1 files changed, 254 insertions, 0 deletions
diff --git a/misc/userdrv/userdrv.c b/misc/userdrv/userdrv.c
new file mode 100644
index 0000000..2d44926
--- /dev/null
+++ b/misc/userdrv/userdrv.c
@@ -0,0 +1,254 @@
+/**
+ * @file
+ * @brief Example User Driver
+ *
+ * @ingroup user_driver Device Driver
+ * @brief Example User Device Driver Implementation
+ */
+
+/*
+ * Copyright (C) 2022 OAR Corporation
+ *
+ * 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.
+ */
+
+#include <rtems.h>
+#include "userdrv.h"
+#include <rtems/libio.h>
+#include <rtems/bspIo.h>
+
+#include <pthread.h>
+#include <string.h>
+
+/** 
+ * This is the major number for this device driver. It is stored during
+ * the initialize entry. It is not used in this driver but may be of use
+ * in other cases.
+ */
+static uint32_t    USERDRV_major;
+
+/**
+ * This variable indicates whether the driver has been initialized.
+ */
+static char initialized = 0;
+
+rtems_device_driver userdrv_initialize(
+  rtems_device_major_number  major,
+  rtems_device_minor_number  minor RTEMS_UNUSED,
+  void                      *pargp RTEMS_UNUSED
+)
+{
+  rtems_device_driver status;
+
+  printk("  userdrv_initialize\n");
+
+  /**
+   * @internal
+   *
+   * If this is the first call to the initialize entry point, then register
+   * the device name(s) for this driver.
+   *
+   * If any device specific initialization needs to be done, this is the time.
+   * Initialization of specific instances sometimes can be deferred until the
+   * open entry point.
+   */
+ 
+  if ( !initialized ) {
+    initialized = 1;
+
+    status = rtems_io_register_name(
+      "/dev/userdrv",
+      major,
+      (rtems_device_minor_number) 0
+    );
+    if (status != RTEMS_SUCCESSFUL)
+      rtems_fatal_error_occurred(status);
+
+    USERDRV_major = major;
+  }
+
+  return RTEMS_SUCCESSFUL;
+}
+
+rtems_device_driver userdrv_open(
+  rtems_device_major_number  major,
+  rtems_device_minor_number  minor RTEMS_UNUSED,
+  void                      *pargp RTEMS_UNUSED
+)
+{
+  printk("  userdrv_open\n");
+
+  /**
+   * @internal
+   *
+   * In a more realistic driver, the open entry would validate the minor
+   * number passed in as representing a valid device instance. It may also
+   * keep track of multiple opens and support the device staying open until
+   * the last close.
+   *
+   * There may be some hardware initialization that occurs related to the
+   * device instance at this point. For example, a termios driver would
+   * register its callbacks with the termios framework and initialize a UART
+   * with the default settings.
+   */
+ 
+  return RTEMS_SUCCESSFUL;
+}
+
+rtems_device_driver userdrv_close(
+  rtems_device_major_number major RTEMS_UNUSED,
+  rtems_device_minor_number minor RTEMS_UNUSED,
+  void *pargp RTEMS_UNUSED
+)
+{
+  printk("  userdrv_close\n");
+
+  /**
+   * @internal
+   *
+   * In a more realistic driver, the close entry would validate the minor
+   * number passed in as representing a valid device instance. It would also
+   * verify that the device is open before closing it. If tracking nested
+   * open and close operations on the same device instance, that would also
+   * be managed here.
+   *
+   * There may be some shutdown for the device instance. For example, it
+   * may be necessary to disable intterrupts from this device instance.
+   */
+  return RTEMS_SUCCESSFUL;
+}
+
+rtems_device_driver userdrv_read(
+  rtems_device_major_number major RTEMS_UNUSED,
+  rtems_device_minor_number minor RTEMS_UNUSED,
+  void *pargp RTEMS_UNUSED
+)
+{
+  rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *) pargp;
+
+  printk("  userdrv_read\n");
+
+  /**
+   * @internal
+   *
+   * In a more realistic driver, the read entry would validate the minor
+   * number passed in as representing a valid device instance. There is
+   * likely more error checking on the arguments passed in. But it should
+   * be safe to trust the file system framework to pass the @a argp buffer
+   * as defined.
+   */
+
+  if ( rw_args == NULL ) {
+    printk("  nothing to read\n");
+  }
+
+  if ( rw_args->count == 0 ) {
+    printk("  buffer of zero\n");
+  }
+
+  /**
+   * @internal
+   *
+   * A functional driver would replace this block with code that accesses
+   * the device instance and returns real data if any is available.
+   */
+  const char *outstr = "this is output";
+  size_t outlen = 15;
+
+  rw_args->bytes_moved = outlen;
+  memcpy(rw_args->buffer, outstr, outlen);
+
+  printk("  %d buffer size\n", rw_args->count);
+  printk("  buffer: %s\n", rw_args->buffer);
+
+  return RTEMS_SUCCESSFUL;
+}
+
+rtems_device_driver userdrv_write(
+  rtems_device_major_number major RTEMS_UNUSED,
+  rtems_device_minor_number minor RTEMS_UNUSED,
+  void *pargp
+)
+{
+  rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *) pargp;
+
+  printk("  userdrv_write\n");
+
+  /**
+   * @internal
+   *
+   * In a more realistic driver, the write entry would validate the minor
+   * number passed in as representing a valid device instance. There is
+   * likely more error checking on the arguments passed in. But it should
+   * be safe to trust the file system framework to pass the @a argp buffer
+   * as defined.
+   *
+   * In a real driver, the data to be written would be passed to the device
+   * driver. That may involve interrupts.
+   */
+
+  if ( rw_args ) {
+    printk("  %d to write\n", rw_args->count);
+    printk("  buffer: %s\n", rw_args->buffer);
+    rw_args->bytes_moved = rw_args->count;
+  } else {
+    printk("  nothing to write\n");
+    rw_args->bytes_moved = 0;
+  }
+
+  return RTEMS_SUCCESSFUL;
+}
+
+rtems_device_driver userdrv_control(
+  rtems_device_major_number  major RTEMS_UNUSED,
+  rtems_device_minor_number  minor RTEMS_UNUSED,
+  void                      *pargp RTEMS_UNUSED
+)
+{
+  rtems_libio_ioctl_args_t *ioctl_args = (rtems_libio_ioctl_args_t *) pargp;
+  rtems_status_code         retval     = RTEMS_SUCCESSFUL;
+
+  printk("  userdrv_control\n");
+
+  /**
+   * @internal
+   *
+   * In a more realistic driver, the ioctl entry would validate the minor
+   * number passed in as representing a valid device instance. Then it would
+   * valid the requested ioctl operation number as valid.  There is
+   * likely more error checking on the arguments passed in. But it should
+   * be safe to trust the file system framework to pass the @a argp buffer
+   * as defined.
+   */
+
+  switch (ioctl_args->command) {
+    case USERDRV_IOCTL_DO_SOMETHING:
+      printk( "  Buffer: %s\n", (const char *) ioctl_args->buffer);
+      ioctl_args->ioctl_return = 0;
+      break;
+    default:
+      ioctl_args->ioctl_return = 0;
+      retval = RTEMS_INVALID_NUMBER;
+  } 
+
+  return retval;
+}