staging/easycap: Improve interface to the videodev module

The changes here represent an intermediate step towards bringing the
driver within the V4L2 framework.

Signed-off-by: Mike Thomas <rmthomas@sciolus.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 61 insertions, 2 deletions

diff --git a/drivers/staging/easycap/easycap_sound.c b/drivers/staging/easycap/easycap_sound.c
index dc97516cca4..24d8bb4e449 100644
--- a/drivers/staging/easycap/easycap_sound.c
+++ b/drivers/staging/easycap/easycap_sound.c
@@ -64,6 +64,11 @@ if (NULL == peasycap) {
         SAY("ERROR: peasycap is NULL\n");
         return;
 }
+if (memcmp(&peasycap->telltale[0], TELLTALE, strlen(TELLTALE))) {
+        SAY("ERROR: bad peasycap\n");
+        return;
+}
+
 much = 0;
 
 if (peasycap->audio_idle) {
@@ -595,6 +600,13 @@ easysnd_open(struct inode *inode, struct file *file)
 struct usb_interface *pusb_interface;
 struct easycap *peasycap;
 int subminor, rc;
+/*vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv*/
+#if defined(EASYCAP_IS_VIDEODEV_CLIENT)
+#if defined(EASYCAP_NEEDS_V4L2_DEVICE_H)
+struct v4l2_device *pv4l2_device;
+#endif /*EASYCAP_NEEDS_V4L2_DEVICE_H*/
+#endif /*EASYCAP_IS_VIDEODEV_CLIENT*/
+/*^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^*/
 
 JOT(4, "begins\n");
 
@@ -612,6 +624,39 @@ if (NULL == peasycap) {
         SAY("ending unsuccessfully\n");
         return -1;
 }
+/*---------------------------------------------------------------------------*/
+#if (!defined(EASYCAP_IS_VIDEODEV_CLIENT))
+#
+/*vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv*/
+#else
+#if defined(EASYCAP_NEEDS_V4L2_DEVICE_H)
+/*---------------------------------------------------------------------------*/
+/*
+ *  SOME VERSIONS OF THE videodev MODULE OVERWRITE THE DATA WHICH HAS
+ *  BEEN WRITTEN BY THE CALL TO usb_set_intfdata() IN easycap_usb_probe(),
+ *  REPLACING IT WITH A POINTER TO THE EMBEDDED v4l2_device STRUCTURE.
+ *  TO DETECT THIS, THE STRING IN THE easycap.telltale[] BUFFER IS CHECKED.
+*/
+/*---------------------------------------------------------------------------*/
+if (memcmp(&peasycap->telltale[0], TELLTALE, strlen(TELLTALE))) {
+        pv4l2_device = usb_get_intfdata(pusb_interface);
+        if ((struct v4l2_device *)NULL == pv4l2_device) {
+                SAY("ERROR: pv4l2_device is NULL\n");
+                return -EFAULT;
+        }
+        peasycap = (struct easycap *) \
+                container_of(pv4l2_device, struct easycap, v4l2_device);
+}
+#endif /*EASYCAP_NEEDS_V4L2_DEVICE_H*/
+#
+#endif /*EASYCAP_IS_VIDEODEV_CLIENT*/
+/*^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^*/
+/*---------------------------------------------------------------------------*/
+if (memcmp(&peasycap->telltale[0], TELLTALE, strlen(TELLTALE))) {
+        SAY("ERROR: bad peasycap: 0x%08lX\n", (unsigned long int) peasycap);
+        return -EFAULT;
+}
+/*---------------------------------------------------------------------------*/
 
 file->private_data = peasycap;
 
@@ -624,7 +669,7 @@ JOM(4, "starting initialization\n");
 
 if ((struct usb_device *)NULL == peasycap->pusb_device) {
         SAM("ERROR: peasycap->pusb_device is NULL\n");
-        return -EFAULT;
+        return -ENODEV;
 }
 JOM(16, "0x%08lX=peasycap->pusb_device\n", (long int)peasycap->pusb_device);
 
@@ -641,7 +686,7 @@ if ((struct usb_device *)NULL == peasycap->pusb_device) {
 /*---------------------------------------------------------------------------*/
 if ((struct usb_device *)NULL == peasycap->pusb_device) {
         SAM("ERROR: peasycap->pusb_device has become NULL\n");
-        return -EFAULT;
+        return -ENODEV;
 }
 rc = usb_set_interface(peasycap->pusb_device, peasycap->audio_interface, \
                                         peasycap->audio_altsetting_on);
@@ -678,6 +723,10 @@ if (NULL == peasycap) {
         SAY("ERROR:  peasycap is NULL.\n");
         return -EFAULT;
 }
+if (memcmp(&peasycap->telltale[0], TELLTALE, strlen(TELLTALE))) {
+        SAY("ERROR: bad peasycap: 0x%08lX\n", (unsigned long int) peasycap);
+        return -EFAULT;
+}
 if (0 != kill_audio_urbs(peasycap)) {
         SAM("ERROR: kill_audio_urbs() failed\n");
         return -EFAULT;
@@ -722,6 +771,10 @@ if (NULL == peasycap) {
         SAY("ERROR in easysnd_read(): peasycap is NULL\n");
         return -EFAULT;
 }
+if (memcmp(&peasycap->telltale[0], TELLTALE, strlen(TELLTALE))) {
+        SAY("ERROR: bad peasycap: 0x%08lX\n", (unsigned long int) peasycap);
+        return -EFAULT;
+}
 if (NULL == peasycap->pusb_device) {
         SAY("ERROR in easysnd_read(): peasycap->pusb_device is NULL\n");
         return -EFAULT;
@@ -753,6 +806,12 @@ if (0 <= kd && DONGLE_MANY > kd) {
                 mutex_unlock(&easycap_dongle[kd].mutex_audio);
                 return -ERESTARTSYS;
         }
+        if (memcmp(&peasycap->telltale[0], TELLTALE, strlen(TELLTALE))) {
+                SAY("ERROR: bad peasycap: 0x%08lX\n", \
+                                                (unsigned long int) peasycap);
+                mutex_unlock(&easycap_dongle[kd].mutex_audio);
+                return -ERESTARTSYS;
+        }
         if (NULL == peasycap->pusb_device) {
                 SAM("ERROR: peasycap->pusb_device is NULL\n");
                 mutex_unlock(&easycap_dongle[kd].mutex_audio);