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-rw-r--r--Documentation/serial/driver44
1 files changed, 41 insertions, 3 deletions
diff --git a/Documentation/serial/driver b/Documentation/serial/driver
index 0a25a9191864..067c47d46917 100644
--- a/Documentation/serial/driver
+++ b/Documentation/serial/driver
@@ -133,6 +133,16 @@ hardware.
Interrupts: locally disabled.
This call must not sleep
+ send_xchar(port,ch)
+ Transmit a high priority character, even if the port is stopped.
+ This is used to implement XON/XOFF flow control and tcflow(). If
+ the serial driver does not implement this function, the tty core
+ will append the character to the circular buffer and then call
+ start_tx() / stop_tx() to flush the data out.
+
+ Locking: none.
+ Interrupts: caller dependent.
+
stop_rx(port)
Stop receiving characters; the port is in the process of
being closed.
@@ -242,9 +252,8 @@ hardware.
pm(port,state,oldstate)
Perform any power management related activities on the specified
- port. State indicates the new state (defined by ACPI D0-D3),
- oldstate indicates the previous state. Essentially, D0 means
- fully on, D3 means powered down.
+ port. State indicates the new state (defined by
+ enum uart_pm_state), oldstate indicates the previous state.
This function should not be used to grab any resources.
@@ -255,6 +264,10 @@ hardware.
Locking: none.
Interrupts: caller dependent.
+ set_wake(port,state)
+ Enable/disable power management wakeup on serial activity. Not
+ currently implemented.
+
type(port)
Return a pointer to a string constant describing the specified
port, or return NULL, in which case the string 'unknown' is
@@ -307,6 +320,31 @@ hardware.
Locking: none.
Interrupts: caller dependent.
+ poll_init(port)
+ Called by kgdb to perform the minimal hardware initialization needed
+ to support poll_put_char() and poll_get_char(). Unlike ->startup()
+ this should not request interrupts.
+
+ Locking: tty_mutex and tty_port->mutex taken.
+ Interrupts: n/a.
+
+ poll_put_char(port,ch)
+ Called by kgdb to write a single character directly to the serial
+ port. It can and should block until there is space in the TX FIFO.
+
+ Locking: none.
+ Interrupts: caller dependent.
+ This call must not sleep
+
+ poll_get_char(port)
+ Called by kgdb to read a single character directly from the serial
+ port. If data is available, it should be returned; otherwise
+ the function should return NO_POLL_CHAR immediately.
+
+ Locking: none.
+ Interrupts: caller dependent.
+ This call must not sleep
+
Other functions
---------------