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authorJeff Garzik <jgarzik@pobox.com>2005-05-31 20:43:57 -0400
committerJeff Garzik <jgarzik@pobox.com>2005-05-31 20:43:57 -0400
commit92bab26be5544d8b495389646490fcfdca6dbcf2 (patch)
tree370094359db3814caa62a02195c2d37c6c61585d
parent0cba632b737fc2de76934137b8dccf92d9fa4d19 (diff)
downloadop-kernel-dev-92bab26be5544d8b495389646490fcfdca6dbcf2.zip
op-kernel-dev-92bab26be5544d8b495389646490fcfdca6dbcf2.tar.gz
libata: more docs updates
-rw-r--r--Documentation/DocBook/libata.tmpl57
1 files changed, 57 insertions, 0 deletions
diff --git a/Documentation/DocBook/libata.tmpl b/Documentation/DocBook/libata.tmpl
index 77b4a22..6df1dfd 100644
--- a/Documentation/DocBook/libata.tmpl
+++ b/Documentation/DocBook/libata.tmpl
@@ -60,9 +60,22 @@
<chapter id="libataDriverApi">
<title>libata Driver API</title>
+ <para>
+ struct ata_port_operations is defined for every low-level libata
+ hardware driver, and it controls how the low-level driver
+ interfaces with the ATA and SCSI layers.
+ </para>
+ <para>
+ FIS-based drivers will hook into the system with ->qc_prep() and
+ ->qc_issue() high-level hooks. Hardware which behaves in a manner
+ similar to PCI IDE hardware may utilize several generic helpers,
+ defining at a bare minimum the bus I/O addresses of the ATA shadow
+ register blocks.
+ </para>
<sect1>
<title>struct ata_port_operations</title>
+ <sect2><title>Disable ATA port</title>
<programlisting>
void (*port_disable) (struct ata_port *);
</programlisting>
@@ -73,6 +86,9 @@ void (*port_disable) (struct ata_port *);
unplug).
</para>
+ </sect2>
+
+ <sect2><title>Post-IDENTIFY device configuration</title>
<programlisting>
void (*dev_config) (struct ata_port *, struct ata_device *);
</programlisting>
@@ -83,6 +99,9 @@ void (*dev_config) (struct ata_port *, struct ata_device *);
issue of SET FEATURES - XFER MODE, and prior to operation.
</para>
+ </sect2>
+
+ <sect2><title>Set PIO/DMA mode</title>
<programlisting>
void (*set_piomode) (struct ata_port *, struct ata_device *);
void (*set_dmamode) (struct ata_port *, struct ata_device *);
@@ -103,6 +122,9 @@ void (*post_set_mode) (struct ata_port *ap);
->set_dma_mode() is only called if DMA is possible.
</para>
+ </sect2>
+
+ <sect2><title>Taskfile read/write</title>
<programlisting>
void (*tf_load) (struct ata_port *ap, struct ata_taskfile *tf);
void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf);
@@ -115,6 +137,9 @@ void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf);
taskfile register values.
</para>
+ </sect2>
+
+ <sect2><title>ATA command execute</title>
<programlisting>
void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf);
</programlisting>
@@ -124,6 +149,9 @@ void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf);
->tf_load(), to be initiated in hardware.
</para>
+ </sect2>
+
+ <sect2><title>Per-cmd ATAPI DMA capabilities filter</title>
<programlisting>
int (*check_atapi_dma) (struct ata_queued_cmd *qc);
</programlisting>
@@ -134,6 +162,9 @@ indicating whether or not it is OK to use DMA for the supplied PACKET
command.
</para>
+ </sect2>
+
+ <sect2><title>Read specific ATA shadow registers</title>
<programlisting>
u8 (*check_status)(struct ata_port *ap);
u8 (*check_altstatus)(struct ata_port *ap);
@@ -146,6 +177,9 @@ u8 (*check_err)(struct ata_port *ap);
the side effect of clearing the interrupt condition.
</para>
+ </sect2>
+
+ <sect2><title>Select ATA device on bus</title>
<programlisting>
void (*dev_select)(struct ata_port *ap, unsigned int device);
</programlisting>
@@ -157,6 +191,9 @@ void (*dev_select)(struct ata_port *ap, unsigned int device);
meaning on FIS-based devices.
</para>
+ </sect2>
+
+ <sect2><title>Reset ATA bus</title>
<programlisting>
void (*phy_reset) (struct ata_port *ap);
</programlisting>
@@ -169,6 +206,9 @@ void (*phy_reset) (struct ata_port *ap);
functions ata_bus_reset() or sata_phy_reset() for this hook.
</para>
+ </sect2>
+
+ <sect2><title>Control PCI IDE BMDMA engine</title>
<programlisting>
void (*bmdma_setup) (struct ata_queued_cmd *qc);
void (*bmdma_start) (struct ata_queued_cmd *qc);
@@ -188,6 +228,9 @@ These hooks are typically either no-ops, or simply not implemented, in
FIS-based drivers.
</para>
+ </sect2>
+
+ <sect2><title>High-level taskfile hooks</title>
<programlisting>
void (*qc_prep) (struct ata_queued_cmd *qc);
int (*qc_issue) (struct ata_queued_cmd *qc);
@@ -208,6 +251,9 @@ int (*qc_issue) (struct ata_queued_cmd *qc);
dispatch. More advanced drivers implement their own ->qc_issue.
</para>
+ </sect2>
+
+ <sect2><title>Timeout (error) handling</title>
<programlisting>
void (*eng_timeout) (struct ata_port *ap);
</programlisting>
@@ -219,6 +265,9 @@ hardware will implement its own error handling code here. IDE BMDMA
drivers may use the helper function ata_eng_timeout().
</para>
+ </sect2>
+
+ <sect2><title>Hardware interrupt handling</title>
<programlisting>
irqreturn_t (*irq_handler)(int, void *, struct pt_regs *);
void (*irq_clear) (struct ata_port *);
@@ -231,6 +280,9 @@ void (*irq_clear) (struct ata_port *);
is quiet.
</para>
+ </sect2>
+
+ <sect2><title>SATA phy read/write</title>
<programlisting>
u32 (*scr_read) (struct ata_port *ap, unsigned int sc_reg);
void (*scr_write) (struct ata_port *ap, unsigned int sc_reg,
@@ -242,6 +294,9 @@ void (*scr_write) (struct ata_port *ap, unsigned int sc_reg,
if ->phy_reset hook called the sata_phy_reset() helper function.
</para>
+ </sect2>
+
+ <sect2><title>Init and shutdown</title>
<programlisting>
int (*port_start) (struct ata_port *ap);
void (*port_stop) (struct ata_port *ap);
@@ -265,6 +320,8 @@ have completed. The hook must finalize hardware shutdown, release DMA
and other resources, etc.
</para>
+ </sect2>
+
</sect1>
</chapter>
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