[PATCH] bsps/shared/ofw: Added and Documented RTEMS OFW interface

Wed Aug 12 19:05:55 UTC 2020

I make a few comments below for you to consider. At a high level, I
think the interface looks reasonable, although plainly mimics the
freebsd naming conventions. I wonder if we should prefer our naming
conventions, which is to aim to use _ to separate different words, and
to limit use of abbreviations except as they help shorten very long
names?

I might suggest something along these lines:
rtems_ofw_get_prop_len() instead of rtems_ofw_getproplen() for example.

It will make mapping to FreeBSD a little more annoying, but will make
the RTEMS interface more RTEMS-friendly.

Other small comments below.

On Wed, Aug 12, 2020 at 10:11 AM G S Niteesh Babu <niteesh.gs at gmail.com> wrote:
>
> ---
>  bsps/shared/dev/ofw/ofw.c |   0
>  bsps/shared/dev/ofw/ofw.h | 437 ++++++++++++++++++++++++++++++++++++++
>  2 files changed, 437 insertions(+)
>  create mode 100644 bsps/shared/dev/ofw/ofw.c
>  create mode 100644 bsps/shared/dev/ofw/ofw.h
>
> diff --git a/bsps/shared/dev/ofw/ofw.c b/bsps/shared/dev/ofw/ofw.c
> new file mode 100644
> index 0000000000..e69de29bb2
> diff --git a/bsps/shared/dev/ofw/ofw.h b/bsps/shared/dev/ofw/ofw.h
> new file mode 100644
> index 0000000000..5a8526c892
> --- /dev/null
> +++ b/bsps/shared/dev/ofw/ofw.h
> @@ -0,0 +1,437 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +
> +/**
> + * @file
> + *
> + * @ingroup ofw
> + *
> + * RTEMS FDT implementation of OpenFirmWare Interface.
> + */
> +
> +/*
> + * Copyright (C) <2020> Niteesh Babu G S <niteesh.gs at gmail.com>

no <> around year

> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
> + * POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +#ifndef _OFW_H
> +#define _OFW_H
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +#include <stdint.h>
> +#include <stddef.h>
> +
> +typedef uint32_t  ihandle_t;
> +typedef uint32_t  pcell_t;
> +typedef uint32_t  phandle_t;
document the types?

> +
> +/**
> + * @brief Gets the node that is next to @a node.

Somewhere the data structure should be explained. Maybe it will take a
new section in our doco to document the new interface.

> + *
> + * @param[in] node Node offset
> + *
> + * @retval Peer node offset Successful operation.
> + * @retval 0 No peer node or invalid node handle
> + */
> +phandle_t rtems_ofw_peer(
> +  phandle_t   node
> +);
> +
> +/**
> + * @brief Gets the node that is the child of @a node.
> + *
> + * @param[in] node Node offset
> + *
> + * @retval child node offset Successful operation.
> + * @retval 0 No child node or invalid node handle
> + */
> +phandle_t rtems_ofw_child(
> +  phandle_t   node
> +);
> +
> +/**
> + * @brief Gets the node that is the parent of @a node.
> + *
> + * @param[in] node Node offset
> + *
> + * @retval child node offset Successful operation.
> + * @retval 0 No child node or invalid node handle
> + */
> +phandle_t rtems_ofw_parent(
> +  phandle_t   node
> +);
> +
> +/**
> + * @brief Gets the length of the property mentioned in @a propname.
> + *
> + * @param[in] node Node offset
> + * @param[in] prop Property name
> + *
> + * @retval -1 Invalid node or property
> + * @retval  Length of property on successful operation
> + */
> +size_t rtems_ofw_getproplen(
> +  phandle_t   node,
> +  const char *propname
> +);
> +
> +
1 blank

> +/**
> + * @brief Gets the value of property mentioned in @a propname.
> + *
> + * @param[in] node Node offset
> + * @param[in] prop Property name
> + * @param[out] buf The property value gets stored in this buffer (Pre-allocated)
> + * @param[in] len Length of the buffer
> +
> + * @retval -1 Invalid node or property
> + * @retval  Length of property on successful operation
> + */
> +size_t rtems_ofw_getprop(
> +  phandle_t    node,
> +  const char  *propname,
> +  void        *buf,
> +  size_t       len
> +);
> +
> +/**
> + * @brief Gets the value of property mentioned in @a propname.
prop

> + *
> + * Gets the value of property of @a node and converts the value into the host's
> + * endiannes.
> + *
> + * @param[in] node Node offset
> + * @param[in] prop Property name
> + * @param[out] buf The property value gets stored in this buffer(Pre-allocated)
> + * after converted to the host's endiannes
typo: endianness
more misspelled below

> + * @param[in] len Length of the buffer
> + *
> + * @retval -1 Invalid node or property
> + * @retval  Length of property on successful operation
> + */
> +size_t rtems_ofw_getencprop(
> +  phandle_t    node,
> +  const char  *prop,
> +  pcell_t     *buf,
> +  size_t       len
> +);
> +
> +/**
> + * @brief Checks if the property @a propname is present in @a node.
> + *
> + * @param[in] node Node offset
> + * @param[in] propname Property name
> + *
> + *  @retval  0 Property not present.
> + *  @retval  1 Property is present.
> + */
> +int rtems_ofw_hasprop(
> +  phandle_t    node,
> +  const char  *propname
> +);
> +
> +/**
> + * @brief Searches for property @a propname in @a node.
> + *
> + * Searches the node and its parent recursively for the property and fills the
> + * buffer with the first found value.
> + *
> + * @param[in] node Node offset
> + * @param[in] propname Property name
> + * @param[out] buf The property value gets stored in this buffer (Pre-allocated)
> + * @param[in] len Length of the buffer
> + *
> + * @retval  Length of the property if property is found.
> + * @retval  -1 Property is not found.
> + */
> +size_t rtems_ofw_searchprop(
> +  phandle_t    node,
> +  const char  *propname,
> +  void        *buf,
> +  size_t       len
> +);
> +
> +/**
> + * @brief Searches for property @a propname in @a node.
> + *
> + * Searches the node and its parent recursively for the property and fills the
> + * buffer with the first value found after converting it to the endiannes of the
> + * host.
> + *
> + * @param[in] node Node offset
> + * @param[in] propname Property name
> + * @param[out] buf The property value gets stored in this buffer(Pre-allocated)
> + * after converted to the host's endiannes
> + * @param[in] len Length of the buffer
> + *
> + * @retval  Length of the property if property is found.
> + * @retval  -1 Property is not found.
> + */
> +size_t rtems_ofw_searchencprop(
> +  phandle_t    node,
> +  const char  *propname,
> +  pcell_t     *buf,
> +  size_t       len
> +);
> +
> +/**
> + * @brief Gets the value of property mentioned in @a propname.
> + *
> + * Same as rtems_ofw_getprop, but the @a buf is allocated in this routine and
> + * the user is responsible for freeing it.
> + *
> + * @param[in] node Node offset
> + * @param[in] propname Property name
> + * @param[out] buf The buffer is allocated in this routine and user is
> + * responsible for freeing.
> + *
> + * @retval  -1 Property is not found.
> + * @retval  Length of the property if property is found.
> + */
> +size_t rtems_ofw_getprop_alloc(
> +  phandle_t    node,
> +  const char  *propname,
> +  void       **buf
> +);
> +
> +/**
> + * @brief Gets multiple values of the property @a propname.
> + *
> + * Same as rtems_ofw_getprop_alloc but it can read properties with multiple
> + * values.
> + * For eg: reg = <0x1000 0x10 0x2000 0x20>
> + *
> + * @param[in] node Node offset
> + * @param[in] propname Property name
> + * @param[in] elsz Size of the single value
> + * @param[out] buf The buffer is allocated in this routine and user is
> + * responsible for freeing.
> + *
> + * @retval  -1 Property is not found.
> + * @retval   Number of values read.
> + */
> +size_t rtems_ofw_getprop_alloc_multi(
> +  phandle_t    node,
> +  const char  *propname,
> +  int          elsz,
> +  void       **buf
> +);
> +
> +/**
> + * @brief Gets the value of property mentioned in @a propname.
> + *
> + * Same as rtems_ofw_getprop_alloc but the value stored in the buffer is
> + * converted into the host's endiannes.
> + *
> + * @param[in] node Node offset
> + * @param[in] propname Property name
> + * @param[out] buf The buffer is allocated in this routine and user is
> + * responsible for freeing.
> + *
> + * @retval  -1 Property is not found.
> + * @retval  Length of the property if property is found.
> + */
> +size_t rtems_ofw_getencprop_alloc(
> +  phandle_t    node,
> +  const char  *propname,
> +  void       **buf
> +);
> +
> +/**
> + * @brief Gets multiple values of the property @a propname.
> + *
> + * Same as rtems_ofw_getprop_alloc_multi but the values stored in the buffer
> + * are converted to the host's endiannes.
> + *
> + * @param[in] node Node offset
> + * @param[in] propname Property name
> + * @param[in] elsz Size of the single value
> + * @param[out] buf The buffer is allocated in this routine and user is
> + * responsible for freeing.
must they call rtems_ofw_prop_free?

> + *
> + * @retval  -1 Property is not found.
> + * @retval   Number of values read.
> + */
> +size_t rtems_ofw_getencprop_alloc_multi(
> +  phandle_t     node,
> +  const char   *propname,
> +  int           elsz,
> +  void        **buf
> +);
> +
> +/**
> + * @brief Free's the buffers allocated by the rtems_ofw_*_alloc functions.
> + *
> + * @param[in] buf Buffer to be freed
> + */
> +void rtems_ofw_prop_free(
> +  void   *buf
> +);
> +
> +/**
> + * @brief Finds the next property of @a node.
> + *
> + * Finds the next property of the node and when @a propname is NULL it returns
> + * the value in the first property.
> + *
> + * @param[in] node Node offset
> + * @param[in] propname Property name
> + * @param[out] buf The value of the next property gets stored in this buffer
> + * (Pre-allocated)
> + * @param[in] len Length of the buffer
> + *
> + * @retval  -1 node or previous property does not exist
> + * @retval   0 no more properties
> + * @retval   1 success
> + */
> +int rtems_ofw_nextprop(
> +  phandle_t    node,
> +  const char  *propname,
> +  char        *buf,
> +  size_t       len
> +);
> +
> +/**
> + * @brief Sets the property @name of @a node to @a buf.
> + *
> + * @param[in] node Node offset
> + * @param[in] name Property name
> + * @param[in] buf Buffer containes the value to be set.
typo; contains

> + * @param[in] len Length of the buffer
> + *
> + * @retval  -1 node does not exist
> + * @retval   0 on success
> + * @retval   libFDT error codes on unsuccessful setting operation
> + */
> +int rtems_ofw_setprop(
> +  phandle_t    node,
> +  const char  *name,
> +  const void  *buf,
> +  size_t       len
> +);
> +
> +/**
> + * @brief Converts a device specifier to a fully qualified path name.
> + *
> + * @param[in] dev device specifier
> + * @param[out] buf The path is filled into the buffer(Pre-allocated)
> + * @param[in] length of the buffer
> + *
> + * @retval  -1 always. Unimplemented.
> + */
> +size_t rtems_ofw_canon(
> +  const char  *dev,
> +  char        *buf,
> +  size_t       len
> +);
> +
> +/**
> + * @brief Finds the node at the given path
> + *
> + * @param[in] path to the node from root
> + *
> + * @retval  -1 node does not exist
> + * @retval   node handle on success
> + */
> +phandle_t rtems_ofw_finddevice(
> +  const char  *path
> +);
> +
> +/**
> + * @brief This routine converts effective phandle of @a node to node offset.
@a xref?

> + *
> + * @param[in] xref Node phandle
> + *
> + * @retval Node offset on success
> + * @retval Node phandle on failure
> + */
> +phandle_t rtems_ofw_node_from_xref(
> +  phandle_t   xref
> +);
> +
> +/**
> + * @brief This routine converts node offset to effective phandle of @a node.
> + *
> + * @retval Node phandle on success
> + * @retval Node offset on failure
> + */
> +phandle_t rtems_ofw_xref_from_node(
> +  phandle_t   node
> +);
> +
> +/*
> + * instance handles(ihandle_t) as same as phandles in the FDT implementation
> + * of OF interface.
> + */
stray comments?

> +
> +/**
> + * @brief Converts @a instance handle to phandle.
> + *
> + * instance are same as node offsets in FDT.
> + *
> + * @param[in] instance Node offset
> + *
> + * @retval phandle of node on success.
> + * @retval instance of node on failure.
> + */
> +phandle_t rtems_ofw_instance_to_package(
> +  ihandle_t   instance
> +);
> +
> +/**
> + * @brief Find the node's path from phandle.
> + *
> + * @param[in] node Node offset
> + * @param[out] buf Path is filled into this buffer(Pre-allocated).
> + * @param[in] len Length of the buffer.
> + *
> + * @retval -1 always. Unimplemented.
> + */
> +size_t rtems_ofw_package_to_path(
> +  phandle_t   node,
> +  char       *buf,
> +  size_t      len
> +);
> +
> +/**
> + * @brief Find the node's path from ihandle.
> + *
> + * @param[in] instance Node offset
> + * @param[out] buf Path is filled into this buffer(Pre-allocated).
> + * @param[in] len Length of the buffer.
> + *
> + * @retval -1 always. Unimplemented.
> + */
> +size_t rtems_ofw_instance_to_path(
> +  ihandle_t  instance,
> +  char      *buf,
> +  size_t     len
> +);
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +#endif /* _OFW_H */
> \ No newline at end of file
> --
> 2.17.1
>