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

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

Documentation/DocBook/libata.tmpl

+16 −33
Original line number Diff line number Diff line
@@ -107,10 +107,6 @@ void (*dev_config) (struct ata_port *, struct ata_device *); 
	issue of SET FEATURES - XFER MODE, and prior to operation.

	</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.

	</para>
@@ -154,8 +150,8 @@ unsigned int (*mode_filter) (struct ata_port *, struct ata_device *, unsigned in 


	<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);

void (*sff_tf_load) (struct ata_port *ap, struct ata_taskfile *tf);

void (*sff_tf_read) (struct ata_port *ap, struct ata_taskfile *tf);

	</programlisting>



	<para>
@@ -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

	taskfile register values.

	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>



	</sect2>



	<sect2><title>PIO data read/write</title>

	<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>



	<para>

All bmdma-style drivers must implement this hook.  This is the low-level

operation that actually copies the data bytes during a PIO data

transfer.

Typically the driver

will choose one of ata_pio_data_xfer_noirq(), ata_pio_data_xfer(), or

ata_mmio_data_xfer().

Typically the driver will choose one of ata_sff_data_xfer_noirq(),

ata_sff_data_xfer(), or ata_sff_data_xfer32().

	</para>



	</sect2>



	<sect2><title>ATA command execute</title>

	<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>



	<para>

	causes an ATA command, previously loaded with

	->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.

	</para>
@@ -218,8 +213,8 @@ command. 


	<sect2><title>Read specific ATA shadow registers</title>

	<programlisting>

u8   (*check_status)(struct ata_port *ap);

u8   (*check_altstatus)(struct ata_port *ap);

u8   (*sff_check_status)(struct ata_port *ap);

u8   (*sff_check_altstatus)(struct ata_port *ap);

	</programlisting>



	<para>
@@ -227,20 +222,14 @@ u8 (*check_altstatus)(struct ata_port *ap); 
	hardware.  On some hardware, reading the Status register has

	the side effect of clearing the interrupt condition.

	Most drivers for taskfile-based hardware use

	ata_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.

	ata_sff_check_status() for this hook.

	</para>



	</sect2>



	<sect2><title>Select ATA device on bus</title>

	<programlisting>

void (*dev_select)(struct ata_port *ap, unsigned int device);

void (*sff_dev_select)(struct ata_port *ap, unsigned int device);

	</programlisting>



	<para>
@@ -251,9 +240,7 @@ void (*dev_select)(struct ata_port *ap, unsigned int device); 
	</para>

	<para>

	Most drivers for taskfile-based hardware use

	ata_std_dev_select() for this hook.  Controllers which do not

	support second drives on a port (such as SATA contollers) will

	use ata_noop_dev_select().

	ata_sff_dev_select() for this hook.

	</para>



	</sect2>
@@ -441,13 +428,13 @@ void (*irq_clear) (struct ata_port *); 
	to struct ata_host_set.

	</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,

	determines which queued command was active (if any), and calls

	ata_host_intr(ap,qc).

	ata_sff_host_intr(ap,qc).

	</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

	flags in the DMA status register.

	</para>
@@ -496,10 +483,6 @@ void (*host_stop) (struct ata_host_set *host_set); 
	data from port at this time.

	</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

have completed.  The hook must finalize hardware shutdown, release DMA

and other resources, etc.