| Message ID | 20240402174353.256627-1-hugo@hugovil.com |
|---|---|
| Headers | show |
| Series | serial: sc16is7xx: split into core and I2C/SPI parts | expand |
On Tue, Apr 2, 2024 at 8:45 PM Hugo Villeneuve <hugo@hugovil.com> wrote: > > From: Hugo Villeneuve <hvilleneuve@dimonoff.com> > > Before, sc16is7xx_lines was checked for a free (zero) bit first, and then > later it was set only if UART port registration succeeded. Now that > sc16is7xx_lines is shared for the I2C and SPI drivers, there is a > possibility that the two drivers can simultaneously try to reserve the same > line bit at the same time. > > To prevent this, make sure line allocation is reserved atomically, and use > a new variable to hold the status of UART port regisration. registration > Now that we no longer need to search if a bit is set, it is now possible > to simplify sc16is7xx_lines allocation by using the IDA framework. ... > -static DECLARE_BITMAP(sc16is7xx_lines, SC16IS7XX_MAX_DEVS); > +static DEFINE_IDA(sc16is7xx_lines); Don't we need to replace bitmap.h with idr.h with this change in place?
On Tue, Apr 2, 2024 at 8:45 PM Hugo Villeneuve <hugo@hugovil.com> wrote: > > From: Hugo Villeneuve <hvilleneuve@dimonoff.com> > > Hello, > this patch series splits the SPI/I2C parts for the sc16is7xx driver into > separate source files (and separate I2C/SPI drivers). > > These changes are based on suggestions made by Andy Shevchenko > following this discussion: > > Link: https://lore.kernel.org/all/CAHp75VebCZckUrNraYQj9k=Mrn2kbYs1Lx26f5-8rKJ3RXeh-w@mail.gmail.com/ > > The changes are split into multiple patches to facilitate the review process. > In the end, some of them could be merged into a single patch. > > I have tested the changes on a custom board with two SC16IS752 DUART over > a SPI interface using a Variscite IMX8MN NANO SOM. The four UARTs are > configured in RS-485 mode. > > I did not test the changes on a real SC16is7xx using the I2C interface. But > I slighly modified the driver to be able to simulate an I2C device using slightly > i2c-stub. I was then able to instantiate a virtual I2C device without > disturbing existing connection/communication between real SPI devices on > /dev/ttySC0 and /dev/ttySC2 (using a loopback cable). For patches 1,2,5 Reviewed-by: Andy Shevchenko <andy@kernel.org>
From: Hugo Villeneuve <hvilleneuve@dimonoff.com> Hello, this patch series splits the SPI/I2C parts for the sc16is7xx driver into separate source files (and separate I2C/SPI drivers). These changes are based on suggestions made by Andy Shevchenko following this discussion: Link: https://lore.kernel.org/all/CAHp75VebCZckUrNraYQj9k=Mrn2kbYs1Lx26f5-8rKJ3RXeh-w@mail.gmail.com/ The changes are split into multiple patches to facilitate the review process. In the end, some of them could be merged into a single patch. I have tested the changes on a custom board with two SC16IS752 DUART over a SPI interface using a Variscite IMX8MN NANO SOM. The four UARTs are configured in RS-485 mode. I did not test the changes on a real SC16is7xx using the I2C interface. But I slighly modified the driver to be able to simulate an I2C device using i2c-stub. I was then able to instantiate a virtual I2C device without disturbing existing connection/communication between real SPI devices on /dev/ttySC0 and /dev/ttySC2 (using a loopback cable). Thank you. Link: [v1] https://lore.kernel.org/lkml/20240206214208.2141067-1-hugo@hugovil.com [v2] https://lore.kernel.org/lkml/20240307161828.118495-1-hugo@hugovil.com Changes for V2: - Move port_registered[] init before the for loop to prevent bug if aborting probe when i = 0 - Since patch f7b487648986 ("lib/find: add atomic find_bit() primitives") has been dropped from linux-next/master, rework patch 2 (sc16is7xx_lines) without find_and_set_bit. Changes for V3: - Simplify sc16is7xx_lines allocation by using the IDA framework Hugo Villeneuve (5): serial: sc16is7xx: unconditionally clear line bit in sc16is7xx_remove() serial: sc16is7xx: simplify and improve Kconfig help text serial: sc16is7xx: split into core and I2C/SPI parts (core) serial: sc16is7xx: split into core and I2C/SPI parts (sc16is7xx_lines) serial: sc16is7xx: split into core and I2C/SPI parts (sc16is7xx_regcfg) drivers/tty/serial/Kconfig | 41 +++-- drivers/tty/serial/Makefile | 4 +- drivers/tty/serial/sc16is7xx.c | 255 ++++++----------------------- drivers/tty/serial/sc16is7xx.h | 41 +++++ drivers/tty/serial/sc16is7xx_i2c.c | 74 +++++++++ drivers/tty/serial/sc16is7xx_spi.c | 97 +++++++++++ 6 files changed, 288 insertions(+), 224 deletions(-) create mode 100644 drivers/tty/serial/sc16is7xx.h create mode 100644 drivers/tty/serial/sc16is7xx_i2c.c create mode 100644 drivers/tty/serial/sc16is7xx_spi.c base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f