tools: usb: ffs-aio-example: Fix build error with aarch64-*-gnu-gcc toolchain(s)

The tools/usb/aio_simple.c file when cross-compiled with
aarch64-*-gnu-gcc toolchain(s) leads to the following errors:

  aio_simple.c:30:10: fatal error: endian.h: No such file or directory
  30 | #include <endian.h>
      |          ^~~~~~~~~~

  aio_simple.c:88:14: note: (near initialization for
                      'descriptors.fs_count')
  aio_simple.c:110:14: error: initializer element is not constant
  110 |  .hs_count = htole32(3),
      |              ^~~~~~~
  aio_simple.c:110:14: note: (near initialization for
                      'descriptors.hs_count')
  aio_simple.c:124:22: error: initializer element is not constant
  124 |    .wMaxPacketSize = htole16(512),
      |                      ^~~~~~~
  aio_simple.c:124:22: note: (near initialization for
                       'descriptors.hs_descs.bulk_sink.wMaxPacketSize')

Fix these compilation issues by:
 - Switching to _DEFAULT_SOURCE:
    _BSD_SOURCE is deprecated and gives a build warning. Let's use
    _DEFAULT_SOURCE instead.
 - Currently this file uses library htole16/32 function calls.
   Replace these with equivalent 'cpu_to_le16/32' calls.

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Link: https://lore.kernel.org/r/20221029161312.171165-1-bhupesh.sharma@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/usb/ffs-aio-example/simple/device_app/aio_simple.c b/tools/usb/ffs-aio-example/simple/device_app/aio_simple.c
index 1f44a29818bf02991cfe264e5b13796d8219067e..96616eb4600b4f917539148783f873772e1ed7b2 100644 (file)
--- a/tools/usb/ffs-aio-example/simple/device_app/aio_simple.c
+++ b/tools/usb/ffs-aio-example/simple/device_app/aio_simple.c
@@ -25,7 +25,9 @@
  * For more information, please refer to <http://unlicense.org/>
  */
 
-#define _BSD_SOURCE /* for endian.h */
+/* $(CROSS_COMPILE)cc -g -o aio_simple aio_simple.c -laio */
+
+#define _DEFAULT_SOURCE /* for endian.h */
 
 #include <endian.h>
 #include <errno.h>
@@ -49,6 +51,22 @@
 
 #define BUF_LEN                8192
 
+/*
+ * cpu_to_le16/32 are used when initializing structures, a context where a
+ * function call is not allowed. To solve this, we code cpu_to_le16/32 in a way
+ * that allows them to be used when initializing structures.
+ */
+
+#if BYTE_ORDER == __LITTLE_ENDIAN
+#define cpu_to_le16(x)  (x)
+#define cpu_to_le32(x)  (x)
+#else
+#define cpu_to_le16(x)  ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8))
+#define cpu_to_le32(x)  \
+       ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >>  8) | \
+       (((x) & 0x0000ff00u) <<  8) | (((x) & 0x000000ffu) << 24))
+#endif
+
 /******************** Descriptors and Strings *******************************/
 
 static const struct {
@@ -62,12 +80,12 @@ static const struct {
        } __attribute__ ((__packed__)) fs_descs, hs_descs;
 } __attribute__ ((__packed__)) descriptors = {
        .header = {
-               .magic = htole32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
-               .flags = htole32(FUNCTIONFS_HAS_FS_DESC |
+               .magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
+               .flags = cpu_to_le32(FUNCTIONFS_HAS_FS_DESC |
                                     FUNCTIONFS_HAS_HS_DESC),
-               .length = htole32(sizeof(descriptors)),
+               .length = cpu_to_le32(sizeof(descriptors)),
        },
-       .fs_count = htole32(3),
+       .fs_count = cpu_to_le32(3),
        .fs_descs = {
                .intf = {
                        .bLength = sizeof(descriptors.fs_descs.intf),
@@ -89,7 +107,7 @@ static const struct {
                        .bmAttributes = USB_ENDPOINT_XFER_BULK,
                },
        },
-       .hs_count = htole32(3),
+       .hs_count = cpu_to_le32(3),
        .hs_descs = {
                .intf = {
                        .bLength = sizeof(descriptors.hs_descs.intf),
@@ -103,14 +121,14 @@ static const struct {
                        .bDescriptorType = USB_DT_ENDPOINT,
                        .bEndpointAddress = 1 | USB_DIR_IN,
                        .bmAttributes = USB_ENDPOINT_XFER_BULK,
-                       .wMaxPacketSize = htole16(512),
+                       .wMaxPacketSize = cpu_to_le16(512),
                },
                .bulk_source = {
                        .bLength = sizeof(descriptors.hs_descs.bulk_source),
                        .bDescriptorType = USB_DT_ENDPOINT,
                        .bEndpointAddress = 2 | USB_DIR_OUT,
                        .bmAttributes = USB_ENDPOINT_XFER_BULK,
-                       .wMaxPacketSize = htole16(512),
+                       .wMaxPacketSize = cpu_to_le16(512),
                },
        },
 };
@@ -125,13 +143,13 @@ static const struct {
        } __attribute__ ((__packed__)) lang0;
 } __attribute__ ((__packed__)) strings = {
        .header = {
-               .magic = htole32(FUNCTIONFS_STRINGS_MAGIC),
-               .length = htole32(sizeof(strings)),
-               .str_count = htole32(1),
-               .lang_count = htole32(1),
+               .magic = cpu_to_le32(FUNCTIONFS_STRINGS_MAGIC),
+               .length = cpu_to_le32(sizeof(strings)),
+               .str_count = cpu_to_le32(1),
+               .lang_count = cpu_to_le32(1),
        },
        .lang0 = {
-               htole16(0x0409), /* en-us */
+               cpu_to_le16(0x0409), /* en-us */
                STR_INTERFACE,
        },
 };