[PATCH 3/3] serial: pl011: allow very high baudrates
From: Linus Walleij <hidden>
Date: 2012-09-20 09:46:08
Also in:
linux-serial
Subsystem:
arm primecell uart pl010 and pl011 drivers, the rest, tty layer and serial drivers · Maintainers:
Russell King, Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: Linus Walleij <redacted> The ST Microelectronics variant of the PL011 is capable of supporting very high non-standard baud rates, even above 4 Mbps. However the uart_get_baud_rate() will not allow us to set these, so override that calculation on very high speeds. Cc: Par-Gunnar Hjalmdahl <redacted> Signed-off-by: Guillaume Jaunet <redacted> Signed-off-by: Christophe Arnal <redacted> Signed-off-by: Matthias Locher <redacted> Signed-off-by: Rajanikanth H.V <redacted> Signed-off-by: Linus Walleij <redacted> --- drivers/tty/serial/amba-pl011.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 32240a7..8ac1a42 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c@@ -1507,10 +1507,19 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios, } /* - * Ask the core to calculate the divisor for us. + * Override baud calculation for very high non-standard baudrates + * on the ST Micro oversampling variant. This must override the + * uart_get_baud_rate() call, because this function changes + * baudrate to the default on these baudrates. */ - baud = uart_get_baud_rate(port, termios, old, 0, - max_baud); + if (uap->vendor->oversampling && + ((termios->c_ispeed > 4000000) || + (termios->c_ospeed > 4000000))) + baud = termios->c_ispeed; + else + /* Ask the core to calculate the divisor for us. */ + baud = uart_get_baud_rate(port, termios, old, 0, + max_baud); if (baud > port->uartclk/16) quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud);
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1.7.11.3