[PATCH v4 00/14] serial: liteuart: add IRQ support

From: Gabriel Somlo
Date: Wed Nov 16 2022 - 09:49:31 EST


Add IRQ support to the LiteX LiteUART serial interface

Changes from v3:
- picked up r/b Ilpo Järvinen on select subset of commits
- rebased entire series on top of tty-next tree
- 2/14 ("use bit number macros"): explicitly include <linux/bits.h>
- 3/14 ("remove unused uart_ops stubs"): don't add gratuitous comment
removed later on in the series
- 12/14 ("add IRQ support for the RX path"): add shadow irq register
to support polling mode and avoid reading hardware mmio irq register
to learn which irq flags are enabled
- this also simplifies both liteuart_interrupt() and liteuart_startup()
- 13/14 ("add IRQ support for the TX path"):
- removed superfluous curly braces from liteuart_interrupt()
- simplified [start|stop]_tx() by using shadow irq register from 12/14
- simplified liteuart_tx_chars() by rebasing on top of tty-next tree

> Changes from v2:
> - further split out "separate RX loop from poll timer" into
> dedicated patches highlighting additional changes explicitly:
> - factoring out tty_flip_buffer_push() (6/14)
> - ack only RX events in RX loop (7/14)
> - pass constant flag to uart_insert_char() directly (8/14)
> - fix variable types in rx loop (9/14)
> - separating RX loop from poll timer (10/14)
> - added patch (11/14) to move function definitions to a more
> convenient location, making subsequent changes easier to read
> in diff patch form.
> - fixes and clarifications for RX path IRQ support patch (now 12/14):
> - only return IRQ_HANDLED for RX events
> - use pr_fmt() to improve style of irq setup error message
> - remove unnecessary locking from around single-register access
> - modify TX path to support both IRQ-mode and polling (13/14)
> - move polling-only liteuart_putchar() behind same conditional
> (CONFIG_SERIAL_LITEUART_CONSOLE) as the rest of the code that's
> still using it.
>
> Changes from v1:
> - split minor cosmetic changes out into individual patches
> (1/3 became 1..5/7)
> - patches 6/7 and 7/7 unchanged (used to be 2/3 and 3/3)

Gabriel Somlo (14):
serial: liteuart: use KBUILD_MODNAME as driver name
serial: liteuart: use bit number macros
serial: liteuart: remove unused uart_ops stubs
serial: liteuart: don't set unused port fields
serial: liteuart: minor style fix in liteuart_init()
serial: liteuart: move tty_flip_buffer_push() out of rx loop
serial: liteuart: rx loop should only ack rx events
serial: liteuart: simplify passing of uart_insert_char() flag
serial: liteuart: fix rx loop variable types
serial: liteuart: separate rx loop from poll timer
serial: liteuart: move function definitions
serial: liteuart: add IRQ support for the RX path
serial: liteuart: add IRQ support for the TX path
serial: liteuart: move polling putchar() function

drivers/tty/serial/liteuart.c | 210 ++++++++++++++++++++--------------
1 file changed, 126 insertions(+), 84 deletions(-)

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2.38.1