diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2019-07-31 20:05:58 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-04 12:43:49 +0200 |
| commit | b2b4b8ed3c06e5fc3586234b2dd2bb802b941261 (patch) | |
| tree | dec84e989cf79dce492786e890bd4e81bd509a7c /drivers/tty/serial/8250/8250_exar.c | |
| parent | ef4e281ecccd5bc824a52a4b1e8fbdff3614c852 (diff) | |
| download | linux-b2b4b8ed3c06e5fc3586234b2dd2bb802b941261.tar.bz2 | |
serial: 8250_exar: Move custom divisor support out from 8250_port
There are Exar custom divisor support in 8250_port which belongs to
8250_exar module. Move it out to the correct module and do not contaminate
generic code with it.
Cc: Aaron Sierra <asierra@xes-inc.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190731170558.52897-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/8250/8250_exar.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_exar.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c index 1bf9adea2e61..3a39368e6e47 100644 --- a/drivers/tty/serial/8250/8250_exar.c +++ b/drivers/tty/serial/8250/8250_exar.c @@ -140,6 +140,31 @@ static void exar_pm(struct uart_port *port, unsigned int state, unsigned int old serial_port_out(port, UART_EXAR_SLEEP, state ? 0xff : 0); } +/* + * XR17V35x UARTs have an extra fractional divisor register (DLD) + * Calculate divisor with extra 4-bit fractional portion + */ +static unsigned int xr17v35x_get_divisor(struct uart_port *p, unsigned int baud, + unsigned int *frac) +{ + unsigned int quot_16; + + quot_16 = DIV_ROUND_CLOSEST(p->uartclk, baud); + *frac = quot_16 & 0x0f; + + return quot_16 >> 4; +} + +static void xr17v35x_set_divisor(struct uart_port *p, unsigned int baud, + unsigned int quot, unsigned int quot_frac) +{ + serial8250_do_set_divisor(p, baud, quot, quot_frac); + + /* Preserve bits not related to baudrate; DLD[7:4]. */ + quot_frac |= serial_port_in(p, 0x2) & 0xf0; + serial_port_out(p, 0x2, quot_frac); +} + static int default_setup(struct exar8250 *priv, struct pci_dev *pcidev, int idx, unsigned int offset, struct uart_8250_port *port) @@ -163,6 +188,9 @@ static int default_setup(struct exar8250 *priv, struct pci_dev *pcidev, status = readb(port->port.membase + UART_EXAR_DVID); if (status == 0x82 || status == 0x84 || status == 0x88) { port->port.type = PORT_XR17V35X; + + port->port.get_divisor = xr17v35x_get_divisor; + port->port.set_divisor = xr17v35x_set_divisor; } else { port->port.type = PORT_XR17D15X; } |