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* Remove redundant checking of sc_leaving (uart_intr() already handles this).marius2010-05-021-1/+1
| | | | Approved by: marcel
* Fix hangs caused by hardware that signals receive errorsmarcel2009-04-081-6/+9
| | | | | | | | | (framing, parity, etc), but does not indicate characters being received. Since no chracters have been received, ignore the line errors. PR: 131006 MFC after: 3 days
* The XScale PXA255 has three generally ns16x50 compatible UARTs. One of thebenno2008-05-301-5/+31
| | | | | | | | | | | | | | | variations from normal 16x50 behaviour however is the the use of a normally unused bit of IER to control RX timeout interrupts independently of the generally used RXRDY bit. If this bit is not enabled, we only ever get interrupts when the FIFO is full, never before. This is not very useful when the UART is being used as a console. In order to support this without causing potential problems on more "normal" 16x50 variants, this change introduces two hints for the uart device, ier_mask and ier_rxbits. These can be used to override which bits get set and cleared when we're enabling and disabling RX interrupts. Reviewed by: marcel
* add device hints to control the rx FIFO interrupt level on 16550A partssam2008-03-121-1/+14
| | | | | | | PR: kern/121421 Submitted by: UEMURA Tetsuya Reviewed by: marcel MFC after: 2 weeks
* Don't use a time-limiting loop that's defined in terms of the baudratemarcel2007-04-031-13/+7
| | | | | | | | | | | | | | | in the putc() method. Likewise, in the getc() method, don't check for received characters with an interval defined in terms of the baudrate. In both cases it works equally well to implement a fixed delay. More importantly, it avoids calculating a delay that's roughly 1/10th the time it takes to send/receive a character. The calculation is costly and happens for every character sent or received, affecting low-level console or debug port performance significantly. Secondly, when the RCLK is not available or unreliable, the delays could disrupt normal operation. The fixed delay is 1/10th the time it takes to send a character at 230400 bps.
* Don't expose the uart_ops structure directly, but instead havemarcel2007-04-021-2/+3
| | | | | | | | | | | | it obtained through the uart_class structure. This allows us to declare the uart_class structure as weak and as such allows us to reference it even when it's not compiled-in. It also allows is to get the uart_ops structure by name, which makes it possible to implement the dt tag handling in uart_getenv(). The side-effect of all this is that we're using the uart_class structure more consistently which means that we now also have access to the size of the bus space block needed by the hardware when we map the bus space, eliminating any hardcoding.
* For embedded UARTs compatible with the ns8250 family it is possiblemarcel2007-03-281-1/+3
| | | | | | | | | that the driver clock is identical to the processor or bus clock. This is the case for the PowerQUICC processor. When the clock is high enough, overflows happen in the calculation of the time it takes to send 1/10 of a character, used in delay loops. Fix the overflows so as to fix bugs in the delay loops that can cause either insufficient delays or excessive delays.
* - Add a uart_rxready() and corresponding device-specific implementationsmarius2007-01-181-6/+4
| | | | | | | | | | | | | | | that can be used to check whether receive data is ready, i.e. whether the subsequent call of uart_poll() should return a char, and unlike uart_poll() doesn't actually receive data. - Remove the device-specific implementations of uart_poll() and implement uart_poll() in terms of uart_getc() and the newly added uart_rxready() in order to minimize code duplication. - In sunkbd(4) take advantage of uart_rxready() and use it to implement the polled mode part of sunkbd_check() so we don't need to buffer a potentially read char in the softc. - Fix some mis-indentation in sunkbd_read_char(). Discussed with: marcel
* The lcr variable in ns8250_probe is now unused. Remove it.benno2006-05-231-1/+1
| | | | Missed by: benno
* Allow uart(4)'s ns8250 driver to work with devices whose regshift is > 0.benno2006-05-231-24/+16
| | | | | | | | | | | | | - Rename REG_DL to REG_DLL and REG_DLH. - Always treat DLL and DLH as two separate 8-bit registers instead of one 16-bit register. Additionally, remove the probe for the high 4 bits of IER being 0 and don't assume we can always read/write 0 to/from those bits. These changes allow uart(4) to drive the UARTs on the Intel XScale PXA255. Reviewed by: marcel
* Use 115200 and not 9600 as the initial baudrate. This speeds upmarcel2006-04-271-1/+1
| | | | detection of the FIFO size. Especially for large FIFOs.
* MFp4: Calculate the divisor before setting the DLAB bit. Thismarcel2006-04-231-2/+2
| | | | | prevents that there's a control flow that leaves the DLAB bit set.
* Eliminate the sc_hasfifo flag from the softc. It was only used bymarcel2006-04-021-3/+3
| | | | | | | the NS8250 class driver. The UART has FIFOs if sc_rxfifosz>1, so test for that instead. While here properly initialize sc_rxfifosz and sc_txfifosz in the case the UART doesn't have FIFOs.
* Don't hold the hardware mutex across getc(). It can wait indefinitelymarcel2006-04-011-5/+15
| | | | | for a character to be received. Instead let getc() do any necesary locking.
* Add support for scc(4).marcel2006-03-301-18/+18
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* Replace our local UART_SIGMASK_* with the global SER_MASK_*.marcel2006-02-241-1/+1
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* MFp4:marcel2006-02-241-5/+5
| | | | | Stop using our local UART_IPEND_* and instead use the global SER_INT_* as defined in <sys/serial.h>.
* Start each of the license/copyright comments with /*-, minor shuffle of linesimp2005-01-061-1/+1
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* Include the common <dev/ic/ns16550.h> instead of the privatemarcel2004-11-201-1/+2
| | | | <dev/uart_dev_ns8250.h>. The latter can be removed now.
* Be slightly more paranoid about using the divisor in a division andmarcel2004-11-151-2/+6
| | | | the calculated baudrate. Neither should be 0.
* Implement UART_IOCTL_BAUD. Consequently, when the baudrate was unsetmarcel2004-11-141-1/+11
| | | | for the console, we emit the actual baudrate during bus enumeration.
* Do not use hardware flow control for the moment. There are some issuesmarcel2004-08-061-0/+8
| | | | | | | with it that need to be understood better before they can be resolved. This takes time and time is already in short supply. Reported & tested by: glebius@
* When sizing the FIFO, don't count all the way up to 1030 if any FIFOmarcel2004-07-261-1/+1
| | | | | size larger than 128 is considered an incompatible size. Stop counting when we reach 130 in the loop.
* Use the new serial port definitions for modemsignals.phk2004-06-241-14/+14
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* It seems that clearing the MCR_IE bit in the modem control registertmm2004-05-261-22/+23
| | | | | | | | | | | | | | | | | does not reliably prevent the triggering of interrupts for all supported configurations. Thus, the FIFO size probe could cause an interrupt, which could lead to an interrupt storm in the shared interrupt case. To prevent this, change ns8250_bus_probe() to use the overflow bit in the line status register instead of the RX ready bit in the interrupt identification register to detect whether the FIFO has filled up. This allows us to clear all bits in the interrupt enable register during the probe, which should prevent interrupts reliably. Additionally, the detected FIFO size may be a bit more accurate, because the overflow bit is only set when the FIFO did actually fill up, while interrupts would trigger a bit early. Reviewed and tested on a lot of hardware by: marcel
* In ns8250_putc() insert a barrier between writing the character andmarcel2004-04-021-0/+1
| | | | checking for transmitter empty.
* In uart_intr() loop until all interrupts have been handled. Previouslymarcel2003-09-171-3/+12
| | | | | | | | | | | | | | an UART interface could get stuck when a new interrupt condition arose while servicing a previous interrupt. Since an interrupt was already pending, no new interrupt would be triggered. Avoid infinite recursion by flushing the Rx FIFO and marking an overrun condition when we could not move the data from the Rx FIFO to the receive buffer in toto. Failure to flush the Rx FIFO would leave the Rx ready condition pending. Note that the SAB 82532 already did this due to the nature of the chip.
* Add locking to the hardware drivers. I intended to figure out moremarcel2003-09-171-9/+33
| | | | | | | | | | precisely where locking would be needed before adding it, but it seems uart(4) draws slightly too much attention to have it without locking for too long. The lock added is a spinlock that protects access to the underlying hardware. As a first and obvious stab at this, each method of the hardware interface grabs the lock. Roughly speaking this serializes the methods. Exceptions are the probe, attach and detach methods.
* Add support for automatic hardware flow control for 16[679]50 UARTs.marcel2003-09-131-1/+37
| | | | | | We simply use the detected FIFO size to determine whether we have a post 16550 UART or not. The support lacks proper serialization of hardware access for now.
* If we failed to size the Rx FIFO, assume the worst. This howevermarcel2003-09-101-1/+1
| | | | | | | | is not a size of 1. Since we already know there is a FIFO, we can safely assume that it is at least 16 bytes. Note that all this is mostly academic anyway. We don't use the size of the Rx FIFO currently. If we add support for hardware flow control, we only care about Rx FIFO sizes larger than 16.
* The uart(4) driver is an universal driver for various UART hardware.marcel2003-09-061-0/+726
It improves on sio(4) in the following areas: o Fully newbusified to allow for memory mapped I/O. This is a must for ia64 and sparc64, o Machine dependent code to take full advantage of machine and firm- ware specific ways to define serial consoles and/or debug ports. o Hardware abstraction layer to allow the driver to be used with various UARTs, such as the well-known ns8250 family of UARTs, the Siemens sab82532 or the Zilog Z8530. This is especially important for pc98 and sparc64 where it's common to have different UARTs, o The notion of system devices to unkludge low-level consoles and remote gdb ports and provides the mechanics necessary to support the keyboard on sparc64 (which is UART based). o The notion of a kernel interface so that a UART can be tied to something other than the well-known TTY interface. This is needed on sparc64 to present the user with a device and ioctl handling suitable for a keyboard, but also allows us to cleanly hide an UART when used as a debug port. Following is a list of features and bugs/flaws specific to the ns8250 family of UARTs as compared to their support in sio(4): o The uart(4) driver determines the FIFO size and automaticly takes advantages of larger FIFOs and/or additional features. Note that since I don't have sufficient access to 16[679]5x UARTs, hardware flow control has not been enabled. This is almost trivial to do, provided one can test. The downside of this is that broken UARTs are more likely to not work correctly with uart(4). The need for tunables or knobs may be large enough to warrant their creation. o The uart(4) driver does not share the same bumpy history as sio(4) and will therefore not provide the necessary hooks, tweaks, quirks or work-arounds to deal with once common hardware. To that extend, uart(4) supports a subset of the UARTs that sio(4) supports. The question before us is whether the subset is sufficient for current hardware. o There is no support for multiport UARTs in uart(4). The decision behind this is that uart(4) deals with one EIA RS232-C interface. Packaging of multiple interfaces in a single chip or on a single expansion board is beyond the scope of uart(4) and is now mostly left for puc(4) to deal with. Lack of hardware made it impossible to actually implement such a dependency other than is present for the dual channel SAB82532 and Z8350 SCCs. The current list of missing features is: o No configuration capabilities. A set of tunables and sysctls is being worked out. There are likely not going to be any or much compile-time knobs. Such configuration does not fit well with current hardware. o No support for the PPS API. This is partly dependent on the ability to configure uart(4) and partly dependent on having sufficient information to implement it properly. As usual, the manpage is present but lacks the attention the software has gotten.
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