Commit 40868c85 authored by Sergei Shtylyov's avatar Sergei Shtylyov Committed by Jeff Garzik

libata: Fix several inaccuracies in developer's guide

Commit 6bfff31e (libata: kill probe_ent
and related helpers) killed ata_device_add() but didn't remove references
to it from the libata developer's guide.

Commits 9363c382 (libata: rename SFF
functions) and 5682ed33 (libata: rename
SFF port ops) renamed the taskfile access methods but didn't update the
developer's guide.  Commit c9f75b04
(libata: kill ata_noop_dev_select()) didn't update the developer's
guide as well.

The guide also refers to the long gone ata_pio_data_xfer_noirq(),
ata_pio_data_xfer(), and ata_mmio_data_xfer() -- replace those by
the modern ata_sff_data_xfer_noirq(), ata_sff_data_xfer(), and
ata_sff_data_xfer32().

Also, remove the reference to non-existant ata_port_stop()...
Signed-off-by: default avatarSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 8777c793
...@@ -107,10 +107,6 @@ void (*dev_config) (struct ata_port *, struct ata_device *); ...@@ -107,10 +107,6 @@ void (*dev_config) (struct ata_port *, struct ata_device *);
issue of SET FEATURES - XFER MODE, and prior to operation. issue of SET FEATURES - XFER MODE, and prior to operation.
</para> </para>
<para> <para>
Called by ata_device_add() after ata_dev_identify() determines
a device is present.
</para>
<para>
This entry may be specified as NULL in ata_port_operations. This entry may be specified as NULL in ata_port_operations.
</para> </para>
...@@ -154,8 +150,8 @@ unsigned int (*mode_filter) (struct ata_port *, struct ata_device *, unsigned in ...@@ -154,8 +150,8 @@ unsigned int (*mode_filter) (struct ata_port *, struct ata_device *, unsigned in
<sect2><title>Taskfile read/write</title> <sect2><title>Taskfile read/write</title>
<programlisting> <programlisting>
void (*tf_load) (struct ata_port *ap, struct ata_taskfile *tf); void (*sff_tf_load) (struct ata_port *ap, struct ata_taskfile *tf);
void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf); void (*sff_tf_read) (struct ata_port *ap, struct ata_taskfile *tf);
</programlisting> </programlisting>
<para> <para>
...@@ -164,36 +160,35 @@ void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf); ...@@ -164,36 +160,35 @@ void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf);
hardware registers / DMA buffers, to obtain the current set of hardware registers / DMA buffers, to obtain the current set of
taskfile register values. taskfile register values.
Most drivers for taskfile-based hardware (PIO or MMIO) use Most drivers for taskfile-based hardware (PIO or MMIO) use
ata_tf_load() and ata_tf_read() for these hooks. ata_sff_tf_load() and ata_sff_tf_read() for these hooks.
</para> </para>
</sect2> </sect2>
<sect2><title>PIO data read/write</title> <sect2><title>PIO data read/write</title>
<programlisting> <programlisting>
void (*data_xfer) (struct ata_device *, unsigned char *, unsigned int, int); void (*sff_data_xfer) (struct ata_device *, unsigned char *, unsigned int, int);
</programlisting> </programlisting>
<para> <para>
All bmdma-style drivers must implement this hook. This is the low-level All bmdma-style drivers must implement this hook. This is the low-level
operation that actually copies the data bytes during a PIO data operation that actually copies the data bytes during a PIO data
transfer. transfer.
Typically the driver Typically the driver will choose one of ata_sff_data_xfer_noirq(),
will choose one of ata_pio_data_xfer_noirq(), ata_pio_data_xfer(), or ata_sff_data_xfer(), or ata_sff_data_xfer32().
ata_mmio_data_xfer().
</para> </para>
</sect2> </sect2>
<sect2><title>ATA command execute</title> <sect2><title>ATA command execute</title>
<programlisting> <programlisting>
void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf); void (*sff_exec_command)(struct ata_port *ap, struct ata_taskfile *tf);
</programlisting> </programlisting>
<para> <para>
causes an ATA command, previously loaded with causes an ATA command, previously loaded with
->tf_load(), to be initiated in hardware. ->tf_load(), to be initiated in hardware.
Most drivers for taskfile-based hardware use ata_exec_command() Most drivers for taskfile-based hardware use ata_sff_exec_command()
for this hook. for this hook.
</para> </para>
...@@ -218,8 +213,8 @@ command. ...@@ -218,8 +213,8 @@ command.
<sect2><title>Read specific ATA shadow registers</title> <sect2><title>Read specific ATA shadow registers</title>
<programlisting> <programlisting>
u8 (*check_status)(struct ata_port *ap); u8 (*sff_check_status)(struct ata_port *ap);
u8 (*check_altstatus)(struct ata_port *ap); u8 (*sff_check_altstatus)(struct ata_port *ap);
</programlisting> </programlisting>
<para> <para>
...@@ -227,20 +222,14 @@ u8 (*check_altstatus)(struct ata_port *ap); ...@@ -227,20 +222,14 @@ u8 (*check_altstatus)(struct ata_port *ap);
hardware. On some hardware, reading the Status register has hardware. On some hardware, reading the Status register has
the side effect of clearing the interrupt condition. the side effect of clearing the interrupt condition.
Most drivers for taskfile-based hardware use Most drivers for taskfile-based hardware use
ata_check_status() for this hook. ata_sff_check_status() for this hook.
</para>
<para>
Note that because this is called from ata_device_add(), at
least a dummy function that clears device interrupts must be
provided for all drivers, even if the controller doesn't
actually have a taskfile status register.
</para> </para>
</sect2> </sect2>
<sect2><title>Select ATA device on bus</title> <sect2><title>Select ATA device on bus</title>
<programlisting> <programlisting>
void (*dev_select)(struct ata_port *ap, unsigned int device); void (*sff_dev_select)(struct ata_port *ap, unsigned int device);
</programlisting> </programlisting>
<para> <para>
...@@ -251,9 +240,7 @@ void (*dev_select)(struct ata_port *ap, unsigned int device); ...@@ -251,9 +240,7 @@ void (*dev_select)(struct ata_port *ap, unsigned int device);
</para> </para>
<para> <para>
Most drivers for taskfile-based hardware use Most drivers for taskfile-based hardware use
ata_std_dev_select() for this hook. Controllers which do not ata_sff_dev_select() for this hook.
support second drives on a port (such as SATA contollers) will
use ata_noop_dev_select().
</para> </para>
</sect2> </sect2>
...@@ -441,13 +428,13 @@ void (*irq_clear) (struct ata_port *); ...@@ -441,13 +428,13 @@ void (*irq_clear) (struct ata_port *);
to struct ata_host_set. to struct ata_host_set.
</para> </para>
<para> <para>
Most legacy IDE drivers use ata_interrupt() for the Most legacy IDE drivers use ata_sff_interrupt() for the
irq_handler hook, which scans all ports in the host_set, irq_handler hook, which scans all ports in the host_set,
determines which queued command was active (if any), and calls determines which queued command was active (if any), and calls
ata_host_intr(ap,qc). ata_sff_host_intr(ap,qc).
</para> </para>
<para> <para>
Most legacy IDE drivers use ata_bmdma_irq_clear() for the Most legacy IDE drivers use ata_sff_irq_clear() for the
irq_clear() hook, which simply clears the interrupt and error irq_clear() hook, which simply clears the interrupt and error
flags in the DMA status register. flags in the DMA status register.
</para> </para>
...@@ -496,10 +483,6 @@ void (*host_stop) (struct ata_host_set *host_set); ...@@ -496,10 +483,6 @@ void (*host_stop) (struct ata_host_set *host_set);
data from port at this time. data from port at this time.
</para> </para>
<para> <para>
Many drivers use ata_port_stop() as this hook, which frees the
PRD table.
</para>
<para>
->host_stop() is called after all ->port_stop() calls ->host_stop() is called after all ->port_stop() calls
have completed. The hook must finalize hardware shutdown, release DMA have completed. The hook must finalize hardware shutdown, release DMA
and other resources, etc. and other resources, etc.
......
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