diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_pci.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_pci.c | 43 |
1 files changed, 34 insertions, 9 deletions
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 0ff3e3624d4c..b14bcba96c25 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1366,23 +1366,44 @@ 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 { - p->uartclk = 44236800; + break; + case 2500000: + m = 40; + n = 100; + p->uartclk = 40000000; + break; + default: + m = 2304; + n = 3125; + p->uartclk = 73728000; } /* Reset the clock */ @@ -3449,6 +3470,10 @@ static struct pciserial_board pci_boards[] = { .base_baud = 921600, .reg_shift = 2, }, + /* + * Intel BayTrail HSUART reference clock is 44.2368 MHz at power-on, + * but is overridden by byt_set_termios. + */ [pbn_byt] = { .flags = FL_BASE0, .num_ports = 1, |