From 50825c57ab80ea44cae6bdcd79ead61e3e4e4e4c Mon Sep 17 00:00:00 2001 From: Aaron Sierra Date: Mon, 3 Mar 2014 19:54:29 -0600 Subject: [PATCH] serial: 8250_pci: more BayTrail error-free bauds Support the following additional baud rates with 0% error: 500000, 1500000, 2500000, 3500000 Signed-off-by: Aaron Sierra Reviewed-by: Heikki Krogerus Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_pci.c | 37 +++++++++++++++++++++++------- 1 file changed, 29 insertions(+), 8 deletions(-) diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 0ff3e3624d4c..a3dbc4d97fa2 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1366,22 +1366,43 @@ byt_set_termios(struct uart_port *p, struct ktermios *termios, struct ktermios *old) { unsigned int baud = tty_termios_baud_rate(termios); - unsigned int m = 6912; - unsigned int n = 15625; + unsigned int m, n; u32 reg; - /* For baud rates 1M, 2M, 3M and 4M the dividers must be adjusted. */ - if (baud == 1000000 || baud == 2000000 || baud == 4000000) { + /* + * For baud rates 0.5M, 1M, 1.5M, 2M, 2.5M, 3M, 3.5M and 4M the + * dividers must be adjusted. + * + * uartclk = (m / n) * 100 MHz, where m <= n + */ + switch (baud) { + case 500000: + case 1000000: + case 2000000: + case 4000000: m = 64; n = 100; - p->uartclk = 64000000; - } else if (baud == 3000000) { + break; + case 3500000: + m = 56; + n = 100; + p->uartclk = 56000000; + break; + case 1500000: + case 3000000: m = 48; n = 100; - p->uartclk = 48000000; - } else { + break; + case 2500000: + m = 40; + n = 100; + p->uartclk = 40000000; + break; + default: + m = 6912; + n = 15625; p->uartclk = 44236800; } -- 2.39.5