path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2009-12-11 15:34:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-11 15:34:40 -0800
commit0f4974c439dd7826c85bae4e6a8088ce2db0f498 (patch)
treefdabc7d9bb7d7bc49aad547c0aac3a633ce01f09 /Documentation
parent3126c136bc30225d7a43af741778aa50e95e467a (diff)
parent36ba782e9674cdc29ec7003757df0b375e99fa96 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (58 commits) tty: split the lock up a bit further tty: Move the leader test in disassociate tty: Push the bkl down a bit in the hangup code tty: Push the lock down further into the ldisc code tty: push the BKL down into the handlers a bit tty: moxa: split open lock tty: moxa: Kill the use of lock_kernel tty: moxa: Fix modem op locking tty: moxa: Kill off the throttle method tty: moxa: Locking clean up tty: moxa: rework the locking a bit tty: moxa: Use more tty_port ops tty: isicom: fix deadlock on shutdown tty: mxser: Use the new locking rules to fix setserial properly tty: mxser: use the tty_port_open method tty: isicom: sort out the board init logic tty: isicom: switch to the new tty_port_open helper tty: tty_port: Add a kref object to the tty port tty: istallion: tty port open/close methods tty: stallion: Convert to the tty_port_open/close methods ...
Diffstat (limited to 'Documentation')
2 files changed, 7 insertions, 156 deletions
diff --git a/Documentation/serial/hayes-esp.txt b/Documentation/serial/hayes-esp.txt
deleted file mode 100644
index 09b5d5856758..000000000000
--- a/Documentation/serial/hayes-esp.txt
+++ /dev/null
@@ -1,154 +0,0 @@
-A big thanks to the people at Hayes, especially Alan Adamson. Their support
-has enabled me to provide enhancements to the driver.
-Please report your experiences with this driver to me (arobinso@nyx.net). I
-am looking for both positive and negative feedback.
-Support for PIO mode. Five situations will cause PIO mode to be used:
-1) A multiport card is detected. PIO mode will always be used. (8 port cards
-do not support DMA).
-2) The DMA channel is set to an invalid value (anything other than 1 or 3).
-3) The DMA buffer/channel could not be allocated. The port will revert to PIO
-mode until it is reopened.
-4) Less than a specified number of bytes need to be transferred to/from the
-FIFOs. PIO mode will be used for that transfer only.
-5) A port needs to do a DMA transfer and another port is already using the
-DMA channel. PIO mode will be used for that transfer only.
-Since the Hayes ESP seems to conflict with other cards (notably sound cards)
-when using DMA, DMA is turned off by default. To use DMA, it must be turned
-on explicitly, either with the "dma=" option described below or with
-setserial. A multiport card can be forced into DMA mode by using setserial;
-however, most multiport cards don't support DMA.
-The latest version of setserial allows the enhanced configuration of the ESP
-card to be viewed and modified.
-This package contains the files needed to compile a module to support the Hayes
-ESP card. The drivers are basically a modified version of the serial drivers.
-- Uses the enhanced mode of the ESP card, allowing a wider range of
- interrupts and features than compatibility mode
-- Uses DMA and 16 bit PIO mode to transfer data to and from the ESP's FIFOs,
- reducing CPU load
-- Supports primary and secondary ports
-If the driver is compiled as a module, the IRQs to use can be specified by
-using the irq= option. The format is:
-The address in brackets is the base address of the card. The IRQ of
-nonexistent cards can be set to 0. If an IRQ of a card that does exist is set
-to 0, the driver will attempt to guess at the correct IRQ. For example, to set
-the IRQ of the card at address 0x300 to 12, the insmod command would be:
-insmod esp irq=0,0,0,0,0,0,12,0
-The custom divisor can be set by using the divisor= option. The format is the
-same as for the irq= option. Each divisor value is a series of hex digits,
-with each digit representing the divisor to use for a corresponding port. The
-divisor value is constructed RIGHT TO LEFT. Specifying a nonzero divisor value
-will automatically set the spd_cust flag. To calculate the divisor to use for
-a certain baud rate, divide the port's base baud (generally 921600) by the
-desired rate. For example, to set the divisor of the primary port at 0x300 to
-4 and the divisor of the secondary port at 0x308 to 8, the insmod command would
-insmod esp divisor=0,0,0,0,0,0,0x84,0
-The dma= option can be used to set the DMA channel. The channel can be either
-1 or 3. Specifying any other value will force the driver to use PIO mode.
-For example, to set the DMA channel to 3, the insmod command would be:
-insmod esp dma=3
-The rx_trigger= and tx_trigger= options can be used to set the FIFO trigger
-levels. They specify when the ESP card should send an interrupt. Larger
-values will decrease the number of interrupts; however, a value too high may
-result in data loss. Valid values are 1 through 1023, with 768 being the
-default. For example, to set the receive trigger level to 512 bytes and the
-transmit trigger level to 700 bytes, the insmod command would be:
-insmod esp rx_trigger=512 tx_trigger=700
-The flow_off= and flow_on= options can be used to set the hardware flow off/
-flow on levels. The flow on level must be lower than the flow off level, and
-the flow off level should be higher than rx_trigger. Valid values are 1
-through 1023, with 1016 being the default flow off level and 944 being the
-default flow on level. For example, to set the flow off level to 1000 bytes
-and the flow on level to 935 bytes, the insmod command would be:
-insmod esp flow_off=1000 flow_on=935
-The rx_timeout= option can be used to set the receive timeout value. This
-value indicates how long after receiving the last character that the ESP card
-should wait before signalling an interrupt. Valid values are 0 though 255,
-with 128 being the default. A value too high will increase latency, and a
-value too low will cause unnecessary interrupts. For example, to set the
-receive timeout to 255, the insmod command would be:
-insmod esp rx_timeout=255
-The pio_threshold= option sets the threshold (in number of characters) for
-using PIO mode instead of DMA mode. For example, if this value is 32,
-transfers of 32 bytes or less will always use PIO mode.
-insmod esp pio_threshold=32
-Multiple options can be listed on the insmod command line by separating each
-option with a space. For example:
-insmod esp dma=3 trigger=512
-The esp module can be automatically loaded when needed. To cause this to
-happen, add the following lines to /etc/modprobe.conf (replacing the last line
-with options for your configuration):
-alias char-major-57 esp
-alias char-major-58 esp
-options esp irq=0,0,0,0,0,0,3,0 divisor=0,0,0,0,0,0,0x4,0
-You may also need to run 'depmod -a'.
-Devices must be created manually. To create the devices, note the output from
-the module after it is inserted. The output will appear in the location where
-kernel messages usually appear (usually /var/adm/messages). Create two devices
-for each 'tty' mentioned, one with major of 57 and the other with major of 58.
-The minor number should be the same as the tty number reported. The commands
-would be (replace ? with the tty number):
-mknod /dev/ttyP? c 57 ?
-mknod /dev/cup? c 58 ?
-For example, if the following line appears:
-Oct 24 18:17:23 techno kernel: ttyP8 at 0x0140 (irq = 3) is an ESP primary port
-...two devices should be created:
-mknod /dev/ttyP8 c 57 8
-mknod /dev/cup8 c 58 8
-You may need to set the permissions on the devices:
-chmod 666 /dev/ttyP*
-chmod 666 /dev/cup*
-The ESP module and the serial module should not conflict (they can be used at
-the same time). After the ESP module has been loaded the ports on the ESP card
-will no longer be accessible by the serial driver.
-If I/O errors are experienced when accessing the port, check for IRQ and DMA
-conflicts ('cat /proc/interrupts' and 'cat /proc/dma' for a list of IRQs and
-DMAs currently in use).
-Andrew J. Robinson <arobinso@nyx.net>
diff --git a/Documentation/serial/tty.txt b/Documentation/serial/tty.txt
index 8e65c4498c52..5e5349a4fcd2 100644
--- a/Documentation/serial/tty.txt
+++ b/Documentation/serial/tty.txt
@@ -42,7 +42,8 @@ TTY side interfaces:
open() - Called when the line discipline is attached to
the terminal. No other call into the line
discipline for this tty will occur until it
- completes successfully. Can sleep.
+ completes successfully. Returning an error will
+ prevent the ldisc from being attached. Can sleep.
close() - This is called on a terminal when the line
discipline is being unplugged. At the point of
@@ -52,7 +53,7 @@ close() - This is called on a terminal when the line
hangup() - Called when the tty line is hung up.
The line discipline should cease I/O to the tty.
No further calls into the ldisc code will occur.
- Can sleep.
+ The return value is ignored. Can sleep.
write() - A process is writing data through the line
discipline. Multiple write calls are serialized
@@ -83,6 +84,10 @@ ioctl() - Called when an ioctl is handed to the tty layer
that might be for the ldisc. Multiple ioctl calls
may occur in parallel. May sleep.
+compat_ioctl() - Called when a 32 bit ioctl is handed to the tty layer
+ that might be for the ldisc. Multiple ioctl calls
+ may occur in parallel. May sleep.
Driver Side Interfaces:
receive_buf() - Hand buffers of bytes from the driver to the ldisc