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>
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>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
iEYEABECAAYFAlWNoSAACgkQMUfUDdst+ymxNQCguSEmkAYNDdLyYhdcOqSxJt9u
U1gAoMThUDoomkx6CTDMU1wn53hxgMk9
=eCUS
-----END PGP SIGNATURE-----
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>
