<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>
unplug).
</para>
+ </sect2>
+
+ <sect2><title>Post-IDENTIFY device configuration</title>
<programlisting>
void (*dev_config) (struct ata_port *, struct ata_device *);
</programlisting>
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 *);
->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);
taskfile register values.
</para>
+ </sect2>
+
+ <sect2><title>ATA command execute</title>
<programlisting>
void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf);
</programlisting>
->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>
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);
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>
meaning on FIS-based devices.
</para>
+ </sect2>
+
+ <sect2><title>Reset ATA bus</title>
<programlisting>
void (*phy_reset) (struct ata_port *ap);
</programlisting>
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);
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);
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>
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 *);
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,
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);
and other resources, etc.
</para>
+ </sect2>
+
</sect1>
</chapter>