linux-toradex.git/drivers/tty/serial/amba-pl011.c, branch v6.11-rc7

serial: amba-pl011: move variable into CONFIG_DMA_ENGINE conditional

2024-04-09T15:07:10+00:00

Variable dmacr is only used if DMA is enabled, so move it into the
CONFIG_DMA_ENGINE conditional.

Signed-off-by: Lino Sanfilippo 
Link: https://lore.kernel.org/r/20240407002709.16224-3-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman

serial: amba-pl011: get rid of useless wrapper pl011_get_rs485_mode()

2024-04-09T15:07:10+00:00

Due to earlier code changes function pl011_get_rs485_mode() is now merely
a wrapper for uart_get_rs485_mode() which does not add any further
functionality. So remove it and instead call uart_get_rs485_mode()
directly.

Reviewed-by: Lukas Wunner 
Signed-off-by: Lino Sanfilippo 
Link: https://lore.kernel.org/r/20240407002709.16224-2-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: switch from circ_buf to kfifo

2024-04-09T13:28:03+00:00

Switch from struct circ_buf to proper kfifo. kfifo provides much better
API, esp. when wrap-around of the buffer needs to be taken into account.
Look at pl011_dma_tx_refill() or cpm_uart_tx_pump() changes for example.

Kfifo API can also fill in scatter-gather DMA structures, so it easier
for that use case too. Look at lpuart_dma_tx() for example. Note that
not all drivers can be converted to that (like atmel_serial), they
handle DMA specially.

Note that usb-serial uses kfifo for TX for ages.

omap needed a bit more care as it needs to put a char into FIFO to start
the DMA transfer when OMAP_DMA_TX_KICK is set. In that case, we have to
do kfifo_dma_out_prepare twice: once to find out the tx_size (to find
out if it is worths to do DMA at all -- size >= 4), the second time for
the actual transfer.

All traces of circ_buf are removed from serial_core.h (and its struct
uart_state).

Signed-off-by: Jiri Slaby (SUSE) 
Cc: Al Cooper 
Cc: Matthias Brugger 
Cc: AngeloGioacchino Del Regno 
Cc: Kumaravel Thiagarajan 
Cc: Tharun Kumar P 
Cc: Russell King 
Cc: Vineet Gupta 
Cc: Richard Genoud 
Cc: Nicolas Ferre 
Cc: Alexandre Belloni 
Cc: Claudiu Beznea 
Cc: Alexander Shiyan 
Cc: Baruch Siach 
Cc: Maciej W. Rozycki 
Cc: Shawn Guo 
Cc: Sascha Hauer 
Cc: Fabio Estevam 
Cc: Neil Armstrong 
Cc: Kevin Hilman 
Cc: Jerome Brunet 
Cc: Martin Blumenstingl 
Cc: Taichi Sugaya 
Cc: Takao Orito 
Cc: Bjorn Andersson 
Cc: Konrad Dybcio 
Cc: Pali Rohár 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Christophe Leroy 
Cc: Aneesh Kumar K.V 
Cc: Naveen N. Rao 
Cc: Manivannan Sadhasivam 
Cc: Krzysztof Kozlowski 
Cc: Alim Akhtar 
Cc: Laxman Dewangan 
Cc: Thierry Reding 
Cc: Jonathan Hunter 
Cc: Orson Zhai 
Cc: Baolin Wang 
Cc: Chunyan Zhang 
Cc: Patrice Chotard 
Cc: Maxime Coquelin 
Cc: Alexandre Torgue 
Cc: David S. Miller 
Cc: Hammer Hsieh 
Cc: Peter Korsgaard 
Cc: Timur Tabi 
Cc: Michal Simek 
Cc: Sumit Semwal 
Cc: Christian König 
Link: https://lore.kernel.org/r/20240405060826.2521-13-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman

serial: amba-pl011: Use uart_prepare_sysrq_char().

2024-03-02T21:06:20+00:00

The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.

Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.

Cc: Russell King 
Signed-off-by: Sebastian Andrzej Siewior 
Link: https://lore.kernel.org/r/20240301215246.891055-2-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman

serial: amba-pl011: Fix DMA transmission in RS485 mode

2024-02-19T08:43:37+00:00

When DMA is used in RS485 mode make sure that the UARTs tx section is
enabled before the DMA buffers are queued for transmission.

Cc: stable@vger.kernel.org
Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support")
Signed-off-by: Lino Sanfilippo 
Link: https://lore.kernel.org/r/20240216224709.9928-2-l.sanfilippo@kunbus.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: amba-pl011: factor QDF2400 SoC erratum 44 out of probe

2023-12-15T13:24:12+00:00

On this platform, different vendor data is used. That requires a
compile-time check as we access (1) a global boolean & (2) our local
vendor data. Both symbols are accessible only when
CONFIG_ACPI_SPCR_TABLE is enabled.

Factor the vendor data overriding to a separate function that is empty
when CONFIG_ACPI_SPCR_TABLE is not defined.

Suggested-by: Ilpo Järvinen 
Reviewed-by: Linus Walleij 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Théo Lebrun 
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-8-e384afa5e78c@bootlin.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: amba-pl011: unindent pl011_console_get_options function body

2023-12-15T13:24:12+00:00

The whole function body is encapsulated inside an if-condition. Reverse
the if logic and early return to remove one indentation level.

Also turn two nested ifs into a single one at the end of the function.

Reviewed-by: Linus Walleij 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Théo Lebrun 
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-7-e384afa5e78c@bootlin.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: amba-pl011: fix miscellaneous checkpatch warnings

2023-12-15T13:24:12+00:00

Fix the following messages from checkpatch:

    $ ./scripts/checkpatch.pl --strict --file \
        drivers/tty/serial/amba-pl011.c

    ERROR: do not initialise statics to false
    WARNING: Possible unnecessary 'out of memory' message
    WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
    WARNING: Prefer [subsystem eg: netdev]_info([subsystem]dev, ... then
             dev_info(dev, ... then pr_info(...  to
    CHECK: Prefer using the BIT macro

Reviewed-by: Linus Walleij 
Signed-off-by: Théo Lebrun 
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-6-e384afa5e78c@bootlin.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: amba-pl011: fix formatting of conditions

2023-12-15T13:24:12+00:00

Fix the following checkpatch warnings & checks:

	$ ./scripts/checkpatch.pl --strict --file \
        drivers/tty/serial/amba-pl011.c

    CHECK: Unbalanced braces around else statement
    CHECK: Unnecessary parentheses around '[...]'
    CHECK: braces {} should be used on all arms of this statement
    CHECK: Comparison to NULL could be written "[...]"
    WARNING: Comparisons should place the constant on the right side of the test

Reviewed-by: Linus Walleij 
Signed-off-by: Théo Lebrun 
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-5-e384afa5e78c@bootlin.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: amba-pl011: avoid quoted string split across lines

2023-12-15T13:24:12+00:00

Remove all instances of quoted strings split across lines. Fix four
checkpatch warnings:

    $ ./scripts/checkpatch.pl --strict --file \
        drivers/tty/serial/amba-pl011.c
    WARNING: quoted string split across lines
    [...]

Reviewed-by: Ilpo Järvinen 
Reviewed-by: Linus Walleij 
Signed-off-by: Théo Lebrun 
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-4-e384afa5e78c@bootlin.com
Signed-off-by: Greg Kroah-Hartman