The hardware book says, the FCR is combined with a register called
CHAR (it will trigger interrupt when a specific character is
received). At first, I used lock/read/modify/write/unlock dance for
the FCR to not affect the upper bits, but the CHAR is actually never
used. It should not hurt to always clear the CHAR and to handle the
FCR as a normal case. It can save the costly locking.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Suggested-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For this driver, uart_port::regshift is always 2. Hardcode the
shift value instead of reading ->regshift to get an already known
value. (pointed out by Denys Vlasenko)
Furthermore, I am using register macros that are already shifted,
which will save code a bit.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At this point, 'value' is always a byte, then this code is clearing
bit 15, which is already clear. I meant to clear bit 7.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reported-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The !defined(MODULE) conditional has been added to the
OF_EARLYCON_DECLARE() define.
Now we can revert commit a2d3ea2f23 ("serial: 8250/uniphier:
fix modular build").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The newly added uniphier serial port driver fails to build as
a loadable module when the base 8250 driver is built-in and
its console support enabled:
ERROR: "early_serial8250_setup" [drivers/tty/serial/8250/8250_uniphier.ko] undefined!
This changes the driver to only provide the early console support
if it is built-in itself as well.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reuses the code of drivers/tty/serial/8250/8250_early.c except
- Overwrite device->port.iotype and device->port.regshift for
UPIO_MEM32 because of_setup_earlycon() has set them for UPIO_MEM.
- Set device->baud to zero to prevent early8250_setup() from
initializing the divisor register because port->uartclk does not
match the frequency expected by this hardware.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The register offset must be shifted by regshift, otherwise the
baudrate is not set. I missed the issue probably because the
divisor register was already set by the boot loader.
Fixes: 1a8d2903cb ("serial: 8250_uniphier: add UniPhier serial driver")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the driver for on-chip UART used on UniPhier SoCs.
This hardware is similar to 8250, but the register mapping is
slightly different:
- The offset to FCR, MCR is different.
- The divisor latch access bit does not exist. Instead, the
divisor latch register is available at offset 9.
This driver overrides serial_{in,out}, dl_{read,write} callbacks,
but wants to borrow most of code from 8250_core.c.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Masahiro Yamada