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>
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>
Enhance the Renesas SCI UART driver to add support for GPIO-controlled
modem lines (CTS, DSR, DCD, RNG, RTS, DTR), using the serial_mctrl_gpio
helpers.
GPIO-controlled modem lines can be used when dedicated modem lines are
not available. Invalid configurations specifying both GPIO RTS/CTS and
dedicated RTS/CTS are rejected.
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>
Documentation/serial/driver clearly states:
If the port does not support CTS, DCD or DSR, the driver should
indicate that the signal is permanently active.
Hence always set TIOCM_CTS, as we currently don't look at the CTS
hardware line state at all.
FWIW, this fixes the transmit path when hardware-assisted flow control
is enabled, and userspace enables CRTSCTS.
The receive path is still broken, as RTS is never asserted.
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>
As of commit 2eaa790989 ("earlycon: Use common framework for
earlycon declarations") it is no longer needer to specify both
EARLYCON_DECLARE() and OF_EARLYCON_DECLARE().
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>
Add support for sparse variable sampling rates on SCIFA and SCIFB.
According to the datasheet, sampling rate 1/5 needs a small quirk to
avoid corrupting the first byte received.
This increases the range and accuracy of supported baud rates.
E.g. on r8a7791/koelsch:
- Supports now 134, 150, and standard 500000-4000000 bps,
- Perfect match for 134, 150, 500000, 1000000, 2000000, and 4000000
bps,
- Accuracy has increased for most standard bps values.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace the single sampling rate and special handling for HSCIF's
variable sampling rates by a bitmask and a custom iterator.
This prepares for the advent of SCIFA/SCIFB's sparse variable sampling
rates.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On SCIx variants different from HSCIF, the bit rate is equal to the
sampling clock rate divided by half the sampling rate. Currently this is
handled by dividing the sampling rate by two, which was OK as it was
always even.
Replace halving the sampling rate by premultiplying the base clock
frequency by 2, to accommodate odd sampling rates on SCIFA/SCIFB later.
Replace the shift value in the BRG divider calculation by a
premultiplication of the base clock frequency too, for consistency.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIFA and SCIFB have additional bit rate config bits in the Serial Mode
Register. Don't touch them when using the port as a serial console, as
we rely on the boot loader to have configured the serial port config.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
"earlyprintk" is architecture specific option.
General "earlycon" option support is much better.
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
[uli: preserve other SCSCR bits when asserting RE and TE]
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
[geert: rewording, #ifdef rework]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The BSP team noticed that there is spin/mutex lock issue on sh-sci when
CPUFREQ is used. The issue is that the notifier function may call
mutex_lock() while the spinlock is held, which can lead to a BUG().
This may happen if CPUFREQ is changed while another CPU calls
clk_get_rate().
Taking the spinlock was added to the notifier function in commit
e552de2413 ("sh-sci: add platform device private data"), to
protect the list of serial ports against modification during traversal.
At that time the Common Clock Framework didn't exist yet, and
clk_get_rate() just returned clk->rate without taking a mutex.
Note that since commit d535a2305f ("serial: sh-sci: Require a
device per port mapping."), there's no longer a list of serial ports to
traverse, and taking the spinlock became superfluous.
To fix the issue, just remove the cpufreq notifier:
1. The notifier doesn't work correctly: all it does is update stored
clock rates; it does not update the divider in the hardware.
The divider will only be updated when calling sci_set_termios().
I believe this was broken back in 2004, when the old
drivers/char/sh-sci.c driver (where the notifier did update the
divider) was replaced by drivers/serial/sh-sci.c (where the
notifier just updated port->uartclk).
Cfr. full-history-linux commits 6f8deaef2e9675d9 ("[PATCH] sh: port
sh-sci driver to the new API") and 3f73fe878dc9210a ("[PATCH]
Remove old sh-sci driver").
2. On modern SoCs, the sh-sci parent clock rate is no longer related
to the CPU clock rate anyway, so using a cpufreq notifier is
futile.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Geert writes:
Summary:
- Clean up the naming of clocks in the sh-sci driver and its DT bindings,
- Add support for the optional external clock on (H)SCI(F), where this pin
can serve as a clock input,
- Add support for the optional clock sources for the Baud Rate
Generator for External Clock (BRG), as found on some SCIF variants
and on HSCIF.
All platforms that used to define an sci_fck clock have now switched to
the fck name. Remove the fallback code.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for using the Baud Rate Generator for External Clock (BRG), as
found on some SCIF and HSCIF variants, to provide the sampling clock.
This can improve baud rate range and accuracy.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for using the SCIx clock pin "(H)SCK" as an external clock
input on (H)SCI(F), providing the sampling clock.
Note that this feature is not yet supported on the select SCIFA variants
that also have it (e.g. sh7723, sh7724, and r8a7740).
On (H)SCIF variants with an External Baud Rate Generator (BRG), the
BRG Clock Select Register must be configured for the external clock.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Refactor the clock and baud rate parameter code to ease adding support
for multiple sampling clock sources.
sci_scbrr_calc() now returns the bit rate error, so it can be compared
to the bit rate error using other sampling clock sources.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The "renesas,scif" compatible value is currently used for the SCIF
variant in all Renesas SoCs of the R-Car family. However, the variant
used in the R-Car family is not the common "SH-4(A)" variant, but a
derivative with added "Baud Rate Generator for External Clock" (BRG),
which is also present in sh7734.
Use the family-specific SCIF compatible values for R-Car Gen1, Gen2, and
Gen3 SoCs to differentiate. The "renesas,scif" compatible value can
still be used as a common denominator for SCIF variants with the
"SH-4(A)" register layout (i.e. ignoring the "Serial Extension Mode
Register" (SCEMR) and the new BRG-specific registers).
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The "renesas,scif" compatible value is currently used for the SCIF
variant in all Renesas SoCs of the R-Car and RZ families. However, the
variant used in the RZ family is not the common "SH-4(A)" variant, but
the "SH-2(A) with FIFO data count register" variant, as it has the
"Serial Extension Mode Register" (SCEMR), just like on sh7203, sh7263,
sh7264, and sh7269.
Use the (already documented) SoC-specific "renesas,scif-r7s72100"
compatible value to differentiate. The "renesas,scif" compatible value
can still be used as a common denominator for SCIF variants with the
"SH-4(A)" register layout (i.e. ignoring the SCEMR register).
Note that currently both variants are treated the same, but this may
change if support for the SCEMR register is ever added.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Store the encoded port and register types directly in of_device_id.data,
instead of using a pointer to a structure.
This saves memory and simplifies the source code, especially when adding
more compatible entries later.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add register definitions for the Baud Rate Generator for External Clock
(BRG), as found in some SCIF and in HSCIF, including a new regtype for
the "SH-4(A)"-derived SCIF variant with BRG.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The maximum baud rate depends on the sampling rate.
HSCIF has a variable sampling rate and sets s->sampling_rate to zero,
hence use the minimum sampling rate of 8.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For low bit rates, the for-loop that reduces the divider returned by
sci_scbrr_calc() and picks the clock select value may terminate without
finding suitable values, leading to out-of-range divider and clock
select values.
sci_baud_calc_hscif() doesn't suffer from this problem, as it correctly
uses clamp().
Since there are only two relevant differences between HSCIF and other
variants w.r.t. bit rate configuration (fixed vs. variable sample rate,
and an additional factor of two), sci_scbrr_calc() and
sci_baud_calc_hscif() can be merged, fixing the issue with out-of-range
values.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When assuming D = 0.5 and F = 0, maximizing the receive margin M is
equivalent to maximizing the sample rate N.
Hence there's no need to calculate the receive margin, as we can obtain
the same result by iterating over all possible sample rates in reverse
order, and skipping parameter sets that don't provide a lower bit rate
error.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The algorithm to find the best parameters for the requested bit rate
calculates the relative bit rate error, using "(br * scrate) / 1000".
For small "br * scrate", this has two problems:
- The quotient may be zero, leading to a division by zero error,
- This may introduce a large rounding error.
Switch from relative to absolute bit rate error calculation to fix this.
The default baud rate generator values can be removed, as there will
always be one set of values that gives the smallest absolute error.
Print the best set of values when debugging.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If bps >= 1048576, the multiplication of the predivider and "bps" will
overflow, and both br and err will contain bogus values.
Skip the current and all higher clock select predividers when overflow
is detected. Simplify the calculations using intermediates while we're
at it.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move the -1 offset of br to the assignment to *brr, so br cannot become
negative anymore, and update the clamp() call. Now all unsigned values
in sci_baud_calc_hscif() can become unsigned.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Blindly writing the default configuration value into the SCSCR register
may change the clock selection bits, breaking the serial console if the
current driver settings differ from the default settings.
Keep the current clock selection bits to prevent this from happening
on e.g. r8a7791/koelsch when support for the BRG will be added.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As F is assumed to be zero in the receive margin formula, frame_len is
not used. Remove it, together with the sci_baud_calc_frame_len() helper
function.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As no platform defines an interface clock the SCI driver always falls
back to a clock named "peripheral_clk".
- On SH platforms that clock is the base clock for the SCI functional
clock and has the same frequency,
- On ARM platforms that clock doesn't exist, and clk_get() will return
the default clock for the device.
We can thus make the functional clock mandatory and drop the interface
clock.
EPROBE_DEFER is handled for clocks that may be referenced from DT (i.e.
"fck", and the deprecated "sci_ick").
Cc: devicetree@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
[geert: Handle EPROBE_DEFER, reformat description, break long comment line]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes an issue that the "length" of scatterlist should be
set using sg_dma_len(). Otherwise, a dmaengine driver cannot work
correctly if CONFIG_NEED_SG_DMA_LENGTH=y.
Fixes: 7b39d90184 (serial: sh-sci: Fix NULL pointer dereference if HIGHMEM is enabled)
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for obtaining DMA channel information from the device tree.
This requires switching from the legacy sh_dmae_slave structures with
hardcoded channel numbers and the corresponding filter function to:
1. dma_request_slave_channel_compat(),
- On legacy platforms, dma_request_slave_channel_compat() uses
the passed DMA channel numbers that originate from platform
device data,
- On DT-based platforms, dma_request_slave_channel_compat() will
retrieve the information from DT.
2. and the generic dmaengine_slave_config() configuration method,
which requires filling in DMA register ports and slave bus widths.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Occasionally, DMA transaction completes _after_ DMA engine is stopped.
Verify if the transaction has not finished before forcing the engine to
stop and push the data
Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When DMA packet completion and timer expiry take place at the same time,
do not terminate the DMA engine, leading by submission of new
descriptors, as the DMA communication hasn't necessarily stopped here.
Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine_submit() will not start the DMA operation, it merely adds
it to the pending queue. If the queue is no longer running, it won't be
restarted until dma_async_issue_pending() is called.
Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
[geert: Add more description]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the DMA engine is not stopped everytime rx_timer_fn is called, the
interrupts have to be redirected back to CPU only when incomplete DMA
transaction is handled
Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This prevents DMA timer timeout that can trigger after the port has
been closed.
Signed-off-by: Aleksandar Mitev <amitev@visteon.com>
[geert: Move del_timer_sync() outside spinlock to avoid circular locking
dependency between rx_timer_fn() and del_timer_sync()]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There's no need to call sci_start_rx() from sci_request_dma() when DMA
setup fails, as sci_startup() will call sci_start_rx() anyway.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For DMA receive requests, the driver is only notified by DMA completion
after the whole DMA request has been transferred. If less data is
received, it will stay stuck until more data arrives. The driver
handles this by setting up a timer handler from the receive interrupt,
after reception of the first character.
Unlike SCIFA and SCIFB, SCIF and HSCIF don't issue receive interrupts on
reception of individual characters if a receive DMA request is in
progress, so the timer is never set up.
To fix receive DMA on SCIF and HSCIF, submit the receive DMA request
from the receive interrupt handler instead.
In some sense this is similar to the SCIFA/SCIFB behavior, where the
RDRQE (Rx Data Transfer Request Enable) bit is also set from the receive
interrupt handler.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The receive DMA workqueue function work_fn_rx() handles two things:
1. Reception of a full buffer on completion of a receive DMA request,
2. Reception of a partial buffer on receive DMA time-out.
The workqueue is kicked by both the receive DMA completion handler, and
by a timer to handle DMA time-out.
As there are always two receive DMA requests active, it's possible that
the receive DMA completion handler is called a second time before the
workqueue function runs.
As the time-out handler re-enables the receive interrupt, an interrupt
may come in before time-out has been fully handled.
Move part 1 into the receive DMA completion handler, and move part 2
into the receive DMA time-out handler, to fix these race conditions.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This allows to:
- Remove forward declarations of static functions,
- Coalesce two sections protected by #ifdef CONFIG_SERIAL_SH_SCI_DMA,
- Avoid shuffling functions around in the near future,
- Avoid adding forward declarations in the near future.
No functional changes.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On receive DMA time-out, avoid calling sci_dma_rx_push() if no data was
transferred by the timed out DMA request.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If CONFIG_SERIAL_SH_SCI_DMA is enabled, the driver doesn't enable TIE
on SCIF or HSCIF. However, this driver may call sci_tx_interrupt()
in sci_er_interrupt(). After that, the driver cannot care of the
interrupt, and then "irq 109: nobody cared" happens on r8a7791/koelsch
board. This patch fixes the issue.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
[geert] Keep kicking tx when using PIO
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The error handler calls sci_rx_interrupt() to drain the receive FIFO if
an error condition happens.
However, if DMA is enabled on SCIFA or SCIFB, this will call
disable_irq_nosync() twice. Due to this imbalance, the receive interrupt
will never be re-enabled, and reception stops forever.
To fix this, restrict draining the FIFO to PIO mode, and just call
sci_receive_chars() directly.
Inspired by a patch from Yoshihiro Shimoda
<yoshihiro.shimoda.uh@renesas.com>.
Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes an issue that this driver causes a NULL pointer
dereference in the following conditions:
- CONFIG_HIGHMEM and CONFIG_SERIAL_SH_SCI_DMA are enabled
- This driver runs on the sci_dma_rx_push()
This issue was caused by virt_to_page(buf) in the sci_request_dma()
because this driver didn't check if the "buf" was valid or not. So,
this patch uses the "buf" from dma_alloc_coherent() as is, not page.
This patch also fixes a WARNING issue in sci_rx_dma_release():
WARNING: CPU: 0 PID: 1328 at lib/dma-debug.c:1125 check_unmap+0x444/0x848()
rcar-dmac e6700000.dma-controller: DMA-API: device driver frees DMA memory with different CPU address [device address=0x000000006dd89000] [size=64 bytes] [cpu alloc address=0x000000016189c000] [cpu free address=0x0000000080000000]
WARNING: CPU: 1 PID: 1 at drivers/base/dma-mapping.c:334 dma_common_free_remap+0x48/0x6c()
trying to free invalid coherent area: (null)
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
[geert] Rebased
[geert] Reworded
[geert] Dropped .rx_chunk, as it's always identical to .rx_buf[0]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There's no need to keep all buffer and DMA pointers on the stack.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switch from using tty_buffer_request_room() and looping over
tty_insert_flip_char() to tty_insert_flip_string().
Keep track of buffer overruns in the icount structure, like
serial_core.c does.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently sci_dma_rx_push() has to find the active scatterlist itself,
but in some cases the caller already knows.
Hence let the caller pass the scatterlist, and introduce a helper to
find the active DMA request while we're at it.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During serial port shutdown, the DMA receive worker function may still
be called after the receive DMA cleanup function has been called.
Fix this race condition between work_fn_rx() and sci_rx_dma_release() by
acquiring the port's spinlock in sci_rx_dma_release().
This requires releasing the spinlock in work_fn_rx() before calling (any
function that may call) sci_rx_dma_release().
Terminate all active receive DMA descriptors to release them, and to
make sure no more completions come in.
Do the same in sci_tx_dma_release() for symmetry, although the serial
upper layer will no longer submit more data at this point of time.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a problem when the sci_dma_rx_complete() is processed
before cancel process of work_fn_rx() completes by rx_timer_fn().
This patch locks work_fn_rx().
Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Resubmission of DMA descriptors is explicitly forbidden by the DMA
engine API.
Hence pass DMA_CTRL_ACK to dmaengine_prep_slave_sg(), and prepare a new
DMA descriptor instead of reusing the old one.
Remove sci_port.desc_rx[], as there's no longer a need to access the
active descriptor.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Simplify the error handling in sci_submit_rx() by
- Moving it to the end of the function,
- Just calling dmaengine_terminate_all() instead of calling
async_tx_ack() for all already submitted descriptors.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As dmaengine_prep_slave_sg() is called with the DMA_CTRL_ACK flag set
for DMA transmit requests, there's no need to explicitly acknowledge DMA
transmit requests in the DMA transmit completion callback.
Hence remove the call to async_tx_ack(), and remove the now unused
dma_async_tx_descriptor pointer in the sci_port structure.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert the SCI driver from the SHDMAE-specific partial DMA transfer
handling to the generic dmaengine residual data framework.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace open-coded
- calls to dma_async_tx_descriptor.tx_submit() by calls to the
dmaengine_submit() helper,
- dma_cookie_t comparisons by calls to dma_submit_error().
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The mapped transmit buffer is never unmapped. This leaks quite some
mappings, as the mapping is done in uart_ops.startup(), i.e. every time
the device is opened. Unmap the buffer on device close.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Simplify the DMA transmit code by using dma_map_single() instead of
constantly modifying the single-entry scatterlist to match what's
currently being transmitted.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When comparing differently sized types, it's better to use
min_t()/max_t() than adding casts.
Also use "unsigned int" instead of "int", as that's the right type for
the length of an SG entry.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To function correctly in the presence of an IOMMU, the DMA buffers must
be managed using the DMA channel's device instead of the platform
device's device.
Make sure to free the DMA memory before releasing the channel, not
after.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Let sci_request_dma() handle failures to initialize DMA itself.
This way sci_tx_dma_release() and sci_rx_dma_release() don't have to
consider partial initialization, and thus don't need to reset DMA
addresses to DMA_ERROR_CODE, which is not 100% portable access
architectures.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the life of the driver developer/debugger easier:
- Add __func__ prefix to identical messages,
- Add DMA directions to messages,
- Add TX failure messages,
- Always use "cookie %d" for DMA cookies,
- "#%d" is reserved for the DMA cookie/descriptor index.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fix an issue that the driver may cause "nobody cared" IRQ
when this driver detects the overrun flag only.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 8b6ff84c2d ("serial: sh-sci: Fix R-Car SCIF and HSCIF
overrun handling") added overrun handling for (H)SCIF using the SCLSR
register, but also accidentally added a bogus call to
sci_handle_fifo_overrun() in the receive interrupt path.
Remove it again.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reorder sampling_rate assignment for consistency in all cases of the
switch statement.
Avoid using the ternary conditional operator to make it more clear that
the value is overridden by platform data.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial_core.c was moved from drivers/serial/ to drivers/tty/serial/ a
while ago. Remove the path to make it move-proof.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIF_ERROR_CLEAR includes SCIFA_ORER, which exists only on SCIFA/SCIFB
and SCIF on sh7705/sh7720/sh7721.
To fix this:
1. Remove SCIFA_ORER from the definition of SCIF_ERROR_CLEAR,
2. During initialization, store the error clear mask to use,
incorporating the overrun bit only if it applies to the SCxSR
register.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The #ifdef logic to clear SCxSR bits using RMW on SCIFA/SCIFB and SCIF
variants with some SCIFA features (sh7705/SH7720/sh7721) has several
drawbacks:
- It wasn't updated for newer R-Mobile variants (APE6),
- It doesn't correctly handle SoCs with both SCIF and SCIFA/B (e.g.
R-Car Gen2, but also legacy sh7723/sh7724),
- It doesn't play well with ARM multi-platform kernels: on R-Car Gen2,
SCIF/SCIFA/SCIFB/HSCIF were handled differently, depending on
whether r8a7740 or sh73a0 support was enabled or not,
Replace the #ifdef logic by runtime logic to fix this.
SCIFA/SCIFB and SCIF on sh7705/sh7720/sh7721 use RMW to clear error
bits, other variants use plain stores, as before.
Note that this changes behavior for SCIFA on sh7723/sh7724 (these SoCs
have both SCIF and SCIFA), which didn't use RMW before.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the tty and serial driver patches for 4.2-rc1.
A number of individual driver updates, some code cleanups, and other
minor things, full details in the shortlog.
All have been in linux-next for a while with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here's the tty and serial driver patches for 4.2-rc1.
A number of individual driver updates, some code cleanups, and other
minor things, full details in the shortlog.
All have been in linux-next for a while with no reported issues"
* tag 'tty-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (152 commits)
Doc: serial-rs485.txt: update RS485 driver interface
Doc: tty.txt: remove mention of the BKL
MAINTAINERS: tty: add serial docs directory
serial: sprd: check for NULL after calling devm_clk_get
serial: 8250_pci: Correct uartclk for xr17v35x expansion chips
serial: 8250_pci: Add support for 12 port Exar boards
serial: 8250_uniphier: add bindings document for UniPhier UART
serial: core: cleanup in uart_get_baud_rate()
serial: stm32-usart: Add STM32 USART Driver
tty/serial: kill off set_irq_flags usage
tty: move linux/gsmmux.h to uapi
doc: dt: add documentation for nxp,lpc1850-uart
serial: 8250: add LPC18xx/43xx UART driver
serial: 8250_uniphier: add UniPhier serial driver
serial: 8250_dw: support ACPI platforms with integrated DMA engine
serial: of_serial: check the return value of clk_prepare_enable()
serial: of_serial: use devm_clk_get() instead of clk_get()
serial: earlycon: Add support for big-endian MMIO accesses
serial: sirf: use hrtimer for data rx
serial: sirf: correct the fifo empty_bit
...
There is much SCI of SoC having within,
and the register size is also different in everyone.
So get from platform device.
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Acked-by: by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
The code it refers to was removed in commit b545e4f406 ("serial:
sh-sci: Compute overrun_bit without using baud rate algo").
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
error_mask is the union of all error indicating bits in the SCxSR
register, while overrun_mask may apply to a different register (SCLSR),
depending on the SCI variant.
Hence overrun_mask should only be ORed into error_mask if it applies to
the SCxSR register.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The various SCI implementations use 3 different methods to signal
overrun errors:
- Bit SCI_ORER in register SCxSR on SCI,
- Bit SCIFA_ORER in register SCxSR on SCIFA and SCIFB, and SCIF on
SH7705/SH7720/SH7721,
- Bit SCLSR_ORER in (optional!) register SCLSR on (H)SCIF.
However:
1. sci_handle_fifo_overrun()
a. handles (H)SCIF and SCIFA/SCIFB only,
b. treats SCIF on SH7705/SH7720/SH7721 incorrectly,
2. sci_mpxed_interrupt()
a. treats SCIF on SH7705/SH7720/SH7721 incorrectly,
b. ignores that not all SCIFs have the SCLSR register, causing
"Invalid register access" WARN()ings.
To fix the above:
1. Determine and store the correct register enum during
initialization,
2. Replace the duplicated buggy switch statements by using the stored
register enum,
3. Add the missing existence check to sci_mpxed_interrupt().
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the missing overrun bit definition for (H)SCIF.
Replace overrun_bit by overrun_mask, so we can use the existing
defines instead of hardcoded values.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the register definitions for the Serial Port Control and Data
Registers on SCIFA/SCIFB, which are needed for RTS/CTS pin control.
Extracted from patches by Magnus Damm <damm+renesas@opensource.se>.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current calculation method in the case of 9600bps, rounding error occurs
has become setting that occur timeout faster than the required time. When we
use 9600bps, 32byte buffer, 10 bit (CS8) and 100 HZ, it becomes 3 jiffies
(30msec). In fact it is necessary 33msec. This updates to the calculation
that are not actually less than the value set by the rounding error.
Also, this is nothing will be calculated value when there is no load. If there
are a lot of case load, overrun error will occur immediately.
This is by the buffer size to be calculated twice the DMA buffer, and add the
change of setting a sufficient time-out value.
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIFA and SCIFB can detect the overrun, but it does not support.
This adds overrun handling of SCIFA and SCIFB.
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the driver cannot return from overrun error if characters
are output during overrun process, use dev_dbg() instead of
dev_notice() to log the error message of overrun in syslog.
Based on a patch by Hisashi Nakamura.
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to make it possible to restore from hibernation not only in Linux but
also in e.g. U-Boot, we have to use sci_{suspend|remove}() for the PM {freeze|
thaw|restore}() methods. It's handy to achieve this by using SIMPLE_DEV_PM_OPS()
macro, however we have to annotate sci_{suspend|remove}() with '__maybe_unused'
in order to avoid compilation warnings when CONFIG_PM_SLEEP is undefined.
Based on orignal patch by Mikhail Ulyanov <mikhail.ulyanov@cogentembedded.com>.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes, just
removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There are
some ath9k patches coming in through this tree that have been acked by
the wireless maintainers as they relied on the debugfs changes.
Everything has been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg KH:
"Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes,
just removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There
are some ath9k patches coming in through this tree that have been
acked by the wireless maintainers as they relied on the debugfs
changes.
Everything has been in linux-next for a while"
* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
fs: debugfs: add forward declaration for struct device type
firmware class: Deletion of an unnecessary check before the function call "vunmap"
firmware loader: fix hung task warning dump
devcoredump: provide a one-way disable function
device: Add dev_<level>_once variants
ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
ath: use seq_file api for ath9k debugfs files
debugfs: add helper function to create device related seq_file
drivers/base: cacheinfo: remove noisy error boot message
Revert "core: platform: add warning if driver has no owner"
drivers: base: support cpu cache information interface to userspace via sysfs
drivers: base: add cpu_device_create to support per-cpu devices
topology: replace custom attribute macros with standard DEVICE_ATTR*
cpumask: factor out show_cpumap into separate helper function
driver core: Fix unbalanced device reference in drivers_probe
driver core: fix race with userland in device_add()
sysfs/kernfs: make read requests on pre-alloc files use the buffer.
sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
fs: sysfs: return EGBIG on write if offset is larger than file size
...
This changes negative values of error rate to be checked, because these
values are valid as error rate. And this changes in the process of adopting
a value close to 0.
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The drivers should use dmaengine_terminate_all() API instead of
accessing the device_control which will be deprecated soon
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
When the error of the same bit rate is detected, we will need to select
the recive margin is large. Current code holds the minimum error, it does
not have to check the recive margin. This adds this calculation.
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If bit-rate calculation result of HSCIF is expect 255 from 0,
driver does not calculate error bit. However, we need to round
the value to calculate error bit in the case of negative value.
This rounds the value of bit-rate using clamp(), and bit-rate is the
case of negative value, it enables the calculation of the error bit.
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the decimal point is discarded calculation of BRR.
Therefore, it can not calculate a value close to the correct value.
This patch fixes this problem by using DIV_ROUND_CLOSEST.
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the big tty/serial driver update for 3.15-rc1.
Nothing major, a number of serial driver updates and a few tty core
fixes as well.
All have been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver update from Greg KH:
"Here's the big tty/serial driver update for 3.15-rc1.
Nothing major, a number of serial driver updates and a few tty core
fixes as well.
All have been in linux-next for a while"
* tag 'tty-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (71 commits)
tty/serial: omap: empty the RX FIFO at the end of half-duplex TX
tty/serial: omap: fix RX interrupt enable/disable in half-duplex TX
serial: sh-sci: Neaten dev_<level> uses
serial: sh-sci: Replace hardcoded 3 by UART_PM_STATE_OFF
serial: sh-sci: Add more register documentation
serial: sh-sci: Remove useless casts
serial: sh-sci: Replace printk() by pr_*()
serial_core: Avoid NULL pointer dereference in uart_close()
serial_core: Get a reference for port->tty in uart_remove_one_port()
serial: clps711x: Give a chance to perform useful tasks during wait loop
serial_core: Grammar s/ports/port's/
serial_core: Spelling s/contro/control/
serial: efm32: properly namespace location property
serial: max310x: Add missing #include <linux/uaccess.h>
synclink: fix info leak in ioctl
serial: 8250: Clean up the locking for -rt
serial: 8250_pci: change BayTrail default uartclk
serial: 8250_pci: more BayTrail error-free bauds
serial: sh-sci: Add missing call to uart_remove_one_port() in failure path
serial_core: Unregister console in uart_remove_one_port()
...
Two cpufreq notifiers CPUFREQ_RESUMECHANGE and CPUFREQ_SUSPENDCHANGE have
not been used for some time, so remove them to clean up code a bit.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Geert Uytterhoeven