +/** + * iio_triggered_buffer_setup() - Setup triggered buffer and pollfunc + * @indio_dev: IIO device structure + * @pollfunc_bh: Function which will be used as pollfunc bottom half + * @pollfunc_th: Function which will be used as pollfunc top half + * @setup_ops: Buffer setup functions to use for this device. + * If NULL the default setup functions for triggered + * buffers will be used. + * + * This function combines some common tasks which will normally be performed + * when setting up a triggered buffer. It will allocate the buffer and the + * pollfunc, as well as register the buffer with the IIO core. + * + * Before calling this function the indio_dev structure should already be + * completely initialized, but not yet registered. In practice this means that + * this function should be called right before iio_device_register(). + * + * To free the resources allocated by this function call + * iio_triggered_buffer_cleanup(). + */ +int iio_triggered_buffer_setup(struct iio_dev *indio_dev, + irqreturn_t (*pollfunc_bh)(int irq, void *p), + irqreturn_t (*pollfunc_th)(int irq, void *p), + const struct iio_buffer_setup_ops *setup_ops) +{ + int ret; + + indio_dev->buffer = iio_kfifo_allocate(indio_dev); + if (!indio_dev->buffer) { + ret = -ENOMEM; + goto error_ret; + } + + indio_dev->pollfunc = iio_alloc_pollfunc(pollfunc_bh, + pollfunc_th, + IRQF_ONESHOT, + indio_dev, + "%s_consumer%d", + indio_dev->name, + indio_dev->id); + if (indio_dev->pollfunc == NULL) { + ret = -ENOMEM; + goto error_kfifo_free; + } + + /* Ring buffer functions - here trigger setup related */ + if (setup_ops) + indio_dev->setup_ops = setup_ops; + else + indio_dev->setup_ops = &iio_triggered_buffer_setup_ops; + + /* Flag that polled ring buffering is possible */ + indio_dev->modes |= INDIO_BUFFER_TRIGGERED; + + ret = iio_buffer_register(indio_dev, + indio_dev->channels, + indio_dev->num_channels); + if (ret) + goto error_dealloc_pollfunc; + + return 0; + +error_dealloc_pollfunc: + iio_dealloc_pollfunc(indio_dev->pollfunc); +error_kfifo_free: + iio_kfifo_free(indio_dev->buffer); +error_ret: + return ret; +} +EXPORT_SYMBOL(iio_triggered_buffer_setup); + +/** + * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup() + * @indio_dev: IIO device structure + */ +void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev) +{ + iio_buffer_unregister(indio_dev); + iio_dealloc_pollfunc(indio_dev->pollfunc); + iio_kfifo_free(indio_dev->buffer); +} +EXPORT_SYMBOL(iio_triggered_buffer_cleanup); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers"); +MODULE_LICENSE("GPL"); |