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authorSergei Shtylyov <sshtylyov@ru.mvista.com>2010-05-07 18:47:50 (GMT)
committerJeff Garzik <jgarzik@redhat.com>2010-05-14 21:35:52 (GMT)
commit41dec29bcb05eb8ec396f70ce791c6e3e4ce4712 (patch)
treee76f63519031769e848dcc6eba63c9207cf4d84e /Documentation/DocBook
parent55787183ade44c4f826f581a068f52a1a80c6a2e (diff)
libata: introduce sff_set_devctl() method
The set of libata's taskfile access methods is clearly incomplete as it lacks a method to write to the device control register -- which forces drivers like 'pata_bf54x' and 'pata_scc' to implement more "high level" (and more weighty) methods like freeze() and postreset(). So, introduce the optional sff_set_devctl() method which the drivers only have to implement if the standard iowrite8() can't be used (just like the existing sff_check_altstatus() method) and make use of it in the freeze() and postreset() method implementations (I could also have used it in softreset() method but it also reads other taskfile registers without using tf_read() making that quite pointless); this makes freeze() method implementations in the 'pata_bf54x' and 'pata_scc' methods virtually identical to ata_sff_freeze(), so we can get rid of them completely. Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'Documentation/DocBook')
-rw-r--r--Documentation/DocBook/libata.tmpl12
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/DocBook/libata.tmpl b/Documentation/DocBook/libata.tmpl
index 70b811e..828748c 100644
--- a/Documentation/DocBook/libata.tmpl
+++ b/Documentation/DocBook/libata.tmpl
@@ -225,6 +225,18 @@ u8 (*sff_check_altstatus)(struct ata_port *ap);
</sect2>
+ <sect2><title>Write specific ATA shadow register</title>
+ <programlisting>
+void (*sff_set_devctl)(struct ata_port *ap, u8 ctl);
+ </programlisting>
+
+ <para>
+ Write the device control ATA shadow register to the hardware.
+ Most drivers don't need to define this.
+ </para>
+
+ </sect2>
+
<sect2><title>Select ATA device on bus</title>
<programlisting>
void (*sff_dev_select)(struct ata_port *ap, unsigned int device);

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