</para>
</chapter>
+ <chapter id="libataDriverApi">
+ <title>libata Driver API</title>
+ <sect1>
+ <title>struct ata_port_operations</title>
+
+ <programlisting>
+void (*port_disable) (struct ata_port *);
+ </programlisting>
+
+ <para>
+ Called from ata_bus_probe() and ata_bus_reset() error paths,
+ as well as when unregistering from the SCSI module (rmmod, hot
+ unplug).
+ </para>
+
+ <programlisting>
+void (*dev_config) (struct ata_port *, struct ata_device *);
+ </programlisting>
+
+ <para>
+ Called after IDENTIFY [PACKET] DEVICE is issued to each device
+ found. Typically used to apply device-specific fixups prior to
+ issue of SET FEATURES - XFER MODE, and prior to operation.
+ </para>
+
+ <programlisting>
+void (*set_piomode) (struct ata_port *, struct ata_device *);
+void (*set_dmamode) (struct ata_port *, struct ata_device *);
+void (*post_set_mode) (struct ata_port *ap);
+ </programlisting>
+
+ <para>
+ Hooks called prior to the issue of SET FEATURES - XFER MODE
+ command. dev->pio_mode is guaranteed to be valid when
+ ->set_piomode() is called, and dev->dma_mode is guaranteed to be
+ valid when ->set_dmamode() is called. ->post_set_mode() is
+ called unconditionally, after the SET FEATURES - XFER MODE
+ command completes successfully.
+ </para>
+
+ <para>
+ ->set_piomode() is always called (if present), but
+ ->set_dma_mode() is only called if DMA is possible.
+ </para>
+
+ <programlisting>
+void (*tf_load) (struct ata_port *ap, struct ata_taskfile *tf);
+void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf);
+ </programlisting>
+
+ <para>
+ ->tf_load() is called to load the given taskfile into hardware
+ registers / DMA buffers. ->tf_read() is called to read the
+ hardware registers / DMA buffers, to obtain the current set of
+ taskfile register values.
+ </para>
+
+ <programlisting>
+void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf);
+ </programlisting>
+
+ <para>
+ causes an ATA command, previously loaded with
+ ->tf_load(), to be initiated in hardware.
+ </para>
+
+ <programlisting>
+u8 (*check_status)(struct ata_port *ap);
+void (*dev_select)(struct ata_port *ap, unsigned int device);
+ </programlisting>
+
+ <para>
+ Reads the Status ATA shadow register from hardware. On some
+ hardware, this has the side effect of clearing the interrupt
+ condition.
+ </para>
+
+ <programlisting>
+void (*dev_select)(struct ata_port *ap, unsigned int device);
+ </programlisting>
+
+ <para>
+ Issues the low-level hardware command(s) that causes one of N
+ hardware devices to be considered 'selected' (active and
+ available for use) on the ATA bus.
+ </para>
+
+ <programlisting>
+void (*phy_reset) (struct ata_port *ap);
+ </programlisting>
+
+ <para>
+ The very first step in the probe phase. Actions vary depending
+ on the bus type, typically. After waking up the device and probing
+ for device presence (PATA and SATA), typically a soft reset
+ (SRST) will be performed. Drivers typically use the helper
+ functions ata_bus_reset() or sata_phy_reset() for this hook.
+ </para>
+
+ <programlisting>
+void (*bmdma_setup) (struct ata_queued_cmd *qc);
+void (*bmdma_start) (struct ata_queued_cmd *qc);
+ </programlisting>
+
+ <para>
+ When setting up an IDE BMDMA transaction, these hooks arm
+ (->bmdma_setup) and fire (->bmdma_start) the hardware's DMA
+ engine.
+ </para>
+
+ <programlisting>
+void (*qc_prep) (struct ata_queued_cmd *qc);
+int (*qc_issue) (struct ata_queued_cmd *qc);
+ </programlisting>
+
+ <para>
+ Higher-level hooks, these two hooks can potentially supercede
+ several of the above taskfile/DMA engine hooks. ->qc_prep is
+ called after the buffers have been DMA-mapped, and is typically
+ used to populate the hardware's DMA scatter-gather table.
+ Most drivers use the standard ata_qc_prep() helper function, but
+ more advanced drivers roll their own.
+ </para>
+ <para>
+ ->qc_issue is used to make a command active, once the hardware
+ and S/G tables have been prepared. IDE BMDMA drivers use the
+ helper function ata_qc_issue_prot() for taskfile protocol-based
+ dispatch. More advanced drivers roll their own ->qc_issue
+ implementation, using this as the "issue new ATA command to
+ hardware" hook.
+ </para>
+
+ <programlisting>
+void (*eng_timeout) (struct ata_port *ap);
+ </programlisting>
+
+ <para>
+ This is a high level error handling function, called from the
+ error handling thread, when a command times out.
+ </para>
+
+ <programlisting>
+irqreturn_t (*irq_handler)(int, void *, struct pt_regs *);
+void (*irq_clear) (struct ata_port *);
+ </programlisting>
+
+ <para>
+ ->irq_handler is the interrupt handling routine registered with
+ the system, by libata. ->irq_clear is called during probe just
+ before the interrupt handler is registered, to be sure hardware
+ is quiet.
+ </para>
+
+ <programlisting>
+u32 (*scr_read) (struct ata_port *ap, unsigned int sc_reg);
+void (*scr_write) (struct ata_port *ap, unsigned int sc_reg,
+ u32 val);
+ </programlisting>
+
+ <para>
+ Read and write standard SATA phy registers. Currently only used
+ if ->phy_reset hook called the sata_phy_reset() helper function.
+ </para>
+
+ <programlisting>
+int (*port_start) (struct ata_port *ap);
+void (*port_stop) (struct ata_port *ap);
+void (*host_stop) (struct ata_host_set *host_set);
+ </programlisting>
+
+ <para>
+ ->port_start() is called just after the data structures for each
+ port are initialized. Typically this is used to alloc per-port
+ DMA buffers / tables / rings, enable DMA engines, and similar
+ tasks.
+ </para>
+ <para>
+ ->host_stop() is called when the rmmod or hot unplug process
+ begins. The hook must stop all hardware interrupts, DMA
+ engines, etc.
+ </para>
+ <para>
+ ->port_stop() is called after ->host_stop(). It's sole function
+ is to release DMA/memory resources, now that they are no longer
+ actively being used.
+ </para>
+
+ </sect1>
+ </chapter>
+
<chapter id="libataExt">
<title>libata Library</title>
!Edrivers/scsi/libata-core.c
</chapter>
<chapter id="SILInt">
- <title>ata_sil Internals</title>
+ <title>sata_sil Internals</title>
!Idrivers/scsi/sata_sil.c
</chapter>
git://git.onelab.eu / linux-2.6.git / blobdiff