user/sven/linux.git/include/linux/serial_8250.h, branch v3.18.75

tty: serial: 8250: use 32bit variable for rpm_tx_active

2014-09-30T01:20:38Z

The kbuild test robot wrote me: | make.cross ARCH=powerpc |>> ERROR: ".__xchg_called_with_bad_pointer" [drivers/tty/serial/8250/8250.ko] undefined! The generic implementation of xchg() on arm and x86 works for variables of size one bye (char). According to the report powerpc does not support xchg() for one byte sized variables and looking further it seems also to be the same case for sparc and tile (or for 10 out of 26 architectures which provide a custom implementation). For that reason I increase the size of the variable from one to four bytes to get it work on powerpc (and the others). Reported-By: kbuild test robot Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Greg Kroah-Hartman

tty: serial: 8250_core: add run time pm

2014-09-26T16:01:56Z

While comparing the OMAP-serial and the 8250 part of this I noticed that the latter does not use run time-pm. Here are the pieces. It is basically a get before first register access and a last_busy + put after last access. This has to be enabled from userland _and_ UART_CAP_RPM is required for this. The runtime PM can usually work transparently in the background however there is one exception to this: After serial8250_tx_chars() completes there still may be unsent bytes in the FIFO (depending on CPU speed vs baud rate + flow control). Even if the TTY-buffer is empty we do not want RPM to disable the device because it won't send the remaining bytes. Instead we leave serial8250_tx_chars() with RPM enabled and wait for the FIFO empty interrupt. Once we enter serial8250_tx_chars() with an empty buffer we know that the FIFO is empty and since we are not going to send anything, we can disable the device. That xchg() is to ensure that serial8250_tx_chars() can be called multiple times and only the first invocation will actually invoke the runtime PM function. So that the last invocation of __stop_tx() will disable runtime pm. NOTE: do not enable RPM on the device unless you know what you do! If the device goes idle, it won't be woken up by incomming RX data _unless_ there is a wakeup irq configured which is usually the RX pin configure for wakeup via the reset module. The RX activity will then wake up the device from idle. However the first character is garbage and lost. The following bytes will be received once the device is up in time. On the beagle board xm (omap3) it takes approx 13ms from the first wakeup byte until the first byte that is received properly if the device was in core-off. v5…v8: - drop RPM from serial8250_set_mctrl() it will be used in restore path which already has RPM active and holds dev->power.lock v4…v5: - add a wrapper around rpm function and introduce UART_CAP_RPM to ensure RPM put is invoked after the TX FIFO is empty. v3…v4: - added runtime to the console code - removed device_may_wakeup() from serial8250_set_sleep() Cc: mika.westerberg@linux.intel.com Reviewed-by: Tony Lindgren Tested-by: Tony Lindgren Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Greg Kroah-Hartman

tty: serial: 8250_core: allow to overwrite & export serial8250_startup()

2014-09-08T23:32:36Z

The OMAP version of the 8250 can actually use 1:1 serial8250_startup(). However it needs to be extended by a wake up irq which should to be requested & enabled at ->startup() time and disabled at ->shutdown() time. v2…v3: properly copy callbacks v1…v2: add shutdown callback Acked-by: Alan Cox Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Greg Kroah-Hartman

serial/8250: Add support for RS485 IOCTLs

2014-09-08T22:26:26Z

This patch allow the users of the 8250 infrastructure to define a handler for RS485 configration. If no handler is defined the 8250 driver will work as usual. Signed-off-by: Ricardo Ribalda Delgado Acked-by: Alan Cox -- v2:Change suggested by Alan "One Thousand Gnomes": - Move rs485 structure further down on the uart_8250_port structure drivers/tty/serial/8250/8250_core.c | 39 +++++++++++++++++++++++++++++++++++++ include/linux/serial_8250.h | 3 +++ 2 files changed, 42 insertions(+) Signed-off-by: Greg Kroah-Hartman

serial/uart/8250: Add tunable RX interrupt trigger I/F of FIFO buffers

2014-07-18T01:23:35Z

Add tunable RX interrupt trigger I/F of FIFO buffers. Serial devices are used as not only message communication devices but control or sending communication devices. For the latter uses, normally small data will be exchanged, so user applications want to receive data unit as soon as possible for real-time tendency. If we have a sensor which sends a 1 byte data each time and must control a device based on the sensor feedback, the RX interrupt should be triggered for each data. According to HW specification of serial UART devices, RX interrupt trigger can be changed, but the trigger is hard-coded. For example, RX interrupt trigger in 16550A can be set to 1, 4, 8, or 14 bytes for HW, but current driver sets the trigger to only 8bytes. This patch makes some devices change RX interrupt trigger from userland. - Read current setting # cat /sys/class/tty/ttyS0/rx_trig_bytes 8 - Write user setting # echo 1 > /sys/class/tty/ttyS0/rx_trig_bytes # cat /sys/class/tty/ttyS0/rx_trig_bytes 1 - 16550A and Tegra (1, 4, 8, or 14 bytes) - 16650V2 (8, 16, 24, or 28 bytes) - 16654 (8, 16, 56, or 60 bytes) - 16750 (1, 16, 32, or 56 bytes) Changes in V9: - Use attr_group instead of dev_spec_attr_group of uart_port structure Changes in V8: - Divide this patch from V7's patch based on Greg's comment Changes in V7: - Add Documentation - Change I/F name from rx_int_trig to rx_trig_bytes because the name rx_int_trig is hard to understand how users specify the value Changes in V6: - Move FCR_RX_TRIG_* definition in 8250.h to include/uapi/linux/serial_reg.h, rename those to UART_FCR_R_TRIG_*, and use UART_FCR_TRIGGER_MASK to UART_FCR_R_TRIG_BITS() - Change following function names: convert_fcr2val() => fcr_get_rxtrig_bytes() convert_val2rxtrig() => bytes_to_fcr_rxtrig() - Fix typo in serial8250_do_set_termios() - Delete the verbose error message pr_info() in bytes_to_fcr_rxtrig() - Rename *rx_int_trig/rx_trig* to *rxtrig* for several functions or variables (but UI remains rx_int_trig) - Change the meaningless variable name 'val' to 'bytes' following functions: fcr_get_rxtrig_bytes(), bytes_to_fcr_rxtrig(), do_set_rxtrig(), do_serial8250_set_rxtrig(), and serial8250_set_attr_rxtrig() - Use up->fcr in order to get rxtrig_bytes instead of rx_trig_raw in fcr_get_rxtrig_bytes() - Use conf_type->rxtrig_bytes[0] instead of switch statement for support check in register_dev_spec_attr_grp() - Delete the checking whether a user changed FCR or not when minimum buffer is needed in serial8250_do_set_termios() Changes in V5.1: - Fix FCR_RX_TRIG_MAX_STATE definition Changes in V5: - Support Tegra, 16650V2, 16654, and 16750 - Store default FCR value to up->fcr when the port is first created - Add rx_trig_byte[] in uart_config[] for each device and use rx_trig_byte[] in convert_fcr2val() and convert_val2rxtrig() Changes in V4: - Introduce fifo_bug flag in uart_8250_port structure This is enabled only when parity is enabled and UART_BUG_PARITY is enabled for up->bugs. If this flag is enabled, user cannot set RX trigger. - Return -EOPNOTSUPP when it does not support device at convert_fcr2val() and at convert_val2rxtrig() - Set the nearest lower RX trigger when users input a meaningless value at convert_val2rxtrig() - Check whether p->fcr is existing at serial8250_clear_and_reinit_fifos() - Set fcr = up->fcr in the begging of serial8250_do_set_termios() Changes in V3: - Change I/F from ioctl(2) to sysfs(rx_int_trig) Changed in V2: - Use _IOW for TIOCSFIFORTRIG definition - Pass the interrupt trigger value itself Signed-off-by: Yoshihiro YUNOMAE Signed-off-by: Greg Kroah-Hartman

serial: 8250: introduce up_to_u8250p() helper

2014-07-18T01:16:23Z

It helps to cast struct uart_port to struct uart_8250_port at runtime. Signed-off-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman

serial: 8250: Add support for dmaengine

2013-01-16T07:03:00Z

Add support for dmaengine API. The drivers can implement the struct uart_8250_dma member in struct uart_8250_port and 8250.c can take care of the rest. Signed-off-by: Heikki Krogerus Signed-off-by: Greg Kroah-Hartman

tty/8250_early: Turn serial_in/serial_out into weak symbols.

2012-11-16T12:39:15Z

Allows overriding default methods serial_in/serial_out. In such platform specific replacement it is possible to use other regshift, biased register offset, any other manipulation that is not covered with common default methods. Overriding default methods may be useful for platforms which got serial peripheral with registers represented in big endian. In this situation and assuming that 32 bit operations / alignment is required then it may be useful to swab words before/after accessing the serial registers. Signed-off-by: Noam Camus Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

8250: three way resolve of the 8250 diffs

2012-07-17T16:11:50Z

This resolves the differences between the original 8250 patch, the revised 8250 patch and the independant clean up of the octeon driver (to use platform devices properly yay!) Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

8250: use the 8250 register interface not the legacy one

2012-07-12T21:46:22Z

The old interface just copies bits over and calls the newer one. In addition we can now pass more information. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman