diff options
| author | Stefan-gabriel Mirea <stefan-gabriel.mirea@nxp.com> | 2019-08-09 11:29:16 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-04 12:43:54 +0200 |
| commit | 09864c1cdf5c537bd01bff45181406e422ea988c (patch) | |
| tree | a646e147848688a6edd6181029d200cf4b85ab2e /drivers/tty/serial/Kconfig | |
| parent | 8d41ab87630bdd249996a7ec1f138a23bcd2f5ff (diff) | |
tty: serial: Add linflexuart driver for S32V234
Introduce support for LINFlex driver, based on:
- the version of Freescale LPUART driver after commit b3e3bf2ef2c7 ("Merge
4.0-rc7 into tty-next");
- commit abf1e0a98083 ("tty: serial: fsl_lpuart: lock port on console
write").
In this basic version, the driver can be tested using initramfs and relies
on the clocks and pin muxing set up by U-Boot.
Remarks concerning the earlycon support:
- LinFlexD does not allow character transmissions in the INIT mode (see
section 47.4.2.1 in the reference manual[1]). Therefore, a mutual
exclusion between the first linflex_setup_watermark/linflex_set_termios
executions and linflex_earlycon_putchar was employed and the characters
normally sent to earlycon during initialization are kept in a buffer and
sent afterwards.
- Empirically, character transmission is also forbidden within the last 1-2
ms before entering the INIT mode, so we use an explicit timeout
(PREINIT_DELAY) between linflex_earlycon_putchar and the first call to
linflex_setup_watermark.
- U-Boot currently uses the UART FIFO mode, while this driver makes the
transition to the buffer mode. Therefore, the earlycon putchar function
matches the U-Boot behavior before initializations and the Linux behavior
after.
[1] https://www.nxp.com/webapp/Download?colCode=S32V234RM
Signed-off-by: Stoica Cosmin-Stefan <cosmin.stoica@nxp.com>
Signed-off-by: Adrian.Nitu <adrian.nitu@freescale.com>
Signed-off-by: Larisa Grigore <Larisa.Grigore@nxp.com>
Signed-off-by: Ana Nedelcu <B56683@freescale.com>
Signed-off-by: Mihaela Martinas <Mihaela.Martinas@freescale.com>
Signed-off-by: Matthew Nunez <matthew.nunez@nxp.com>
[stefan-gabriel.mirea@nxp.com: Reduced for upstreaming and implemented
earlycon support]
Signed-off-by: Stefan-Gabriel Mirea <stefan-gabriel.mirea@nxp.com>
Link: https://lore.kernel.org/r/20190809112853.15846-6-stefan-gabriel.mirea@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/Kconfig')
| -rw-r--r-- | drivers/tty/serial/Kconfig | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 7041107ea78d..db524e2c6db3 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1416,6 +1416,21 @@ config SERIAL_FSL_LPUART_CONSOLE If you have enabled the lpuart serial port on the Freescale SoCs, you can make it the console by answering Y to this option. +config SERIAL_FSL_LINFLEXUART + tristate "Freescale linflexuart serial port support" + select SERIAL_CORE + help + Support for the on-chip linflexuart on some Freescale SOCs. + +config SERIAL_FSL_LINFLEXUART_CONSOLE + bool "Console on Freescale linflexuart serial port" + depends on SERIAL_FSL_LINFLEXUART=y + select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON + help + If you have enabled the linflexuart serial port on the Freescale + SoCs, you can make it the console by answering Y to this option. + config SERIAL_CONEXANT_DIGICOLOR tristate "Conexant Digicolor CX92xxx USART serial port support" depends on OF |