On 6/8/2012 1:13 PM, Lars-Peter Clausen wrote:
Add a helper function for executing the common tasks which are usually involved in setting up a simple software ringbuffer. It will allocate the buffer, allocate the pollfunc and register the buffer. Signed-off-by: Lars-Peter Clausen<lars@xxxxxxxxxx>
Other than the patch title... Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>
--- Changes since v2: * Add missing header... I've only resent this one patch for v3 since all the others are unchanged. Changes since v1: * Move function declarations to their own header * Mention that iio_triggered_buffer_setup should usually be called right before iio_device_register * Minor code cleanups --- drivers/iio/Kconfig | 7 ++ drivers/iio/Makefile | 1 + drivers/iio/industrialio-triggered-buffer.c | 110 +++++++++++++++++++++++++++ include/linux/iio/triggered_buffer.h | 15 ++++ 4 files changed, 133 insertions(+) create mode 100644 drivers/iio/industrialio-triggered-buffer.c create mode 100644 include/linux/iio/triggered_buffer.h diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig index 103349f..612073f 100644 --- a/drivers/iio/Kconfig +++ b/drivers/iio/Kconfig @@ -30,6 +30,13 @@ config IIO_KFIFO_BUF no buffer events so it is up to userspace to work out how often to read from the buffer. +config IIO_TRIGGERED_BUFFER + tristate + select IIO_TRIGGER + select IIO_KFIFO_BUF + help + Provides helper functions for setting up triggered buffers. + endif # IIO_BUFFER config IIO_TRIGGER diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile index c38fa2a..34309ab 100644 --- a/drivers/iio/Makefile +++ b/drivers/iio/Makefile @@ -7,6 +7,7 @@ industrialio-y := industrialio-core.o industrialio-event.o inkern.o industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o +obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o obj-y += adc/ diff --git a/drivers/iio/industrialio-triggered-buffer.c b/drivers/iio/industrialio-triggered-buffer.c new file mode 100644 index 0000000..a462a57 --- /dev/null +++ b/drivers/iio/industrialio-triggered-buffer.c @@ -0,0 +1,110 @@ + /* + * Copyright (c) 2012 Analog Devices, Inc. + * Author: Lars-Peter Clausen<lars@xxxxxxxxxx> + * + * 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 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 + * iio_triggered_buffer_cleanup() should be called. + */ +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@xxxxxxxxxx>"); +MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/iio/triggered_buffer.h b/include/linux/iio/triggered_buffer.h new file mode 100644 index 0000000..c378ebe --- /dev/null +++ b/include/linux/iio/triggered_buffer.h @@ -0,0 +1,15 @@ +#ifndef _LINUX_IIO_TRIGGERED_BUFFER_H_ +#define _LINUX_IIO_TRIGGERED_BUFFER_H_ + +#include<linux/interrupt.h> + +struct iio_dev; +struct iio_buffer_setup_ops; + +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); +void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev); + +#endif
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