This commit was manufactured by cvs2svn to create tag

[linux-2.6.git] / Documentation / sound / alsa / DocBook / writing-an-alsa-driver.tmpl

diff --git a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
index 557786c..d08c20d 100644 (file)
--- a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
+++ b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
@@ -1479,7 +1479,7 @@
   struct snd_mychip {
           ....
           unsigned long iobase_phys;
-          unsigned long iobase_virt;
+          void __iomem *iobase_virt;
   };
 ]]>
           </programlisting>
@@ -1495,8 +1495,7 @@
           return err;
   }
   chip->iobase_phys = pci_resource_start(pci, 0);
-  chip->iobase_virt = (unsigned long)
-                      ioremap_nocache(chip->iobase_phys,
+  chip->iobase_virt = ioremap_nocache(chip->iobase_phys,
                                       pci_resource_len(pci, 0));
 ]]>
           </programlisting>
@@ -1511,7 +1510,7 @@
   {
           ....
           if (chip->iobase_virt)
-                  iounmap((void *)chip->iobase_virt);
+                  iounmap(chip->iobase_virt);
           ....
           pci_release_regions(chip->pci);
           ....
@@ -4060,8 +4059,8 @@ struct _snd_pcm_runtime {
       <para>
         Also, there is a function to change the sample rate (of a
         certain register such as
-        <constant>AC97_PCM_FRONT_DAC_RATE</constant>) when VRA is
-        supported by the codec:
+        <constant>AC97_PCM_FRONT_DAC_RATE</constant>) when VRA or
+        DRA is supported by the codec:
         <function>snd_ac97_set_rate()</function>. 
 
         <informalexample>
@@ -4341,7 +4340,39 @@ struct _snd_pcm_runtime {
       </para>
 
       <para>
-        If this function returns successfully with 0, then create a
+        When the accessing to the hardware requires special method
+        instead of the standard I/O access, you can create opl3 instance
+        separately with <function>snd_opl3_new()</function>.
+
+        <informalexample>
+          <programlisting>
+<![CDATA[
+  opl3_t *opl3;
+  snd_opl3_new(card, OPL3_HW_OPL3_XXX, &opl3);
+]]>
+          </programlisting>
+        </informalexample>
+      </para>
+
+      <para>
+       Then set <structfield>command</structfield>,
+       <structfield>private_data</structfield> and
+       <structfield>private_free</structfield> for the private
+       access function, the private data and the destructor.
+       The l_port and r_port are not necessarily set.  Only the
+       command must be set properly.  You can retrieve the data
+       from opl3-&gt;private_data field.
+      </para>
+
+      <para>
+       After creating the opl3 instance via <function>snd_opl3_new()</function>,
+       call <function>snd_opl3_init()</function> to initialize the chip to the
+       proper state.  Note that <function>snd_opl3_create()</function> always
+       calls it internally.
+      </para>
+
+      <para>
+        If the opl3 instance is created successfully, then create a
         hwdep device for this opl3. 
 
         <informalexample>