summaryrefslogtreecommitdiff
path: root/drivers/tty/serial/sh-sci.c
AgeCommit message (Collapse)AuthorFilesLines
2020-05-02serial: sh-sci: Make sure status register SCxSR is read in correct sequenceKazuhiro Fujita1-3/+10
commit 3dc4db3662366306e54ddcbda4804acb1258e4ba upstream. For SCIF and HSCIF interfaces the SCxSR register holds the status of data that is to be read next from SCxRDR register, But where as for SCIFA and SCIFB interfaces SCxSR register holds status of data that is previously read from SCxRDR register. This patch makes sure the status register is read depending on the port types so that errors are caught accordingly. Cc: <stable@vger.kernel.org> Signed-off-by: Kazuhiro Fujita <kazuhiro.fujita.jg@renesas.com> Signed-off-by: Hao Bui <hao.bui.yg@renesas.com> Signed-off-by: KAZUMI HARADA <kazumi.harada.rh@renesas.com> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/1585333048-31828-1-git-send-email-kazuhiro.fujita.jg@renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-31serial: sh-sci: Fix TX DMA buffer flushing and workqueue racesGeert Uytterhoeven1-7/+15
[ Upstream commit 8493eab02608b0e82f67b892aa72882e510c31d0 ] When uart_flush_buffer() is called, the .flush_buffer() callback zeroes the tx_dma_len field. This may race with the work queue function handling transmit DMA requests: 1. If the buffer is flushed before the first DMA API call, dmaengine_prep_slave_single() may be called with a zero length, causing the DMA request to never complete, leading to messages like: rcar-dmac e7300000.dma-controller: Channel Address Error happen and, with debug enabled: sh-sci e6e88000.serial: sci_dma_tx_work_fn: ffff800639b55000: 0...0, cookie 126 and DMA timeouts. 2. If the buffer is flushed after the first DMA API call, but before the second, dma_sync_single_for_device() may be called with a zero length, causing the transmit data not to be flushed to RAM, and leading to stale data being output. Fix this by: 1. Letting sci_dma_tx_work_fn() return immediately if the transmit buffer is empty, 2. Extending the critical section to cover all DMA preparational work, so tx_dma_len stays consistent for all of it, 3. Using local copies of circ_buf.head and circ_buf.tail, to make sure they match the actual operation above. Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com> Suggested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Link: https://lore.kernel.org/r/20190624123540.20629-2-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31serial: sh-sci: Terminate TX DMA during buffer flushingGeert Uytterhoeven1-2/+9
[ Upstream commit 775b7ffd7d6d5db320d99b0a485c51e04dfcf9f1 ] While the .flush_buffer() callback clears sci_port.tx_dma_len since commit 1cf4a7efdc71cab8 ("serial: sh-sci: Fix race condition causing garbage during shutdown"), it does not terminate a transmit DMA operation that may be in progress. Fix this by terminating any pending DMA operations, and resetting the corresponding cookie. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Link: https://lore.kernel.org/r/20190624123540.20629-3-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-09serial: sh-sci: disable DMA for uart_consoleGeorge G. Davis1-0/+7
commit 099506cbbc79c0bd52b19cb6b930f256dabc3950 upstream. As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for console UART"), UART console lines use low-level PIO only access functions which will conflict with use of the line when DMA is enabled, e.g. when the console line is also used for systemd messages. So disable DMA support for UART console lines. Reported-by: Michael Rodin <mrodin@de.adit-jv.com> Link: https://patchwork.kernel.org/patch/10929511/ Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable@vger.kernel.org Signed-off-by: George G. Davis <george_davis@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03serial: sh-sci: Fix setting SCSCR_TIE while transferring dataHoan Nguyen An1-11/+1
commit 93bcefd4c6bad4c69dbc4edcd3fbf774b24d930d upstream. We disable transmission interrupt (clear SCSCR_TIE) after all data has been transmitted (if uart_circ_empty(xmit)). While transmitting, if the data is still in the tty buffer, re-enable the SCSCR_TIE bit, which was done at sci_start_tx(). This is unnecessary processing, wasting CPU operation if the data transmission length is large. And further, transmit end, FIFO empty bits disabling have also been performed in the step above. Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-04serial: sh-sci: Stop RX FIFO timer during port shutdownGeert Uytterhoeven1-0/+2
[ Upstream commit c5a9262fa8bfed0dddc7466ef10fcd292e2af61b ] The RX FIFO timer may be armed when the port is shut down, hence the timer function may still be called afterwards. Fix this race condition by deleting the timer during port shutdown. Fixes: 039403765e5da3c6 ("serial: sh-sci: SCIFA/B RX FIFO software timeout") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-03serial: sh-sci: Use spin_{try}lock_irqsave instead of open coding versionDaniel Wagner1-5/+3
commit 8afb1d2c12163f77777f84616a8e9444d0050ebe upstream. Commit 40f70c03e33a ("serial: sh-sci: add locking to console write function to avoid SMP lockup") copied the strategy to avoid locking problems in conjuncture with the console from the UART8250 driver. Instead using directly spin_{try}lock_irqsave(), local_irq_save() followed by spin_{try}lock() was used. While this is correct on mainline, for -rt it is a problem. spin_{try}lock() will check if it is running in a valid context. Since the local_irq_save() has already been executed, the context has changed and spin_{try}lock() will complain. The reason why spin_{try}lock() complains is that on -rt the spin locks are turned into mutexes and therefore can sleep. Sleeping with interrupts disabled is not valid. BUG: sleeping function called from invalid context at /home/wagi/work/rt/v4.4-cip-rt/kernel/locking/rtmutex.c:995 in_atomic(): 0, irqs_disabled(): 128, pid: 778, name: irq/76-eth0 CPU: 0 PID: 778 Comm: irq/76-eth0 Not tainted 4.4.126-test-cip22-rt14-00403-gcd03665c8318 #12 Hardware name: Generic RZ/G1 (Flattened Device Tree) Backtrace: [<c00140a0>] (dump_backtrace) from [<c001424c>] (show_stack+0x18/0x1c) r7:c06b01f0 r6:60010193 r5:00000000 r4:c06b01f0 [<c0014234>] (show_stack) from [<c01d3c94>] (dump_stack+0x78/0x94) [<c01d3c1c>] (dump_stack) from [<c004c134>] (___might_sleep+0x134/0x194) r7:60010113 r6:c06d3559 r5:00000000 r4:ffffe000 [<c004c000>] (___might_sleep) from [<c04ded60>] (rt_spin_lock+0x20/0x74) r5:c06f4d60 r4:c06f4d60 [<c04ded40>] (rt_spin_lock) from [<c02577e4>] (serial_console_write+0x100/0x118) r5:c06f4d60 r4:c06f4d60 [<c02576e4>] (serial_console_write) from [<c0061060>] (call_console_drivers.constprop.15+0x10c/0x124) r10:c06d2894 r9:c04e18b0 r8:00000028 r7:00000000 r6:c06d3559 r5:c06d2798 r4:c06b9914 r3:c02576e4 [<c0060f54>] (call_console_drivers.constprop.15) from [<c0062984>] (console_unlock+0x32c/0x430) r10:c06d30d8 r9:00000028 r8:c06dd518 r7:00000005 r6:00000000 r5:c06d2798 r4:c06d2798 r3:00000028 [<c0062658>] (console_unlock) from [<c0062e1c>] (vprintk_emit+0x394/0x4f0) r10:c06d2798 r9:c06d30ee r8:00000006 r7:00000005 r6:c06a78fc r5:00000027 r4:00000003 [<c0062a88>] (vprintk_emit) from [<c0062fa0>] (vprintk+0x28/0x30) r10:c060bd46 r9:00001000 r8:c06b9a90 r7:c06b9a90 r6:c06b994c r5:c06b9a3c r4:c0062fa8 [<c0062f78>] (vprintk) from [<c0062fb8>] (vprintk_default+0x10/0x14) [<c0062fa8>] (vprintk_default) from [<c009cd30>] (printk+0x78/0x84) [<c009ccbc>] (printk) from [<c025afdc>] (credit_entropy_bits+0x17c/0x2cc) r3:00000001 r2:decade60 r1:c061a5ee r0:c061a523 r4:00000006 [<c025ae60>] (credit_entropy_bits) from [<c025bf74>] (add_interrupt_randomness+0x160/0x178) r10:466e7196 r9:1f536000 r8:fffeef74 r7:00000000 r6:c06b9a60 r5:c06b9a3c r4:dfbcf680 [<c025be14>] (add_interrupt_randomness) from [<c006536c>] (irq_thread+0x1e8/0x248) r10:c006537c r9:c06cdf21 r8:c0064fcc r7:df791c24 r6:df791c00 r5:ffffe000 r4:df525180 [<c0065184>] (irq_thread) from [<c003fba4>] (kthread+0x108/0x11c) r10:00000000 r9:00000000 r8:c0065184 r7:df791c00 r6:00000000 r5:df791d00 r4:decac000 [<c003fa9c>] (kthread) from [<c00101b8>] (ret_from_fork+0x14/0x3c) r8:00000000 r7:00000000 r6:00000000 r5:c003fa9c r4:df791d00 Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Daniel Wagner <daniel.wagner@siemens.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-16serial: sh-sci: Stop using printk format %pCrGeert Uytterhoeven1-2/+2
commit d63c16f8e1ab761775275adcf54f4bef7c330295 upstream. Printk format "%pCr" will be removed soon, as clk_get_rate() must not be called in atomic context. Replace it by open-coding the operation. This is safe here, as the code runs in task context. Link: http://lkml.kernel.org/r/1527845302-12159-4-git-send-email-geert+renesas@glider.be To: Jia-Ju Bai <baijiaju1990@gmail.com> To: Jonathan Corbet <corbet@lwn.net> To: Michael Turquette <mturquette@baylibre.com> To: Stephen Boyd <sboyd@kernel.org> To: Zhang Rui <rui.zhang@intel.com> To: Eduardo Valentin <edubezval@gmail.com> To: Eric Anholt <eric@anholt.net> To: Stefan Wahren <stefan.wahren@i2se.com> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-doc@vger.kernel.org Cc: linux-clk@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-serial@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-renesas-soc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable@vger.kernel.org # 4.5+ Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-25serial: sh-sci: Fix out-of-bounds access through DT aliasGeert Uytterhoeven1-0/+4
[ Upstream commit 090fa4b0dccfa3d04e1c5ab0fe4eba16e6713895 ] The sci_ports[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Note that the array size is defined by a Kconfig symbol (CONFIG_SERIAL_SH_SCI_NR_UARTS), so this can even be triggered using a legitimate DTB. Fixes: 97ed9790c514066b ("serial: sh-sci: Remove unused platform data capabilities field") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-19serial: sh-sci: prevent lockup on full TTY buffersUlrich Hecht1-0/+2
commit 7842055bfce4bf0170d0f61df8b2add8399697be upstream. When the TTY buffers fill up to the configured maximum, a system lockup occurs: [ 598.820128] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 598.825796] 0-...!: (1 GPs behind) idle=5a6/2/0 softirq=1974/1974 fqs=1 [ 598.832577] (detected by 3, t=62517 jiffies, g=296, c=295, q=126) [ 598.838755] Task dump for CPU 0: [ 598.841977] swapper/0 R running task 0 0 0 0x00000022 [ 598.849023] Call trace: [ 598.851476] __switch_to+0x98/0xb0 [ 598.854870] (null) This can be prevented by doing a dummy read of the RX data register. This issue affects both HSCIF and SCIF ports. Reported for R-Car H3 ES2.0; reproduced and fixed on H3 ES1.1. Probably affects other R-Car platforms as well. Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable <stable@vger.kernel.org> Tested-by: Nguyen Viet Dung <dung.nguyen.aj@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-10serial: sh-sci: suppress warning for ports without dma channelsAndy Lowe1-0/+8
[ Upstream commit 7464779fa8551b90d5797d4020b0bdb7e6422eb9 ] If a port has no dma channel defined in the device tree, then don't attempt to allocate a dma channel for the port. Also suppress the warning message concerning the failure to allocate a dma channel. Continue to emit the warning message if a dma channel is defined but cannot be allocated. Signed-off-by: Andy Lowe <andy_lowe@mentor.com> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: sh-sci: use of_property_read_bool()Sergei Shtylyov1-2/+1
Use more compact of_property_read_bool() call for a boolean property instead of of_find_property() call in sci_parse_dt(). Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-17serial: sh-sci: Uninitialized variables in sysfs filesDan Carpenter1-4/+8
The kstrtol() function returns -ERANGE as well as -EINVAL so these tests are not enough. It's not a super serious bug, but my static checker correctly complains that the "r" variable might be used uninitialized. Fixes: 5d23188a473d ("serial: sh-sci: make RX FIFO parameters tunable via sysfs") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-24serial: sh-sci: Update warning message in sci_request_dma_chan()Geert Uytterhoeven1-2/+1
The commit below changed a function call from dma_request_slave_channel_compat() to dma_request_slave_channel(), but forgot to update the printed failure message. Fixes: 219fb0c1436e4893 ("serial: sh-sci: Remove the platform data dma slave rx/tx channel IDs") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18serial: sh-sci: Move uart_register_driver call to device probeSjoerd Simons1-11/+15
uart_register_driver call binds the driver to a specific device node through tty_register_driver call. This should typically happen during device probe call. In a multiplatform scenario, it is possible that multiple serial drivers are part of the kernel. Currently the driver registration fails if multiple serial drivers with overlapping major/minor numbers are included. Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18serial: sh-sci: Fix race condition causing garbage during shutdownGeert Uytterhoeven1-2/+14
If DMA is enabled and used, a burst of old data may be seen on the serial console during "poweroff" or "reboot". uart_flush_buffer() clears the circular buffer, but sci_port.tx_dma_len is not reset. This leads to a circular buffer overflow, dumping (UART_XMIT_SIZE - sci_port.tx_dma_len) bytes. To fix this, add a .flush_buffer() callback that resets sci_port.tx_dma_len. Inspired by commit 31ca2c63fdc0aee7 ("tty/serial: atmel: fix race condition (TX+DMA)"). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31serial: sh-sci: Fix (AUTO)RTS in sci_init_pins()Geert Uytterhoeven1-6/+19
If a UART has dedicated RTS/CTS pins, and hardware control flow is disabled (or AUTORTS is not yet effective), changing any serial port configuration deasserts RTS, as .set_termios() calls sci_init_pins(). To fix this, consider the current (AUTO)RTS state when (re)initializing the pins. Note that for SCIFA/SCIFB, AUTORTS needs explicit configuration of the RTS# pin function, while (H)SCIF handles this automatically. Fixes: d2b9775d795ec05f ("serial: sh-sci: Correct pin initialization on (H)SCIF") Fixes: e9d7a45a03991349 ("serial: sh-sci: Add pin initialization for SCIFA/SCIFB") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31serial: sh-sci: Fix late enablement of AUTORTSGeert Uytterhoeven1-0/+4
When changing hardware control flow for a UART with dedicated RTS/CTS pins, the new AUTORTS state is not immediately reflected in the hardware, but only when RTS is raised. However, the serial core does not call .set_mctrl() after .set_termios(), hence AUTORTS may only become effective when the port is closed, and reopened later. Note that this problem does not happen when manually using stty to change CRTSCTS, as AUTORTS will work fine on next open. To fix this, call .set_mctrl() from .set_termios() when dedicated RTS/CTS pins are present, to refresh the AUTORTS or RTS state. This is similar to what other drivers supporting AUTORTS do (e.g. omap-serial). Reported-by: Baumann, Christoph (C.) <cbaumann@visteon.com> Fixes: 33f50ffc253854cf ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31serial: sh-sci: Fix hang in sci_reset()Geert Uytterhoeven1-4/+0
When the .set_termios() callback resets the UART, it first waits (busy loops) until all characters in the transmit FIFO have been transmitted, to prevent a port configuration change from impacting these characters. However, if the UART has dedicated RTS/CTS hardware flow control enabled, these characters may have been stuck in the FIFO due to CTS not being asserted by the remote side. - When a new user opens the port, .set_termios() is called while transmission is still disabled, leading to an infinite loop: NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! - When an active user changes port configuration without waiting for the draining of the transmit FIFO, this may also block indefinitely, until CTS is asserted by the remote side. This has been observed with SCIFA (on r8a7740/armadillo), and SCIFB and HSCIF (on r8a7791/koelsch). To fix this, remove the code that waits for the draining of the transmit FIFO. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14serial: sh-sci: Fix panic when serial console and DMA are enabledTakatoshi Akiyama1-4/+6
This patch fixes an issue that kernel panic happens when DMA is enabled and we press enter key while the kernel booting on the serial console. * An interrupt may occur after sci_request_irq(). * DMA transfer area is initialized by setup_timer() in sci_request_dma() and used in interrupt. If an interrupt occurred between sci_request_irq() and setup_timer() in sci_request_dma(), DMA transfer area has not been initialized yet. So, this patch changes the order of sci_request_irq() and sci_request_dma(). Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.") Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com> [Shimoda changes the commit log] Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10serial: sh-sci: fix hardware RX trigger level settingUlrich Hecht1-2/+9
1. Do not set the RX trigger level for software timeout devices on reset; there is no timeout by default, and data will rot. 2. Do set the RX trigger level for hardware timeout devices when set via sysfs attribute. Fixes SCIFA-type serial consoles. Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-06serial: sh-sci: make RX FIFO parameters tunable via sysfsUlrich Hecht1-0/+87
Allows tuning of the RX FIFO fill threshold and timeout. (The latter is only applicable to SCIFA and SCIFB). Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-06serial: sh-sci: SCIFA/B RX FIFO software timeoutUlrich Hecht1-33/+68
Implements support for FIFO fill thresholds greater than one with software timeout. This mechanism is not possible (or at least not useful) on SCIF family hardware other than SCIFA and SCIFB because they do not support turning off the DR hardware timeout interrupt separately from the RI interrupt. Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-06serial: sh-sci: increase RX FIFO trigger defaults for (H)SCIFUlrich Hecht1-1/+28
Sets reasonable trigger defaults for the various SCIF variants. Also corrects the FIFO size for SH7705-style ports. Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-03serial: sh-sci: implement FIFO threshold register settingUlrich Hecht1-0/+59
Sets the closest match for a desired RX trigger level. Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-03serial: sh-sci: add FIFO trigger bitsUlrich Hecht1-0/+2
Defines the bits controlling FIFO thresholds, adds the additional HSCIF registers to the register map. Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-27serial: sh-sci: Reformat sci_parse_dt() for git diffGeert Uytterhoeven1-2/+2
As the function header of sci_parse_dt() is split in an unusual way, "git diff" gets confused when changes to the body of the function are made, and attributes them to the wrong function. Reformat the function header to fix this. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Compute the regshift value for SCI portsLaurent Pinchart1-1/+7
SCI instances found in SH SoCs have different spacing between registers depending on the SoC. The platform data contains a regshift field that tells the driver by how many bits to shift the register offset to compute its address. We can compute the regshift value automatically based on the memory resource size, there's no need to pass the value through platform data. Fix the sh7750 SCI and sh7760 SIM port memory resources length to ensure proper computation of the regshift value. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Remove unused platform data capabilities fieldLaurent Pinchart1-4/+7
The field isn't set by any platform but is only used internally in the driver to hold data parsed from DT. Move it to the sci_port structure. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Remove manual break debouncingLaurent Pinchart1-117/+7
The sh-sci driver implements manual break debouncing for a few SH platforms by reading the value of the RX pin port register. This feature is optional and the driver considers all negative or zero values of the platform data port_reg field as invalid. As the four platforms that set the field to a register address all use an address higher than 0x7fffffff, the driver will always consider the value as invalid and never perform debouncing. The feature is unused, remove it. Debouncing could be implemented properly in the future using the pinctrl and GPIO APIs if desired. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Remove the platform data dma slave rx/tx channel IDsLaurent Pinchart1-17/+6
Only SH platforms still use platform data for the sh-sci, and none of them declare DMA channels connected to the SCI. Remove the corresponding platform data fields and simplify the driver accordingly. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Extend sci_port_params with more port parametersLaurent Pinchart1-81/+100
The fifo size, overrun register and mask, sampling rate mask and error mask all depend on the port type only and don't need to be computed at runtime. Add them to the sci_port_parameters structure. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Constify platform dataLaurent Pinchart1-48/+49
The driver modifies platform data for internal purpose only. Fix that and make the platform data structure const. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Replace regmap array with port parametersLaurent Pinchart1-123/+155
Turn the regmap two-dimensional array to an array of port parameters and store a pointer to the port parameters in the sci_port structure. This will allow handling additional port type dependent parameters. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Remove initialization of zero fields in sci_port_paramsLaurent Pinchart1-94/+0
The compiler zeros uninitialized fields, don't zero them manually. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Fix register offsets for the IRDA serial portLaurent Pinchart1-9/+8
Even though most of its registers are 8-bit wide, the IRDA has two 16-bit registers that make it a 16-bit peripheral and not a 8-bit peripheral with addresses shifted by one. Fix the registers offset in the driver and the platform data regshift value. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Don't rely on platform data flags when not neededLaurent Pinchart1-4/+3
The UPF_BOOT_AUTOCONF platform data flag is set by all platforms, hardcode it. The UPF_IOREMAP flag is set by a single SH platform and thus needs to be kept. However, for ARM platforms, we can base the decision on whether an OF node is present and bypass the platform data flags completely. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19serial: sh-sci: Set the SCSCR TE and RE bits in the driverLaurent Pinchart1-6/+7
The Transmit Enable and Receive Enable bits are set in the scscr field of all instances of the sh-sci platform data. Set them in the driver directly to prepare for their removal from platform data. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-12tty: serial: sh-sci: set error code when kasprintf failsPan Bian1-1/+3
When the call to kasprintf() returns a NULL pointer, function sci_request_irq() frees the preallocated memory and returns 0 is returned. Because 0 means no error, the caller of sci_request_irq() will keep going, and the freed memory may be used or freed again. To avoid the above issue, this patch assigns "-ENOMEM" to the return variable ret. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188691 Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10serial: sh-sci: Fix deadlock caused by serial output requestTakatoshi Akiyama1-15/+5
While spin is already locked, serial output request causes the deadlock, because serial output process also tries to lock the spin. This patch removes serial output with spin locked. Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com> Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com> Signed-off-by: Simon Horman <horms+renesas@verge.net.au> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-02tty: serial: constify uart_ops structuresJulia Lawall1-1/+1
Check for uart_ops structures that are only stored in the ops field of a uart_port structure. This field is declared const, so uart_ops structures that have this property can be declared as const also. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r disable optional_qualifier@ identifier i; position p; @@ static struct uart_ops i@p = { ... }; @ok@ identifier r.i; struct uart_port e; position p; @@ e.ops = &i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct uart_ops e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct uart_ops i = { ... }; // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-26serial: sh-sci: Stop transfers in sci_shutdown()Geert Uytterhoeven1-0/+4
Make sure the transmitter and receiver are stopped when shutting down the port, and related interrupts are disabled. Without this: - New input data may be received into the RX FIFO, possibly triggering a new RX DMA completion, - Transfers will still be enabled on a subsequent startup of the UART, before the UART's FIFOs have been reset, causing reading of stale data. Inspired by a patch in the BSP by Koji Matsuoka <koji.matsuoka.xm@renesas.com>. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25serial: sh-sci: Clear (H)SCIF timeout and overrun during resetGeert Uytterhoeven1-0/+5
Add the missing timeout bit definition for (H)SCIF. Clear the timeout and overrun flag bits during UART reset, cfr. the initialization flowchart in the datasheet. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25serial: sh-sci: Clear RX, error, and break flags during resetGeert Uytterhoeven1-0/+4
Setting the FIFO reset bits is not sufficient to reset the RX FIFO. After this the status register's RDF flag bit may still be set, causing the reception of one stale byte of data. To fix this, clear all status flag bits related to reception, error, and break handling, cfr. the initialization flowchart in the datasheet. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25serial: sh-sci: Do not start transfers from sci_startup()Geert Uytterhoeven1-6/+0
FIFO reset is done in sci_reset(), called from sci_set_termios(), while sci_start_tx() and sci_start_rx() are called before, from sci_startup(). However, starting transfers before the UART's FIFOs have been reset may cause reading of stale data. Remove the calls to sci_start_tx() and sci_start_rx() from sci_startup() to fix this. Transfers are still started when needed: - sci_start_rx() is called from sci_set_termios() after FIFO reset, if the CREAD flag is set, - sci_start_tx() is called from uart_change_speed() immediately thereafter, if transmission is enabled. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25serial: sh-sci: Add DT support for dedicated RTS/CTSGeert Uytterhoeven1-0/+3
Add support for indicating the availability of dedicated lines for RTS/CTS hardware flow control, using the standard "uart-has-rtscts" DT property. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25serial: sh-sci: Fix support for hardware-assisted RTS/CTSGeert Uytterhoeven1-7/+83
The existing support for hardware-assisted RTS/CTS is rudimentary and doesn't work. Add support for hardware-assisted RTS/CTS hardware flow control for the (H)SCIF, SCIFA, and SCIFB variants. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25serial: sh-sci: Add pin initialization for SCIFA/SCIFBGeert Uytterhoeven1-1/+15
Before, the driver relied on initialization by the boot loader, or by implicit reset state. Note that unlike on (H)SCIF, the RTS/CTS bits exist only if dedicated RTS/CTS pins are available, which depends on the SoC and UART instance. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25serial: sh-sci: Correct pin initialization on (H)SCIFGeert Uytterhoeven1-15/+8
Correct pin initialization on (H)SCIF: - RTS must be deasserted (it's active low), - SCK must be an input, as it may be used as the optional external clock input. Initial pin configuration must always be done: - Regardless of the presence of dedicated RTS and CTS pins: if the register exists, the RTS/CTS bits exist, too, - Regardless of hardware flow control being enabled or not: RTS must be deasserted. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25serial: sh-sci: Do not open-code sci_getreg()Geert Uytterhoeven1-5/+2
Replace open-coded variants of sci_getreg() by function calls, and drop intermediate variables where appropriate. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.39.0) at 2025-08-31 10:41:51 +0300