aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial/serial-tegra.c (follow)
AgeCommit message (Collapse)AuthorFilesLines
2019-11-13tty: serial: tegra: Use dma_request_chan() directly for channel requestPeter Ujfalusi1-2/+1
dma_request_slave_channel_reason() is: #define dma_request_slave_channel_reason(dev, name) \ dma_request_chan(dev, name) Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Link: https://lore.kernel.org/r/20191113094618.1725-4-peter.ujfalusi@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: Add PIO mode supportKrishna Yarlagadda1-31/+86
Add PIO mode support in receive and transmit path with RX interrupt trigger of 16 bytes for Tegra194 and older chips. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-13-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: report clk rate errorsKrishna Yarlagadda1-2/+57
Standard UART controllers support +/-4% baud rate error tolerance. Tegra186 only supports 0% to +4% error tolerance whereas other Tegra chips support standard +/-4% rate. Add chip data for knowing error tolerance level for each soc. Creating new compatible for Tegra194 chip as it supports baud rate error tolerance of -2 to +2%, different from older chips. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-12-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: add support to adjust baud rateKrishna Yarlagadda1-0/+68
Add support to adjust baud rates to fall under supported tolerance range through DT. Tegra186 chip has a hardware issue resulting in frame errors when tolerance level for baud rate is negative. Provided entries to adjust baud rate to be within acceptable range and work with devices that can send negative baud rate. Also report error when baud rate set is out of tolerance range of controller updated in device tree. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-11-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: add support to use 8 bytes triggerKrishna Yarlagadda1-2/+11
Add support to use 8 bytes trigger for Tegra186 SOC. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-9-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: set maximum num of uart ports to 8Krishna Yarlagadda1-2/+17
Set maximum number of UART ports to 8 as older chips have 5 ports and Tergra186 and later chips will have 8 ports. Add this info to chip data. Read device tree compatible of this driver and register uart driver with max ports of matching chip data. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-8-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: check for FIFO mode enabled statusKrishna Yarlagadda1-6/+46
Chips prior to Tegra186 needed delay of 3 UART clock cycles to avoid data loss. This issue is fixed in Tegra186 and a new flag is added to check if FIFO mode is enabled. chip data updated to check if this flag is available for a chip. Tegra186 has new compatible to enable this flag. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-7-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: report error to upper tty layerKrishna Yarlagadda1-3/+16
Report overrun/parity/frame/break errors to top tty layer. Add support to ignore break character if IGNBRK is set. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-5-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: flush the RX fifo on frame errorShardar Shariff Md1-0/+14
FIFO reset/flush code implemented now does not follow programming guidelines. RTS line has to be turned off while flushing FIFOs to avoid new transfers. Also check LSR bits UART_LSR_TEMT and UART_LSR_DR to confirm FIFOs are flushed. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-4-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: avoid reg access when clk disabledAhung Cheng1-6/+11
This avoids two race conditions from the UART shutdown sequence both leading to 'Machine check error in AXI2APB' and kernel oops. One was that the clock was disabled before the DMA was terminated making it possible for the DMA callbacks to be called after the clock was disabled. These callbacks could write to the UART registers causing timeout. The second was that the clock was disabled before the UART was completely flagged as closed. This is done after the shutdown is called and a new write could be started after the clock was disabled. tegra_uart_start_pio_tx could be called causing timeout. Given that the baud rate is reset at the end of shutdown sequence, this fix is to examine the baud rate to avoid register access from both race conditions. Besides, terminate the DMA before disabling the clock. Signed-off-by: Ahung Cheng <ahcheng@nvidia.com> Signed-off-by: Shardar Mohammed <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-3-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-05serial: tegra: add support to ignore readShardar Shariff Md1-0/+12
Add support to ignore read characters if CREAD flag is not set. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Link: https://lore.kernel.org/r/1567572187-29820-2-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04serial: tegra: protect IER against LCR.DLABAhung Cheng1-0/+3
The IER and DLH registers occupy the same address space, selected by the LCR.DLAB bit. Hence, add port lock to protect IER when LCR.DLAB bit is set. Signed-off-by: Ahung Cheng <ahcheng@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/1565609303-27000-5-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04serial: tegra: add internal loopback functionalityAndreas Abel1-4/+22
Add the internal loopback functionality that can be enabled with TIOCM_LOOP. Signed-off-by: Andreas Abel <aabel@nvidia.com> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/1565609303-27000-2-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: Remove dev_err() usage after platform_get_irq()Stephen Boyd1-3/+1
We don't need dev_err() messages when platform_get_irq() fails now that platform_get_irq() prints an error message itself when something goes wrong. Let's remove these prints with a simple semantic patch. // <smpl> @@ expression ret; struct platform_device *E; @@ ret = ( platform_get_irq(E, ...) | platform_get_irq_byname(E, ...) ); if ( \( ret < 0 \| ret <= 0 \) ) { ( -if (ret != -EPROBE_DEFER) -{ ... -dev_err(...); -... } | ... -dev_err(...); ) ... } // </smpl> While we're here, remove braces on if statements that only have one statement (manually). Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20190730181557.90391-45-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09serial: tegra: fix some spelling mistakesMarcel Ziswiler1-5/+5
Fix a few spelling mistakes I stumbled upon while debugging a customers UART issues. Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08tty: serial: Remove redundant license textGreg Kroah-Hartman1-12/+0
Now that the SPDX tag is in all tty files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Jiri Slaby <jslaby@suse.com> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman1-0/+1
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30serial: tegra: explicitly request exclusive reset controlPhilipp Zabel1-1/+1
Commit a53e35db70d1 ("reset: Ensure drivers are explicit when requesting reset lines") started to transition the reset control request API calls to explicitly state whether the driver needs exclusive or shared reset control behavior. Convert all drivers requesting exclusive resets to the explicit API call so the temporary transition helpers can be removed. No functional changes. Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: linux-serial@vger.kernel.org Cc: linux-tegra@vger.kernel.org Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-27tty: serial: constify uart_ops structuresBhumika Goyal1-1/+1
Declare uart_ops structures as const as they are only stored in the ops field of an uart_port structure. This field is of type const, so uart_ops structures having this property can be made const too. File size details before and after patching. First line of every .o file shows the file size before patching and second line shows the size after patching. text data bss dec hex filename 2977 456 64 3497 da9 drivers/tty/serial/amba-pl010.o 3169 272 64 3505 db1 drivers/tty/serial/amba-pl010.o 3109 456 0 3565 ded drivers/tty/serial/efm32-uart.o 3301 272 0 3573 df5 drivers/tty/serial/efm32-uart.o 10668 753 1 11422 2c9e drivers/tty/serial/icom.o 10860 561 1 11422 2c9e drivers/tty/serial/icom.o 23904 408 8 24320 5f00 drivers/tty/serial/ioc3_serial.o 24088 224 8 24320 5f00 drivers/tty/serial/ioc3_serial.o 10516 560 4 11080 2b48 drivers/tty/serial/ioc4_serial.o 10709 368 4 11081 2b49 drivers/tty/serial/ioc4_serial.o 7853 648 1216 9717 25f5 drivers/tty/serial/mpsc.o 8037 456 1216 9709 25ed drivers/tty/serial/mpsc.o 10248 456 0 10704 29d0 drivers/tty/serial/omap-serial.o 10440 272 0 10712 29d8 drivers/tty/serial/omap-serial.o 8122 532 1984 10638 298e drivers/tty/serial/pmac_zilog.o 8306 340 1984 10630 2986 drivers/tty/serial/pmac_zilog.o 3808 456 0 4264 10a8 drivers/tty/serial/pxa.o 4000 264 0 4264 10a8 drivers/tty/serial/pxa.o 21781 3864 0 25645 642d drivers/tty/serial/serial-tegra.o 22037 3608 0 25645 642d drivers/tty/serial/serial-tegra.o 2481 456 96 3033 bd9 drivers/tty/serial/sprd_serial.o 2673 272 96 3041 be1 drivers/tty/serial/sprd_serial.o 5534 300 512 6346 18ca drivers/tty/serial/vr41xx_siu.o 5630 204 512 6346 18ca drivers/tty/serial/vr41xx_siu.o 6730 1576 128 8434 20f2 drivers/tty/serial/vt8500_serial.o 6986 1320 128 8434 20f2 drivers/tty/serial/vt8500_serial.o Cross compiled for mips architecture. 3005 488 0 3493 da5 drivers/tty/serial/pnx8xxx_uart.o 3189 304 0 3493 da5 drivers/tty/serial/pnx8xxx_uart.o 4272 196 1056 5524 1594 drivers/tty/serial/dz.o 4368 100 1056 5524 1594 drivers/tty/serial/dz.o 6551 144 16 6711 1a37 drivers/tty/serial/ip22zilog.o 6647 48 16 6711 1a37 drivers/tty/serial/ip22zilog.o 9612 428 1520 11560 2d28 drivers/tty/serial/serial_txx9.o 9708 332 1520 11560 2d28 drivers/tty/serial/serial_txx9.o 4156 296 16 4468 1174 drivers/tty/serial/ar933x_uart.o 4252 200 16 4468 1174 drivers/tty/serial/ar933x_uart.o Cross compiled for arm archiecture. 11716 1780 44 13540 34e4 drivers/tty/serial/sirfsoc_uart.o 11808 1688 44 13540 34e4 drivers/tty/serial/sirfsoc_uart.o 13352 596 56 14004 36b4 drivers/tty/serial/amba-pl011.o 13444 504 56 14004 36b4 drivers/tty/serial/amba-pl011.o Cross compiled for sparc architecture. 4664 528 32 5224 1468 drivers/tty/serial/sunhv.o 4848 344 32 5224 1468 drivers/tty/serial/sunhv.o 8080 332 28 8440 20f8 drivers/tty/serial/sunzilog.o 8184 228 28 8440 20f8 drivers/tty/serial/sunzilog.o Cross compiled for ia64 architecture. 10226 549 472 11247 2bef drivers/tty/serial/sn_console.o 10414 365 472 11251 2bf3 drivers/tty/serial/sn_console.o The files drivers/tty/serial/zs.o, drivers/tty/serial/lpc32xx_hs.o and drivers/tty/serial/lantiq.o did not compile. Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25TTY: serial, handle platform_get_irq retval properlyJiri Slaby1-1/+6
platform_get_irq can fail, so we should handle negative value when returned. [v2] platform_get_irq can actually return zero on some platforms. So do not remove checks for irq == 0 there. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-tegra@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30serial: tegra: Remove unused variableThierry Reding1-2/+0
The local mcr variable is never used in the tegra_uart_set_mctrl() function, so it should be removed. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17serial: tegra: Add helper function for handling RX bufferJon Hunter1-42/+24
In the tegra UART driver there are three places where the RX DMA buffer is handled and pushed up to the tty layer. In all three instances the same functions are called and so instead of duplicating the code in three places, move this code to a new helper function and use this new function. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17serial: tegra: Remove redundant code and check in tegra_uart_stop_rx()Jon Hunter1-10/+7
The serial-tegra driver always uses DMA and hence the driver always allocates DMA channels. Therefore, the test to see if the RX DMA channel is initialised in tegra_uart_stop_rx() is unnecessary and so remove the test and the code that corresponds to the case where the RX DMA channel is not initialised. Please note that the call to tegra_uart_stop_rx() should always be before the call to tegra_uart_shutdown() which will uninitialise the RX DMA channel. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17serial: tegra: Remove unnecessary return statementsJon Hunter1-11/+0
Some functions in the serial-tegra driver have unnecessary return statements at the end of a void function and so remove them. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17serial: tegra: Handle another RX race conditionJon Hunter1-8/+2
Commit 853a699739fe ("serial: tegra: handle race condition on uart rx side") attempted to fix a race condition between the RX end of transmission interrupt and RX DMA completion callback. Despite this fix there is still another case where these two paths can race and result in duplicated data. The race condition is as follows: 1. DMA completion interrupt occurs and schedules tasklet to call DMA callback. 2. DMA callback for the UART driver starts to execute. This will copy the data from the DMA buffer and restart the DMA. This is done under uart port spinlock. 3. During the callback, UART interrupt is raised for end of receive. The UART ISR runs and waits to acquire port spinlock held by the DMA callback. 4. DMA callback gives up spinlock after copying the data, but before restarting DMA. 5. UART ISR acquires the spin lock and reads the same DMA buffer because DMA has not been restarted yet. The release of the spinlock during the DMA callback was introduced by commit 9b88748b362c ("tty: serial: tegra: drop uart_port->lock before calling tty_flip_buffer_push()") to fix a spinlock lock-up issue when calling tty_flip_buffer_push(). However, since then commit a9c3f68f3cd8 ("tty: Fix low_latency BUG") migrated tty_flip_buffer_push() to always use a workqueue, allowing tty_flip_buffer_push() to be called from within atomic sections. Therefore, we can remove the unlocking of the spinlock from the DMA callback and UART ISR and this will ensure that the race condition no longer occurs. Reported-by: Christopher Freeman <cfreeman@nvidia.com> Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24serial: tegra: Fix memory leak on DMA setup failureJon Hunter1-21/+11
If the call to dmaengine_slave_config() fails, then the DMA buffer will not be freed/unmapped. Fix this by moving the code that stores the address of the buffer in the tegra_uart_port structure to before the call to dmaengine_slave_config(). Reported-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10serial: tegra: Correct error handling on DMA setupJon Hunter1-23/+28
Function tegra_uart_dma_channel_allocate() does not check that dma_map_single() mapped the DMA buffer correctly. Add a check for this and appropriate error handling. Furthermore, if dmaengine_slave_config() (called by tegra_uart_dma_channel_allocate()) fails, then memory allocated/mapped is not freed/unmapped. Therefore, call tegra_uart_dma_channel_free() instead of just dma_release_channel() if dmaengine_slave_config() fails. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10serial: tegra: Correct shutdown of UARTsJon Hunter1-7/+4
There are two issues in the shutdown path of the UARTs which are: 1. The function tegra_uart_shutdown() calls tegra_uart_flush_buffer() to stop DMA TX transfers. However, tegra_uart_flush_buffer() is called after the DMA channels have already been freed and so actually does nothing. 2. The function that frees the DMA channels (tegra_uart_dma_channel_free()), unmaps the dma buffer before freeing the DMA channel and does not ensure the DMA has been stopped. Resolve this by fixing the code in tegra_uart_dma_channel_free() to ensure the DMA is stopped, free the DMA channel and then unmap the DMA buffer. Finally, remove the unnecessary call to tegra_uart_flush_buffer(). Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10serial: tegra: Fix cookie used by TX channelJon Hunter1-1/+1
The DMA cookie for the RX channel is being used by the TX channel. Therefore, fix driver to use the correct DMA cookie for the TX channel. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10serial: tegra: Use unsigned types for RX and TX byte countsJon Hunter1-7/+8
The function tty_insert_flip_string() takes an argument "size" which is of type size_t. This is an unsigned type. Update the count, rx_bytes_requested and tx_bytes_requested in the tegra serial driver to be unsigned integers so that an unsigned type is passed to tty_insert_flip_string(). Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10serial: tegra: handle race condition on uart rx sideShardar Shariff Md1-1/+12
The tegra serial driver has two paths through which receive data is copied up to the tty layer. These are: 1. DMA completion callback 2. UART RX interrupt A UART RX interrupt occurs for either RX_TIMEOUT (data has been sitting in the Rx FIFO for more than 4 character times without being read because there is not enough data to reach the trigger level), End of Receive Data event (receiver detects that data stops coming in for more than 4 character times) or a receive error. In the RX interrupt path, the following happens ... - All RX DMA transfers are stopped - Any data in the DMA buffer and RX FIFO are copied up to the tty layer. - DMA is restarted/primed for the RX path In the DMA completion callback, the DMA buffer is copied up to the tty layer but there is no check to see if the RX interrupt could have occurred between the DMA interrupt firing the the DMA callback running. Hence, if a RX interrupt was to occur shortly after the DMA completion interrupt, it is possible that the RX interrupt path has already copied the DMA buffer before the DMA callback has been called. Therefore, when the DMA callback is called, if the DMA is already in-progress, then this indicates that the UART RX interrupt has already occurred and there is nothing to do in the DMA callback. This race condition can cause duplicated data to be received. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> [jonathanh@nvidia.com: Moved async_tx_ack() call to after check to see if DMA has completed because if the DMA is in progress we do not need to ACK yet. Changed the print from dev_info to dev_debug. Updated changelog to add more commentary on the race condition based upon feedback from author.] Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10serial: tegra: check the count and read if any from dmaShardar Shariff Md1-4/+6
It is only necessary to read data from the dma buffer when the count value is non-zero and hence, tegra_uart_copy_rx_to_tty() so only be called when this is the case. Although, this was being tested for in two places, there is a third place where this was not tested. However, instead of adding another if-statement prior to calling tegra_uart_copy_rx_to_tty(), move the test inside the function. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> [jonathanh@nvidia.com: Re-worked patch to move the check for the count value inside the function tegra_uart_copy_rx_to_tty(). Updated changelog with more commentary.] Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10serial: tegra: Add delay after enabling FIFO modeJon Hunter1-0/+10
For all tegra devices (up to t210), there is a hardware issue that requires software to wait for 3 UART clock periods after enabling the TX fifo, otherwise data could be lost. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10serial: tegra: Correct delay after TX flushJon Hunter1-2/+22
For all tegra devices (up to t210), there is a hardware issue that requires software to wait for 32 UART clock periods for the flush to propagate otherwise TX data could be post. Add a helper function to wait for N UART clock periods and update delay following FIFO flush to be 32 UART clock cycles. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26tty: constify of_device_id arrayFabian Frederick1-1/+1
of_device_id is always used as const. (See driver.of_match_table and open firmware functions) Signed-off-by: Fabian Frederick <fabf@skynet.be> Acked-by: Peter Korsgaard <peter@korsgaard.com> Acked-by: Timur Tabi <timur@tabi.org> Acked-by: Patrice Chotard <patrice.chotard@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-25serial: tegra: clean up tty-flag assignmentsJohan Hovold1-3/+3
The tty break and error flags are not bit masks so do not to use bitwise OR when assigning them. Note that there is no functional change due to the if-else construct and flag having been initialised to zero (TTY_NORMAL). Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05serial: Refactor uart_flush_buffer() from uart_close()Peter Hurley1-14/+16
In the context of the final tty & port close, flushing the tx ring buffer after the hardware has already been shutdown and the ring buffer freed is neither required nor desirable. uart_flush_buffer() performs 3 operations: 1. Resets tx ring buffer indices, but the tx ring buffer has already been freed and the indices are reset if the port is re-opened. 2. Calls uart driver's flush_buffer() method 5 in-tree uart drivers define flush_buffer() methods: amba-pl011, atmel-serial, imx, serial-tegra, timbuart These have been refactored into the shutdown() method, if required. 3. Kicks the ldisc for more writing, but this is undesirable. The file handle is being released; any waiting writer will will be kicked out by tty_release() with a warning. Further, the N_TTY ldisc may generate SIGIO for a file handle which is no longer valid. Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10serial: tegra: ack the rx dma desc after transfer terminatedPradeep Goudagunta1-0/+1
The Rx dma descriptor allocated without the DMA_ACK flags so that once after tarnsfer done or terminated, client can ack the descriptor to free it for later use. If the Rx DMA is terminated for some reason then rx-dma descriptor is not getting acked which causes the memory leak and list of usage desc to grow continuously. Hence, acknowledge the rx-dma descriptor once transfer is terminated to avoid memory leak and desc list to grow. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10serial: tegra: update tx_circular buffer only when TX_DMA is in progressPradeep Goudagunta1-0/+3
When channel is require to stop transmit then update the Tx circular buffer only when DMA based transfer is in progress. If there is no DMA based transfer then no need to update the Tx buffer. Signed-off-by: Pradeep Goudagunta <pgoudagunta@nvidia.com> Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11serial: tegra: convert to standard DMA DT bindingsStephen Warren1-18/+6
By using dma_request_slave_channel_or_err(), the DMA slave ID can be looked up from standard DT properties, and squirrelled away during channel allocation. Hence, there's no need to use a custom DT property to store the slave ID. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Thierry Reding <treding@nvidia.com>
2013-12-11serial: tegra: use reset frameworkStephen Warren1-4/+10
Tegra's clock driver now provides an implementation of the common reset API (include/linux/reset.h). Use this instead of the old Tegra- specific API; that will soon be removed. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thierry Reding <treding@nvidia.com>
2013-10-07serial: tegra: remove deprecated IRQF_DISABLEDMichael Opdenacker1-1/+1
This patch proposes to remove the use of the IRQF_DISABLED flag It's a NOOP since 2.6.35 and it will be removed one day. Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-17serial: tegra: fix tty-kref leakJohan Hovold1-1/+3
Fix potential tty-kref leak in stop_rx path. Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold <jhovold@gmail.com> Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-27tty: serial: tegra: drop uart_port->lock before calling tty_flip_buffer_push()Viresh Kumar1-2/+8
The current driver triggers a lockdep warning for if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels and comes up only on SMP kernels. Crash looks like this (produced with samsung.c driver): ----- [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0) [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0) [<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+) [<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x) [<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c) [<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30) [<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94) [<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68) [<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70) Exception stack(0xc04cdf70 to 0xc04cdfb8) df60: 00000000 00000000 0000166e 00000000 df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000 dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff [<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30) [<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148) [<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c) BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2 Workqueue: events flush_to_ldisc [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34) [<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738) [<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348) [<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c) [<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0) [<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c) ----- Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call. Similar stuff was already done for few other drivers in the past, like: commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner <tglx@linutronix.de> Date: Tue May 29 21:53:50 2007 +0100 [ARM] 4417/1: Serial: Fix AMBA drivers locking Cc: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12serial: tegra: use NULL instead of 0Jingoo Han1-3/+3
'cons' is a pointer; thus NULL should be used instead of 0. Also, local symbols are staticized. Fix the following sparse warnings: drivers/tty/serial/serial-tegra.c:1209:27: warning: Using plain integer as NULL pointer drivers/tty/serial/serial-tegra.c:1240:29: warning: symbol 'tegra20_uart_chip_data' was not declared. Should it be static? drivers/tty/serial/serial-tegra.c:1246:29: warning: symbol 'tegra30_uart_chip_data' was not declared. Should it be static? Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-28treewide: Fix typo in printkMasanari Iida1-1/+1
Correct spelling typo in various part of drivers Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-03-15serial: tegra: Convert to devm_ioremap_resource()Sachin Kamat1-5/+4
Use the newly introduced devm_ioremap_resource() instead of devm_request_and_ioremap() which provides more consistent error handling. devm_ioremap_resource() provides its own error messages; so all explicit error messages can be removed from the failure code paths. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de> Cc: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-15serial: tegra: assume CONFIG_OFStephen Warren1-3/+2
Tegra only supports, and always enables, device tree. Remove all ifdefs for DT support from the driver. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-25serial: tegra: Fix compilation errorVenu Byravarasu1-1/+1
Fix compilation error, by adding the correct header file for Tegra clocks. Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com> Reviewed-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17serial: tegra: Switch to using struct tty_portThierry Reding1-12/+15
Many of the tty functions were converted to use a struct tty_port instead of a struct tty_struct. Update the Tegra driver accordingly to avoid build breakage. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.