serial: 8250: introduce get_divisor() and set_divisor() hook

Add these two hooks so that they can be overridden with driver specific
implementations.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 9342fc2..a0bb772 100644 (file)
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1023,6 +1023,10 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
                        uart->port.get_mctrl = up->port.get_mctrl;
                if (up->port.set_mctrl)
                        uart->port.set_mctrl = up->port.set_mctrl;
+               if (up->port.get_divisor)
+                       uart->port.get_divisor = up->port.get_divisor;
+               if (up->port.set_divisor)
+                       uart->port.set_divisor = up->port.set_divisor;
                if (up->port.startup)
                        uart->port.startup = up->port.startup;
                if (up->port.shutdown)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 709fe6b..ce0dc17 100644 (file)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2498,9 +2498,9 @@ static unsigned int npcm_get_divisor(struct uart_8250_port *up,
        return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2;
 }
 
-static unsigned int serial8250_get_divisor(struct uart_port *port,
-                                          unsigned int baud,
-                                          unsigned int *frac)
+static unsigned int serial8250_do_get_divisor(struct uart_port *port,
+                                             unsigned int baud,
+                                             unsigned int *frac)
 {
        struct uart_8250_port *up = up_to_u8250p(port);
        unsigned int quot;
@@ -2532,6 +2532,16 @@ static unsigned int serial8250_get_divisor(struct uart_port *port,
        return quot;
 }
 
+static unsigned int serial8250_get_divisor(struct uart_port *port,
+                                          unsigned int baud,
+                                          unsigned int *frac)
+{
+       if (port->get_divisor)
+               return port->get_divisor(port, baud, frac);
+
+       return serial8250_do_get_divisor(port, baud, frac);
+}
+
 static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
                                            tcflag_t c_cflag)
 {
@@ -2570,7 +2580,7 @@ static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
        return cval;
 }
 
-static void serial8250_set_divisor(struct uart_port *port, unsigned int baud,
+static void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud,
                            unsigned int quot, unsigned int quot_frac)
 {
        struct uart_8250_port *up = up_to_u8250p(port);
@@ -2603,6 +2613,15 @@ static void serial8250_set_divisor(struct uart_port *port, unsigned int baud,
        }
 }
 
+static void serial8250_set_divisor(struct uart_port *port, unsigned int baud,
+                                  unsigned int quot, unsigned int quot_frac)
+{
+       if (port->set_divisor)
+               port->set_divisor(port, baud, quot, quot_frac);
+       else
+               serial8250_do_set_divisor(port, baud, quot, quot_frac);
+}
+
 static unsigned int serial8250_get_baud_rate(struct uart_port *port,
                                             struct ktermios *termios,
                                             struct ktermios *old)

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 06ea4ee..406edae 100644 (file)
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -127,6 +127,13 @@ struct uart_port {
                                             struct ktermios *);
        unsigned int            (*get_mctrl)(struct uart_port *);
        void                    (*set_mctrl)(struct uart_port *, unsigned int);
+       unsigned int            (*get_divisor)(struct uart_port *,
+                                              unsigned int baud,
+                                              unsigned int *frac);
+       void                    (*set_divisor)(struct uart_port *,
+                                              unsigned int baud,
+                                              unsigned int quot,
+                                              unsigned int quot_frac);
        int                     (*startup)(struct uart_port *port);
        void                    (*shutdown)(struct uart_port *port);
        void                    (*throttle)(struct uart_port *port);