Copy iio kernel code from legato kernel source

linux_kernel_modules/iio/README.md

 IIO Kernel Module Definitions
 =============================
 
-The source for the IIO kernel modules is part of the standard Legato Linux
-kernel source tree, but the module is not built by default.  As a result, we
-build this as an out of tree kernel module, but we don't want to version a copy
-of the source files.
-
-Instead, it is suggested to put a symlink to each of the sdef files in `[yocto
-working copy]/kernel/drivers/iio/` and then refer to the mdef files in the sdef
-using an environment variable.  For example:
-`${LEGATO_KERNELSRC}/drivers/iio/iio`.
-
-The IIO modules are required by the BMP280 pressure sensor driver module.
+The source for the IIO kernel modules comes from the standard Legato Linux kernel source tree.  The
+source is copied into this directory so that it isn't necessary to have the full kernel source code
+in order to build the mangOH SDEF.
 
+The kernel source in this folder was copied from the tag `SWI9X15Y_07.12.01.00`
 

linux_kernel_modules/iio/iio-triggered-buffer.mdef

+cflags:
+{
+    -DCONFIG_IIO
+    -DCONFIG_IIO_BUFFER
+    -DCONFIG_IIO_TRIGGER
+    -DCONFIG_IIO_KFIFO_BUF
+    -DCONFIG_IIO_TRIGGERED_BUFFER
+}
+
+sources:
+{
+    // IIO_KFIFO_BUF
+    industrialio-triggered-buffer.c
+}
+

linux_kernel_modules/iio/iio_core.h

+/* The industrial I/O core function defs.
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * 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.
+ *
+ * These definitions are meant for use only within the IIO core, not individual
+ * drivers.
+ */
+
+#ifndef _IIO_CORE_H_
+#define _IIO_CORE_H_
+#include <linux/kernel.h>
+#include <linux/device.h>
+
+struct iio_chan_spec;
+struct iio_dev;
+
+extern struct device_type iio_device_type;
+
+int __iio_add_chan_devattr(const char *postfix,
+			   struct iio_chan_spec const *chan,
+			   ssize_t (*func)(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf),
+			   ssize_t (*writefunc)(struct device *dev,
+						struct device_attribute *attr,
+						const char *buf,
+						size_t len),
+			   u64 mask,
+			   enum iio_shared_by shared_by,
+			   struct device *dev,
+			   struct list_head *attr_list);
+void iio_free_chan_devattr_list(struct list_head *attr_list);
+
+ssize_t iio_format_value(char *buf, unsigned int type, int val, int val2);
+
+/* Event interface flags */
+#define IIO_BUSY_BIT_POS 1
+
+#ifdef CONFIG_IIO_BUFFER
+struct poll_table_struct;
+
+unsigned int iio_buffer_poll(struct file *filp,
+			     struct poll_table_struct *wait);
+ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
+				      size_t n, loff_t *f_ps);
+
+
+#define iio_buffer_poll_addr (&iio_buffer_poll)
+#define iio_buffer_read_first_n_outer_addr (&iio_buffer_read_first_n_outer)
+
+void iio_disable_all_buffers(struct iio_dev *indio_dev);
+void iio_buffer_wakeup_poll(struct iio_dev *indio_dev);
+
+#else
+
+#define iio_buffer_poll_addr NULL
+#define iio_buffer_read_first_n_outer_addr NULL
+
+static inline void iio_disable_all_buffers(struct iio_dev *indio_dev) {}
+static inline void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) {}
+
+#endif
+
+int iio_device_register_eventset(struct iio_dev *indio_dev);
+void iio_device_unregister_eventset(struct iio_dev *indio_dev);
+void iio_device_wakeup_eventset(struct iio_dev *indio_dev);
+int iio_event_getfd(struct iio_dev *indio_dev);
+
+#endif

linux_kernel_modules/iio/iio_core_trigger.h

+
+/* The industrial I/O core, trigger consumer handling functions
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * 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.
+ */
+
+#ifdef CONFIG_IIO_TRIGGER
+/**
+ * iio_device_register_trigger_consumer() - set up an iio_dev to use triggers
+ * @indio_dev: iio_dev associated with the device that will consume the trigger
+ **/
+void iio_device_register_trigger_consumer(struct iio_dev *indio_dev);
+
+/**
+ * iio_device_unregister_trigger_consumer() - reverse the registration process
+ * @indio_dev: iio_dev associated with the device that consumed the trigger
+ **/
+void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev);
+
+#else
+
+/**
+ * iio_device_register_trigger_consumer() - set up an iio_dev to use triggers
+ * @indio_dev: iio_dev associated with the device that will consume the trigger
+ **/
+static int iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
+{
+	return 0;
+}
+
+/**
+ * iio_device_unregister_trigger_consumer() - reverse the registration process
+ * @indio_dev: iio_dev associated with the device that consumed the trigger
+ **/
+static void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
+{
+}
+
+#endif /* CONFIG_TRIGGER_CONSUMER */

linux_kernel_modules/iio/industrialio-triggered-buffer.c

+ /*
+ * 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 = {
+	.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)
+{
+	struct iio_buffer *buffer;
+	int ret;
+
+	buffer = iio_kfifo_allocate(indio_dev);
+	if (!buffer) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	iio_device_attach_buffer(indio_dev, buffer);
+
+	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");

linux_kernel_modules/iio/kfifo_buf.c

+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/workqueue.h>
+#include <linux/kfifo.h>
+#include <linux/mutex.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/sched.h>
+#include <linux/poll.h>
+
+struct iio_kfifo {
+	struct iio_buffer buffer;
+	struct kfifo kf;
+	struct mutex user_lock;
+	int update_needed;
+};
+
+#define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
+
+static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
+				int bytes_per_datum, int length)
+{
+	if ((length == 0) || (bytes_per_datum == 0))
+		return -EINVAL;
+
+	return __kfifo_alloc((struct __kfifo *)&buf->kf, length,
+			     bytes_per_datum, GFP_KERNEL);
+}
+
+static int iio_request_update_kfifo(struct iio_buffer *r)
+{
+	int ret = 0;
+	struct iio_kfifo *buf = iio_to_kfifo(r);
+
+	mutex_lock(&buf->user_lock);
+	if (buf->update_needed) {
+		kfifo_free(&buf->kf);
+		ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
+				   buf->buffer.length);
+		buf->update_needed = false;
+	} else {
+		kfifo_reset_out(&buf->kf);
+	}
+	mutex_unlock(&buf->user_lock);
+
+	return ret;
+}
+
+static int iio_get_length_kfifo(struct iio_buffer *r)
+{
+	return r->length;
+}
+
+static IIO_BUFFER_ENABLE_ATTR;
+static IIO_BUFFER_LENGTH_ATTR;
+
+static struct attribute *iio_kfifo_attributes[] = {
+	&dev_attr_length.attr,
+	&dev_attr_enable.attr,
+	NULL,
+};
+
+static struct attribute_group iio_kfifo_attribute_group = {
+	.attrs = iio_kfifo_attributes,
+	.name = "buffer",
+};
+
+static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r)
+{
+	return r->bytes_per_datum;
+}
+
+static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
+{
+	struct iio_kfifo *kf = iio_to_kfifo(r);
+	kf->update_needed = true;
+	return 0;
+}
+
+static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
+{
+	if (r->bytes_per_datum != bpd) {
+		r->bytes_per_datum = bpd;
+		iio_mark_update_needed_kfifo(r);
+	}
+	return 0;
+}
+
+static int iio_set_length_kfifo(struct iio_buffer *r, int length)
+{
+	/* Avoid an invalid state */
+	if (length < 2)
+		length = 2;
+	if (r->length != length) {
+		r->length = length;
+		iio_mark_update_needed_kfifo(r);
+	}
+	return 0;
+}
+
+static int iio_store_to_kfifo(struct iio_buffer *r,
+			      const void *data)
+{
+	int ret;
+	struct iio_kfifo *kf = iio_to_kfifo(r);
+	ret = kfifo_in(&kf->kf, data, 1);
+	if (ret != 1)
+		return -EBUSY;
+
+	wake_up_interruptible_poll(&r->pollq, POLLIN | POLLRDNORM);
+
+	return 0;
+}
+
+static int iio_read_first_n_kfifo(struct iio_buffer *r,
+			   size_t n, char __user *buf)
+{
+	int ret, copied;
+	struct iio_kfifo *kf = iio_to_kfifo(r);
+
+	if (mutex_lock_interruptible(&kf->user_lock))
+		return -ERESTARTSYS;
+
+	if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf))
+		ret = -EINVAL;
+	else
+		ret = kfifo_to_user(&kf->kf, buf, n, &copied);
+	mutex_unlock(&kf->user_lock);
+	if (ret < 0)
+		return ret;
+
+	return copied;
+}
+
+static bool iio_kfifo_buf_data_available(struct iio_buffer *r)
+{
+	struct iio_kfifo *kf = iio_to_kfifo(r);
+	bool empty;
+
+	mutex_lock(&kf->user_lock);
+	empty = kfifo_is_empty(&kf->kf);
+	mutex_unlock(&kf->user_lock);
+
+	return !empty;
+}
+
+static void iio_kfifo_buffer_release(struct iio_buffer *buffer)
+{
+	struct iio_kfifo *kf = iio_to_kfifo(buffer);
+
+	mutex_destroy(&kf->user_lock);
+	kfifo_free(&kf->kf);
+	kfree(kf);
+}
+
+static const struct iio_buffer_access_funcs kfifo_access_funcs = {
+	.store_to = &iio_store_to_kfifo,
+	.read_first_n = &iio_read_first_n_kfifo,
+	.data_available = iio_kfifo_buf_data_available,
+	.request_update = &iio_request_update_kfifo,
+	.get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo,
+	.set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
+	.get_length = &iio_get_length_kfifo,
+	.set_length = &iio_set_length_kfifo,
+	.release = &iio_kfifo_buffer_release,
+};
+
+struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
+{
+	struct iio_kfifo *kf;
+
+	kf = kzalloc(sizeof *kf, GFP_KERNEL);
+	if (!kf)
+		return NULL;
+	kf->update_needed = true;
+	iio_buffer_init(&kf->buffer);
+	kf->buffer.attrs = &iio_kfifo_attribute_group;
+	kf->buffer.access = &kfifo_access_funcs;
+	kf->buffer.length = 2;
+	mutex_init(&kf->user_lock);
+	return &kf->buffer;
+}
+EXPORT_SYMBOL(iio_kfifo_allocate);
+
+void iio_kfifo_free(struct iio_buffer *r)
+{
+	iio_buffer_put(r);
+}
+EXPORT_SYMBOL(iio_kfifo_free);
+
+MODULE_LICENSE("GPL");